T95 A Gamble in High-Risk Technology

The use of high-risk technology, in the design and development of armored vehicles can be defined as the employment of any technology of unproven design or capability. The fielding of a weapon system incorporating this type of technology would clearly be regarded as a gamble, or high risk. The decision to take this gamble, or not, thus becomes very important to the future of any armored vehicle program. In 1954, a series of design studies was begun to develop anew family of armored vehicles of the medium or main battle tank (MBT) class. One of the resulting designs, the T12, was accepted and moved into the development phase and redesignated the T95. It was intended to make extensive use of innovative, unproven technologies. The specific purpose of the T95 is not very clear. Some sources state it was intended to fulfill the missions of both the M48 MBT as well as the M103 heavy tank. Other sources, however, disagree, and refer to the 295 as primarily an experimental vehicle; intended for testing all of the recently available technologies. No matter what role the T95 was intended to perform, it was clear from the beginning that it was to be a truly revolutionary tank. The innovations built into the T95 were included in all three of the basic tank design criteria: firepower, mobility and protection. The main armament fitted to the T95 pilot model was the T-208 smoothbore, 90-mm gun, carried in the T191 non-recoiling mount. This new, fixed gun mount had several advantages over the conventional recoil system. First, it eliminated the weight, complexity and cost of a recoil system. Second, it reduced the turret opening required to mount the main gun. Third, it reduced the amount of space needed inside the turret to allow for the gun's recoil. Although the smoothbore gun and its rigid mount were very innovative, the most important feature of the tank's firepower was its ammunition. This was an armor-piercing fin-stabilized, discarding-sabot (APFSDS) round, with a 37-mm tungstencarbide penetrator. The round had the penetrator centered in the cartridge case and supported by a forward discarding sabot at the mouth of the case and looked much like the current 105-mm APDS round The muzzle velocity of 5,000 fps and the low drag projectile were expected to produce target effeds similar to those currently achieved.' The T95E1, mounted the same main gun as the pilot model, but in a conventional recoiling mount. The following models were fitted with a complete turret from the M48A2; the T95E2 was fitted with the T140E1 105mm smoothbore gun. The T95 was also fitted with a developmental turret fiom the M60A2 program. This latter modified T95 was used to successfully conduct the first cant-angle firing of the Shillelagh guided missile. Finally, the British 12CLmm rifled gun which was then being considered as a replacement for the Centurion's 105mm main gun was considered for use on the T95. As for secondary armament, the T95 and the T95E1 were both equipped with a.30 caliber coaxial machinegun and a.50 caliber cupola-mounted machinegun. Personnel armament included a.45 caliber submachinegun and a.30 caliber M2 carbine. Another important aspect of the 2'95's firepower can be found in its various fire control systems. While some models were fitted with conventional range finders, such as the T57 coincidence type, a very innovative system was used on the pilot model. Another rangefinder, known as the T53 Optical Tracking Acquisition and Ranging (OF'TAR) system, was tested on the T95 from 1955 to 1957. The OPTAR system consisted of alight-beam transmitter, a receiver unit, and an offset sighting system. The transmitter, and receiver were located on the right side of the turret, proseptern ber-October 1983 39 tected by a large, armored blister. The system was designed to enable the tank commander to lay the range finder on a target; and by pressing a button, fire a single pulse light beam. This beam would reflect off the target and return to the receiver. The data would be processed and given as a range readout. Since the OPTAR used a noncoherent beam of light, the beam had a tendency to scatter, resulting in multiple returns to the receiver. The tank commander was required to visually estimate the target range and determine which of the beam returns was correct. Despite this problem, the OPTAR was a major breakthrough that would prove to be the