Super-Heavy Tank T28 - Tank Encyclopedia (2024)

United States of America (1943-1947)
Superheavy Assault Tank – 2 Prototypes Built

Few prototype armored fighting vehicles are as recognizable as the American Super-Heavy Tank T28. This unique vehicle was first conceptualized in August 1943 to assault and destroy heavy defenses, but the T28 project’s low priority and various manufacturing difficulties meant that the first prototypes were not ready until January 1946, long after the need for any such vehicle had passed. Designed to use as many existing parts as possible, the T28 featured a number of rather unusual design features, including the lack of a turret and a quadruple track system. After taking part in post-war trials, the T28 was officially canceled in August 1949 as a result of its unacceptably bad mobility, poor reliability, and the development of superior heavy tanks.

Thickest Armor, Largest Gun

The United States of America entered the Second World War in 1941 with a rather unimpressive tank force. Although some steps towards remilitarization were taken by the US during 1940, such as the development and production of the Light Tank M3 to replace the older Light Tank M2A4, they were still relatively underprepared. The development of superior armored vehicles, however, began in earnest and the United States was able to field effective and modern equipment, such as the Medium Tank M4 and 3 in Gun Motor Carriage M10, by the end of 1942.

One category of vehicle that saw comparatively little development, however, was the heavy tank. The first serious attempt to produce a heavy tank fit for US service, the Heavy Tank M6, began in mid-1940. As development on the tank continued, the M6, much like many other early heavy tanks of the Second World War, had numerous teething issues that made it undesirable for service. Furthermore, the higher-ups in the United States Army did not see a tactical use or requirement for such a tank. From their perspective, it was decided that shipping two 30-ton medium tanks would be a better tactical investment than one 60-ton heavy tank. Consequently, only 40 Heavy Tanks M6 were ever manufactured and none saw combat.

American development of heavy armored vehicles remained relatively stagnant until August 1943, at which point the United States of America began to reconsider the idea of adopting a domestic heavy tank. One reason for this decision was that a vehicle with significant armor protection and firepower was thought to be all but necessary for shattering heavy fortifications in Europe, such as the fearsome Siegfried Line. There was also the fact that the Germans were fielding armored fighting vehicles bearing extreme amounts of protection and firepower, most notably the ‘Ferdinand’ tank destroyer, which was protected by 200 mm (7.87 in) of frontal armor and equipped with the powerful 8.8 cm PaK 43 gun. Recognizing the inevitable trend towards thicker armor and larger guns, the previously apprehensive United States Army became more accepting of heavily armed and armored tanks. In response, the Ordnance Department’s Head of Research and Development, Major General Gladeon M. Barnes, began developmental work almost immediately on a vehicle known only as the Assault Tank Project.

Development

Gatehouse’s ‘Super-tank’ – July 1943

Although work on the Assault Tank Project began in August 1943, the project’s earliest roots can be traced to a proposal submitted in July 1943 by one Major General Alexander Gatehouse. An accomplished British tank commander in both the First World War and the deserts of North Africa, Major General Gatehouse became the Chief Administration Officer at the British Military Mission Washington at the end of 1942, a position which afforded him a front row seat in the newest American armored developments. During a July 12, 1943 meeting in Washington D.C., Gatehouse presented a series of points drawn from his first-hand experiences in North Africa in which he felt Allied armored fighting vehicles could be improved. These suggestions included some of Gatehouse’s own designs in the form of rough sketches. Although most of Gatehouse’s attention was directed towards the lack of sufficient mine clearing vehicles, he also conceptualized a so-called super-tank designed expressly to penetrate European defenses. As the memo from the meeting states, “[Gatehouse] stressed that it was necessary to have a vehicle of this type in order to penetrate the first 50 miles into Europe and later on the Ziegfried [sic] line and lastly the defence into Berlin.”

Placing an extreme emphasis on protection above all else, this tank was said to have armor approximately 18” (457 mm) thick, although this was expected to vary from 12” (305 mm) to 24” (610 mm) across the front of the vehicle. Floor armor was given as 4” (102 mm) while roof armor was 4.5” (114 mm). Propelled by six sets of tracks, as seen in the front-facing sketch of the vehicle, the tank was to feature a very low silhouette turret and unknown armament. Mobility was not a priority, with the tank’s top speed given as no higher than 5 or 6 mph (8 or 9.7 km/h). This tank of unusual size never left the drawing board, although the sketch (along with Gatehouse’s other suggestions) was passed along to the United States Ordnance Department, where Major General Barnes most likely took note of it.

The A.T. Project – August 1943

Likely inspired by Gatehouse’s flawed yet well-meaning ‘super-tank,’ General Barnes worked to develop a more practical proposal for a super-heavy assault tank over the following month. This new tank was to feature heavy armor, a 105 mm main gun, a low profile, and use as many existing parts as possible. After sketching out some rough early designs, Barnes submitted a report on August 27, 1943, to the Commanding General of the Army Service Forces concerning his proposal for a new armored fighting vehicle designed to penetrate heavy fortifications. Known as the Assault Tank (A.T.) Project, this tank was, in many ways, extremely novel.

The A.T. Project was described in the proposal as a low-profile turretless vehicle weighing 75 tons (68 tonnes) and was said to have armor “which cannot be penetrated by any guns which the enemy can bring to bear upon it,” more specifically an armor basis of 10” (254 mm) on the front and 8” (203 mm) on the sides. The tank was to be armed with the powerful 105 mm Anti-Aircraft Gun T4 in a special tank-type mounting, which was reportedly capable of penetrating 7”(178 mm) of armor plate or 5 ft (1.52 m) of concrete @ 0° and 500 yds. Although not shown in the illustration, the assault tank was also to be armed with four .30 caliber M1919A4 machine guns in blister mounts. Despite its weight, the Project was predicted to be about as tactically mobile as the Medium Tank M4 ‘Sherman.’ To reduce the amount of time and money required to build a pilot vehicle, the report states that “the power train for this tank, engine and transmission, together with many other components from the heavy tank, can be utilized.” The overall design of the vehicle, however, was also said to be rather fluid.

As for what role such a heavily armed and armored tank could fill, the proposal explains:

General Barnes concluded his proposal by recommending that 25 pilot vehicles be manufactured in secret, citing an urgent need for vehicles capable of destroying heavy fortifications overseas. General Lucius D. Clay, the Director of Material of the Army Service Forces, approved this recommendation on September 6.

The characteristics of the Assault Tank Project, as outlined in the report, are tabulated below in full.

A.T. Project – August 27, 1943

The Heavy Tank T28 is Born – December 1943

On December 22, 1943, a special sub-committee on automotive equipment, which was composed of six high-ranked representatives, including General Barnes and General Clay, met to discuss the design, production, and designation of this new tank. This was far from standard procedure, as most if not all American armored fighting vehicles of the time were processed by the Ordnance Technical Committee. It was during this meeting that the designation of Heavy Tank T28 was first applied to the tank. As far as general design was concerned, the newly christened T28 was introduced in the post-meeting report as follows:

Almost no aspect of the T28’s design was left unexpanded as the project was dissected and revised. The tank’s specifications are summarized in the following table for the sake of comprehension.

Heavy Tank T28, as of December 22, 1943

Compared to the original characteristics given in the A.T Project proposal, the T28’s specifications were adjusted quite a bit. These changes included the predicted length of the tank, which increased significantly, the weight, which grew by 5 tons (4.54 tonnes), and both the quantity and the mounting locations of the .30 caliber machine guns. This report was also the first direct mention of a quadruple-track system, although the A.T. Project sketch does seem to feature a second, smaller set of tracks. In addition, the vehicle’s engine and transmission, which were both derived from the Medium Tank T23, were finally specified. The sub-committee concluded their report by recommending that 24 Heavy Tanks T28 be produced to ensure that “a tactical organization can be armed with this vehicle” for use overseas.

