Soviet Tanks: An Israeli View

by Lieutenant Colonel David Eshel, IDF (Retired) (This article appeared in the September 1987 "National Defense." Reprinted with permission.) Soon after the Six Day War, with hundreds of Soviet tanks captured by the Israeli Defense Forces (IDF) in Sinai and the Golan Heights, Israel began to evaluate these vehicles. It was soon established that the Soviet tanks had substantial combat potential and compared favorably with Western counterparts. The IDF Ordnance Corps decided to bring these tanks into service. Although the captured T-54/55 tanks at lkst retained their original D-IOT IOU-mm gun, modifications includcd the replacement of the Russian radio set with the standard VRC type in service with the IDF, and the fitting of Browning machine guns.

During the War of Attrition (1968-1970), the IDF used the Soviet tanks in several operations along the Suez Canal, the most audacious being the large armored raid on the coastal road of the Gulf of SUCZ in September 1969. The raiding force, which included several T-55 and BTR carriers painted in Egyptian army colors, was landed at night by LST. It roanicd the coastal rod southward destroying Egyptian military traffic and radar installations. The operation lasted for almost half a day, after which the force was rccovercd by amphibious craft and returned to base. This was the first time that Israeli crews opcrated Soviet tanks under combat conditions.

Their experience served to modify the vehicles within an extensive upgrading program which was imple-mentcd in the mid-1970's. During the Yom Kippur War, a complete brigade of partially-upgradcd T-55 tanks served in Sinai, fighting alongside the IDF Patton and Centurion tanks. The T-55s were by then upgunned with the 105-mm gun, but still retained most of the original features of the Russian model. During the fighting in Sinai, the IDF T-55s were badly mauled in combat during the Octobcr 14 battles, when the brigade stemmed an all-out Egyptian assault almost unassisted. After the war, the upgrading program was continued and included imoortant Soviet T-55, as modified by the Israelis, with 105-mm. gun modifications based on the battlefield experience gained in Sinai. Austere Modifications The. guidelines dictated by the Ministry of Defense were strict: the modifications were to be made with utmost economy. However, the ordnance experts agreed unanimously that the basic T-55 was a good tank with excellent automotive capabilities riding on one of the world’s best suspension and track systcms, its heavy armor but low weight adding survivability. The tank had an extremely low silhouette, and was fast even over rough terrain and sand. Its powerpack was fairly reliable and simple to maintain.

After evaluating the gun/turret structure, it was decided to leave the original Soviet D-IOT gun systems and assembly intact and replace only the barrel and sleeve. However, due to the higher barrel pressure, muzzle velocity, and recoil forces of the L7A1, the gun assembly had to be acijusted. Because the original systems were kept, no modifications to the turret ring, trunnions, or turret layout became necessary and the tank was rcady lor firing tests just a few months after project launch.

The post-Yom Kippur War retrofit program included installation of metal stowage boxes on the sides and rear of the turret, which added protection against HEAT and shoped-charge hits. This also changed the silhouette, facilitating recognition in battle. An additional upgrading scheme fitted Blazer reactive add-on armor plates, enhancing protection.

Currently, the IDF Ordnance Corps main depot is upgrading the Soviet T-55 and T-62 tanks to Israeli standards. Designated Model S, the T-55s is re-cngined with the American General Motors 8V-73T diescl powerpack developing 600 hp, a considerable improvement over the Russian 500-hp engine. The Soviet manual transmission was also rcplaced by a semiautomatic hydromechanical transmission fitted with a torque converter, which ensures optimal output power in all gears. This facilitates gear shifting, a very tiring and physically exhausting job on the original tank. The new combination made driving a lot easier, permitting acceleration lo 27 mph in only 30 seconds, a marked improvement.

