This iteration of the BMP family is technically excellent in the application of available technologies and the number of features it has, especially when compared to its predecessor, the BMP-1. It might seem that the BMP-2 is nothing more than a "rehash" of the old and obsolete BMP-1 design, and while that is technically true, the sentiment behind such an accusation points to an incorrect mindset. The BMP-2 is a product improved BMP-1, but it is not quite the same thing as its predecessor. Far from it. It is so heavily modified that the only similarities are in the general layout, and the powertrain, which was retained as is. Everything else was changed to some extent, the most obvious being, of course, the new turret, now bristling with gadgets appropriate for its era. The modifications resulted in an almost entirely different vehicle with entirely different capabilities.
From 1980 to 1989, Kurganmashzavod produced about 14,000 BMP-2s. At the peak of production in 1989, between 1,800 to 1,900 units exited factory gates - triple the maximum annual rate of production of the M2 Bradley. Some may take this at face value and assume that the BMP-2 is purely a "quantity" product and not a quality one. This is incorrect. Lets see why:
The commander has his own hatch, which has an unusual clam shell shape to grant enough space to accommodate the extremely sparse array of two periscopes.
The commander of the BMP-2 is only given a miserly two (!) general vision periscopes to supplement his ubiquitous TKN-3B - not only is that less than what the gunner gets, it's also much less than what the commander's NATO counterparts get. The commander of the Marder 1, for instance, is furnished with a generous array of five periscopes covering 160 degrees frontally. The situation seems pretty horrifically horrible for the BMP-2 if taken at face value, but no, of course it's not that bad. Unlike the gunner and the Marder 1, the commander's periscopes are mounted in a rotating cupola, so if needed, he could spin the cupola around to see all 360 degrees around him. It's certainly not as convenient as being able to glance in whichever direction at leisure, but the overall effectiveness is arguably comparable, if not better.
To top it all off, there is a TNPT-1 rear view periscope mounted in the hatch to give the commander some rearwards awareness. It is useful for directing the driver when buttoned up. In non-combat situations the commander may opt to peek out of his hatch instead.
As usual, all of the periscopes are heated with the RTS heating system to prevent fogging... If it worked, that is. The RTS periscope heating system is installed in nearly all Soviet vehicles, including the T-72, BMP-3, BTR-80, and many, many more. However, none of them have had any complaints about periscopes fogging up, except for the BMP-2 and its predecessor.
One considerable advantage to the BMP-2 in overall fighting efficiency over its contemporaries is that the commander has the TKN-3B combined active/passive pseudo-binocular periscope at his disposal. Pseudo-binocular meaning that although the device has two eyepieces, the two optic feeds are combined to one aperture, which the viewer sees out of. The TKN-3B has a fixed 5x magnification in the day channel with an angular field of view of 10°, and a fixed 3x magnification in the night channel with an angular field of view of 8°. The periscope can be manipulated up and down for elevation, but the commander's cupola must be manually spun for horizontal viewing.
For a tank like the T-72B, the TKN-3B might be a somewhat mediocre tool compared to the PERI-R17 panoramic sight with television feed for the Leopard 2, but for an IFV like the BMP-2, it was rather remarkable. It wasn't stabilised, and featured only rudimentary rangefinding capabilities, and its nightvision capabilities were not competitive by 1980 (the TKN-3 first entered service in 1963), but it at least had nightvision capabilities, and it had a decently high magnification. Night vision came in two flavours; passive light intensification or active infrared. In the passive mode of operation, the TKN-3B uses its light intensification module to amplify ambient light to produce a legible image. This mode is useful down to ambient lighting conditions of at least 0.005 lux, which would be equivalent to an overcast, moonless and starless night. In these conditions, the TKN-3B can be used to identify a tank-type target at a nominal maximum distance of only 400 m, due to the resolution limit, but as the amount of ambient light increases such as on starlit or moonlit nights, the distance at which a tank-sized target is discernible can be extended. In dark twilight hours, the TKN-3M may be able to make out the silhouette of a tank at a distance of up to 800 m or more, but the sight is hamstrung again, this time not by the absence of light, but by the low magnification. Any brighter than dawn or dusk, and the image will be oversaturated and unintelligible.
The active mode requires the use of the OU-3GA2, an IR spotlight operating on 110W, connected directly to the BMP-2's 27V electrical system. With active infrared imaging, the commander can reliably spot thing from a distance of more than a kilometer depending on meteorological conditions, but identifying targets as a tank can only be done at around 800 m, or potentially more if the opposing side is also using IR spotlights, in which case, the TKN-3 can be set to the active mode but without turning on the IR spotlight. This is possible because the switch for activating the spotlight is the right thumb button while the operating channel selector is on the TKN-3 itself, meaning that they can be turned on separately.
The problem with IR spotlights as a whole is that although the user can use them to spot for targets, the targets can use them to spot the user too, but from much further away. Because of the diffraction of light waves, anybody observing the user won't just see a dot of light. If you observe a tank with its IR spotlight on, most of the tank would be brightly illuminated from miles away. The diffracted light does have the benefit of lighting up the ground better for the driver to see, though, so the common issue of speed control due to short visibility distance with the complementary IR periscope for the driver is slightly alleviated in battle conditions. If you look at the photo above, you can clearly see what I mean by this. The spotlight (running on a small pocket battery in this case) illuminates the apartment building, but also the most of the ground. If you had an infrared filter on your gunsight or rifle scope, like the PSO-1 for the SVD rifle, you could very easily see the tank and call out its position.
Any shortcomings in the night vision capabilities of the TKN-3B may be solved by the use of illumination rounds fired over enemy positions. This doesn't solve all of its problems, of course, because the low resolution may complicate the quick and proper identification of enemy vehicle types at long distances, and overhead lighting doesn't penetrate dense forest canopies. More recently, IR illumination rounds similar to the British L58A1 have been developed and put into service, which may benefit the TKN-3B greatly. Needless to say, this new type of ammunition is a Godsend for the ageing BMP-2s of today, all of which are now quite obsolete in more than just the optronics aspect.
Rangefinding is accomplished through the use of a stadiametric scale sighted for a target with a height of 2.7 m, which is the average size of the average NATO tank or IFV. The TKN-3 is unstabilized, making it exceedingly difficult to properly identify enemy tanks or other vehicles at extended distances while the tank is travelling over rough terrain, let alone determine the range. The left thumb button initiated turret traverse for target cuing. The range of elevation is +10° to -5°. The OU-3GA2 spotlight is also directly mechanically linked to the periscope to enable it to elevate with the TKN-3B.
The TKN-3B gave the BMP-2 a true hunter-killer capability, something totally foreign to NATO IFVs of the era. By simply placing the crosshairs on the target and pressing left thumb button, whereupon the turret will spin to meet the target, though the cupola lacks a contra-rotating motor, so the cupola might spin away with the turret, if not for its much lighter weight compared to tank cupolas. Its light weight makes it easy for the commander to simply hold it steady with nothing but a little bodily force. This was not so easy in the T-62, which gave the commander a steel rung for the commander to hold on to. The fact that this feature exists is of huge importance, as the commander is elevated from a simple observer to an active participant. He could participate even further if required, using his 1PZ-3 multipurpose sight.
Besides the periscopes, the commander is also in charge of fending off air attacks. To do this, he is provided with a 1PZ-3 high elevation sight, installed not in the rotating cupola but the turret roof.
The 1PZ-3 sight is a monocular sight with a very large range of elevation in the vertical plane. As it lacks independent stabilization, the sight piggybacks on the weapons stabilizer via a mechanical linkage, so in effect, the sight can elevate and depress as far as the cannon can, which would be from -5 degrees to +75 degrees in elevation.
The sight has two magnification settings; 1.2x and 4x. The field of view through the sight is 49 degrees in the former setting, and 14 degrees in the latter setting. Obviously, the lower magnification was only suitable for engaging aircraft. Even seeing a half-heartedly camouflaged APC would be a tough job at less than a kilometer's distance unless the 4x magnification setting was used, and even then, it's not the best view either.
Here is the sight under 1.2x magnification:
And here it is under 4x magnification.
As far as anti-aircraft sights go, the 1PZ-3 was as good as it gets in 1980, but the sight also has the secondary purpose of serving as the commander's general use gunsight for land targets and being the BMP-2's backup gunsight as well, and to that end, it has a stadiametric rangefinder and range scales embossed on the reticle, as you may have noticed in the photos above.
The commander may override turret and weapons control at the press of a button and take over using the handgrips he is furnished with.
These tools, taken as a singularity, mean much more than the sum of their parts. The independent surveillance equipment, rangefinding, target designation, duplicated gunnery controls and independent sighting systems give the commander a level of dominance over his own machine that many of his NATO counterparts did not have. While the commander of an M2 Bradley did have a gunsight extension to see what the gunner sees and a set of gunnery controls to use them with, he did not have a sight of his own, as there was no backup sight, he did not have his own cupola and he did not have a magnified optic with a rangefinder. The BMP-2 had all of these, and the BMP-2 had a fully matured hunter-killer capability to go with it.
From the introduction of the BMP-2 in 1980 until 1984, the commander was in charge of the R-123M radio, installed at the very rear of the turret shelf (the turret is wider than the turret ring, so there is a wide shelf at the base). Voice transmissions are done using the throat microphone integrated into his tanker's helmet. The throat microphone is reportedly of good quality and much more useful than an open microphone. The commander can listen to both extra-vehicular transmissions or communications from his own crew from the headphones of his tanker helmet.
The R-123 radio had a frequency range of between 20 MHZ to 51.5 MHZ. It could be tuned to any frequency within those limits via a knob, or the commander could switch between four preset frequencies for communications within a platoon. The switching process takes 3 seconds to complete. The radio has a transmitting and receiving range of between 16km to 50km, depending on the antenna used and the type of terrain. The R-123M had a novel glass prism window at the top of the apparatus that displayed the operating frequency. An internal bulb illuminated a dial, imposing it onto the prism where it is displayed. The R-123M had an advanced modular design that enabled it to be repaired quickly by simply swapping out individual modules.
The dismounted squad leader will have an R-392 or R-126 radio to communicate with the commander of the BMP-2 at shorter distances. The squad should be operating 800 meters away from its BMP at the most, though this obviously is dependent on the tactical situation as well.
In 1984, the now-outdated R-123 radio was replaced by the R-173 radio, which had a frequency range of between 30 MHZ to 75.999MHZ. It has 10 preset frequencies. It had an electronic keypad for entering the desired frequency, and a digital display. Its main improvement over older radios is the ability to send encrypted analogue and digital signals.
Sometime in the late 2000's, most BMP-2s had a new and advanced R-168-2UE-2 frequency-hopping encypted radio installed to replace the obsolete R-173, which was susceptible to eavesdropping and jamming.
The R-168 family of radios is now standard throughout the Russian ground forces, from infantry platoons to tank companies. It can produce frequency hops 100 times a second, and the data is encrypted as well. It can also send and receive digital data.
The commander can exit the vehicle by two means - the hatch above him, or by spinning the turret to face the rear, and then going out through the passenger compartment. In the latter case, he must swing open the turret basket perimeter shield (shown below) to exit the turret. The last two photos are provided courtesy of Mr. Tim Gow from the excellent megablitzandmore blog for modelers.
Besides the necessary tools and spare parts, there isn't much space inside the vehicle for stowing long term supplies. The turret doesn't have external bins or baskets either, but it does have numerous loops around its rear perimeter, as you can see below.
The loops are meant for securing foliage and camouflage netting on the turret, but the crew can strap their personal effects onto them too.
The gunner's station is sparse, in a good way. All of the weapon controls are placed right in front of him, and most of the accessories, including the intercom relay box, dome light and the turret lock are placed on the turret wall. The gunner has the strange fortune of having three fixed general vision periscopes of his own, two on each side of his primary sight and another aimed to the left. Pretty good, especially since only a few vehicles of this class offer the same luxury, including the Marder 1A3. The gunner in an M2 Bradley, for instance, is practically blind outside of his main sight.
The gunner also gets a TNPT-1 rear view periscope of his own in his hatch. This periscope lets him see directly behind the turret
As said before, the problem with these periscopes is, as many BMP-2 crewmen have remarked, that the heating system just doesn't work. The BMP-2 doesn't have interior heating or heated seats either, so in cold weather conditions, the periscopes usually fog up. It is some consolation that at least the gunsights are properly heated.