In response, the Army Ground Forces issued a short report on March 19, 1944 with some recommendations of their own. These suggestions were:

1. Provision of a mechanical drive instead of the electric drive;
2. An increase in ammunition stowage to the greatest possible amount consistent with sound engineering;
3. The provision of adequate room for the loader, together with some mechanical lift for handling ammunition;
4. Provision of alternate sights – coaxial as well as periscopic;
5. Provision of a built-in range finder [sic];
6. Provision of suitable means to overcome blast obscuration and permit observation;
7. Provision of increased traverse to maximum extent possible consistent with sound engineering.

Although some of these changes, including the adoption of a mechanical drive derived from the Medium Tank T26 instead of the Medium Tank T23’s electric drive, would be pursued, others, such as increased traverse angles or a mechanical loading assistant, would not. However, the Army Ground Forces’ most polarizing suggestion was that of the number of T28 pilots to be produced. Instead of the two dozen T28s requested by the sub-committee for use overseas, AGF approved the production of just three pilots for automotive testing. Three days after the report, on March 22, Barnes himself wrote to the Commanding General of the Army Service Forces requesting that a final decision be made as far as the number of T28s to be constructed. Within this letter, Barnes confusingly described the T28 as having “armor equal to an 8” armor basis” despite all other reports up until this date indicating a 10” basis. In reply, the Army Service Forces compromised and authorized the production of five Heavy Tanks T28 on April 26, 1944.

As the development of the T28 continued into July 1944, the tank’s predicted weight once again increased, this time to a healthy 95 tons (86.2 tonnes), surpassing the December 1943 estimate by 15 tons (13.6 tonnes). A thoroughly unimpressed General Clay warned General Barnes of this fact in a letter dated July 6, 1944:

“It is desired that the Chief of Ordnance immediately initiate a review of the probable characteristics, indicating in this review wherein this tank exceeds the approved military characteristics. It is further desired that in this review every effort be made, by redesign if necessary, to bring this vehicle within the approved characteristics. Pending receipt of this review by this Headquarters, any contracts based upon the previous authorization of this Headquarters for the construction of pilot models will be held in abeyance.”

Essentially, by the order of the Army Service Forces, the T28 was in developmental limbo until it could be reduced to a weight of at most 80 tons (72.6 tonnes). This weight restriction was especially important because, at the time, there were serious doubts as to whether any existing bridging equipment could support such a massive vehicle. On July 17, 1944, General Barnes promised, albeit emptily, that the T28’s weight would be kept within the previously established 80 ton margin.

Refining the Design – July 1944

Meanwhile, General Barnes and the Ordnance Department began the arduous search for a firm both willing and able to manufacture the 5 pilots. At first, General Barnes approached Baldwin Locomotive, but their schedule was too heavy to accommodate a job as taxing and complex as the T28. General Electric was also approached, but they were also unable to accept the contract. Finally, it was decided on July 18, 1944, that the Pacific Car and Foundry company would assemble the 5 pilot vehicles. Pacific Car was, however, unable to machine the massive frontal hull castings of the T28, a job which was instead delegated to the General Steel Castings Company.

There were still, as always, more issues to straighten out before T28 production could commence. At the beginning of August 1944, conceptual drawings and specifications of the T28 were forwarded to the Chief of Engineers for the express purpose of designing ferrying and bridging equipment capable of supporting the massive tank. However, given the previous failures with the T6, T7, and T12 Wading Devices, which performed poorly on much lighter vehicles, fording equipment for the T28 was not pursued. There were also some disagreements between the Army and the Pacific Car and Foundry Company. As a July 17, 1944 note from General Barnes explains:

“The proposal from Pacific Car and Foundry Company is in already, but there is some debate on the design, based on misinformation, and they must be in complete accord before proceeding.”

What exactly Pacific Car’s proposal was, or how it differed from the Army’s design, is unknown. However, it was reportedly a significant departure from both the ‘official’ design and the final vehicle. After the design was eventually corrected to align more with the views of the Ordnance Committee, approval was given on August 14, 1944 to begin the construction of a wooden mock-up. However, a mock-up of the gun mount specifically would instead be made by Chevrolet and shipped to Pacific Car upon completion.

Throughout fall 1944, the T28’s specifications were given yet another coat of polish. It was decided that the T28 would mount the 105 mm Gun T5E1, a redesigned and lightened version of the earlier 105 mm Anti-Aircraft Gun T4, as its main armament. One characteristic that had not been given much attention was the vehicle’s suspension, so in October 1944, it was decided that the T28 would use horizontal volute spring suspension (HVSS), the same suspension type as later M4 Shermans. The topic that was subject to the most contention was the T28’s armor layout. According to British Army Staff AFV Situation Report No. 27, dated October 18, 1944, the T28 carried 10” (254 mm) of frontal armor, 4” (102 mm) of side armor, and 2” (25.4 mm) of floor armor. For the most part, this aligns with the armor profile given in the December 22, 1943 report. However, exactly one month later, BAS AFV Situation Report No. 28 states that the frontal armor has been reduced to 8” (203 mm) and the side armor has been increased to 4.5” (114 mm). The reduction in frontal armor was most likely a weight-saving measure, especially given the Army Service Forces’ desire that the T28 weigh no more than 80 tons (72.6 tonnes) by any means necessary.

By December 18, 1944, Chevrolet’s mock-up of the gun mount was completed and shipped to Pacific Car. Work on the wooden mock-up continued at a slow but steady pace. On January 24, 1945, the specifications of the T28 were, once again, adjusted and compiled into an official report. The results are summarized in the table below.

Heavy Tank T28, as of January 24, 1945

The hull of the T28 mock-up was fitted with Chevrolet’s gun mount mock-up during late January and tests were conducted on the mock-up to determine the amount of available space inside the tank. According to the British Army Staff Situation Report No. 31, “as the hull was unstowed it was not possible to assess the amount of free fighting space. It is likely, however, that when the tank is fully stowed, fighting space will be restricted. It was stated that in this respect the design had no advantage over a conventional turreted vehicle.” The T28’s armor would once again be adjusted around this time, with the sides increased to a hefty 6” (152 mm) in addition to a 4” (102 mm) side skirt. It was estimated that a pilot vehicle could be finished by July 1945.

From T28 to T95 – February 1945

The Heavy Tank T28, despite its designation, had little in common with other heavy tanks of the time. Although it was both heavily armed and armored, the T28’s lack of a turret and the relative absence of machine guns made it hard to consider as a true to-the-doctrine ‘heavy tank’. Recognizing this, the Chief of Ordnance, Major General Levin Campbell, first proposed on February 7, 1945 that the Heavy Tank T28 be redesignated as a heavy self-propelled gun. This decision was, however, far from spur-of-the-moment. The T28 was referred to as the ‘105 mm Gun Motor Carriage T28’ in official documents dating as far back as October 1944, indicating that the vehicle had been toeing the line between heavy tank and self-propelled gun for quite some time.

This redesignation request was officially proposed to the Ordnance Department on March 8, 1945 and approved on April 5, 1945 by the Ordnance Committee in OCMs 26898 and 27219 respectively, officially re-christening the vehicle as the 105 mm Gun Motor Carriage T95. As was customary, the T95’s technical characteristics were once more adjusted to reflect recent changes to the design.

The most notable change was a significant increase to the vehicle’s frontal armor, which grew from an already impressive 8” (203 mm) to a monstrous 12” (305 mm) as a result of recent advances in German composite ammunition. The subsequent weight increase that would accompany this up-armoring was, thankfully, less of an issue than anticipated due to further developments in American bridging equipment. As a result, the previously established 80-ton (72.6-tonne) weight limit was abandoned altogether.

105 mm Gun Motor Carriage T95, as of March 8, 1945

Meanwhile, production of the first T95 pilot was just beginning. Armor plate was shipped to Pacific Car on February 10, 1945, with the construction of the T95 pilots set to begin as soon as final design plans were received. Realizing that the earlier July estimate was a bit too optimistic, the Ordnance Department pushed the predicted completion date of the first pilot vehicle to September or October 1945. Pacific Car was given the basic design details of the T95 in May 1945, allowing for the construction of the pilots to truly begin. Work on the pilots continued throughout the following months. Welding on the first T95 hull began promptly in May and, after the first machined casting was delivered by the General Steel Castings Company on June 20, 1945. The first T95 hull was finished in August.