Further modifications in the powerpack involved the final drive. The original design was a two-part planetary device, one permanently installed in the hull, the other hinged to the engine. The new final drive is a custom-made single unit which can be removed with the engine and is, therefore, easily replaceable. Engine change is now down to a 30-minute job in the field. All engine accessories have been rcplaced. Among these are the air cleaners. The original device used a particle filter and oil bath for air cleaning. This proved totiilly unreliable under desert dust conditions, rcquiring major cleaning evcry 25 hours. The new systcm, lociltcd inside an armored box, is more elTec-live in cleaning and air volume supply (8OOm /sec), and needs only compressed air for cleaning every 50 hours.

Reducing Vulnerability The old fuel system, comhining external and internal fuel and oil tanks, was scrapped as both incffec-rive and vulnerable in combat. It was replaced by four fuel tanks located in various places inside the hull, some of which are dual-purpose, combining diesel fuel and ammunition storage. Armament improvements include anew Cadillac <;age stabilizer replacing the electro-hydraulic systcm used by the Soviets. The old system gave fine vertical stabilization (hydraulic) but the electrical horizontal stabilization was poor. The new unit provides superior performance in both axes. The hazards of comhuslihle hydraulic hid, demonstrated by exploding tanks during the latest wars, have been reduced. The stabilization system’s more vulnerable parts, the accumulator and powerpack have been located in the hull in a relatively safe place, feeding the stabilizers through a special hydraulic line over thc hydro-electric collector. To enhance survivability, several systems are added. These include a standard IDF low-profile commander’s cupolo,replacing the original Soviet bolted, lorward-opening hatchcover, which dangerously blocked the commander’s forward view. The original smoke screen generator, operatcd on a system under which diesel fuel was injected into the exhaust, produced only local smoke screens vulnerable to wind direction. The new system is fired away, masking the tank immediately. One of the main drawbacks of the original Soviet design was the total disregard ol human engineering for crew members. The Soviets pick the smallest of their recruits to serve in tank units, but even these midgets did not feel too happy in the confines of their tank turret and driver’s compartment. Bad ventilation in the cramped interior caused Fatigue and exhaustion, reducing combat efficiency and endurance. In fact, Arab tank crews, overcome by deadly fumes and heat stress under severe climatic conditions, often abandoned their tanks, which were picked up pcrfcctly intact. Although the Israeli designers could not alter the overnll configurations of the original model, human engineering considerations were given high priority in the retrofitting process wherever possible. Consequently, the S model is a few centimeters higher than the original T-55. Cross-country ride comfort is improved by raising the wheels and torsion bars, improving road whecl travel. The rear of the turrct was enlarged with a rectangular box which houses the communication sets, clearing the lighting compartment of space-consuming items. In spite of these improvements, the T-55 is still far less cornfortahle than Western tanks, especially the Merkava, which was designed with human engineering priorities in mind.

However, if the Israeli modilica-tion of the T-55 is a marked advance over Soviet tank design concepts, the T-62, which is an advance over the T-55, presents even more problems in human engineering. While the T-62 is a much later model, it is in several respects, a step backwards.

Several hundred T-62s served with Arab arnues in the Yom Kippur war and gave tlie IDF a considerable shock with the first appearance of its highly effective smoothbore I 15-mm gun. Captured tanks enabled the Israelis to take a closer look. Human engineering of the T-62 proved even worse than in the T-55. The fighting compartment wits even more craniped due to the lower deck, and the egg-shaped lur-ret, flatter by some centimetcrs than the T-55’s, leaving less headroom for the crew. The T-64 or T-72 crew members are evcn worse on, as thc even later turret is reduced and much space inside the fighting compartment taken up by the automatic loader, which makes movement inside almost impossible.

Driving Problems Driving the T-62 is not much fun, either. The driver’s position is on the left side of the hull. His seat can be lifted to permit driving with his head out of thc hatch, or lowered, if driving buttoned up. If the hatch is open, thc turrct is blocked and cannot be traversed.

A compressed-air starter device is available, in addition to the normal electric startcr. The T-62 has retained the manual transmission system with five forward gears and one reverse gear.