For all intents and purposes, the BPK-1-42 was a bare-bones design, lacking even a laser rangefinder. It was only a combined passive/active day/night sight with features not improved from the same type of sighting system available since the late 60's. It has a fixed magnification of 5.6x in the day channel, and a 5x magnification in the night channel. Rangefinding is accomplished with a stadiametric scale embossed onto the lower right corner of the sight aperture.
The active mode requires the use of the co-axially mounted OU-5G IR spotlight to supply infrared light. The nominal maximum detection range for a tank-type target is about 800m, but infrared illumination shells or enemy vehicles turning on their own infrared spotlights will make it much easier for the gunner. The passive mode has the obvious advantage of not emitting any radiation which might be picked up by infrared imagers (though not thermal imagers, which operate in a distinctly different range of wavelengths), but it was becoming very obsolete very quickly in light of recent Western advances in thermal imaging technology, and the light intensification capabilities of the BPK sights were not very competitive by 1980 standards anyway. Although it is fascinating from a technological point of view how they crammed so many features into a sighting complex so compact and so lightweight (only 25 kg). The reticle in the nightvision channels was illuminated.
A modified Russian BMP-2 sporting the PL-1 laser beamer was displayed during the opening of the 2016 Tank Biathlon. The PL-1 is a laser beamer box that can be used for illumination, replacing the earlier OU-3 spotlights. The PL-1 has a better range than the OU-3, so that the viewing range at night is greatly improved. The PL-1 can be used to emit coded signals as well, enabling it to be used as a laser rangefinder emitter, but it is not known if the BPK sight for this modernized BMP-2 was upgraded for this.
The nightvision optic is equipped with an electric shutter linked to the trigger on the gunner's handgrip, which is in turn linked to the BU-25-2S control console (we will examine this later under the 2A42 section). Every time the cannon fires, the shutter activates and protects the aperture from the blinding flash. This is because the light intensification tube operate on extremely high voltages to amplify ambient light to visible levels. If a bright flash was captured, the intensification tubes would burn out from the huge power surge, or even explode. The gunner is not safe either. Although the intensification tube would be destroyed, it would still put the amplified image on the eyepiece for a split second.
The right eyepiece is for daytime use. There are not many points of interest to write about. It operates just like old tank gunsights from the 50's and 60's. First, the gunner finds the range to the target using the stadiametric rangefinder. Then, he inputs the range into the sight using a dial located on the right side of the sight housing. The chevron reticle will then drop, and the range indicator bars next to the range scales for the ammunition types will rise. To apply the proper superelevation, the gunner uses the handgrips and elevates the cannon until the chevron is placed squarely on the target. This video is recommended if the written description is insufficient (link). The reticle may be illuminated by an internal light bulb to facilitate aiming at twilight hours.
Both the active and passive nightvision channels use the same viewfinder. The reticle is much simpler, lacking a stadia rangefinder and range scales for different ammunition types. This is because the viewing range of the sight was so short - 800 meters maximum - that such accessories were deemed unnecessary. However, you could still shoot further than 800 m if you wanted to. The tip of the chevron is battlesighted for 800m, which means that if the target is 800m away, you only had to lay the chevron on the target and fire. If the target was closer, the chevron would be lowered below the target. Also, if you looked at the bottom of the picture above, you can see an instruction card on the bottom of the BPK-1-42 that tells the gunner that the upper tip of the lead lines are sighted to 800m, and that the bottom tip is for 1200m. That means that if the target was 1200m away, the gunner would have to line up the bottom tip of the lead line to the target. Rangefinding can be done knowing the angular values of the chevron and lead lines. By comparing the height and width of the target to these markings, the gunner could then estimate the distance using a formula.
The sight picture is shown below. Daytime channel to the left, nighttime channel to the right,
Unlike the smaller and simpler 1PZ-3 anti-aircraft sight, the BPK-1-42 is independently stabilized in two planes throughout its range of vision of -8 degrees to +30 degrees in elevation.
Obviously, the lack of any serious rangefinding equipment is an serious detriment to the ability of the gunner to quickly and efficiently dispatch armoured threats. Still, it is some consolation that this shortcoming is not something exclusive to the BMP-2, and that all of its chief rivals, namely the Marder 1 and Bradley, are similarly neglected in this department. The Bradley, for example, did not receive a laser rangefinder until the M2A2 ODS modification in 1991, by which time the BMP-2 could hardly be considered a threat anymore, for obvious reasons.
In March 1986, the BPK-2-42 combined passive/active universal sight replaced the BPK-1-42. The most noticeable difference is the addition of an extra ballistic scale for the recently introduced 'Kerner' APDS rounds. The daytime sight channel was slightly improved with a fixed 6x magnification, and the nighttine channel was also slightly improved with a 5.5x magnification. The sight provides an angular field of view of 10° in the daytime channel and the 6°40′ in the night channel. The reticle was also modified to a crosshair with mil post markings instead of the classical chevron, as you can see below.
The sight aperture is protected by a pane of ballistic glass, but there is also a retractable steel sight cover that could be opened and closed from the inside of the turret. The steel cover only covers the nightvision channel aperture.
STABILIZERS, GUNNER'S CONTROLS
At a cruising speed of 25 km/h to 35 km/h, the stabilizer is capable of maintaining its orientation with an average stabilization accuracy of less than 1 mrad (accuracy of 1 m from point of aim at 1000 m), and even better at slower speeds, but the capabilities of the 2E36 stabilizer complex are very limited compared to what the West was installing on their IFVs at the same period. At speeds of around 20 km/h ± 15 km/h, the stabilizer is good enough to keep the cannon approximately on target, perhaps not precisely enough to score a hit with the first, second or third shot on an M113-sized target at ranges greater than 1000 meters, but certainly precise enough for area targets and tank-sized targets at short range. To be frank, the key word here is saturation.
Precision decreases exponentially as the speed of the vehicle exceeds 35 km/h, and sight drifting starts to become a significant factor as well. Still, the stabilizer is very useful even at high speeds, as the photo above shows. Even on a sudden brake, the stabilizer is quick enough to keep the cannon approximately on target.
Time for full turret rotation: 12 seconds
Maximum Traversal Speed: 30°/sec
Minimum Traversal Speed: 0.07°/sec
Maximum Elevation Speed: 30°/sec
Minimum Elevation Speed: 0.07°/sec
Minimum Traversal Speed: 0.1°/sec
The turret traverse motor is the EDM-20M. It runs on 400W. The elevation motor is the EDM-14, and it runs on 180W.
There are two gyroscopic tachometers installed. One for the horizontal plane and another for the vertical. They measure any changes in the orientation of the turret and weapons and sends commands to the stabilizer motors to apply the necessary corrections to keep the weapons oriented in the same direction as before the turret turns.
The gunner uses the same make and type of handgrips, or "Cheburashka", that the commander is furnished with. Apparently, the triggers are prone to malfunctioning, so the gunner is forced to make a habit of using the manual mechanical trigger on the cannon whenever he can.
If the stabilizers fail, or if the power supply is cut off, there is a set of manual controls in the form of a pair of flywheels familiar to all Soviet AFVs. The turret rotation flywheel is located on the turret ring to the left of the gunner, for his left hand. The weapons elevation flywheel is located behind the BPK sight, used with his right hand. The handle for the elevation flywheel has two electric solenoid triggers, one for the co-axial machine gun, and the other for the cannon.
The BMP-2's armament suite is installed in the 1370 kg steel turret. It is composed of a 2A42 automatic autocannon and a PKT co-axial machine gun. It was necessary to widen the turret ring to 1740mm in order to accommodate the two-man turret.
It has variable rate of fire settings for either semi automatic, 'low' for 250 rounds per minute or 'high' for about 550 rounds per minute, although the cannon can in fact achieve a rate of fire of 800 rounds per minute on the 'high' setting if it gets hot enough. Whether this is deliberate or not is hazy, since KBP, the manufacturer of the cannon, specifically lists the rate of fire in the 'high' setting to be "550 to 800 RPM". The 2A42's unusually high rate of fire is invaluable during engagements with anything from aircraft to large concentrations of infantry, or when attacking a well-fortified position, whereby extra demolition power may be necessary. The 2A42 is simply irreplaceable during engagements with stealthy adversaries, operating under unconventional tactics. Even with thermal imaging sights, it may prove nigh impossible to spot and hit skilled and agile opponents hidden behind foliage or rubble and constantly on the move, as was the case in both Afghanistan and Chechnya, where the BMP-2 was quite consistently rated more highly than the BMP-1 in usefulness. Under such difficult circumstances, the ability to saturate and suppress likely hiding spots and areas of interest with powerful cannon shells is absolutely invaluable for preserving the vehicle itself as well as the lives of the dismounts.
The 2A42 cannon was the subject of a rivalry between the GRAU and Kurganmashzavod. We won't get too much into their histories here, but in short, GRAU insisted on keeping their 73mm cannon, and favoured the 2A41 presented by the ChTZ (Chelyabinsk Tractor Plant). Kurganmashzavod insisted on the 2A42 developed by the KBP design bureau. In one attempt to persuade top brass to adopt the Object 681 with the 2A41 73mm smoothbore cannon, a comparison trial was organized to demonstrate the "superior anti-tank capabilities" of the 2A41. The target was a T-72 tank, and the distance was 1200m. The Object 681 opened fire first (on the side of the tank), and not one single round penetrated the tank. One went over, one fell short, and the other successfully impacted the side skirt, but the reinforced plastic skirt flexed in such a way that the round did nothing. Then, the Object 675 - the BMP-2 prototype - stepped up. It let off three bursts of 8 rounds in the high rate of fire mode. All external equipment including periscopes and the gunsights were completely destroyed, and the roof mounted anti-aircraft machine gun was rent from its mount and landed 15m away from the tank.
Later on during its acceptance trials, the BMP-2 fired on a combat loaded T-55 (modernized) and T-72 (probably T-72A) from the sides, again with 3 x 8 round bursts on the high rate of fire mode. The T-55 had its anti-aircraft mount, IR searchlight, and externally mounted laser rangefinder shredded away. The 100mm cannon was hit and penetrated in two places. The external fuel tanks mounted on the overtrack fenders ignited and burned outside the tank, but the gunsight was unharmed and tank was in a drivable state. A total firepower kill was achieved. Its partner the T-72 had also had its anti-aircraft machine gun ripped off, and its optical devices were damaged. The overtrack fender fuel tanks were hit and the inferno damaged the turret seals (compromised NBC system) and some of the burning fuel leaked to engine compartment and damaged the engine, though the automatic fire suppression system worked. A mobility and firepower kill was achieved. These results are published in Sergey Suvorov's volumes on the BMP-1 and BMP-2, which you can check for yourselves.
With just 24 rounds out of 500, the BMP-2 could mission-kill a tank at a distance of 1200 meters. The number of shots the Object 675 was permitted to fire was controlled for trial reasons. In combat, the gunner could easily choose shoot until he was sure that his target was truly out of action.
Accuracy degrades as the cannon heats up, and as the cannon can fire so quickly, it also heats up more rapidly than other cannons. Stresses are also very high on the barrel, leading to a short barrel life. The maximum number of shots that the gunner is allowed to fire continuously on full auto in the high rate of fire mode is 50 shots, equivalent to five full seconds of continuous shooting. Another 50 rounds of short bursts is allowed after that, after which the barrel must be left to cool to prevent any lasting damage. Firing on the low rate of fire mode, if done in short bursts, can be done until the entire ammunition supply is depleted. The cannon is equipped with a barrel swap-out system to enable quick replacement of eroded barrels in the field without special tools or heavy machinery. It is possible to replace a barrel with only the participation of the three crew members.
In addition to high effectiveness on ground targets, the extremely high elevation of 75 degrees, which is unusually high even among other autocannon-ed vehicles, enables the gunner to effortlessly engage targets located on elevated positions and low flying aircraft, even if they are flying almost directly overhead. Combined with the basic target leading capabilities provided by the fire control system, the BMP-2 can boast of a high level of self-sufficiency against any assailant, whether it be an aircraft, infantry or a tank, and the increased anti-aircraft capability should not be underestimated; the NATO Air Force plays a critical role in ground operations, and the surge of interest in the concept and technology of attack helicopters in the late 60's and 70's has led to the insurgence of an entirely new class of air power that was especially lethal to landbound assets. Even though its own development was plagued with challenge after challenge and delay after delay, the BMP-2 was introduced just in time to become a sufficiently relevant part of the BMP fleet of the Soviet Army by the time the vaunted AH-64 Apache and A-10 Warthogs arrived on the scene in the mid-80's, even if it was only by a lucky coincidence.