The General Steel Castings Company also delivered a few T95 hull castings to Aberdeen Proving Ground for firing trials in May 1945. Castings on both an 8” (203 mm) and 12” (305 mm) basis were delivered. From May 26 to 28, Aberdeen subjected these castings to ballistic tests by the German 88 mm PaK 43/41 and two American 90 mm guns, the M1 and the M3, from various angles at a range of 1,100 yds (1,006 m). The towed German PaK 43/41 fired standard Armor-Piercing Capped Ballistic Capped (APCBC) rounds while the American 90 mms fired powerful and experimental T30E16 High-Velocity Armor-Piercing (HVAP) rounds.

Data adapted from Armor Branch Report No. Ar-16576 – Ballistic Test of Front End Casting for Heavy Tank T28

The Ordnance Department used two different sets of penetration criteria for determining the results of these firing tests. The first, the Army criterion, defined a complete penetration as a hole through which light was capable of shining through. In practice, this meant that only the very tip of the shell needed to actually punch through the armor to count as a penetration. An Army criterion penetration was signified as CP(A). The other criterion was known as the Protection criterion. It relied heavily upon observing a witness plate, which was a thin sheet of metal placed 6” behind the armor plate that was being fired upon. If this witness plate was penetrated by spall, or shrapnel, created by the shell breaking through the main armor, it was counted as a complete penetration and signified as CP(P). If the impact did not produce spall, or the spall failed to penetrate the witness plate, it was signified as a partial penetration, or PP(P).

Regardless of metric, the tests proved that the T95’s armor would hold up admirably, even when faced with some very powerful projectiles. The T95 was far from invulnerable, however, as the weakest spots on the frontal armor were determined to be the gunner and driver’s hood bulges. Either way, the T95’s armor would have been perfectly capable of shrugging off almost anything fired at it, allowing the vehicle to perform its primary role of super-heavy breakthrough to a T.

Scaling Back – August 1945

On August 15, 1945, the Empire of Japan surrendered, bringing an end to the Second World War. This left the T95 in an interesting position; generally, there are not many uses for super-heavy breakthrough vehicles in a world without massive fortifications to breach. The Ordnance Committee, accordingly, reduced the number of T95 pilots to be produced from 5 to just 2.

The first 105 mm Gun Motor Carriage T95 pilot, registration number 40226809, was finished by the Pacific Car and Foundry Company in December 1945. After some preliminary tests at Pacific Car, the vehicle was shipped to Aberdeen Proving Ground on December 21, 1945. The second T95 pilot, registration number 40226810, was finished not long after and was shipped on January 10, 1946. The vehicles arrived at Aberdeen on January 15 and February 17 respectively. The plan was to keep one vehicle at Aberdeen for technical tests and to send the other to Fort Knox for demonstration and tactical tests.

Design

Weighing in at 95 tons (86.2 tonnes) fully-loaded, the 105 mm Gun Motor Carriage T95 was a vehicle of extremes. It was extremely well protected, with up to 12 in (305 mm) of armor on the front of the vehicle, and its potent main gun, the 105 mm Gun T5E1, gave the vehicle impressive firepower. The T95’s mobility, however, was extremely poor. The vehicle’s immense weight and the desire to use as many existing parts as possible necessitated a unique (and troublesome) quadruple-track arrangement and the T95’s underpowered engine gave it an absolute maximum top speed of just 8.5 mph (13.7 km/h). The 105 mm Gun Motor Carriage T95 was operated by 4 crew: gunner, driver, commander, and loader.

Firepower

Main Gun

The T95’s main gun was the 105 mm Gun T5E1, a weapon derived from the 105 mm Anti-Aircraft Gun T4. This gun was chosen as the T95’s main armament because of its impressive anti-concrete performance, an absolute necessity for an armored vehicle designed to destroy bunkers and other heavy fortifications. The powerful armor-piercing power of the gun was a nice bonus, although the T95 was not purpose-built to kill tanks. The first attempt to adapt the T4 for use in tanks was the 105 mm Gun T5, a 48-caliber long ‘sawed-off’ version of the 65-caliber long anti-aircraft gun. The T5, designed in early 1944, had a muzzle velocity of 2,800 ft/s (853 m/s), which was a downgrade compared to the T4, which was capable of producing muzzle velocities in excess of 3,000 ft/s (914 m/s).To bring the firepower of the T5 back into line with the T4, the 65-caliber long T5E1 was developed in late 1944 for armored vehicle mounts. The T5E1’s muzzle velocity was predicted to be about 3,000 ft/s (914 m/s), just as potent as the T4’s. To help manage the recoil and provide a better view after firing, the T5E1 was equipped with a 180 lb (81.6 kg) double-baffle Muzzle Brake T10.

In order to mate the T5E1 to the hull of the T95, a specialized gun mount was developed by Chevrolet. Designated as the Gun Mount T40, this was a special gimbal-type mounting capable of traversing approximately 11° to the left, 13° to the right, and between -4° and 18° vertically. Traverse was manual only and was controlled by the gunner via two separate hand cranks, one for horizontal and one for vertical. To manage the recoil of the gun, three large recoil cylinders were mounted on top of the gun. A 3x zoom Telescope T139 was mounted to the right of the gun for direct fire purposes and a Panoramic Telescope T141 was provided for indirect fire.

Ammunition

The T5E1, owing to the size and length of its shells, was designed to use separately-loaded two-piece ammunition. It could fire quite a few different types of ammunition, including the explosive-filled T13E1 Armor-Piercing Capped Ballistic Capped (APCBC) shell, the T32 APCBC round, the T30E1 High-Explosive (HE) shell, and the T29E3 High-Velocity Armor-Piercing (HVAP) round.

Originally designed for the T4 anti-aircraft gun, the 41 lb (18.6 kg) T13E1 APCBC shell was the only shell with an explosive filler that the T5E1 could fire. It was essentially a scaled-up version of the 75 mm M61 APCBC shell, complete with roughly 180 g of Explosive D filler. When fired from the T5E1, the T13E1 had a muzzle velocity of roughly 2,800 ft/s (850 m/s) and was capable of penetrating as much as 8.5 in (216 mm) of vertical armor at point blank range. Penetration against concrete was predicted to be roughly 5 ft (1.52 m), although actual firing tests were not conducted.

Another type of ammunition available to the T95 was the T32 APCBC round. This was an unfilled solid shot based on the 90 mm T33 APBC round. The T32 was developed specifically for use in the T5E1 and was designed to match or supersede the earlier T13E1 round in anti-armor performance. The projectile weighed 39 lbs (17.7 kg), had a recorded velocity of 2,841 ft/s (866 m/s), and was capable of penetrating 9.25 in (235 mm) of vertical armor at point blank range.

The most powerful armor-piercing round that the T95 was capable of firing was the T29E3 HVAP (also called Armor-Piercing Composite Rigid, or APCR) round. This was a 24.6 lb (11.2 kg) round with a 10 lb (4.54 kg) armor-piercing core capable of muzzle velocities up to 3,700 ft/s (1,128 m/s). At point blank range, the T29E3 was calculated to be capable of penetrating a monstrous 15 in (381 mm) of vertical armor, which would have been more than a match for any armored vehicle of the time.

In addition to a wide array of armor-piercing projectiles, the T5E1 could also fire the T30E1 HE shell. This was a 35 lb (15.9 kg) projectile with about 4 lb (1.76 kg) of explosive filler. At a muzzle velocity of 3,100 ft/s (945 ms), the shell had a maximum range of about 27,000 yds (24.69 km).

A total of 62 105 mm rounds of the aforementioned types could be carried within the T95. Racks for the propellant charges and projectiles were located at the back of the fighting compartment, against the bulkhead and in the sponsons. Due to a variety of factors, including having just one loader and using two-piece ammunition, the T95 had a practical rate of fire of just three rounds per minute.