The first gear is used for emergency driving only. To start up, the driver selects second gear and sets tlie throttle to about 600 rpm. On the move, gear-shifting becomes a very tedious affair, as double-clutching is necessary and if not caught just when the idler is synchronized, it presents difficulties. Changing to the higher fourth gear, the driver has to shift the lcver across the width of the gate, pushing it backwards very forcibly. Gear shifting sometimes even requires a sharp blow from a heavy hammer. No wonder that clutch and transmission breakdowns occur often, leaving an otherwise perfectly serviceable tank abandoned on the battlelield! The two-stage planetary steering system uses two three-position tillers (laterals). Although this is a very simple method, it requires suh-stantial hrce to operate under combat driving conditions; this, plus frequent gear shifting, soon leaves the driver’s arms numb with exhaustion, especially with the lack of oxygen in the cramped and ill-vcntilated coni-partnient. With the stewing tillers, maneuvctahility is limited. To turn the tank requires added acceleration, maintaining speed, which in turn produces telltale exhaust smoke, clearly visible at long range. The fighting compartment is very cramped and restricts movement of the crew if a position change becomes necessary. The commander and gunner are seated in tandem on 16 III the left side of the 11s-mm gun. This arrangement actually seats three of the crew in line, and if the tank is penetrated by a kinetic-energy shot on the left side, all three are usually killed by one round. The loader is seated on the right side of the gun. Although he has most of the space in the turret, he has to load the gun to the left, which, unless he is left-handcd, makes it a very trying occupation, soon reducing the firing sequence.

Although the U-STS(2A20) 115-mm smoothbore gun, at first, seems a very efficient tank gun, its combat effectiveness leaves much to be desired.

The firing sequence presents most of the drawbacks. The gun’s exhaust fumes are overwhelming and the fighting compartment soon fills with carbon monoxide, despite the bore evacuator dcsigned to remove fumes. Poor ventilation causes combat fatigue, and crews have been known to abandon their mounts totally exhausted, choking from the poisonous fumes.

An automatic ejection device is provided, under which the spent shell is propelled outside the turret through a porthole in the rear. But this arrangement frequently gets knocked out of line by jouncing over rough country or by nonpenetrating hits. The result is deadly. The empty brass containers (poorly aimed by the damaged system) rebound off the turret wall and ricochct at high speed around the cramped fighting compartment, where the loader is the most vulnerable.

Another defect is the loading sequence.

This requires vigorous force to shove the heavy 25- “... Although the T-72 is an advanced design incorporating many technical improvements, especially in the later models, it still retains some of the old Soviet tank maladies.

Driving the T-72 seems as tiring as driving earlier Soviet tanks...” kilogram round into the rapidly closing horizontal breech. As the gun is elevated during the loading process, all power is cut off to prevent ac-cidentd firing of the gun until the loader has chambered the round and depressed the safety button to lire.

This arrangement reduces the rate of fire considerably helow Westcrn standards. In spite of these drawbacks, the 115-mm gun is very effective in killing tanks at ranges below 1,500 meters, where most tank engagerncnts occur.

The Sovict T-55 and T-62 still make up major parts of Middle Eastern arsenals. In spite of their deficiencies, their excellent silhouette design and turret shape make them difficult to pinpoint and hit, and they frequently deflect rounds coming in at wide angles. The Soviets keep many thousands of these tanks in storage and could use them in combat as second-echelon reserves, a threat which should not be discounted. Other Tanks There are three other main battle tank models in the Soviet arsenal, of which one, the T-72, is in wide service with several Arab armies. The other two, the T-64 variants and the new T-80, are at present in service only with the Sovict armored corps. The T-72 has been in production since the early 1970s, a parallel developmcnt of the T-Ci4A which was already introduced into active service with the Soviet Army in 1967. The T-72 has a combat weight of 41 tons and is crewed by three men, in contrast to four crew members in most Eastern and Western tanks. Its silhoucttc is even lower than the T-62 and with the automatic loader, which takes up about half of the fighting compartment, makes life in the T-72 turret even more cramped than in previous designs.