forerunner of today's laser rangefhders.2 The 795's mobility was also given a high priority, and the most important item in this area was the powerpack This was a Continental Model AOI-11955 engine coupled in Allison Model XTG-410-1 manually-controlled, full-hrqueshifthg transmission. Power was supplied by the hylinder, 18Odegree horizontally-opposed, air-cooled fuel-injected engine that delivered 560 gross horsepower at 2,800 rpm. This gave the 795 a power-to-weight ratio of 13.5 hp/ton and a maximum speed of 3537.6 mph. Other engines were also tested. There was an engine with its cylinders arranged as an X, as well as a commercial diesel engine that was mounted in the late model 795E8. Finally, in March 1961, a 295 was displayed at the Pentagon with a Solar Saturn 1,100 hp gas turbine engine3 As for running gear, the tank was fitted with a flat track suspension system without support rollers. The track was carried on the top of the five largediameter dual road wheels that were suspended on torsion bars. Each of the road wheel hubs was fitted with a transparent plastic plug that allowed visual inspection of the hub lubricant level. Many different running gear systems were tested on the 795, ranging from a variable height hydropneumatic suspension to anew type of titanium track mobility trials pitting a 795E2 against an M48A2 from June, 1957 to September, 1959. Two hulls were used logging a total of 3,774 miles and it was determined that the 795E2, with its decreased weight at no sacrifice in armor protection, in most cases exceeded or equalled the M48A2 in perfor-The final trial report recommended that the 795 tank chassis, after modifications for improved mobility on muddy terrain and component reliability, be strongly considered for future MBT proddion. Since WW 11, there has been a concentrated effort to provide tanks and other armored vehicles with some degree of protection against high explosive antitank (HEAT) ammunition. Early ideas ranged from simple spaced armor to an asphalt and pebble composition known as HCR-2. These early designs, however, did not provide a workable solution. As a result, the Continental Army Command requested the initiation of a program in 1952 to develop an armor that offered built-in protection against shaped-charged projectiles, without sacrificing protection against kineticenergy projectiles or increasing the vehicle's total weight. This armor development program was combined with the T95 program and resulted in the construction of 36 siliceous-cored T95 turrets and hulls. While it is true that most of the T95s were built with conventionally armored glacis plates and turret fronts, these specially armored turrets made the T95 the first American tank model to be fitted with composite armor. The armor consisted of an outer layer of about one inch of cast armor, an inner layer of about two inches of cast armor and a center layer of about four inches of fuzed silica Silica, or glass, was chosen for the armor because it does not "flow plastically" after an impact as does steel. Silica, instead, rebounds after the shock wave and radially bombards the 40 oncoming shaped-charge metal jet particles and disrupts the jet's shape.6 A series of ballistic tests were conducted on composite armored 795 turrets and hulls from 1 June 1958 to 1 August 1960. The purpose of the tests was to confirm the effectiveness of the composite armor against currently fielded antitank weapons. The following projectiles were firred: 12 rounds of 9@mm HEAT, 33 rounds of 3.5inch rocket, 54 rounds of 105mm armor piercing (AP), 24 rounds of 120-mm high explosive (HE), 12 rounds of 105 mm HE, 1 round of Soviet 100-mm armor-piercing, high-explosive (APHE) and 64 rounds of 1Wmm HEAT. The most interesting result is clearly that of the Soviet 100-mm APHE round. The round was fired to impact on the upper glacis plate, which was sloped at 65 degrees. The round displaced apiece of armor from the cast armor outer layer measuring 38% inches by 14% inches, and caused several outer layer cracks. No damage was classified as a protection, partial penetration (PP-P).7 The entire arqa from the inner layer of the glacis plate to the rear of the hull was undamaged. However, despite the effectiveness of the fuzed-silica composite armor, it's design had some severe limitations. First, upon impact by either a shaped charge or an AP projectile, an undetermined amount of fuzed-silica would