Alternate Gun Proposals

Although the 105 mm gun was intended from the very beginning to be the T95’s main armament, there were a few short-lived proposals from mid-1945 to mount larger guns to the vehicle. The first proposed gun was the 120 mm Gun T53, the same anti-tank gun used to arm the later Heavy Tank T34. This larger gun would have given the T95 a decent boost in both armor-piercing and high-explosive power, but the heavier shells would have slowed its rate of fire, especially with just one loader. Ultimately, this proposal was never pursued further than a casual recommendation.

The second proposal suggested that a much larger gun, the 155 mm M1, be mounted instead. Unlike the 120 mm tank gun, this was an artillery piece, meaning that extensive modifications would be required to mount it in the turret (or, in the T95’s case, hull) of an armored vehicle. As tests conducted during the development of the Heavy Tank T30, which was also equipped with a 155 mm main gun, illustrated, the 155 mm gun had poorer armor-piercing performance than the 105 mm T5E1 but had a much more powerful high-explosive round. There was also the issue of ammunition weight and size. Each propellant charge for the massive separately-loaded 155 mm shells weighed about 40 lbs (18 kg) and each projectile roughly 95 lbs (43 kg). In the Heavy Tank T30, which had two loaders, this added up to an effective rate of fire of less than two rounds per minute. If this gun were to have been mounted to the T95, which had only one loader, its fire rate would probably have been measured in minutes per round. As with the 120 mm gun project, this proposal was never pursued beyond a suggestion.

Machine Gun and Other Weapons

A standard pintle .50 caliber M2 Browning Machine Gun mount, as fitted to other American tanks, would have provided a very limited arc of fire if fitted to the turretless T95. Therefore, a specialized ring mount for use against both ground and air targets was developed specifically for the vehicle. It was a modified version of the Ring Mount M49C, which was a machine gun mounting intended for wheeled vehicles.

The modified mount was secured above the commander’s cupola, but it had to be cut down to allow room for the hatch to open completely. This limited the machine gun’s traverse to approximately 300° horizontally and between -19.5° and 77° vertically. Up to 660 rounds of .50 caliber ammunition could be carried within the vehicle.

In addition to its main gun and the machine gun, the T95 could also carry an assortment of weapons and ammunition for personal crew use. One .45 caliber Submachine Gun M3 and three .30 caliber Carbine M2s could be carried within the vehicle, alongside 180 rounds of .45 and 225 rounds of .30 caliber ammunition. Stowage was also provided for up to 12 hand grenades.

Protection

Armor

To describe the T95 as ‘well-armored’ would be an understatement. Designed from the beginning to be impervious to “any gun which the enemy could bring to bear upon it,” the T95’s armor was, in terms of raw thickness, some of the heaviest to ever be fitted to an armored vehicle.

The frontal hull of the T95, as evidenced by its complex shape, was one massive casting. The thickest part of the vehicle’s armor was the vertical area around the gun port, which was a solid 12 in (305 mm) of vertical armor. The T95’s massive hemispherical gun mantlet was just slightly thinner, at about 11.5 in (292 mm) thick. Other parts of the T95’s frontal armor relied more on advantageous angles than raw thickness, such as the areas to the left and right of the gun, which were only about 8.5 in (216 mm) thick but sloped anywhere from 30° to 59° against incoming fire. The vehicle’s small lower plate was similar in that it was 5.5 in (140 mm) thick but angled at 60°. As ballistic tests from May 1945 indicated, the weakest part of the vehicle’s frontal armor was the driver’s hood bulge, which was ‘only’ 9.2 in (234 mm) thick at set at a very shallow angle.

The remainder of the T95’s armor was composed of rolled hom*ogeneous armor plates cut and welded together. The massive track assemblies of the vehicle were protected by 3 in (76.2 mm) of armor at the front, 1 in (25.4 mm) on the top, and 4 in (102 mm) on the sides. As for the hull of the vehicle itself, the T95’s upper side armor was 2.5 in (63.5 mm) at 57.5° from vertical and its lower side armor was 2 in (50.8 mm) at 0°. Its roof armor was 1.5 in (38.1 mm) thick, its floor armor was 1 in (25.4 mm) thick, and its rear armor was 2 in (50.8 mm) thick at 9°. Finally, there was a water-tight, pressure-sealed armored bulkhead that separated the crew compartment from the engine compartment, which protected the crew from fires and provided additional structural support for the roof armor.

Mobility

Video footage of the 105 mm Gun Motor Carriage T95 driving over some rough ground during demonstrations. The vehicle was likely operating at, or close to, its top speed.

The T95’s mobility was, in short, abysmal. The vehicle had a theoretical top speed of 8.5 mph (13.7 km/h) and a maximum recommended sustained speed of just 6.96 mph (11.2 km/h). The reverse speed was an equally pitiful 3.99 mph (6.42 km/h). Not to be outdone, the T95 had a very poor fuel economy of 0.16 mpg (0.068 km/L), although the vehicle’s rate of oil consumption was a much less egregious 4.13 mi/qt (7.02 km/L). As far as its automotive performance was concerned, the T95 could ford up to 47 in (1.19 m) of water, cross a trench up to 9.5 ft (2.90 m) wide, overcome a vertical wall up to 2 ft (.61 m) high, and had a grade ability of 60%, meaning that the vehicle was capable of climbing slopes at angles below 31°.

Powerpack

The T95 was powered by the Ford GAF V8, a V-type 8-cylinder tank engine capable of producing up to 500 gross hp @ 2,600 rpm. The engine weighed 1,470 lbs (667 kg) including accessories and its configuration in the T95 was more or less copied directly from the 46.2-ton (41.9-tonne) Medium Tank M26 ‘Pershing.’ Although this parts commonality shortened development and construction time, it left the T95 with cripplingly poor mobility. The M26, which was less than half the weight of the T95, was regarded by many as an underpowered tank. The GAF produced a measly 410 net hp in its configuration on the T95, giving the vehicle an extremely poor hp/ton ratio of 4.23 (4.66 hp/tonne). The vehicle’s total fuel capacity was 400 gal (1514 L), and although operational range tests were never performed, one could predict that the T95 would have been unable to travel more than 100 miles (161 km) without refueling.

Coupled to the engine and differential for ease of removal, the transmission of the T95 was also derived from the M26 ‘Pershing’. This was a Torqmatic type transmission with three forward gears and one reverse gear. The maximum speed in each gear was 3.05 mph in first, 6.06 mph in second, 6.96 mph in third, and 3.99 mph in reverse. To account for its massive weight, the T95’s final drive ratio was increased from the standard M26’s 3.95:1 to 12.216:1. Reaching its top speed in just 8.8 seconds from rest and coming to a complete stop within 9.4 ft (2.87 m), the vehicle’s acceleration and braking were, as a result of the final drive adjustments, quite impressive.

The T95 was also fitted with a cooling unit consisting of four blower fans, two radiators for the engine cooling system, and one oil cooler each for the differential and transmission. The entire assembly could be easily removed for maintenance and was sandwiched between the T95’s engine and transmission.

Tracks and Suspension

The quadruple-track system of the T95 is probably its most distinctive design feature. To reduce the ground pressure of the massive vehicle to acceptable levels, two equal-width tracks were mounted to each side of the T95. This system, however, had a trick up its sleeve. With the aid of a jack and a pair of hydraulic winches, the outer set of tracks could be detached from the vehicle, coupled together, and towed as a separate unit. Because this system allowed for some 29 tons (26.3 tonnes) of its weight and about 4.6 ft (1.40 m) of its width to be shaved off, the T95 could be transported by rail or trailer and cross certain types of floating bridges that it otherwise would not be able to with both sets of tracks fitted.

