Fresh off the design table, a selection of concept light tanks from the early 1950s. --R.P. Hunnicutt		It is still a great looking design! The Aircraft Armaments T92 project as a late model prototype, probably from 1955. --R.P. Hunnicutt

Starting with a blank sheet of paper, industry began to work up concepts. Just like Detroit marketed "cars of the future", the tank designers looked for radical new designs, low and fast, light and lethal. GM's Cadillac Motor Car Division worked overtime to produce mock ups and detailed concepts that always received special attention at the recurring Question Mark Conference held at the Detroit Tank Plant. Increasingly, the requirement of "air transportability" became a major design facet and an amazing number of concept tank designs were proposed. By the 1955 Question Mark Conference, the requirement for an 105 mm gun was added to the mix. Much of this design work never progressed beyond blueprints and plywood mock ups but it certainly had the designers looking for new solutions to old problems.

In 1954, the Army was anxious for a design leader to emerge as the potential replacement for the M41. Detroit Arsenal, Cadillac and Aircraft Armaments Incorporated, AAI, all had promising designs. An improved 76 mm cannon was allowed and after review, the Cadillac and Aircraft Armaments concepts were selected for funding of prototypes. But is was the T92, of AAI that stood out and funding was soon removed from the Cadillac prototype before it was completed. A bold new design from a blank sheet was taking shape.

3/4 view from the rear, the innovative crew doors at the rear of the hull can be seen. Also note the unique method to carry spare track. --R.P. Hunnicutt		This photo shows how radical the design was, at left, the T92 and at right, the in service M41. --R.P. Hunnicutt

The T92 looked like nothing US tankers had seen before. The low slung turret was positioned at the rear of the hull with the engine and drive line pulled forward. Cupolas were incorporated to allow both a 50 caliber and 30 caliber machine gun to fire while under armor. There were access doors at the rear hull to allow the crew to re-arm or leave a disabled tank while protected by the vehicle mass. Light weight alloys, a new fuel bladder configuration and improved steering system were all integral to the new concept. It had the standard crew of four, both the tank commander or gunner could range and fire, there was a semi automatic loading system, space for 60 main gun rounds and the ability to automatically eject the spent shell casing from the tank. After the prototype went through a rigorous testing phase at Aberdeen Proving Ground about fifty design modifications were specified. Among them, an improved shell casing ejection system, drive line improvements and abandonment of the "rubber band" track in favor of a more durable and reliable track link system.

Seen at APG, the little red tank that sank the program. The Soviet PT 76 was not particularly advanced in terms of design, but it was fast, could fight and could float. They are still in service in some African nations. --Gamma		A sad reminder of the defunct program on the display line at APG. If anyone lives near Aberdeen and could provide some additional photos, it would be greatly appreciated. --Gamma

Additional prototypes were funded but in early 1957, the program hit stormy seas. The Soviets had been parading their interesting new PT 76 light tank and in Washington they noticed that it could swim. In Congress, a simple question was asked , "what was the swim capability of the T92?". The answer was that as designed, it had no swim capability and after extensive design review, no solution to this new design requirement could be accommodated in the existing program. Further funding was canceled and the designers went back to the blank sheet.

The impact of the PT 76 Soviet light tank continued for the next few years. In the height of the Cold War, the US Army managed to "obtain" a complete, operational copy of the tank and study it at the Detroit Arsenal. The technology was considered "generally inferior" to US standards but it had "... an unusual jet system to propel it through the water.". This design was passed out to US manufacturers.

Government funded defense programs were making progress by the late 1950s in a number of armor related areas not incorporated into the T92 program. Combustible case ammunition, originally a Navy initiative, the Army tank laser range finder and the 152 mm cannon-missile launcher programs were well underway and significant early successes were reported. The programs had yet to merge but clearly, the direction was established.

The M56 Self Propelled Anti - Tank gun in final development by Cadillac.  To meet airborne and air transport requirements, side and top armor was deleted.  Bottom image, at corporate headquarters, one of the prototypes of the T92, light enough to be air transportable but it had no swim capability.  US designers felt they were falling behind the Russians in armor development.		By 1957, the M41 and M47 tandem was being replaced Army wide with the M48 main battle tank.  Discussion at all levels continued over the need and design of a potential heavy battle tank and a light tank.

In Germany, by the middle-late 1950s, the M41-47 tank combination was being replaced across the board with the M48 program. The Army was without a light tank and the designers worked late into the night.