This data should be valid for full caliber rounds like the 3BR6 and 3OF8. Subcaliber rounds like the 3BR8 will display superior accuracy and better consistency at all ranges, but the difference is only truly visible at longer ranges. 3BR8 APDS should have a maximum dispersion of 2 mils when fired from the 2A42, and just like with full caliber rounds, most of the shots will likely be located in an oval group less than 2 mils in size, as shot patterning depends more on the particular harmonic properties of the weapon system rather than the ammunition itself.
The autocannon is mounted slightly off to the right, which causes an unfortunate tendency for the turret to be pushed slightly to the right when the autocannon fires long bursts in full automatic. The effect is totally negligible if the gunner uses short bursts, so this idiosyncrasy shouldn't pose any harmful effects to accuracy when accuracy matters. However, the huge recoil forces generated even when firing in the low rate of fire is a tremendous burden on the horizontal stabilizer if the turret were spinning while firing. Special modifications had to be made to allow the stabilizer to properly realign the cannon after each shot.
Although much less accurate than its immediate counterparts, the 2A42 cannon is more than capable of engaging pinpoint targets, though not as efficiently as the British RARDEN or American Mk44, which are more accurate by nearly two times. The RARDEN is accurate by virtue of special dampening and a very tame rate of fire, while the Mk44 is accurate thanks to a 69.4 kg barrel. If the gunner went for the RARDEN route and switched to semi-automatic to fire the cannon only about twice every second, it should be possible to approach (not meet) the same level of accuracy. In situations where accuracy may only have supplementary value, such as when engaging large concentrations of manpower, the 2A42 is at a clear advantage. Still, all this means that in an encounter with armoured vehicles, the 2A42 must fire approximately twice as many shots to get the same number of hits. Fortunately, the 2A42 can fire twice as fast, and the BMP-2 carries twice as much ammunition.
The ammunition load of 500 rounds is stowed in separate curving containers above which the seats for the gunner and commander are mounted. 340 HEI or HEI-T rounds and 160 AP-T or APDS-T rounds are carried. This gives the BMP-2 an edge over rival IFVs in combat endurance. Using the unlucky Bradley as an example again, the M2 carries just 70 rounds of APDS and 230 rounds of HE. The Marder 1 series is even worse off, carrying just 420 rounds of incredibly anemic 20mm rounds in a 4.6:1 HE:AP mix ratio.
The tops of the containers are clipped on. They must be removed to load the ammunition.
Under certain mission conditions where encounters with armoured vehicles are not expected, both containers can be loaded purely with HEI/-T ammunition. This was not uncommonly done in low intensity conflicts or peacekeeping operations.
Empty links are collected in a metal bin underneath the cannon. Shell casings are ejected out of the turret.
The 2A42 is far from perfect. The gas piston system upon which the 2A42 operates on has a rather negative influence on the accumulation of fumes in its receiver assembly, and as the receiver is mounted in a flame-proof box that isn't particularly air-tight, the result is that the turret is usually flooded with almost comical volumes of smoke after firing off a few dozen or so rounds. Throwing open the hatches solves this problem, but as the crew can hardly be expected to do that in combat, the turret has a powerful MU-431 ventilator fan installed in the roof on the gunner's side. The exhaust vent is located just beside the BPK sight head and in front of one of the TNPO-170A periscopes, as you can see in the photo below.'
The 400-Watt ventilator fan activates whenever the trigger button for the cannon is pressed and runs for another 0.65 seconds after the trigger is released. Using the cannon in the 'low' setting is the least taxing on the ventilator system. Firing too many shots too quickly and the ventilator can't catch up. In order to reduce the concentration of fumes in the fighting compartment, the electric firing system is programmed to limit a burst to 8 rounds in the 'high' setting, and 48 rounds in the 'low' setting. Fumes can exit the flameproof box through the imperfect seals around the edges of the access doors (which are for maintenance purposes, e.g. lubrication) and through a valved vent at the rear of the flameproof box designed to export the fumes into the turret, pictured below. Yes, you read that right.
The photo on the left shows the gap for the valved vent, which is on the right side of the flameproof box. The photo on the right shows the rear door of the box opened, with the valve and its spring visible.
But despite the powerful ventilator, and despite disciplined control of ammunition expenditure, the fighting compartment just always gets flooded with fumes. One early attempt in the history of the BMP-2 to bypass this problem entirely was to mount the cannon externally, a la Marder 1. See the photo below.
Besides reducing the rate of the ingress of fumes to zero, this turret had a smaller front profile and it also reduced the height of the occupied space. So why was this vastly superior version rejected? Apparently, the turret was not airtight enough, so it was not safe in an NBC environment. The final production turret itself had some issues with the fume ventilator not being airtight enough too. Makes you wonder if it was worth it, knowing now in hindsight that almost none of the conflicts today involved chemical, biological or nuclear weapons.
The A-670M nose fuze is used. It will self-destruct after the shell has travelled approximately 4000m or so, depending on the strength of head and tail winds.
Cartridge weight: 835 g
Projectile weight: 388 g
Muzzle velocity: 960m/s
Guaranteed Kill area: 1.4sq.m (Blast and fragmentation)
Explosive mass: 11.5 g
Explosive filling: A-IX-2 (Phlegmatized RDX + Aluminium filings) (Aluminium is pyrophoric. Detonation produces incendiary effects, increasing the chance of igniting or burning objects in its proximity)
Tracer burn time: >9 seconds
Although this shell has a mere 23% the amount of explosives contained in the 3OF8, it is encased with the same mass of steel, which somewhat compensates for that fact. Since a sizable portion of the shell's mass is composed of the tracer element, the 3UOR6 shell tends to undershoot the constant-mass 3OF8. This is especially noticeable at longer distances.
3OR6 shells have a smaller explosive charge than 30x170mm RARDEN HE-I-T shells, which weigh 360 grams and pack 20 grams of Hexal.
Cartridge mass: 856 g
Projectile mass: 400 g
Muzzle velocity: 970 m/s
Core: High-hardness tool steel (60KhNM ?), blunt tip
Penetration, RHA (0 degrees)
0m = 48mm (Calculated)
700m = 43mm (Calculated)
1500m = 39mm (Calculated)
Tracer burn time: >3.5 seconds
These penetration values are quite believable. 30x165mm "STING" ammunition, manufactured by arcus (link) with a tungsten core penetrates 30mm at 60 degrees at 500 m, 28mm RHA at 60 degrees at 1000 m and 25mm RHA at 60 degrees at 1500 m.
Due to its mediocre properties, its performance on light armour is rather modest, although it is certain that it is fully capable of perforating the armour of lightly armoured APCs such as the American M113, German Luchs, French VAB, or perhaps the generally light armour of scout cars and other armoured cars, while some modern vehicles like the Stryker and LAV III still prove totally vulnerable, being no better armoured than their tracked peers from the 60's and 70's. It is capable of defeating older IFVs like the Marder 1A2 and M2A1 Bradley from the front at ranges in excess of 1500m, but against the latest IFVs or IFVs specifically uparmoured afainst it like the M2A3 Bradley and Puma, the 3UBR6 shell is, for the most part, less useful than HEI shells.
It quite interesting to note that this shell should be able to perforate the side armour of some tanks of its time, particularly at close ranges. The AMX 30, Leopard 1 and Chieftain are three such unfortunate examples. Legacy tanks like the Centurion are highly vulnerable as well.
Another interesting fact is that this shell is not insignificantly affected by steeply angled armour due to its full-bore steel construction. This is demonstrably proven by their tendency to ricochet when striking armour at low angles of attack, despite the blunt-but-vaguely-pointy nose, and despite overmatching thinner plates due to its large diameter. As such, it is inferred that their performance on flat targets is significantly higher than on angled ones. This was duly expressed in the penetration listings above.
A pyrotechnic charge is used to instantaneously cock the cannon and ready it for firing. However, if a pyrotechnic charge is not loaded, then the gunner can still manually cock the gun by repeatedly working a lever attached to the cannon receiver. The process is laborious and time consuming (due to the heavy springs necessary to withstand the tremendous recoil forces), but it does have its own advantages. Although such eccentricities would not be necessary in an electrically operated chaingun, a chaingun requires external power to fire. If the power source was interrupted, a chaingun would be rendered useless. Due to its gas-powered nature, the 2A42 can still be fired with the vehicle operating in "degraded mode" - knocked out engine and no battery power, all operations reverted to manual control. The advantages are few, but significant. For instance, if the BMP-2 were to be hit by an RPG in the engine compartment, or if it ran over a large mine, it could still aid its squad in holding off the enemy until help arrives. However, one wonders if the trade offs are really worth this extra feature.
Selecting the ammunition type and checking the ammunition reserve is done from the BU-25-2S digital console located between the commander's and gunner's seats, to the right of the PKT ammunition container. Ammunition reserves for both the 2A42 cannon and the PKT coax is shown on a small digital display, along with the ammunition type currently selected for the 2A42. Switching between ammo types is done by twisting small knobs. The commander may use the console if he is going to take over from the gunner.
Loading small sections of ammo belts can be done by hand, but loading the full load of 500 rounds requires the help of mechanical advantage. 500 rounds really is a lot of ammunition, given how big the bullets are. "First page of search results" internet sites say that the time needed to replenish all 500 rounds is two hours, but personally, I honestly can't see how that is even possible. I don't have any sources to contradict the two-hour claim, so your guess is as good as mine. However, this seems a very small price to pay for the BMP-2 having such a huge advantage over its contemporaries.
The PKTM is fed from a single belt of 2000 rounds, which is a weighty improvement over the individual 250-round boxes used in the BMP-1. The container for this very long belt is mounted just to the right of the gunner's seat, as you can see below.
|Not the thing he has his finger on. It's the big long box to its left that, coincidentally, looks about wide enough for 7.62x54mm bullets|
Having talked about the PKT and the PKTM so much in the previous 9 articles published on this blog, it seems pointless to add anything more. The PKTM, as you all already know, is a universal machine gun firing the 7.62x54mm cartridge. The PKTM is distinguishable from the PKT by the long flash hider and the modified mounting trunnion. Ball ammunition and tracer ammunition is usually loaded in a 4:1 ratio. The PKTM machine gun has a rate of fire of around 800 rounds per minute, and it has a thicker barrel than the infantry-based PKM to allow for longer periods of sustained fire. There are two ways to fire the PKTM: The left thumbswitch on the "Cheburashka", or by pressing the manual trigger on the back of the machine gun, just behind the disassembly button. Since the gunner has the 30mm cannon to play with, the PKT is mostly used in situations where the firepower of the cannon might be overkill.
As you may have noticed, the smooth sides of the BMP-2 are intermittently interrupted by a few oddly shaped outlines. Refer to the photo above (don't mind the tank). These are firing ports. Each passenger gets one, so that there are six ports for the passenger compartment, and another near the driver's station for the seventh passenger.
There are two types of firing port. Squared ones, and teardrop-shaped ones. The square ports are aimed aggressively forward to take better advantage of the firepower of the PKM machine gun, and the teardrop ports are aimed more to the sides. These are meant for AK rifles. However, all firing ports can accommodate the same variety of weapons. Even G3 rifles can fit into them, and so can M16 rifles. However, the cuff-on clip (the yellow thing in the photo below) that was designed to fit around the barrel and gas tube of Kalashnikov rifles will not be able to fit other types of weapons, so they will have to be removed.
Firing ports may be useful in some very specific situations, but modern conflicts show us that anything running on wheels or tracks is subject to an RPG attack, so the moment the enemy is seen, the best course of action - as proven through decades of unconventional warfare experience - is for the passengers to dismount and eliminate any attackers while the IFV lays down suppressive fire of its own. Although the passengers could theoretically suppress ambushers from their firing ports, nobody wants to be inside when an RPG hits, and the limited field of view from the firing ports makes the job too difficult to guarantee that this won't happen. However, if there was a need to use them, and the situation is appropriate, they can be quite useful. See this video (link) to see some soldiers fire out of the firing ports of their bulletproof BTR-80 at an unseen enemy.