Although the T-72 is an advanced design incorporating many technical improvements, especially in the later models, it still retains some of the old Soviet tank maladies. Driving the T-72 seems as tiring as driving the earlier Soviet tanks, and although the stccring mcchanism is hydraulically assisted, it still retains the old clutch and braking system, with the two steering levers as More. This seems somewhat odd, as Western tanks have long since adopted the automatic transmission system, which permits driving a tank almost like driving a sports car. The automatic loader is extremely controversial. The T-72, like the ear-A licr T-64, has two different loading systems, both of which are cranky. The Soviets were the first to adopt this type of gun loading in turreted tanks. The West has, so far, shunned this technique, although several attempts have been made to replace the human loadcr with an automatic feeder, based on the Soviet experience.

Both the T-CA and T-72 mount a 125-mm smoothbore gun, firing semi-fixed ammunition. In the T-64, the projectile and shell casing are fed together onto the loading tray and are rammed into the breech. In the T-72, the projectile is rammcd home, followed by the shell casing. In both tanks, the ammunition carousel is placed below the crew on the floor of the hull. However, in the T-W, the separate projectile and shell casings are stored vertically, whereas in the T-72 they are horizontal, facing the center.

This kind of storage, of course, affords more protection to the ammunition bunker, but also makes the reloading of the magazine in the field an almost impossible task. The siime would be true of any manual override of the automatic loader by either gunner or commander. Thc gunner sits to the left or the gun and is separated from the breech by the ranimer. This would require the commander to load manually in an emcrgcncy, hut hc is already busy commanding the tank, operating the antiaircraft machine gun and, in one case of three, he is also a unit leader. If that were not all. loading would have to be made left-handed, as the breech opens to the right. Soviet sources mention a rate of fire of eight rounds per minute. Even if the loader functions perfectly, which it often docs not, this rate of fire seems highly optimistic. Unconfirmed reports from the Iran-Iraq war indicated that thanks to malfunctions, Iraqi T-72 crews have dismantled the automatic loader completcly and reintroduced a manual loader. In the engagements in the Lebanese Bekaa Valley in 1982, the T-72 did not perform impressively and its rate of fire was inferior to that of the IDF Mcrkava tanks.

As for optics, the Russian tanks, excepting the T-80 (inform aion 1' on which is still extremely scarce), still use the infrarcd image intensifier, instead of the more effective passive thcrmal image systcm, which has much longer ranges.

As for armor protection, it was bclieved that the Soviets used special armor plating on the T-72/64, but recent photos rclcased in the West show that add-on reactive armor plates have been mounted, both on the hull front and on the turret. It seems the Russiiins have taken a leaf out o f Israeli hook in Lebanon, where this type of armor protection proved extrenicly effcc-tive against RPG and HEAT rounds. Solar, as can be deduced from the shape of the Soviet tanks, there is no sign of the Chobham-type armor uscd in the latest Western designs, such as the German Leopard 2 or the US. M I Abrams. The T-72s knocked out in the Bekaa Valley were killed by TOW missiles which penetritted the frontal armor without visible difficulty, which indicates they could not have had specialized armor plating. Reports from the Gulf front also indicate that Iraqui T-72s have been destroyed, probably with shaped-charge hits, from antitank weapons launched from pound or helicopter platforms, as the Iranians rarely send their remaining tanks into combat.

The latest Soviet tiink, the T-80. is still little known in the West, but from what has been seen, improvements are in superior optics, armor protection, and probably in mobility, rather than a radical change in design. It seems that the Soviets will wait for a full-gcnera-tion change to enter service in the late 1990s or early in the next century, with a fundamentally new modcl, which may or may not he revolutionary in design.

In short, Israeli experience in tank combat reveals shortcomings in Soviet tank designs.

However, Soviet tanks are, in principle, excellent fighting machines, combat-proven and viable under ficld conditions. If manned by determined and highly-trained crews, they can be a most dangerous and deadly opponent.

Lieutenant Colonel David Eshel, IDF (Retired), is senior defense advisor to Eshel Dramit Ltd. publications. He served many years as a career officer with the Israeli Defense Forces with which he saw much combat duty including action with signal and tank units.