By Kurt Laughlin

One of the most frequent questions appearing on tank modeling newsgroups is "What tracks should I use for a …?" Generally people rely on period photographs (always a good idea) but other information indicates that the answer is not nearly as clean as the surviving photographs might indicate.

Wartime Tracks

The pre-war tanks of the US Army were designed to use a track block consisting of steel tubes vulcanized into a symmetrical rubber block. This minimized wear on the tank running gear and road surfaces, reduced noise, and allowed for the track blocks to be flipped after one side had worn. Although these reversible rubber blocks were adequate for good ground, they suffered in soft terrain. The official solution was to install steel grousers over the end connectors on every four to seven blocks that would act as paddles in the soft mud. Unfortunately running the tank with grousers installed on hard ground reduced track and suspension life and made steering more difficult. The time involved in mounting and dismounting the grousers made switching to match the terrain impractical. As an alternate the Ordnance department developed rubber chevron tracks which gave good performance and life in both hard and soft ground.

With the approach of war the Army sought to reduce the use of strategic materials such as rubber. Because tracks accounted for something like 10-15% of the Army's total rubber allotment, Ordnance began developing an all-steel track block. Initially these steel blocks had relatively shallow integral grousers because deep grousers were too hard on the suspensions and increased rolling resistance. Although these designs had long life, their traction was poor and the steel wore out suspensions easily. As a compromise rubber-backed steel tracks of various grouser designs were eventually developed combining the conservation and wear properties of steel tracks with the suspension-saving features of rubber.

The track situation was never settled during the war, with numerous combinations of grouser styles and fabrication methods in development. The desires of the using arms also changed with the season and terrain, such that in December 1943 Army Service Forces essentially threw up its hands and authorized the production of both steel and rubber tracks and in April 1944 allowed the issue of whatever tracks the theater commanders thought best for the current or expected conditions.

A series of meetings in the fall of 1942 assigned preferences for light and medium tank tracks, "based entirely upon functioning" and without "consideration of ease of manufacture or availability of materials." The tracks used by Fifth Army were ranked by the Ordnance Technical Committee thusly:

Light: T16 (1), T36E6 (2)
Medium: T49 (2), T48 (3), T51 (4), T54E1 (5)

Curiously, the preferred medium tank track, the T56E1, seems to have been little used by US forces while quite common on Allied vehicles. Equally as strange was the decision to restrict light tank rubber chevron track to stateside usage while medium tanks used them wordlwide.

Tracks for Light Tanks
Tracks for Medium Tanks
The Fifth Army Report
Conclusion and References