There is a fume evacuation system compatible with AK-type weapons, Once installed in the firing port, the operator is to clap the sheet steel casing deflector (the AK spits spent brass out with extreme violence) on the top cover before firing. There is an air hose on the deflector, and once the evacuation system - powered by a moderately powerful (164W) MBP-3N suction fan, one per each side of the hull - is turned on, gunpowder fumes will be sucked out and vented off outside via a small outlet on the side of the hull, one on each side.
A single RPG-7 may be carried on board in the passenger compartment. There is also a special rack for a Strela or Igla MANPADS launcher for self defence. One of the passengers can stick himself out of a roof hatch and use it, but anyone else with a hatch over their heads can do it too, though it would be counterproductive for the gunner to abandon his 30mm autocannon for a missile when you could have both, unless, of course, the passengers have all dismounted. Apparently, this was the case for the guys in the photo below.
But as you might expect, firing your weapons accurately from the confines of the BMP-2 is not such an easy task. The dismounts are most useful when dismounted, and the BMP-2 is most useful when backing them up.
Ignoring the fruits of various modernization efforts, the only ATGM compatible with the original BMP-2 is the Konkurs and the Fagot family of SACLOS missiles.
The original Konkurs missile from 1974 vintage. Packs the 9N131 single charge warhead with waveshaper. The maximum range of this missile is 4km, and the minimum range is 75 meters, because the fuse is distance-armed for the operator's safety.
Throughout its 4-kilometer long maximum firing range, guidance commands are transmitted through a very fine wire. The spool fits inside the missile container and gradually unravels as the missile speeds off. The spool weighs 740 grams. The missile stays steady in flight thanks to a 9B61 gyroscope which interfaces with the four small steering fins at the nose of the missile.
Mass of Missile: 14.6 kg (Excluding tube)
Warhead Caliber: 135mm
Warhead Mass: 2.75 kg
600mm RHA at 0 degrees
250mm RHA at 60 degrees (strange)
Missile Cruising Speed: 208 m/s
Rate of Spin: 5 - 7 RPM
The Konkurs was far superior to other missile systems of the first half of the 70's like the MILAN, and its performance was still highly competitive by the time the ITOW appeared eight years after it. In fact, the Konkurs was directly comparable to the ITOW in performance, only that it was slower, but this was balanced out by a much lighter overall weight and a slightly better maximum flight range. But while the Konkurs could be rightly held in high esteem as an extremely effective system throughout the 70's, the appearance of the next generation of NATO armour in 1980 rendered the missile nearly obsolete. Konkurs could defeat the hull armour of the Leopard 2 and the M1 Abrams from any direction, but the turret was a much tougher nut to crack. The vast majority of the West German tank fleet was still composed of obsolete M48 derivatives and Leopard 1 tanks up until the late 80's, so the situation was not so bleak after all, but it certainly does not speak well of the BMP-2's capacity to deal with the most modern threats.
Tandem warhead descendant of the original Konkurs. Due to internal disagreements and repeated delays, the Konkurs-M only entered service in the late 80's, too late to make a difference, as by the late 80's, the much-improved M1A1 Abrams and Leopard 2A4 had already been fielded. The hull would still have been vulnerable, but the turret would still be impenetrable, so the Soviets were back at square one. Still, the Konkurs-M would still have been useful on ERA-clad tanks like M60A3s fitted with Blazer.
Warhead Caliber: 135mm
Warhead Mass: 4.75 kg
750mm - 800mm RHA at 0 degrees
300mm RHA at 60 degrees
Missile Cruising Speed: 206 m/s
Rate of Spin: 5 - 7 RPM
The Fagot came before the Konkurs, originally meant purely for dismounted infantry, but as the missile launcher in the BMP-2 is almost identical to the universal 9P135M launcher, the BMP-2 may fire Fagot missiles as well. The minimum firing distance is 70 meters, and the maximum guided distance is 2000 m. Although quite capable of defeating any NATO armour of the era, it became obsolete like the Konkurs in the early 80's.
Total Weight (With Missile Tube): 12.9kg
Missile Weight: 7.7 kg
Missile Diameter: 119mm
Penetration: 400mm RHA
Average Flight Velocity: 186 m/s
Faktoria (9M111M)The Faktoria, sometimes referred to as the "Fagot-M" is an updated Fagot, introduced in 1980. The maximum firing range was increased to 2500m, and the armour penetration capability was raised to 460mm RHA, while simultaneously cutting down the weight of the missile very slightly to 12.9kg. The cruising speed was very slightly reduced to 180 m/s.
Total Weight (With Missile Tube): 13.2kg
Missile Weight: 8.0 kg
Missile Diameter: 120mm
Warhead Mass: 1.76 kg
Explosive Charge Mass: 1.0 kg
Penetration: 460mm RHA at 0 degrees
Average Flight Velocity: 180 m/s
LAUNCHING THE MISSILES
Launching the missiles is done from the proprietary 9P56M launcher unit contained inside the armoured box on the turret roof. The gunner is equipped with the 9Sh119M1 sighting unit taken from the more familiar 9P135M man-portable launcher complex to aim the missile with. As missile guidance is of the SACLOS variety, all the gunner has to do is lay the sights on target. The 9Sh119M1 sighting unit is pictured below, shown from the gunner's perspective. Beside the 9Sh119M1 is the 9S474 control unit, which is essentially a set of flywheels to control the elevation and rotation of the launcher complex, plus a trigger button.
The photo above shows the eyepiece of the 9Sh119M1 sighting system. The aperture is housed in the armoured box atop the turret, as you can see in the photo below. If you look closely, you can see the distinctive double-eyed sight head within. The bottom eye is the gunner's aperture, and the upper eye is the automatic missile tracking optic. The sight has a 10x magnification.
The viewfinder for the 9Sh119M1 sighting unit is pictured below.
Since the 9Sh119M1 sight is from the 9P135M missile launching complex, it has all its features, including a jamming detection and warning system and manual MCLOS backup control capability in case the system does get jammed. Guiding the missile in the horizontal plane is done by aiming the crosshairs somewhere else, and to do that, the traverse flywheel is spun to rotate the entire armoured box. Guiding the missile in the vertical plane is done by traversing another flywheel, which rotates the sight up and down within the armoured box, which is fixed in place. The manpack-based 9P135M launcher is capable of aiming -20 degrees down and +20 degrees up, but due to the constricted opening of the armour box, the range of vertical elevation is greatly reduced.
Speaking of the 9P135M, the BMP-2 carries an extra one, complete with its tripod and everything, in case the dismounted infantry need the extra punch of Konkurs missiles (it is also compatible with the Fagot series of missiles too). The 9P135M launcher is stowed separate from its tripod behind the commander's seat. The tripod is stowed in the passenger compartment, usually propped up against the wall. The 9P135M folds up into a very compact rectangular-ish package, and it weighs only 22.5 kg total with the tripod, less without the tripod, of course. The commander can easily dismount the missile launcher from behind his seat and hand it over to someone sitting in the passenger compartment.
Before the missile leaves the tube, the 9B61 gyroscope must be given about half a second to power up to its operating speed of 10,000 revs/min. This is the source of the whirring sound you might hear just before the missile speeds away with a bang.
Launching the missile is accomplished along the lines of a typical recoiless rifle design with an expulsion charge (a "gas generator") installed in the very rear of the missile tube to provide the initial push. The charge is contained inside a metal housing of a smaller diameter than the missile tube. About half a second after the launch operator presses the trigger to fire, the missile is ejected from a restraining cup attached to its rear (you can see it in the photo above). Then, a substantial charge of stick powder burns inside the gas generator and releases the gasses into the empty chamber between the missile and the gas generator, and the thrust from the rear turns the gas generator into a rocket nozzle and propels the missile forwards. Residual pressure within the gas generator is vented out from the rear of the missile tube via twelve small vent holes.
The gas generator kicks the missile out of the tube at a speed of 60 m/s. The rocket engine is not ignited until the missile has left the container and traveled about 15 meters. First, the 9Ch237-1 electric ignition cartridge for the main engine ignites the black powder ignition booster charge for the sustainer motor. This ignites the fuelstick 9Ch179-1 in the main engine, packed in a green rubber heat resistant pouch which accelerates the missile, already travelling at 60 m/s, to a speed of 250 m/s and maintains it at around 208 m/s throughout the rest of the flight. The Fagot and Faktoria missiles are ejected at about the same speed, and accelerate to a slightly lower maximum speed of 240 m/s before falling to a cruising speed of 186 m/s.
The Fagot missile, which we do not really want to examine in too much detail, is ejected out in the same fashion, though with a proportionately smaller gas generator. As you can see in the photo below, the gas generator for the Fagot missile tube has just six vent holes.
LOADING THE MISSILES
There is always one missile loaded onto the launcher prior to entering combat, and there is a stowage rack for three more in the starboard side hull wall in the passenger compartment, directly behind the turret and just in front of the passenger sitting in the frontmost seat (the seat furthest from the door). Reloading it is a cooperative effort between the gunner and the commander.
Now, some people might jump at the mention of missiles openly strapped to the side of the hull and point to this as yet another "fatal weakness" of the BMP-2 design, and it certainly is, but this isn't something exclusive to the BMP-2. It's the same deal with a multitude of other IFVs, including the BMP-2's nemesis the Bradley.
If the passengers have not dismounted yet, they can help pass fresh missile tubes up to the commander whilst he is still seated in his station. After the passengers have dismounted, the commander will have to reach down to the missile tube rack beside him (the rack is not behind the turret, as it may seem in the photos, but beside it) and extract one from the rack, but this is only possible if the turret is not aimed between the 9 o'clock to 12 o'clock positions, and most easily done if the turret is facing to the right. Depending on whether the turret is aimed to the left or to the right within the aforementioned boundaries, either the commander or the gunner will be able to reach the missile rack.
The process of loading the missile itself is done under armour by the gunner. First, the gunner will spin the 9P56M missile launcher 90 degrees to the right, and then he will pull the empty missile tube down towards him.
The photo below shows a BMP-2 turret mounted on something that isn't a BMP-2. Notice the missile rail raised for loading and unloading, and the rotated missile launcher post, which should be aimed directly to the left to allow the gunner to load the missile (remember that the gunner sits at the right side of the turret).
Each missile tube being a full 1.26 meters in length, maneuvering one around the inside of the BMP-2's turret is no mean feat, but still, the whole process should take no more than 20 seconds if the commander isn't an idiot and starts getting his hands on a fresh missile as soon as the last one is airborne. As such, the minimum rate of fire - that is, the speed of reload plus the time taken when firing on a target at the maximum flight range of 4000 m - is about three shots per two minutes, or 1.5 RPM. That's quite fast compared to the Marder 1, but not compared to the M2 Bradley with its dual missile pod and ability to loose both missiles within 30 seconds, but the missile launcher on the Bradley cannot be reloaded if all passengers have dismounted, and the Marder 1's Milan launcher cannot be loaded under armour. The BMP-2 allows both. The Fagot missile and its small size and low weight make it a more attractive option than the Konkurs in this context, but the reduced firing range and lethality make it an unreasonable choice. The maximum firing rate can be as high as 3 RPM under the most optimal conditions (short range, highly proficient crew).
The research paper here (link) is of critical importance in finding insight into the true value of the BMP-2's armour protection. The contents of this document pertains to the testing of ATI 500-MIL high strength steel plate of the ATI brand name using three different caliber of common machine gun ammunition: .308 cal M2 AP, .50 cal M2 AP, 14.5mm B32 AP, and 14.5mm BS41 AP (WC core). Range is a factor of velocity, and since the V50 figures in the document are velocity values and not ones for range, we must find out range for ourselves with a range-velocity chart, which I happen to have here (link). Here are charts for .50 cal M2 AP and 14.5mm M-44 Ball (ballistically equivalent to B32). Reading this document in its entirety is recommended. An understanding of V50 is needed to correctly interpret the results.
Though the steel hull appears to be outwardly identical to the hull of the BMP-1, the BMP-2 uses a more advanced Cr-Ni-Mo steel alloy designated BT-70Sh, which is used for the new turret as well. BT-70Sh is almost exactly equivalent to the ATI 500-MIL steel used for the tests described in the aforementioned paper, as you can see for yourself in this patent mentioning the hardness of BT-70Sh (link). BT-70Sh steel has a hardness of 534 BHN when processed to the type of thin plates used on the vehicle (it becomes exponentially more difficult to treat steel to extreme levels of hardness past a certain thickness using available thermomechanical techniques at the time, and thinner plates are typically much easier to process).