be pulverized. This would occur whether or not the round defeated the armor. Second, upon impact from nonpenetrating AP projectiles, the cast armor could be severely damaged. The amount of damage could vary from displacement of apiece of outer layer cast armor (as above) to largescale silica pulverization and inner layer cast armor bowing. In either case, the effectiveness of the armor against a subsequent projectile impact would be greatly reduced. Even so, it was determined that fuzed-silica composite armor provided superior protection Table 1. Physical Characteristics Weight Combat loaded, 83,471 Ibs. Crew, 4 Fuel Capacity, 220 gal. Length (travel lock) 31' 1%" Length (Gun frd) 33' 9%" Height 9' 5" Width 10 4%" Ground Clearance 1' 1%" Dimensions Armament Main Gun 90-mm Gun, T208 Elevation, 20" Depression, 10" 1 Cal..30 MG 1 Cal..50 MG Comdr's 1 Cat..30 Carbine, M2 1 Cal..45 SMG Secondary: l1.3 Ammunition ll. O 90-mm, 50 rds Ground Pressure Hp per ton ratio Engine: Continental, horizontal ODDOSed..50 Cal. 1500 rds Model AOI-1195-5, (8 Cy!..30 cat, 4500 rds.. ai r-cooled) and Geared Steer Flat Track Double Pin-Rubber Backed T115 Steel, T114 Rubber Electrical System: 24 volts Transmission: X-Drive, Steering: Clutch Brake Suspension: Torsion Bar Tracks: Final Reduction Planetary Concentric Ratio, 5.4:1 FVRev 6.38 Sprocket Pitch Diameter 22.19" Ere Control Periscope, T50E2 Gunner's Telescope, Comdr's Telescope Quadrant, M13 Elev. Range Finder-Optar Indicator, Azimuth T28El T171E1 Ord #a289340 Performance Maximum speed, 35 mph Cruise Range, 150 miles Maximum Grade, 60% Trench Crossing, 8' 6" Vertical Obstacle, 36" Fording 4' against shaped-charge HEAT projectiles, and at least equivalent protection against AP projectiles as that of an equal weight of solid steel armor.8 In 1961, after Congressional criticism and the appearance of several problems during its develop ment, the Army decided to halt the T95 program in favor of a product-improved M48. The T95 program was widely regarded as a failure. It ran for 7 years and cost $26.6 million. In spite of all the time and money spent on the project, no new tank entered the service. The program experienced many problems that ranged from the fact the 295 did not comply with the Berne International Loading Table because it was 1 inch too wide? to the fact that the nonrecoiling main gun mount transmitted too many G-forces into the turret structure.’’’ However, these limitations must be kept in perspective, If the innovative technology of each of its subsystems is examined individually, the 795 does not appear to be such a failure. A high-velocity smoothbore main gun firing APFSDS ammunition, alight-beam, or laser, rangefinder, a powerful diesel or gas turbine engine, and composite, or special, armor, are almost mandatory characteristics of the modem main battle tank. It is hard to say what the exact impact of the T95 would have been had it been fielded. Perhaps the best way to determine this impact is to compare the T95 to a tank that also made extensive use of high-risk technology, the Soviet T-64. In spite of numerous reported problems, it was put into production and service in the mid-to-latel960s. The similarities between the T-64 and the T95 are surprising. While the 125mm smoothbore gun and its APFSDS ammunition, as well as the probable mounting of a newly-developed laser rangefinder are well known, the engine and armor protection fitted to the T-64 are still surrounded by speculation and concern. The T-64’s powerplant is a 750 hp diesel engine that represents a drastic change from conventional Soviet designs: being a flat, fivecylinder design, with horizontally opposed pistons.11 The performance and reliability of this new engine has been under close examination by the west for some time. Some of the most recent information indicates that this engine has been plagued by problems. The Soviets, however, seem to be pleased with this innovative engine and, according to some sources, have incorporated an uprated version of it into the “T-80” MBT.12 Some reports indicate that the “T- 80” possibly incorporates a T-64 hull fitted with a hydropneumatic suspension system. The smaller roadwheels on the T-64 (as compared to those fitted to the T-72 MBT) would be more applicable to such a suspension systern.l3 The T-64’s armor has been the subject of much speculation in the west. When the tank first appeared, it was widely assumed