The tracks of the T95 were essentially standard rubber-backed steel T80 tracks cut down to 19 ½ in (.50 m) wide. Each complete track weighed approximately 9,500 lbs (4,309 kg) and was composed of 100 individual links. With its outer tracks fitted, the vehicle’s total ground contact area was 10,584 in2 (6.83 m2) and its ground pressure was 11.7 psi (80.7 kPa), although some documents claim that its ground pressure was as low as 9.7 psi (66.9 kPa). Without its outer tracks, the ground pressure of the vehicle climbed to 16.2 psi (112 kPa). For reference, a bog standard Medium Tank M4A3 had a ground pressure of 13.7 psi (94.5 kPa) and the Heavy Tank M26 had a ground pressure of 12.5 psi (86.2 kPa).

The T95 featured four suspension systems, all identical in structure. Each system consisted of four double row HVSS bogies, three return rollers, a front-mounted idler wheel, and a rear-mounted drive sprocket. The HVSS units had a capacity of 13,000 lbs (5897 kg), resulting in a total load limit of 208,000 lbs (94,347 kg) for the vehicle. Additionally, the HVSS suspension units were 19 ½ in (49.5 cm) wide and equipped with two pairs of 20 ½ in (52.1 cm) diameter road wheels, with each road wheel possessing a 4 in (10.2 cm) wide galvanized rubber tire.

Radio and Other Equipment

For communicating over long distances, the T95 was equipped with two radios, the SCR-508 and the AN/VRC-3. The SCR-508, which had a range of approximately 7 mi (11.3 km), was standard on many American armored fighting vehicles of the Second World War and was used for communicating with other armored vehicles or headquarters. The lighter AN/VRC-3, which had a range of between 3 and 5 mi (4.8 and 8.0 km), was used for communicating directly with infantry or artillery. Power for the radio, among other devices, was provided by the vehicle’s internal 24-volt electrical system, which drew from two 12-volt batteries mounted near the main generator and was capable of producing up to 150 amps.

Crew

The T95 tank had a crew of four, consisting of a commander, gunner, loader, and driver. The gunner and driver occupied the front of the tank, with the gunner on the right and the driver on the left. The loader was positioned at the rear left of the fighting compartment, behind the driver. The commander was situated behind the gunner. The commander and driver were each provided standard direct vision cupolas. Incidentally, these cupolas were also the only way in and out of the vehicle, which would have proved troublesome if the crew needed to abandon the vehicle quickly.

Having just four crew members was one of the T95’s most defining characteristics compared to its contemporary super-heavy brethren. The enormous German Panzerkampfwagen VIII Maus, for example, was operated by an equally massive crew of six, including a gunner, driver, two loaders, a commander, and a dedicated radio operator. Even the T95’s closest counterpart, the A.39 Tortoise Heavy Assault Tank, had a seven-person crew, including two loaders and two machine gunners. The T95, with its one loader and paltry four-member crew, was at a direct disadvantage from a maintenance standpoint (as an extra pair of hands or two would have been invaluable for tasks such as removing and attaching the outer tracks) and a combat effectiveness standpoint. For example, by having only one loader, the rate of fire of the T95’s gun (which used heavy, two-piece ammunition) was a rather anemic 4 rounds per minute.

Trials

Engineering Tests

Engineering tests of the first T95 pilot began promptly at Aberdeen Proving Ground on January 15, 1946. As was customary, these trials began with an initial mechanical inspection. No major defects were found, but the generator overrunning clutch was found to be inoperative and required replacement. The first proper engineering test conducted was to determine the vehicle’s center of gravity, which usually involved lifting the armored vehicle with a large crane and taking measurements. The T95’s excessive weight, however, was too much for even the largest crane at Aberdeen, so the vehicle’s outer tracks had to be detached and weighed separately from the main vehicle. Similar issues were encountered during weight distribution tests, as the platform typically used to measure weight distribution was not built to handle such a heavy vehicle. The T95’s outer tracks and main hull were once again measured separately and calculations were made to ascertain its weight distribution, which was determined to be 15,187 lbs (6,888.7 kg) per suspension unit with the outboard tracks removed and 11,812 lbs (5,357.8 kg) with them installed.

The next two tests conducted were designed to determine the T95’s fording potential and turning characteristics. At a maximum speed of approximately 2 mph (3.2 km/h), it was found that the T95 was capable of fording 48” (1.22 m) of water. At higher speeds, it was found that water could enter the fighting compartment through holes in the gun mantlet. The vehicle’s minimum turning diameter, in addition, was found to be 79’9” with the outer tracks attached and 79’10” with them removed. It was noted, however, that the T95’s auxiliary brakes were not used during these tests due to mechanical defects. The next segment of tests involved measuring the vehicle’s obstacle crossing ability. The T95 was driven both forward and backwards across a 9.5 ft special bridging device with no issues reporting, which is surprising considering the weight of the vehicle. The T95’s performance during the trench crossing test, however, was much less successful. The vehicle was unable to cross the artificial concrete shell hole used for the test as a result of interference from the gun, which was locked at maximum elevation, and “excessive track slippage.” Following this, the T95 was subject to vertical wall obstacles of 18” (0.46 m), 24” (0.61 m), 36” (0.91 m), and 42” (1.07) in height to test its ability to clear high obstacles. From a stationary start, the vehicle was able to navigate the 18”, 24”, and 36” obstacles while driving forwards and the 18” and 24” obstacles while driving backwards. The 42” wall was not attempted because of potential interference with the vehicle’s armored fenders and the 36” obstacle was unable to be cleared in reverse because of the positioning of the vehicle’s final drive housings.

The final set of engineering tests, which took place on January 17, were a series of cooling tests. These tests were conducted in third gear and at speeds of 2.4 mph (3.9 km/h) and 5.5 mph (8.9 km/h). Converter ratios during the test varied from .17 to .39. At the low converter ratio (.17), cooling was unsatisfactory. The test was stopped after 25 min, when the transmission oil exceeded the maximum recommended temperature. During this phase of the test, it was also found that the temperature of the engine, transmission, and differential rose steadily instead of stabilizing, signifying a critical failure of the cooling system. At the high converter ratio (.39), however, the results were much more positive. During the 1 hr and 45 min testing period, the oil temperature of almost all components remained stable. Some problems were encountered with the final drives, however. After the tests, it was determined that the issues with the cooling system were a result of the design of the large, rectangular air intakes located on the vehicle’s engine deck restricting airflow.

Field Engineering Tests

After the engineering tests were finished, field engineering tests began. These field tests, as opposed to the more technical detail-oriented engineering tests, were focused on gathering feedback about the vehicle from a relatively inexperienced crew. The first order of business was to determine the vehicle’s automotive capabilities, specifically its minimum speed in first gear, time required to accelerate from rest to near maximum speed in each gear, maximum speed in each gear, braking distance at maximum speed, and drawbar pull and horsepower characteristics. The T95 was operated exclusively with its outer tracks attached due to, as the vehicle’s test report states, “the extremely high ground pressure that would be encountered with single tracks.”

The acceleration characteristics of the T95 were, as the field tests determined, rather impressive, with the vehicle requiring 2.2 seconds to reach its top speed in first gear, 4.4 seconds in second gear, and 8.8 seconds in third gear. The vehicle’s top speed characteristics, however, put these numbers into perspective, with the top speed in first gear recorded as 3.7 mph (6.0 km/h) @ 2,800 rpm, second gear as 7.0 mph (11 km/h) @ 2,800 rpm, and third gear as 8.5 mph (14 km/h) @ 2,800 rpm. Minimum operative speed in first gear was 0.5 mph (0.8 km) @ 700 rpm. From its top speed of 8.5 mph (14 km/h), the T95 was able to come to a complete stop after just 9.4 ft (2.9 m). The final field engineering test was the drawbar pull, a test that evaluated the T95’s available reserve power, or the amount of power produced by the engine in excess of that required for propulsion on a level road. This data can be used to predict a vehicle’s slope-climbing ability, or gradeability, when proper slopes are not available. In the case of the T95, the vehicle was too wide to navigate any of the slopes at the testing grounds, necessitating a drawbar pull. Pulls were performed on January 17 in first, second, and third gears and resulted in drawbar horsepower measurements of 272, 234, and 175 respectively.