The front of the hull was split into two halves. The lower glacis is totally devoid of anything of inerest, but the upper glacis was dominated by the peculiar armoured aluminium engine access panel. This panel is made from armour-grade aluminium alloy, but as nobody ever mentioned what alloy it is, we can assume that it is most likely made from the same ABT-101 aluminium alloy used in the BMD-1 and BMD-2 airborne IFVs. ABT-101 has a hardness of 145 BHN, and it is much stronger than aluminium alloy 5083 used in armoured vehicles like the M113 and the M2 Bradley. But besides the strangeness of having aluminium in a predominantly steel hull, the most noteworthy feature pf the engine access panel is the seven ribs running across it laterally. If viewed head-on, they line up such that they form a seamless virtual "wall":
These ribs are profoundly important to the efficacy of the protective qualities of the engine access panel. It achieves this with a combination of its own innately unique ballistic properties and the benefit of increasing the stiffness of the plate, which it does brilliantly without significantly increasing the mass of the plate. Original research on the usefulness of protruding ribs as a way to defeat ballistic threats was done parallel to Swedish efforts in the same vein during the mid-60's. The Russians applied the concept to the BMP of 1966, and the Swedes to the Stridsvagn 103.
The Swedish version had ribs 30mm thick, 50mm tall, and spaced 120mm apart placed on a 40mm glacis plate. These were designed with 100mm APDS in mind, and since its trials against 105mm APDS (which, incidentally, was what the test rig in the photo above was shot with) were extremely successful, we can infer that the ribbed glacis armour of the Strv 103 could deflect 100mm APDS fairly easily. They also tested an un-ribbed 50mm glacis plate with the same ammunition, and it managed to deflect the shot too, but only barely. A large portion of the 50mm plate was mostly destroyed where it was hit, and the plate was severely deformed. Compared to the result from the ribbed plate above, where only the ribs were annihilated, it's quite clear which option was more appealing. I should add that all this information comes thanks to super-user Wiedzmin, who shared some of his knowledge here (link).
The ribs on the BMPs measured 25mm in height, 12mm in thickness, and were spaced 200mm apart, but due to the sharper slope of the BMP's engine access panel, the difference in spacing is nullified. One very important detail is that the ribs are not exactly vertical, but perpendicular to the engine access panel, so they are sloped inwards at 12 degrees, thus forming a sort of wonky 'L'. It's also worth noting that the geometry of the panel was molded around the presence of these ribs, as you can see in the third photo below.
The panel is surprisingly complex. It is thinnest immediately behind each rib, and gradually thickens as it approaches the next one. By comparing the thickness of the ribs to the thickness of the panel, we can determine that the panel ranges from 12mm thick to 19.5mm thick - thicker where the bullet might only nick the edge of the rib, and thinner where the bullet might be eroded against the wonky 'L' of the base of the rib. How effective the panel actually is, is sadly unknown, but there can be no doubt that it is at least proofed against 7.62mm bullets of all varieties, and 12.7mm bullets too.
As far as I know, there is not a single site on the internet that has provided any information on the ribs, and all of your thanks goes to friend of the blog Chris Conners, proprietor of the excellent afvdb.50megs website, whose photos here below prove the figures he's given.
The lower glacis is probably the stronger half of the front hull. Its construction is simple. 19mm of steel sloped at 57 degrees. This compares favourably to the 30mm at 24 degrees of the Marder 1, A1 and A2 when attacked by Spitzer-type bullets and autocannon shells, including the ordnance from the Marder 1. For instance, German DM43 AP-T ammunition of 20x139mm caliber fired from the Marder 1's excellent Rh202 autocannon is able to penetrate 32mm of RHA steel armour at 0 degrees at 1000m, but its performance drops sharply down to just 8mm of penetration on the same steel armour at 60 degrees at 1000m. For the better half of its life during the Cold War, the BMP-2 was therefore frontally immune to 12.7mm machine gun bullets to 20mm AP shells and anything in between from not-quite-point-blank ranges. I say "for the better half" because the vastly more effective DM63 APDS was introduced sometime in the mid-80's, and that would have been able to defeat the BMP-2's frontal armour quite handily out to 1000 m and more.
The side armour is quite good for a vehicle of its weight. The thickness of the side armour is actually quite well known already, but I like to prove things for myself. The photo below was used for that purpose.
Knowing that the width of the roadwheel is 155mm, it is possible to scale the side plate in terms of the width of the roadwheel. Taking care to avoid any errors from poor image sharpness, the measurement comes out as 18.5mm, ± 1mm max. This figure happily matches consistent claims presented on the internet from a plethora of sources. The overtrack hull sides are slightly thinner at 16mm, which its very shallow slope of 10 degrees cannot compensate for. The firing port covers embedded in the overtrack hull are themselves no less thick, and are no weaker than the rest of the hull. These figures compare favourably to the 15mm side armour on the Marder 1 series.
The thin strip of sloped armour (above) at the very top of the overtrack side hull is no better nor worse than the rest of the side armour. The photo below, courtesy of Mr. Conners once again, gives us an idea of how thick it really is. Knowing that the overtrack side armour is 16mm thick, we can compare that (the straight bit) to the bent flap of steel, which is bent directly from the sloped strip of the overtrack hull. After pixel scaling, the thickness comes out at 7.13mm. Not very thick, sure, but with its slope of 60 degrees, it is more than enough to deflect 7.62x51mm AP bullets from any distance.
Now, let's move on to the turret.
FAS and the Wikipedia article linking to it plus a handful of some other sources, including one or two examples of published literature (including books by Zaloga), mention that the maximum thickness of the armour on the BMP-2 is "33mm", but none of these figures have ever proven or traced to any original source, so the credibility of these claims have always been in doubt (for good reason). Therefore, I took it upon myself to investigate the thickness of the turret armour on the BMP-2. This was done using the photo below.
|The areas of interest are marked in white lines|
First, the diameter of the circular port for the BPK sight in front of the gunner's hatch was calculated from the known dimensions of the BPK-1-42 sight, which was provided by the Army Guide (link). Having determined the diameter of the port to be 196mm, the thickness of the roof plate would therefore be 13.6mm. Assuming that the middle plate in the mantlet cross-section (the rusted middle layer) is the actual turret itself, and that the metal behind it is the mounting trunnion for the weapons and the metal in front of it is merely welded on for non-armour purposes, then the thickness of the turret should be... 34mm. Close to the oft-repeated "33mm" claim, so close that the 1mm difference could be attributed to human error on my part. Therefore, consider it confirmed that the front half of the BMP-2's turret is 33mm thick.
Sloped at 45 degrees, the turret of the BMP-2 has a LOS thickness of 46.7mm. The turret is immune to .50 cal M2 AP bullets, .50 cal M903 SLAP-T, 14.5mm B-32 bullets and 14.5mm BS-41 bullets from point-blank range. It is also immune to 20x139mm DM41 AP-T fired from the Rh202 autocannon from point-blank ranges, but the newer 20x139mm DM63 APDS introduced in the mid-80's is capable of penetrating exactly 35mm of steel sloped at 45 degrees at 1000 meters. However, since the type of steel target was not mentioned, we can only assume that it was NATO standard hardness steel of some 360 BHN, but as we are not entirely sure, we could call it an "error margin" of 200m, meaning that the BMP-2 turret should be resistant at a range of 800m at the most, and 1200m at the least. That way, we have all our bases covered.
The level of resistance from 25mm shells offered by the turret is not much different from its performance against 20mm ones. Despite the 5mm difference in caliber, M791 cannot maintain its edge over the 8 year-newer DM63, so M791 shells should be able to perforate the BMP-2's turret at 1600 meters at most.
The rear half of the turret is weaker. Zaloga states that the thickness of the turret is "23mm to 33mm". Judging from the difference between the rear and front halves at the weld line (see photo below), he was right. So the rear half is only 23mm thick, but is still sloped from 40 degrees as it comes from the side to 30 degrees at the very rear. It can very easily shrug off 7.62x51mm AP bullets as well as .50 cal M2 AP bullets at point blank range, but nothing more than that, including 14.5mm bullets and up. This is quite consistent with the lack of applique armour on the side of the turret on the uparmoured BMP-2D, which we will examine later. Because of the rounded shape of the turret, shooting the weak half of the side of the turret at anything but almost perpendicular angles will result in only glancing blows, so the front 120 degree arc of the turret is essentially immune to all forms of machine gun fire, and somewhat resistant to 20mm and 25mm fire.
The mantlet is as thick as the rest of the front half of the turret, but the trunnion (the part that actually elevates with the weapons) is the thinnest part of the turret, thinner than the roof, even, as you can see in the photo below:
Once opened, the turret hatches serve as armoured shields. As they are about as thick as the turret roof armour is, which is about 13.6mm, they are fully proof against anything less than a 12.7mm bullet. The shield gives the commander full body and arm protection once he is outside, making him a very tricky target for any potential snipers. If the commander would prefer not to have his head above the hatch so conspicuously, he can rotate the cupola a bit to the side to poke his field binoculars out so that everything except his eyes can be sheltered behind the shield-hatch.
The conflict in Ukraine has proven that artillery is still an incredibly important asset, even in an unconventional war. Apparently, the majority of armoured vehicle losses were due to artillery fire. Among the many victims was the BMP-2 below. As you can see, the roof armour was no match for a 122mm high explosive shell.
BMP-2D APPLIQUE ARMOUR
Immediately as the Afghan situation began in earnest during the turn of the decade, chinks in the BMP-2's armour began to show as the political aspect of the conflict quickly evolved into a military one. Though the vanilla BMP-2 was more than good enough when faced with Kalashnikov fire, it was almost immediately apparent that heavy machine gun fire from Mujahideen ambushes (usually from a DShK) could easily perforate the 16 - 18mm side armour at very close distances. To counter this development, the BMP-2D, also known as the 'Afghan BMP' variant was created. It introduced an array of armoured spaced plates mounted over the upper sides of the hull and a steel side skirt draping down from the overtrack sponsons to protect the bottom half of the hull. The top strip on the upper side was also reinforced with an extra sheet of 6mm-ish steel welded to it. Contrary to some claims, the front hull armour was not reinforced, only the belly.
The steel side skirts are 6mm thick, and so are the steel panels on the overtrack side hull that were mounted about two inches away from the base armour. The protective mechanism was twofold - it forced the incendiary element of an API bullet to deflagrate early and expend itself in the spaced gap, and it also chips off part of the penetrator core and creates fractures, so that when it impacts the hard steel hull, the bullet shatters completely. Those two factors, in addition to the thickness of the panels themselves, entirely neutered the threat of 12.7mm and 14.5mm shots across the side of the hull. Extensive research on the effects of spaced armour with hard but thin sheets on high caliber armour piercing bullets has shown that even sheets as thin as 4.4mm are capable of shattering 12.7mm B-32 steel cored API bullets at shallow angles beginning from 20°, and that the same can be done with 5mm sheets on 14.5mm B-32 steel cored API bullets, or even tungsten carbide-cored BS-41 bullets. Indeed, that was precisely what the famous "bazooka plate" spaced armour on Pz. IV tanks was actually meant for, and not for defence from bazookas, same as the original double spaced side hull armour configuration on the M2 Bradley - protection from the carbide bite of the BS-41. Once shattered or fractured, the bullet - or rather, what remains of it - is easily destroyed upon impact with the hard steel side hull armour. As a side note, the Bradley's side armour required two layers of spacing because bullets do not shatter easily on the soft aluminium hull.
In addition to ballistic protection, the new side hull armour contributed greatly increased the vehicle's survivability from roadside IEDs, which were often composed of a cluster of partially buried artillery shells rigged to explode all at once. The dense spray of high velocity shrapnel and fragmentation could be powerful enough to potentially rip through the side armour at close range, ignoring the armour as assuredly as .50 cal armour piercing bullets. In fact, protection from IED blasts typically requires just as many protective measures to defend against as bullets, because steel splinters from 152mm or 155mm artillery shells often have the same penetrating energy that a .50 cal bullet has, as they can weigh close to what a .50 cal bullet weighs, and travel at speeds close to what a .50 cal bullet speeds along at, only that splinters lack a proper aerodynamic shape and thus cannot retain that energy for very long or very far. The extra steel side skirts would be extremely useful for defeating such shrapnel.