that the design could not incorporate any form of advanced armor because of the use of a cast armor turret. This assumption, however, now appears to have been in error. As details of the T-64’s frontal armor package became available, it has been determined that it is, in fact, proteded by at least a first generation of advanced armor.l* The deployment of this tank, with its innovative frontal armor, caused the west to make urgent plans to counter this new threat. These efforts were primarily concerned with the development and deployment of enhanced capability HEAT warheads, like the improved TOW and TOW 2 antitank missiles. These two systems were needed because of the obvious requirement to knock out a T-64 from the front.. It had been determined that the standard TOW missile (with its conventional HEAT warhead) was suddenly faced by a threat that it not only could not kill from the front, but might only cause significant damage to (the) T-64 sights, tracks and running gear; and, if approp riate tactics are employed, cause outright kills if fired against the tank‘s side, rear or top.armor.15 While the determination of the effectiveness of the T-64’s frontal armor was being pieced together, very little information concerning its exact composition was available. It had already been proven, however, by the design and testing camed out on the T-95, that a cast armor turret could be fitted with composite armor. The type of frontal armor fitted to the T-64, although not necessarily a duplicate design, is most likely of the same (primarily) HEAT-defeating family as that composite armor employed on the T95. Thus, the impact of the T-64 can be measured by the massive reaction it caused in the west; a reaction that is still being felt today. A comparable reaction might well have swept through the Soviet Union had the T95 been fielded. It seems very clear that the most important lesson that can be drawn from the T95 program, is that the time spent waiting for the ultimate in tank technology is in fact time wasted. The innovative, high-risk technology incorporated into tanks like the T95 and T-64 will certainly cause them to experience initial teething problems; problems which can, however, be dealt with and temporarily accepted. Once such a design is fielded, it can be modified and upgraded as necessary. Today’s technology, even if it is classified as high-risk, must be put to use today. If it is not, and our capabilities are kept from the field to be fine tuned, the tank technology that has been developed for so long will finally reach the field as nothing more than a workhorse from the Dast. Footnotes 1 Shiovitz, Nathan N., “The T-95 Tank.” ARMOR, January-February 2 Tillotson, Geoffrey “Modem Combat Vehicles: 4 M48,” (London: Ian 1976, pp. 2527. Allen LTD, 1981), p. 106. 2 Tillotson, p. 106. 4 Misiora, D. A. J. “Engineering and Endurance Test of Tank T-95E2, pilot No. 1,” DPS TW-401 8, Aberdeen Proving Ground, Maryland, September 1959 (available as AD #314438 from the Defense Technical Information Center, Alexandria, Virginia). 5 Ibid. fi Frye, W. B. “Evaluation of Special Armor Castings Under Attack with Shaped-Charge, Armor-Piercing and High-Explosive Projectiles,” DPSl2l Aberdeen Proving Grounds, Maryland, February 1961 (available as AD #I3218911 from the DefenseTechnid Information Center, Alexandria, V i a ). ’ Ibid. 8 Ibid. 9 Keil, William A. “Test of Tank, Combat Full Tracked, Medium Gun, T-95, DA Project #54507-028, Headquarters, United States, Continental Army Command, Ft. Monroe, Virguua, January 1960 (avadable as AD #314275 from the Defense Technical Information Center, Alexandria, Virginia). 1‘’ Shiovitz, Nathan N. “The T-95 Tank,” ARMOR, January-February 1976, pp. 2527. Jenkins, D. H. C. ‘T-34 to T80: The Evolution of Sovie Battletanks, plus IDR’s T-62 Test Report,” International Defense Reutew, December 1981, p. 1651. 12 Ibid., p. 1654. 13 Ibid., p. 1652. 1‘ Furlong, R. D. M. “Soviet Tank Armor of ‘Grave Concern’,” Intern- 15 Furlong, R D. M. “Delay in Improved TOWS for Europe?,” Zntern-tional Defense ReuLew, March, 1980, p. 311. tional Defense Reutew. September 1980. p. 1343.

FORD was commissioned in armor in 1979 as a distinguished military graduate from University of Santa Clara, CA. He has served as a tank platoon leader and support platoon leader with the 1st Armored Division. He has recently been assigned to Fort Hood, TX. I septern ber-October 1983 41