Other Tests and a Second Redesignation

As the testing of the T95 was moving along, slowly but surely, concerns were once again raised in April 1946 over the appropriateness of the vehicle’s designation. The sub-committee on automotive equipment, the very same which was originally formed in December 1943 to discuss the T95’s technical characteristics, reached out to the Ordinance Committee on April 15, 1946, to suggest that the T95 be redesignated as a traditional heavy tank. Gun motor carriages, they reasoned, were typically rather lightly armored, while the 105 mm Gun Motor Carriage T95 was both extremely well armed and well armored, much the same as a typical heavy tank. They also contended that the limited traverse of the vehicle’s main gun should not be considered when deciding whether or not to designate the vehicle as a tank. In agreement, the Ordnance Committee, in OCM 30758, officially redesignated the 105 mm Gun Motor Carriage T95 as the Super-Heavy Tank T28 in June 1946, citing the tank’s record-topping weight as the reason for including it in its own super-heavy classification. The T28 will be referred to as such for the remainder of this article, although it should be kept in mind that the T95 and T28 are one and the same.

According to the tank’s lengthy testing report, a number of other miscellaneous tests that were not categorized specifically as either engineering tests or field engineering tests were performed on the first T28 pilot at Aberdeen Proving Ground, with some offering better results than others. The first and arguably most successful test was that of the tank’s main gun, the 105 mm Gun T5E1. The gun was proof fired and no malfunctions were noted in the operation of the weapon. The same could not be said, however, for the muzzle brake, which was blown apart during tests. After the upper portion of the brake was recovered approximately 500 ft (152 m) downrange, the damaged part was shipped to Watertown Arsenal for analysis, where it was determined that the failure was due to defective manufacturing and not the fault of the ammunition used with the gun.

The T5E1 gun was also test-fired at maximum elevation and traverse angles to test both the durability of the mechanisms and the conditions within the tank. The first step in this process was, as one may expect, to calculate the maximum traverse limits of the gun, which were determined to be between -4° and +18° in the vertical plane, 11° to the left, and 13° to the right. During the firing process, no malfunctions were noted, but some less-than-satisfactory observations were made. The first was that it was difficult to load the two-piece ammunition at extreme angles of elevation due to the tendency of the projectile to slide out of the gun tube before the propellant cartridge could be added. The temporary solution was to employ a second crewmember to hold the projectile in place while the loader inserted the propellant, which was by no means ideal. The second observation was that the loader was required to load the gun from the right side instead of the left side, as he usually would, when the gun was traversed all the way to the right. This restricted the amount of space available to the gunner, who was already sitting to the right of the gun, and resulted in both crewmembers having problems performing their duties. The next complaint concerned the fact that the T28’s fighting compartment had a tendency to fill with smoke and fumes when the main gun was fired. This issue was compounded by the fact that these firing tests were performed with the crew hatches open, indicating that the quantity of fumes produced by the gun was rather excessive. Although the T28 was equipped with an air filtration and pressurizing system, it was turned off during this test after previous firing tests indicated that the system was not sufficient to adequately vent the fighting compartment. The final complaint concerned the gunner’s periscopic sight, which was not properly coupled to the gun, resulting in excessive play and poor accuracy when the gun was fired at high elevations during tests.

A brief examination of the T28’s radio systems began following the firing tests. Two radios, the SCR 508 and the AN/VRC-3, were fitted to the tank. It was noted that no suppression tests were performed on either radio.

Next on the chopping block was a standard endurance test, which involved simply driving the T28 for a long time and seeing what fails. The standard distance was 2,000 mi (3,219 km), but this was reduced to 1,000 mi (1,609 km) at the request of the Development and Proof Service in charge of testing the tank. The report notes, unsurprisingly, that it took quite a while to accumulate mileage on the T28 as a result of the “slow operating speed (5 – 6 mph, 8.0 – 9.7 km/h) and low priority assigned for maintenance requirements.” As a result, Aberdeen was only able to put 541 mi (871 km) on the tank’s odometer, with 128 mi (206 km) having been driven on paved road and the remaining 413 mi (665 km) on gravel. The tank was not tested cross-country, which was probably due to its limited slope-climbing ability and poor suspension durability. After the tests finished, the average fuel and oil consumption were calculated to have been 0.16 mi/gal (0.068 km/l) and 4.13 mi/qt (7.02 km/l), respectively.

Testing of the T28’s automotive components, including its differential, engine, and transmission, was rife with issues as the powerpack, which was originally intended for a tank of less than half the T28’s weight, was being pushed to its limit. The tank was, however, described as easy-to-drive, with the vehicle accelerating and turning responsively.

Summary of Engine, Transmission, and Differential Failures

The endurance test was followed by a test of the T28’s most unique characteristic, its detachable outer tracks. In order to determine how long it would take to remove the outer tracks, an inexperienced four-man crew was given an area of approximately 30 x 40 ft (9.1 x 12 m) and two hydraulic jacks, one rated for 3 tons and the other for 35 tons. No other specialized tools were provided. The first attempt by the crew to remove the tracks took approximately 4 hrs, and an equal amount of time was required to reattach them. The second attempt was significantly faster, at 3 hrs each to remove and reattach the tracks, and the third attempt was faster yet, with the final time noted as 2.5 hrs for each operation.

As the final 2.5 hour figure would indicate, the process of removing or reattaching the T28’s outer tracks was by no means quick or easy. It required extreme precision to align the track units so they could be securely bolted to each other or to the tank and lots of elbow grease and patience to perform the repetitive work of securing the many, many connections between the track units and the hull. The test report indicated that the most troublesome part of the process was the attachment of the spacer, a part secured by four bolts that was required for assembling the track-trailer unit. The fit between the spacer and the outboard track was extremely tight and required a near-perfect alignment before the two parts could be connected, which took a significant amount of time to obtain. To solve this problem, the use of self-aligning bolts was proposed, which was thought to have been able to shave up to an hour off the time required to remove the outer tracks. Keeping the T28’s many moving parts in good shape took a similarly obnoxious amount of time, with Aberdeen’s final report indicating that a total of 13 service hours were required to perform a 250 mi (402 km) lubrication and inspection service under ideal conditions. It was noted that this time could be somewhat shortened after the operators became more familiar with the tank, but the report does not seem optimistic on this matter. The largest portion of the service time was spent locating grease fittings and lubricating the two inner sets of bogie wheels, a process made all the more time-consuming when the T28’s outer tracks were fitted. Unsurprisingly, it was noted that the lubrication of the suspension could be hastened if the outer tracks were removed.

The unique suspension of the T28 was many things, but durable was certainly not one of them. The unwieldy system attracted numerous criticisms by Aberdeen Proving Ground for its fragility and overall complexity, with many of its issues having been made apparent after just a few hundred miles of operation. The tank’s right inner final drive, for example, suffered a failure at the pinion bearings at just 282 mi (454 km) that was a result of an earlier oil leak, which caused a lack of lubrication. When the outer tracks of the T28 were removed to fix this issue, however, it was noted that all of the studs and nuts of the outer final drives, with the exception of one, had become loose. A metal lock to secure the 8 studs in place was manufactured and fitted to both final drives, but this example of mechanical failure, followed by the discovery of another problem, is quite representative of the T28’s automotive tests as a whole.

Issues with the T28’s suspension were identified before the tank even began proper testing. One of its idlers was discovered to have come loose during preliminary operations. After drilling and wiring together the idler’s lug nuts as a corrective measure, no further hiccups were encountered. Further problems with the T28’s suspension were discovered during the attachment and removal of its outer tracks, including the failure of the end and intermediate suspension links. When the outer tracks were coupled together and towed a short distance over rough ground, it was discovered that all but four of these links broke. This was due to the links being underproportioned to withstand the load of the tank and the poor quality of the welds holding them together. Problems were also identified with the sprag arms, which were of unsatisfactory stiffness and bent easily, causing the right outer track to nearly tip over when it was removed as part of operations. Another double-edged suspension failure was encountered after 432 mi (695 km), when the hubcap from the rear top return roller fell off and wedged itself between the rear support and No. 7 inner bogie wheel on the right outboard track, damaging the wheel bearing shaft and seal of the bogie wheel. It was also noted, however, that a majority of the studs on the tank’s four sprocket wheels were either loose or, in the case of the outboard tracks, broken off entirely. The solution was to install longer bolts and utilize additional nuts to secure them in place.