The floor of the hull is incredibly thin. It has a literal maze of reinforcing ribs zigzagging all over it to give it stiffness, but it is not enough for anything bigger than perhaps a frag grenade or a 60mm mortar shell. A small 1.5kg mine exploding under the track would easily rend the track and blow off a roadwheel, but it won't do much to pierce the belly. Anti-tank mines lighter than 6kg are hardly much more effective against BMP-2s as they are against tanks, but most of the mines encountered in low intensity conflicts tend to be rather unconventional.
PERFORMANCE OF ANTI-ARMOUR MEANS
If you haven't read the bullet penetration test document presented here (link). I have condensed the relevant information to a usable format:
Muzzle Velocity of M2 AP: 876 m/s
V50 of 7.7mm ATI 500-MIL plate at 30 deg: 627 m/s
V50 of 9.7mm ATI 500-MIL plate at 30 deg: 723 m/s
This means that at 960 m, .50 cal AP will go through 7.7mm of 534 BHN steel angled at 30 degrees to the vertical. At 600 m, it will go through 9.7mm of the same steel angled at 30 degrees. The third test result is a brilliant example of armour thickness overmatching the diameter of the penetrator with slope. The "Actual Thickness" lists only 3.1mm of penetration, meaning that the bullet simply glanced off, only denting the plate. Imagine, if a 12.7mm hard steel plate at 30 degrees slope does this to .50 cal M2 AP bullets, what sort of protection would a 19mm hard steel plate at 57 degrees offer?
Here is the graph generated as part of the test conclusion and discussion.
Keeping in mind that the muzzle velocity of a .50 caliber bullet is 2910 ft/s, we can see that the only velocity at which the penetration of the bullet will exceed 16mm (0.63 inches) is far above 2700 ft/s. Referring to our ballistic chart here (link), we can see that the velocity of 2705 ft/s corresponds with the distance of 250 meters. Therefore, the side of the BMP-2 can reliably guarantee total immunity from .50 caliber M2 AP rounds from 250 meters, and guarantee 50% immunity from a distance of 200 meters.
But let's move on to 14.5mm bullets:
Muzzle Velocity of 14.5 B32: 988 m/s
V50 of 15.6mm of ATI 500-MIL plate at 30 deg: 730 m/s
V50 of 15.4mm of ATI 500-MIL plate at 30 deg: 739 m/s
V50 of 18.8mm of ATI 500-MIL plate at 30 deg: 841 m/s
This means that 980 m, a 14.5mm B32 bullet will go through 15.6mm of ATI 500-MIL plate angled at 30 degrees to the vertical. This is almost exactly double the performance of the .50 M2 round for a very small increase in caliber and small increase in overall dimensions, but I digress. At 915 meters, the 14.5mm B32 bullet will go through 15.4mm of the same steel at the same slope. Odd, but not a big deal. A 0.2mm error margin is easily explained away by quality issues. At 525 m, the 14.5mm B32 bullet will go through 18.8mm of the same steel at the same slope.
Here is the graph of thickness against V50:
As you can see, the side hull will be defeated from any distance within 600m.
14.5mm Tungsten-Carbide (WC) Bullets
Muzzle Velocity of 14.5mm BS41 bullet: 1005 m/s
V50 of 24.5mm of ATI 500-MIL plate at 30 deg: 869 m/s
The inherent suitability of a WC (Wolfram-Carbide, or Tungsten Carbide) core for anti-armour purposes is very apparent here. At 435 m, the BS41 bullet can perforate 24.5mm of ATI 500-MIL plate steel angled at 30 degrees. According to widespread claims on various websites and old Army documents, the 14.5mm BS-41 bullet is apparently also capable of perforating 40mm of steel armour (the properties of which are not specified, but assumed to be around 360 BHN steel) at 100m at 0 degrees, and 32mm of the same steel at 0 degrees at 500m. While not directly confirmed by the test results, these figures do seem to fit quite neatly around them, so we can reasonably assume that they are correct.
Reading the graph tells us what we already know. The sides of the BMP-2 cannot defend from this type of bullet from a reasonable distance, but the frontal armour will have no problem.
THE FUEL TANK DOORS
Contrary to popular belief, the infamous fuel-filled rear doors were far from being a hazard to the crew. In fact, they were probably one of the most ingenious features of the BMP family. The walls of the fuel tank are stamped from thinly rolled sheets of medium hardness steel just 6mm thick, enough to stop ball ammunition, grenade fragmentation, and splinters from small mortars.
There is a prevailing myth that the fuel tanks could be set afire if the fuel tanks were hit by incendiary ammunition. Firstly, this certainly begs the question: What incendiary ammunition? Incendiary 7.62x51mm ammunition is pretty rare, and so is incendiary 5.56mm ammunition. What we will focus on instead, then, is .50 caliber AP-I ammunition.
In the event of a penetration from an API bullet, the incendiary element will only ignite fuel just behind the exterior wall, because fuel needs to be oxidized in order to burn, and the only source of oxygen for the fuel that is exposed to the incendiary blast is the fuel just around the entry hole of the bullet, since fuel will leak out from that hole into open air. In which case, the entire tank is completely safe from ignition. Burning fuel will simply leak out of the tank in harmless rivulets. If the interior wall of the fuel tank is perforated as well, the fuel will not be ignited due to a lack of heat, since the incendiary blast is on the other side of the fuel tank. This is because the incendiary element is located in front of the armour piercing core, and the 6mm external wall of the door-tank is more than enough to initiate ignition, and the incendiary blast will be partially outside the fuel tank, and partially inside, but due to the spaced effect and the presence of fuel, the blast will not be able to reach the interior side of the fuel tank.
So we know that if fuel is to be ignited, it will only be ignited outside the fuel tank. But what of the steel penetrator core that's still flying straight through the fuel tank? Fluids, including diesel fuel, are more than capable of slowing down or even outright defeating ballistic projectiles given sufficient volumes of it. How much is needed to stop specific bullets is not known, but with two 6mm-thick walls on either side, it's not hard to imagine that the rear doors could probably resist 7.62x51mm AP rounds without much effort. Large caliber artillery splinters would find themselves quickly stopped due to their irregular shape. The parts of the rear doors cut out for firing ports are compensated with extra armour welded on, as you can see below:
Given these facts, it's easy to see how the designers approached the task of increasing protection without increasing weight, as that was critical to the vehicle's amphibious qualities. Despite having very limited abilities as armour on its own, the rear doors can still resist shell splinters from large caliber artillery as well as small arms fire. The only credible challenger would be heavy machine guns firing API ammunition, but in reality, the chances of a BMP-2 exposing its rear end to a heavy machine gun emplacement or a vehicle armed with one is exceedingly low so as to be a total non issue, and if there were a heavy machine gun aimed at the BMP-2's rear, the chance of survival, fire or no fire, is practically nil.
But for all that, the crew's initiative still plays the most important role. The idea is to avoid exposing your ass to the enemy altogether, but if you wanted an absolute guarantee, both rear doors only hold a combined total of 122 liters of fuel out of a net total of 460 liters. In other words, the crew could easily make do without having them filled when in combat. It was never an issue in the first place, since Soviet vehicles have always carried more fuel than most, and even without the contents of the rear doors, the BMP-1 would still carry nearly the same amount as the M113. The rear doors may be filled with water, or soil, or sand to totally nullify the chance of fire and further boost its resilience. The website "Box O' Truth" did their own tests on the effectiveness of sand as a bullet stopping obstacle in their article "The Sands of Truth", which can be found here (link). As it turns out, 7.62x51mm ball ammo won't go through 5 1/2 inches of sand (139.7mm) of sand, nor will 5.56mm SS109 rounds, not even close. But what are the dimensions of the rear doors?
Well, they measure about 275mm wide at the widest at the top, tapering down to 172mm wide at the thinnest at the bottom. This site (link) states that a single .50 cal M2 AP round fired from the barrel of an M2 machine gun is capable of penetrating:
355.6mm at 200m
304.8mm at 600m
152.4mm at 1500m
275 to 172 milimeters of sand, plus the two 6mm steel walls of the rear doors, and the doors have a pretty good chance of shrugging off .50 cal AP bullets, given enough distance and a little bit of an angle. If not, then the occupants are at least fully shielded from 7.62x51mm AP bullets, though they probably wouldn't need the sand for that. Even if the fuel doors were empty, they would still be as good as what some other IFVs have for armour. Take the CV90 as an example:
So, I hope that I have convinced you that the rear door-fuel tanks are hardly the hazard that they are made out to be. The centerline fuel tank right in the passenger compartment, on the other hand...
In conclusion, you would be very justified in saying that the armour on the BMP-2 was far from "paper thin", far from it. Although we have not examined the BMP-2's nemeses with the same detail as we have examined the BMP-2, rest assured, I did my homework, and all of the claims I made, I will defend. I am fully aware that this topic is a particular incendiary one, but facts are facts. Yes, it is true that the M2 Bradley had superior side armour with its double 6.4mm spaced armour configuration over its one inch thick 5083 aluminium hull, but some context is needed to before direct comparisons can be drawn. The M2 Bradley had to contend with powerful Soviet 14.5mm machine guns, whereas the BMP-2 only had to face off against .50 caliber ones. Now, Hunnicutt says that the Bradley's side armour is resistant to 14.5mm rounds from 200m, and I have proven that the BMP-2's side armour is resistant to .50 cal rounds from about the same distance. Unless everyone on our side of the Iron Curtain ditched their M2 machine guns for KPVs at every chance they got, the fact that the BMP-2's side armour is nominally weaker hardly means much. Perhaps in today's world, things are a little different, with .50 caliber SLAP-T circulating quite freely in the American ground forces and insurgent groups happily using all sorts of weapons without regard to their countries of origin, but in that context, I would be the first to admit that a BMP-2 as it is (that is, without a modification like the BMP-2D) is quite obsolete. However, if we are to go back to the BMP-2's heydays in 1980, no one, absolutely no one, can deny that it was nothing short of world class in this regard.
The BMP-2 can either lay its own smokescreen by injecting a fine mist of diesel fuel into the exhaust manifold, or make use of its smoke grenade mortars. The former option is an an ingenious, inexpensive, extremely useful and near-inexhaustible source of anti-IR smoke cover - a little-known fact is that the smoke generated from this method is the temperature as the exhaust, thereby completely masking the vehicle's thermal signature. The only shortcoming of this system is the time taken to envelop the vehicle, but it is often used in platoon formations, so that a single tank or BMP can produce enough smoke to cover the entire platoon and its surroundings. A large number of battlefield maneuvers revolve around the use of this method of smoke generation for concealment.
But aside from this, the BMP-2 was equipped with the 902V Tucha smoke grenade system. It can launch two types of caseless grenades; the 3D6 and the 3D17. They take advantage of a high-low propulsion system much like 40mm VOG series of grenades to launch them out of their tubes at a relatively low velocity. The commander is in charge of the launch control box, which is used to control the direction of the projection of the smoke grenade.
The 3D6 smoke grenade emits "normal" smoke that can only obscure the tank in the visual spectrum. This type of grenade has been rendered next to useless with the gaining popularity of thermal imaging sights in the mid-80's, now long supplanted by the 3D17 model. It is of the slow-burning type, emitting smoke from the ground-up. It travels anywhere from 200m to 350m after launch, and it takes between 7 to 12 seconds to produce a complete smokescreen 10m to 30m in width and 3m to 10m in height, depending on various environmental factors like wind speed, humidity, altitude, etc. This is not including the time taken from launch to the grenade actually hitting the ground. This is in accordance with frontal assault tactics where tanks advance and maneuver behind a continual wall of smoke generated every forward 300m until they literally overrun enemy positions. The smokescreen can last as long as 2 minutes, again depending on environmental factors.
The 3D17 is an advanced IR-blocking aerosol smoke grenade. It completely obturates the passage of IR signatures or IR-based light as well as light in the visible spectrum. It is effective at concealment from FLIR sights and cameras as well as at blocking and scattering laser beams for tank rangefinders and laser-homing missiles. Unlike the 3D6, the 3D17 grenade detonates just 1 second after launch, allowing it to produce a complete smoke barrier in 3 seconds flat. The drawback to this is that the lingering time of the smokescreen is only about 20 seconds, depending on environmental factors. This is enough for the BMP to hastily shift its position, but not much more. This grenade detonates 50m away from the vehicle.
The 3D17 is an advanced IR-blocking aerosol smoke grenade. It completely obturates the passage of IR signatures or IR-based light as well as light in the visible spectrum. It is effective at concealment from FLIR sights and cameras as well as at blocking and scattering laser beams for tank rangefinders and laser-homing missiles. Unlike the 3D6, the 3D17 grenade detonates just 1 second after launch, allowing it to produce a complete smoke barrier in 3 seconds flat. The drawback to this is that the lingering time of the smokescreen is only about 20 seconds, depending on environmental factors. This is enough for the BMP to hastily shift its position, but not much more. This grenade detonates 50m away from the vehicle.
The BMP-2 features a collective NBC protection suite, collective meaning that the interior of the vehicle is fully sealed from the outside environment, so that the crew and passengers need not don hazard suits. Beginning in 1984, the BMP-2 received a lining and cladding of anti-radiation pads.
The turret cladding is most likely laminated borated polyethylene fiber sheets, about an inch thick. If you look closely at frayed edges (photo below), you can see that it is distinctly fiber-like.
Wikipedia says that this is "kovriki" armour, but I could not find any sources that can elaborate on this. Still, we can surmise by their thickness, construction and their exclusive presence over the occupied areas of the vehicle as signs that they are designed to absorb neutrons from a nuclear explosion.
The interior walls of all of the occupied compartments of the vehicle is lined with an anti-radiation lining. It is effective at capturing neutrons, but more importantly, it has the secondary purpose of providing some much needed insulation. This is especially important if the vehicle is coated in burning napalm, seeing as the steel for the roof is only a little more than half an inch thick.
Swedish tests on purchased ex-East German T-72s found that its lining of borated polyethylene was extremely effective at capturing spall, so it should be no different for the BMP-2, although the lining in the BMP-2 is much thinner. The external cladding should also give some small bonuses towards the overall effectiveness of the turret armour. The anti-radiation lining is notably absent from the the rear fuel doors, but this is not a problem. Water is surprisingly effective at absorbing radiation. Presumably diesel fuel is, too.
The protruding bow of the hull is crammed chock full of equipment, including a GO-27 gamma radiation detector. You can see it mounted to the starboard side hull in the photo below, to the left of the steering column.
The GO-27 sensor and automatic sealing system is responsible for detecting nuclear and chemical particles and for initiating the lockdown protocol. Every gap and port exposing the interior of the tank to the outside environment will be sealed, and the ventilation system will be put into supercharge mode.
The BMP-2D introduced the ability to attach the KMT-10 mineplow. Prior to that particular modification, the BMP-2 did not have any attachment points for mineplows.
The entire KMT-10 complex weighs 450 kg. It is light enough that it won't permanently damage the front suspension, but it is quite a lot of strain nonetheless, especially if the applique armour is installed as well.
The automatic fire extinguishing system is only installed in the engine compartment. It operates on four TD-1 thermal sensors placed strategically around the engine to ensure a higher chance of prompt detection. On paper, at least. There are two five-liter fire extinguishers containing halocarbon agent 114B connected to the automatic fire extinguishing system. The fire extinguishers and a single TD-1 thermal sensor can be seen in the photo below (TD-1 is on the left side of the frame, above the green tube)
In addition to that, there is a single handheld OU-5 five liter carbon dioxide fire extinguisher placed in the passenger compartment. Not very effective, to be honest. If the vehicle was hit and the interior was on fire, the first thing to do would be to bail out and run, because any fire would probably escalate into a blaze, because of the centerline fuel tank. Although the BMP-2 is just as well armoured as any other IFV, it is distinctly worse off if the armour were penetrated.
The BMP-2 is the communal steed for the ten white knights that comprise the Soviet mechanized squad. Of the ten, three are crew members, and seven are dismounts. There is:
1 x Squad commander (Sergeant) (AK-74 or AKM)
1 x Grenadier (Private) (RPG-7, PM)
1 x Machinegunner (Private) (RPK-74 or RPK-47)
1 x Senior Rifleman (Corporal) (AK-74 or AKM with grenade launcher)
3 x Riflemen (Privates) (AK-74 or AKM)
The passenger compartment of the BMP-2 is unsuitable for human habitation. On paper, the BMP-2 is designed to fit seven people. Six would be seated in the passenger compartment behind the turret, and the seventh - the squad leader - is seated at the front left hull behind the driver. The dismounts are coloured green, and the crew members are blue.
Now, before we go into the details of how thick the cushions are and about the best places to stow extra ammo and all that, keep this in mind: The height of the hull is 1.1 meters, and the bench on which three people are supposed to sit on is only 1.4 meters long. Now, that may not seem that bad to casually clad aficionados like you and I, but add on bulky body armour, personal firearms, hundreds of rounds of ammo, winter clothing, and it suddenly a ride in the BMP-2 becomes very oppressive indeed. For a short trip of half an hour or so, a seasoned soldier should have very little to complain about, and on long marches in unattractive weather, it certainly beats walking, but the total lack of stretching room and the shoulder-to-shoulder arrangement becomes incredibly uncomfortable when time drags on. It's not just because of the risk of physical harm that many soldiers prefer to ride on top of a BMP rather than in it.
Incidentally, the bench cushions are about an inch and a half thick. The half-bench is mounted to the floor only about 150mm high, so passengers have to draw their knees up almost to chest level when seated, which is rather disconcerting, truth be told.
The real estate underneath the port side half-bench is perfectly sized for two "spam cans" of 5.45mm or 7.62x39mm ammo, or a crate of hand grenades, or a crate of 40mm grenades. The other half of the bench is a fuel tank with a cushion on it, so nothing can be stowed under it. The starboard side half-bench has the fuel pump underneath it, so no luck there.
The seat behind the driver's, or the squad leader's seat, as we will call it, is only accessible through the rectangular hatch above it. The squad leader has the "privilege" of being provided with two periscopes. One aimed forward, and one aimed to the forward-left. The view from the forward periscope is pictured above. There is nothing else of interest in his station. It's worth noting, however, that being forced to use the hatch the exit the vehicle and not doors like the rest of the passengers makes the squad leader's station a poor place to be, as you'd not only take longer to dismount, you'd be exposed to all and sundry while you are on the hull roof. It's also a lot harder to get out if you are wearing body armour or winter clothing. All this has made the squad leader's seat a rather unpopular one, so unsurprisingly, some armies have opted to cut the squad down to six men and omit the seventh passenger. Instead, his spot is usually by the crew to stow their personal effects, plus extra ammunition and first aid kit and anything else that might be needed.
The passengers get one fixed TNPO-170A periscope each, aimed to the side and slightly forwards. Not very good visibility, especially since the heating system doesn't work, but at least it improves the lighting conditions in the passenger compartment.
Both of the rear doors have a single TNPO-170A periscope in them as well. (photo below is of Czech OT-90, but is identical)
The ventilation system of the BMP-2 is composed of four small air inlets located on the edges of the hull roof. Filtration of chemical and biological particles is accomplished by fabric-type filters inside. The ventilators is also responsible for generating an overpressure inside the vehicle when entering NBC-contaminated areas.
This ventilation system also has a heating system and directed air outlets for every passenger (Green) in front of the fume evacuation inlets (Red). The pipes for these systems can be seen here:
|This is the interior of a BMP-2 "Berezhok". It lacks firing ports, so the fume evacuator hose is missing|
As you can see, the air outlets are placed just next to a periscopes. This is approximately eye level, so each passenger gets a weak stream of either cool or warm air blown in his face. Heat for the heating system is not generated electrically, but by the circulation of engine coolant around heat sinks. It would get hotter when the vehicle is in motion, and less so when idling.
The corridor between the driver's station and the passenger compartment has been narrowed down due to the installation of the new turret. It is still possible to pass through, of course, but not nearly as easily as before, if you could have ever called it "easy".
A simple perimeter shield separates the turret from the passenger compartment, lest any accidents happen to the person sitting closest to the turret.
For the passengers in the passenger compartment, there are two entry and exit paths to choose from; the roof hatches, or the infamous rear doors. The former option admits only one person at a time, and jumping down from almost six feet up isn't the most appealing idea when the vehicle is in motion, and even if the vehicle was motionless, the roof hatches are mostly used only in the gravest emergencies anyway (like if the vehicle is sinking in water). They are far more suitable for other things like getting fresh air, shooting at airplanes, etc. The less interesting option is, of course, the rear doors.
So imagine if the BMP suddenly stopped for ten seconds or more when it was that close to the enemy. A sitting duck while the squad materializes around it. The only way to stay alive in the absence of adequate cover is to keep moving, and keep shooting, so the infantry must disembark while the vehicle is doing both at a minimum speed of 10 to 15 km/h. The now widely accepted 'ramp with single door' convention would not suffice, as the door would be suitable on the move, but would be (and it usually is, even in modern vehicles) too small, and vice versa for the wide ramp. The most optimal configuration for the expected role of the BMP, as it was envisioned, was a pair of wide doors. In terms of size, the doors really aren't that bad. They measure 0.865 meters tall and 0.8 meters wide, almost as tall and almost as wide as the doors of a Lada Riva, and almost as tall as the doors on a Volkswagen Golf. Though the quality of a ride in the BMP-2 may not be the epitome of luxury, there's certainly nothing especially oppressive about getting out of it.
Of course, things would not work out so well unless a certain set of criteria were fulfilled, like having a sufficiently powerful breakthrough force, and a conventional battlefield against a conventional enemy using conventional defensive tactics, or else the BMP would not be doing any breaking-throughs at all. In urban combat, the rear doors are a liability. Cargo is less easily loaded, and stretchers cannot be used on the fly, and the benches are not really wide enough for a person to lie down on. The small silhouette is inconsequential in the down-and-dirty close quarters combat of the urban jungle, and the reduced capacity of the passenger compartment means less supplies carried per round trip.
The interior volume of the BMP-2 is extremely small. The seat back of the seat closest to the door is designed with a shelf inside it. Here, a predetermined quantity of ammunition can be stowed. These are; 12 F-1 handgrenades, 1 "spam can" of 700 rounds of 7.62x39mm rounds, a single 200-round box for a PKM machine gun and a single belt of 440 rounds for reloading the PKT machine gun. There is also a hook for a bag of PG-7 rocket grenades for the RPG-7, and as mentioned in the "Supplementary Weapons" section, racks for a single RPG-7 and a single Strela or Igla MANPADS launcher. All in all, there's very little room for extra ammunition, which means that if a 1-day or 2-day mission is planned, most of the supplies will have to be lashed on the roof. A mixed blessing, perhaps, because surely ammunition kept inside the vehicle would be a liability?
Driving the BMP-2 is much, much easier than driving, say, a T-64 tank. This is because of the motorcycle bar-style steering wheel, which is reportedly extremely responsive.
The driver has superb vision out through his four TNPO-170 periscopes, three covering a 120 degree arc and another aimed to the left. The center periscope can be removed from inside the vehicle and replaced with an optical nightvision periscope. The TNPO-170 periscopes offer a rather small field of vertical vision compared to what the driver of, say, an M2 Bradley gets,
Oddly enough, they didn't seem to think that wipers or screen blowers were necessary. The geometry of the front slope has some positive influence on the amount of dirt and grim that ends up on the periscopes while driving, but some former BMP-2 drivers have complained of the inconvenience of not being able to wipe it off when buttoned up. Some drivers and some lucky bystanders have commented on the foggy state of the periscopes as well, but this is most likely because all of the BMPs encountered are usually very old, and tend to be very worn out.
The driver can replace his TNPO-170A periscope with a TVNE-1PA infrared periscope for night driving. Used in tandem with the small infrared headlamp, the driver can see as far as 60 meters using this periscope. Not far enough to drive at 60 km/h, perhaps, but far enough that he has enough time to avoid obstacles while driving at around 30 km/h or more.
There is also an elongated TNP-350B periscope. It is 350mm tall, tall enough to look above the trim vane when extended for swimming.
In terms of comfort, the driver's station is satisfactory. His station is widest at the top and narrowest at the feet, because of the overtrack hull sponson. The top is about a meter wide, and the area at the feet is about 0.7 meters wide.
The driver is also supplied with a GPK-59 gyrocompass to help him navigate at night.