After 514 mi (827 km), the right outboard track of the tank was thrown twice. The T28’s lack of track link guide flanges on the sprocket hubs was determined to be the cause and modifications were made to add them to the right outboard sprocket, which corrected the error. One of the final suspension failures identified was to do with the track tensioning system. The cable system that was designed to raise and lower the idler wheel, which adjusted the track tension, was not compatible with the included winch assembly due to a lack of available space. The best solution found by Aberdeen was to use a 3-ton hydraulic jack placed directly on the track and braced against the eccentric to operate the cables and properly tension the tracks.

Arguably the least functional part of the T28 was its auxiliary brakes, which earned the dubious honor of never working properly during the entire testing period of the tank. The brakes were designed to operate by using a master cylinder to turn large pistons to build up oil pressure, which was then used to drive multiple smaller pistons with the goal of making braking easier. The master cylinders, however, were defective, and the manufacturer, who agreed to send in a replacement, never provided the extra parts necessary to fix the brakes. The exact reason why the cylinders failed was unknown, but several potential contributing issues were identified, including the failure of the seals around the outer pistons, the poor quality of the springs that held in the inner piston, and the malfunctioning of the hose leading from the master cylinder to the actuating cylinder.

After the disasters that were the suspension and auxiliary brakes, Aberdeen Proving Ground turned their attention to a series of less significant faults in the T28’s design, notably the fuel gauges, batteries, and ammunition stowage. To indicate the fuel level of the T28, a relatively simple series of gauges indicating ¼, ½, ¾, or ‘full’ were installed. These gauges, however, only measured the height of fluid within the fuel tanks, which, due to the fact that the tanks themselves had uneven cross-sectional areas, gave an extremely inconsistent estimate of fuel level. In addition, an accurate reading was an implausibility when the vehicle was in motion or on sloped ground. It was also noted that the batteries that powered the T28’s electrical systems were located inconveniently and required significant time to remove and prepare for servicing. Finally, it was noted that the ammunition stowage situation could use some improvements. The close proximity of some of the racks, for example, prevented the stowage of a round or two depending on the rack. The maximum amount of 105 mm ammunition that Aberdeen managed to cram inside the T28 was listed as 58 rounds, which was not quite the 62 round figure that the manufacturer claimed. Issues were also identified with the clamps that held the ammunition in place, with it having been noted that removing the rounds was made unnecessarily difficult. The opposite problem was encountered with the locking devices fitted to the ammunition racks, which were relatively fragile. Six of the devices were bent out of shape beyond use and two of them broke apart as a result of defective welds.

Pilot No. 2

While the first T28 pilot vehicle remained at Aberdeen Proving Ground for approximately a year and a half, as the tests were conducted, the second pilot vehicle spent no longer than a few months at the Proving Ground. After a mechanical baseline for Pilot #2 was established at Aberdeen, in April 1946 the tank was shipped to Fort Knox, KY for demonstration and evaluation purposes under the Army Ground Forces. The AGF, however, had little to no desire to perform extensive tests concerning what they saw as a dead-end, low-priority project, so the tank was transferred indefinitely to the Corps of Engineers in Yuma, Arizona on May 20, 1946 after a brief demonstration at Fort Knox.

Under the direction of the Corps of Engineers, Pilot #2 was to be used to test various floating bridges; however, these tests were cut short for two reasons. The first of these was the thought of canceling the T28 program, which was first tossed around in October 1947. The second, and much more pressing, issue, was the total destruction of the vehicle. Although most sources concerning the incident are vague, it can be deduced that T28 #2 suffered a catastrophic engine fire in late 1947 while at Yuma. The damage was reportedly so severe that the only possible course of action was to break the vehicle into scrap. Following this decision, the number of Super-Heavy Tanks T28 dropped from two to just one.

Cancellation and Heavy Load Tests

Testing of the first T28 pilot at Aberdeen Proving Ground concluded on August 18, 1947, and the first conclusive report on the vehicle was submitted on October 9, 1947. The report, as a result of the many shortcomings noted during tests of the vehicle, concluded that “the increase in armor and weight, without corresponding increase in power capacity, has critically reduced the mobility of this vehicle. From the standpoint of mobility, reliability, and performance, the Super-Heavy Tank T28 is unsatisfactory.” The 105 mm Gun T5E1, in contrast, was received favorably and recommended as the main armament for future heavy armored vehicles. The final nail in the coffin for the T28 was the delivery of the first Heavy Tank T29 pilot in October 1947. Mounting the same gun as the T28 in a fully-rotating turret and with far superior mobility, the T29 was the first of a new breed of American heavy tanks designed to leave the T28 behind in the dust, both literally and figuratively.

Although the official termination of the T28 program would not occur until August 11, 1949, all developmental work on the vehicle effectively ceased following Aberdeen’s test report. After this point, the remaining pilot vehicle was relegated to the role of a testing aid, with the T28’s impressive weight used to evaluate the limits of tank trailers, bridges, and landing crafts.

The most notable of these heavy load tests took place between April and May 1948 under the direction of the US Navy. Although they recognized the obsolescence of the T28, the Navy wanted to gather experience with heavy vehicles to prepare themselves for future heavy tank designs (notably the T29 and T30 Heavy Tanks) and to ensure that, in the words of a memo appended to the report, “should the present ‘Cold War’ suddenly develop into a ‘shooting war’,” the T28 could be deployed to battle, if so desired”.

To transport the T28 to Little Creek, VA, where the Navy tests took place, the T28 was loaded onto a Landing Craft, Tank, Mark 6 (LCT(6)) at Aberdeen Proving Ground. Sea transport was preferred to ground transport due to T28’s excessive weight (which could have damaged the State of Maryland’s public roads) and poor early-spring road conditions. An M26 truck tow bar was used to bring the tank onto the craft, and the vehicle was loaded backwards to facilitate easy unloading. Afterwards, the LCT met up with a Landing Ship, Dock (LCD) stationed near Howell Point to begin the journey to Virginia.

After arriving in Virginia, the T28 was unloaded from the LCT using a purpose-built ramp and loaded (sans outer tracks) onto LST-1153, the tank landing ship used for the tests. The loading procedure was reportedly a success, and the T28 was removed from the ship, fitted with its outer tracks, and loaded aboard LST-1153 once again. This was also a success, although it was noted that there was no more than 1 in (2.54 cm) between each side of the tank and the ship’s guard rails. One final loading test was conducted the next day at a different nearby beach, after which the T28 was returned to Aberdeen.

Lost and Found

After the Navy trials, the T28 continued to see occasional use around Aberdeen Proving Ground as a testing vehicle. Its activities post-1948 were evidently of little importance and saw little, if any, documentation, which makes pinpointing the timeline of the T28 into the 1950s and 1960s very difficult. It can be confirmed, according to one Captain J. R. Shrader of Chicillocothe, Ohio, that the T28 was kept in working order at Aberdeen until at least February 1964. In his own words, as he wrote to the Army Reserve Magazine:

“In February 1964, I was a private on a work detail painting the T28 tank at Aberdeen Proving Ground. One night, as we were coming back from the ‘1-2-3 Club,’ we saw the T28 moving out of the base’s industrial area. Its passing was something like a freight locomotive, as the ground moved under our feet – not a lot, but enough to let you know that about 100 tons was passing by. I never saw the T28 again…”

Not long after Captain Shrader spotted the tank in motion at Aberdeen, the T28 appeared to drop off the face of the earth completely. The tank did not appear in Aberdeen’s equipment lists and sources from the late 1960s claim that the remaining T28 pilot was broken up for scrap during the Korean War, but this would later prove to be false.