ENGINE, TRANSMISSION, SUSPENSION, MAINTENANCE
Many uninformed accusations have been leveled at the BMP-2 concerning its armament, its armour, and its (lack of) amenities, but its mobility has never been in question, and for very good reason.
Contrary to what some sites may claim, the BMP-2 mounts the very same UTD-20 diesel engine that powered the BMP-1, not a more powerful one. The UTD-20 produces 300 hp at 2600 rpm, with a maximum torque output of 100 kgm at 1500 rpm to 1600 rpm, which is very good for the weight of the vehicle. The engine weighs 665 kg dry. It has a specific fuel consumption rate of around 175 g/hph to 178 g/hph.
There are two ways to start the engine. The standard method is, of course, the electric ignition switch, but that tends to be useless in extremely cold weather. To start the engine in such conditions, the BMP-2 gets the traditional compressed air tanks commonly found on tanks since the T-34. These air tanks blast air into the combustion chambers to get the pistons working and burning diesel once more.
The engine air intake fan, or respirator, is located behind the turret. It is a ducted centrifugal fan with a powerful 1.1kW VNSTs-200 integral supercharger with inertial dust separation. The respirator can guarantee that the air fed into the engine will have a purity of at least 99.5%. The respirator housing can be raised when swimming, to ensure that water does not enter the air intake ducts.
The picture below shows the transmission. There is power steering. Braking is hydraulic. The transmission and the engine are built together as a single powerpack unit, thus simplifying replacements in the field.
The air cleaning system sucks in air from the deck. It is protected by armoured louvers. The air cleaning system is self-cleaning. Dust is ejected out through the exhaust. This greatly reduces the time between filter replacements.
However, it's definitely not all bad news. The torque output and low speed characteristics are marvellous, so the BMP-2 has superb passability over rough terrain at average cross country speeds of 20 km/h to 35 km/h. According to private owners, the BMP-2 is also extremely agile. Its obstacle crossing capabilities are quite standard. It can climb a vertical slope of 35 degrees, traverse a side slope of 20 degrees, and climb a vertical wall 0.7m in height, but not more, due to the overhang of the nose of the hull. The BMP-2 can cross a trench 2.5m in width by driving over it at low speed, but it can cross much wider tranches by literally jumping over them, which isn't very difficult for it to do.
Still, keep in mind that nothing is infallible. The BMP-2 can still get stuck, just like any other vehicle, though it is definitely not anywhere close to being overweight. Its thin tracks might be a liability for some other platform, but thanks to the compressed design of the BMP-2, it only exerts a ground pressure of 0.65 kg/sq.cm when combat loaded. The Marder 1, with its much wider tracks, still cannot escape the fact that it is about 2 times heavier than the BMP-2. The Marder 1 exerts 0.83 kg/sq.cm of ground pressure.
The tracks, torsion bars and drive sprockets were not carried over from the BMP-1, despite being almost indistinguishable from one other aesthetically. Besides the frontmost and rearmost torsion bars being reinforced, the tracks are of a different type. Unlike the old type, the BMP-2's tracks can accept rubber track pads for driving on asphalt, and they have contact needles for better grounding of the radio, thus apparently reducing radio interference. Not too sure how this works, though. Anyways, the roadwheels were also replaced with sturdier ones that could better handle the stress from the greater weight. It should also be mentioned that the this combination of three upgrades gave the vehicle an extra 50mm of ground clearance over the BMP-1, so that the BMP-2 has a ground clearance of 420mm. This means that the vehicle can be driven with more authority over rocky or lumpy terrain.
If the BMP is stuck fast in some soft sand or in sticky mud, which is rare, it is possible for it to extricate itself with the use of the famous log. The video below demonstrates how it is done. You can see for yourself how invaluable the log can be.
More than 90% of all maintenance can be done by simply lifting the engine access panel on the upper glacis. Its lightweight aluminium construction and hinged mounting makes it into sort of an oversized bonnet. Two men could hinge it open. The radiator block deck is slightly less convenient, though. It is bolted securely to the hull roof, and a crane is needed to lift it. This will be necessary to replace a broken radiator. There is also another small hatch on the top deck for access to the engine and radiator.
Most would opt to lift the engine access panel to do regular scheduled maintenance, but doing that is not the only way of getting to the engine. Inspections and oil top-ups may be done without leaving the vehicle by opening the 1 inch-thick insulated bulkheads separating the engine compartment from the inhabited compartments. The small one-man turret of the BMP-1 made accessing the rear engine bulkhead hatch from the passenger compartment relatively easy, but the wider turret and the missile stowage racks made this impossible, but this is no big loss. You could still get to it just as easily from the commander's station, where it would be right in front of you, as you can see below. This hatch allows you to see the rear part of the engine, the radiator pack, and the air compressor used to fill up the compressed air tanks used for starting the engine.
The hatches on the driver's station fireproofed bulkhead allows him to inspect the engine itself. An experienced driver-mechanic can diagnose and troubleshoot a faulty powertrain directly from his station. An opened bulkhead hatch can be seen in the "Driver's Station" section.
Electricity in the vehicle is supplied by two 6STEN-140M or 6ST-140R accumulator batteries connected in series, with a combined capacity of 140 Ah. Each battery weighs 62kg.
The BMP-2 has five fuel tanks; three internal tanks and two rather infamous exterior ones - the rear doors, which we have already talked about quite a bit. The port side rear door holds 55 liters and the starboard side door holds 67 liters (the port side door has less as it has a firing port embedded in it). The main tank in the passenger compartment - which forms half of the partition splitting the passenger compartment into halves - holds 225 liters.
The D-100 fuel pump is located underneath the seat of the starboard side bench closest to the door. It is a reasonably sized pump, running on 150W. The vehicle in the photo below is a Czech OT-90, but the pump is the same model and in the same location.
Because the bench was shortened to seat only three passengers as opposed to four as in the BMP-1, it became necessary to add an additional two fuel tanks to compensate for the reduced main tank capacity. In some hilariously misguided attempt to store as much fuel as possible in the passenger compartment, these two tanks are made to be half of the bench on either side of the passenger space, meaning that one passenger will be seated on the fuel tank itself. The port side tank can be observed below:
The port side tank holds 55 liters and the starboard side tank holds 58 liters.
With all fuel tanks filled, the BMP-2 has a maximum cruising range of 600 km on paved roads. That means that if the highways were clear, you could drive from Berlin to Cologne on a single tank! But no one really expects that to happen. Indeed, armoured vehicles on the frontline don't really get to drive around much once they reach contested territory, so why carry around so much fuel? Well, a generous cargo of fuel means that a BMP-2 could fight for two to three days in a continuous, unstoppable offensive push on a single fill of fuel, giving it a great deal of independence and autonomy in the field. It becomes possible to conduct a deep penetration offensive or counterattack with minimal supporting assets like fuel trucks and bridgelayers, though obviously these assets are still very necessary, but among all the other little details and idiosyncrasies of its construction, this one is perhaps the best proof that BMP-2 was designed with just that one, single objective in mind - continental domination. One of the other details, as many should already know, is its amphibious capabilities.
The BMP-2 is almost as adept in the water as it is on land. In fact, several compromises had to be made to the structure of the hull for the sole purpose of improving its performance in the water, including the slight tapering of the passenger compartment (see here), which reduced the amount of stowage space for the person sitting closest to the rear doors, but also reduced drag. The short and stubby bow of the original BMP from 1966 gave the driver a good view of what was in front of the vehicle when driving, but the bow was too short to properly enter rivers from a steep bank, as the bow would tip too deeply into the water, so the bow was lengthened. This created a large blindspot in front of the BMP, but made it possible to enter bodies of water from any angle. Suffice to say, they took this requirement quite seriously.
Propulsion in water is produced by the flowing of water around the tracks being channeled rearwards with the use of a special aluminium alloy hydrodynamic grille which is placed where the rear fenders usually are. The rearwards stream of water produces forwards thrust. The faster the tracks move, the more the water that flows through the hydrodynamic grilles. This system is the same as in the M113 in principle - movement of the tracks in water - only better optimized thanks to the addition of the grilles and the more hydrodynamic shape of the hull.
As one might expect, one of the biggest dangers while swimming is that cannonfire punctures the hull and springs a leak. This is not normally possible, since the only parts of the vehicle that are liable to get hit are above water, and since they are above water, the only way water could get in is if the waves are tall enough to wash over the hull, and even then the rate of the inflow of water isn't really worth worrying about if the holes are nickel-sized, which would be how big of a hole you'd get if hit by a shaped charge grenade. Still, these are other, distinct hazards, like large caliber artillery shells exploding right next to the vehicle and rupturing weld seams. In the unlikely event of something like that occurring, the vehicle is insured by a pair of MBP-2 bilge pumps located underneath the squad leader's seat. The bilge pumps are electrically powered and run on 300W each. It is powerful enough to suck in water from the floor of the hull and eject it out through a small valve on the belly of the hull. If it is not enough to keep the vehicle afloat until it reaches the shore, the bilge pumps can at least buy the passengers and crew enough time to bail out through the roof hatches and swim to safety.
Just as with the BMP-1, the ventilator must be erected and the trim vane must be extended before entering water.
Because the chassis and hull design of the BMP-2 was not altered despite the weight gain, it became necessary to revise the fenders and sideskirts to add foam filled flotation aids to boost the vehicle's buoyancy.
Here is proof that the fenders and skirts are in fact solid:
Thanks to full two-plane stabilization for the 2A42 cannon and its inherent adeptness at providing suppressive fire, the BMP-2 can launch an accurate and relentless attack on coastal or riverbank targets with all weapons (including the ATGM) while swimming, which may contribute to ensuring a successful landing operation. It is also possible for the passengers to fire out of their firing ports, which is somewhat more effective in water than on land since the vehicle really can't possibly go much faster than 7 km/h.
Thanks to bureaucratic depravity, the BMP-2 was introduced far later than it could have, and should have been, and that impacted the number of units the USSR managed to churn out prior to its disintegration. Still, as I've already said in the introduction, Kurganmashzavod produced about 14,000 BMP-2s in the space of 9 years, that is, from 1980 to 1989. At the peak of production in 1989, between 1,800 to 2,000 units exited factory gates, three times higher than the highest ever annual rate of production of the M2 Bradley. This information comes courtesy of a declassified CIA report available here (link). According to Forecast International, serial production of the BMP-2 was wrapped up in the Russian Federation and in Slovakia in 2008. No new units have been produced by any major contractor since then, but modernization efforts have been ongoing in India and other operator nations for years. Forecast International estimates that a sum total of 33,939 BMP-2 and BMP-2 variants have been produced since its inception in 1980. According to them, a new-production Russian BMP-2 costs $404,000 in 2007 U.S Dollars, and used Russian BMP-2s are available at the jaw-dropping price of $78,000. India's "Sarath" costs $398,000 apiece.
Here is a list of the nations operating the BMP-2, and the quantities owned:
Afghanistan (168, Pre-Operation Enduring Freedom; current status unknown),
Czech Republic (186),
Democratic People’s Republic of Korea (70),
Iraq (194, Pre-Operation Iraqi Freedom; current status unknown),
Russian Federation (21,719),
Sierra Leone (3),
Slovak Republic (93),
Sri Lanka (51),
In some ways, the BMP-2 can be considered the "T-72 of IFVs". They are a close second to the most mass-produced vehicle of its type (the BMP-1), just like the T-72, and just like the T-72, the BMP-2 is obsolete, but still very, very capable even in this day and age, and even more so if upgraded and evolved a la T-90A. Speaking of the BMP-1, it should be mentioned that although the production of the BMP-2 was deliberately curtailed by internal strife, it still managed to end up to compete closely with its predecessor in numerical strength within the ranks of the Red Army, though it came as close as it is only in recent years. Production of the BMP-1 ended very soon after the introduction of the BMP-2 - a development catalyzed by the superior combat performance of the latter in Afghanistan.
The fact that a whopping 34 nations are operators of the BMP-2 says something about its desirability, and also the eagerness of the Soviet Union and its satellite states to sell to whomever they could. These sales were often for political reasons, sometimes with trade agreements on the side and promises of "enduring friendship", but discounts and package promotions are simply not the only reason for the popularity of the BMP-2. If this is not evident to you after reading this article, feel free to talk about it in the comments section below.
BMP Infantry Fighting Vehicle 1967–94 By Steven J. Zaloga
The Bear Went Over the Mountain: Soviet Combat Tactics in Afghanistan By Lester W. Grau