At some point in 1974, an Army Reserve Captain working at Fort Belvoir, VA, named Gil Burhmann, sent a letter to the Office of the Chief of Military History claiming that there was a T28 sitting on a classified night-vision testing range at the fort. The historian who received Capt. Burhmann’s letter immediately went to confirm this assertion, discovering the weather-beaten and brush-covered (yet remarkably intact) Super-Heavy Tank T28. How it got there was a mystery, but the historian immediately reached out to the Patton Museum at Fort Knox to arrange for the vehicle’s recovery. The museum’s curator thought this was some kind of joke until photographs of the forgotten tank were produced, at which point immediate plans were made for the Army Reserve to disassemble and ship the tank to the museum.

The T28, as it arrived at the Patton Museum on March 5, 1975, was in surprisingly good shape. Despite having spent at least a decade exposed to the elements, the tank and its components were deemed restorable. The T28 was officially entered into the Museum’s collection on April 15, 1975, at which point it was noted that the tank had a few missing parts, such as the driver’s hatch direct vision block, which had caused visitors to stuff pieces of garbage into the T28’s crew compartment. In late 1975, all parts of the T28’s power plant were removed to prepare it for outdoor display as a gate guardian. In an attempt to spruce the vehicle up a little bit, a fresh coat of olive drab paint was applied to the T28 in May 1988, although this had faded to a dull reddish-brown color by the mid-2000s.

The Patton Museum closed on September 6, 2010, and preparations were made to ship the museum’s entire tank collection to its new home at the US Army Armor and Cavalry Museum in Fort Benning, GA. After arriving at Benning in 2011, the T28 sat outdoors alongside its outer tracks while the new museum space was prepared and the collection’s other vehicles were slowly restored. The T28’s time for a proper refurbishment finally arrived in January 2017, and the vehicle was transported via Heavy Equipment Transporter (HET) to the workshop where it would be cleaned up and repainted inside and out. During this journey, however, disaster struck when the HET’s brakes failed while driving downhill, forcing the personnel driving the vehicle to turn sharply. This maneuver caused the T28 to break free from its restraints and roll off the trailer and into a ditch. Miraculously, nobody was injured and the T28 suffered only minor damage to a few of its suspension units.

After spending about 24 hrs in the ditch, the stranded super-heavy tank was rescued by a pair of M88A2 ‘Hercules’ Armored Recovery Vehicles and returned to its trailer. After a few years of restorative work, the freshly cleaned and repainted (although still non-functional) Super-Heavy Tank T28 was mated with its outer tracks for the first time in nearly a decade in October 2020 at the newly-built Armor Heritage Training Support Facility in Fort Benning. The T28, alongside many other prototype American armored fighting vehicles, is now on display at the Armor and Cavalry Collection, where it is thought that the vehicle may, eventually, drive again under its own power.

Conclusion

The Heavy Tank T28, or 105 mm Gun Motor Carriage T95, or even Super-Heavy Tank T28, was a vehicle that was doomed to fail. Although having an invulnerable bunker-busting heavy tank was an alluring idea in late 1943, the US Army’s time-consuming development processes and arguments over the perceived need for such a tank pushed the T28’s production far too late for the Second World War. Furthermore, the decision to reuse parts from other tank programs severely handicapped the vehicle, especially in the mobility department. The T28, due to the mechanical prowess required to self-propel such a heavy vehicle, was at its most useful as a testing aid and engineering study for future heavy vehicles.

Sources

Primary

Minutes of meeting held in Washington, D.C., at 2300 hrs – 12 July 1943
Development History of the 105mm Gun Motor Carriage T95 (Formerly Heavy Tank, T28)
Development History of 105 mm Gun and Howitzer Motor Carriages and 25-pounder Gun Motor Carriages – Compiled by E. J. Zawadzki
Detroit Arsenal Research and Development Division Final Report on Project No. TT2-491 – Tank, Super-Heavy, T28 – 6 January 1955
Aberdeen Proving Ground Armor Branch Report No. Ar-16576 – Ballistic Test of Front End Casting for Heavy Tank T28 – 14 July 1945
British Army Staff (AFV) Situation Report No. 20 – 18 March 1944
British Army Staff (AFV) Situation Report No. 21 – 18 April 1944
British Army Staff (AFV) Situation Report No. 26 – 18 September 1944
British Army Staff (AFV) Situation Report No. 27 – 18 October 1944
British Army Staff (AFV) Situation Report No. 28 – 18 November 1944
British Army Staff (AFV) Situation Report No. 29 – 18 December 1944
British Army Staff (AFV) Situation Report No. 31 – 18 February 1945
British Army Staff (AFV) Situation Report No. 32 – 18 March 1945
British Army Staff (AFV) Situation Report No. 33 – 18 April 1945
British Army Staff (AFV) Situation Report No. 34 – 18 May 1945
British Army Staff (AFV) Situation Report No. 35 – 18 June 1945
British Army Staff (AFV) Situation Report No. 36 – 18 July 1945
British Army Staff (AFV) Situation Report No. 37 – 18 August 1945
British Army Staff (AFV) Situation Report No. 38 – 18 September 1945
B.A.S. Royal Artillery S.D. and T. (R.A.) Monthly Letter to the War Office September 1943
B.A.S. Royal Artillery S.D. and T. (R.A.) Monthly Letter to the War Office November 1944
B.A.S. Royal Artillery S.D. and T. (R.A.) Monthly Letter to the War Office April 1945
B.A.S. Royal Artillery S.D. and T. (R.A.) Monthly Letter to the War Office June 1945
Technical Services Armaments Letter Number 17 March 26th 1945
Technical Services Armaments Letter Number 20 June 30th 1945
Development of Armored Vehicles, Volume I: Tanks (AGF Board no. 2, 1 September 1947)
TM 9-1731B Ford Tank Engines (Models GAA, GAF, and GAN)
America’s Thiccest Tank! Rare T28/ T95 History Pt. I: Documents, Diagrams, and Test Results – youtube.com via Solfilein

Books/Magazines

Firepower – A History of the American Heavy Tank by R. P. Hunnicutt
Can Openers – The Development of American Anti-Tank Gun Motor Carriages by Nicholas Moran
Super-Heavy Tanks of World War II by Kenneth W. Estes
Tank Zone #7 – T28 105 mm Super Heavy Tank by Nicolas Couderc
Army Reserve Magazine, Volume XXI, #3, May-June 1975
Army Reserve Magazine, Volume XXII, #2, March-April 1976
Classic Military Vehicle July 2012 – The Super-Heavy Tank T28 by David Doyle
Bellona Military Vehicle Prints Series 8: Sd.Kfz.173 Jagdpanther, T28 Super-Heavy Tank, and Cruiser Tank Mk.I Comet
Making Tracks – A Pictorial Account of the Move of the U.S. Army’s Armor and Cavalry Museum by Charles Lemons
Hitler’s Fortresses: German Fortifications and Defences 1939–45 by Chris McNab

Websites/Videos

SCR-528 – RadioNerds – radionerds.com
SCR-300 – RadioNerds – radionerds.com
AN/VRC-3 – RadioNerds – radionerds.com
T28 Accident – ritastatusreport.live
The Chieftain’s Hatch: T28 vs T95 | History | World of Tanks – worldoftanks.com
ID: 0061585 22/Sep/2017 Replacing 105 mm T13 with T13E1 – Documented Bug Reports – Windows – War Thunder – forum.warthunder.com
105mm T5E1/2L65 T32 – Already Reported & Solved Issues – War Thunder – Official Forum – forum.warthunder.com
Crew positions and interior features of the last T28 / T95 American superheavy tank – youtube.com via Sofilein
Alexander Gatehouse (March 20, 1895 — 1964), British commandant, army officer | World Biographical Encyclopedia – prabook.com
Biography of Major-General Alexander Hugh Gatehouse (1895 – 1964), Great Britain – generals.dk
Medium Tank M4 Sherman – afvdb.50megs.com