Soviet tank track extensions

During the late 1940s, the Soviet Union was experimenting with the integration of wider tank tracks to reduce ground pressure on soft terrain. Development was separated into 2 parallel frameworks. The first framework focused on the development of new tracks with integrated extensions. The second program focused on improving standard tracks with the addition of attachable track extensions.  

The first idea was represented using new cast tracks with integrated extensions. The extension was one-sided. The results showed that these new tracks had some success at reducing standard ground pressure, from the standard 80,4kPa to 63,8kPa. The success was limited since these tracks only increased mobility slightly and had several drawbacks. Bending of the lower track branch and inability to transport vehicles using trains due to overall wider body of the T-54. 

T-54 track with casted extension

T-54 with snow tracks

 The time required to mount these new track extensions was between 8-9 hours. Each individual extension weighed 7,3kg. The average endured ground pressure was reduced from 75,5kPa to 54,0kPa.

Similar issues plagued the framework during the development of snow tracks on a T-54 that were tested in 1947. The entire caterpillar assembly was made out of 2 different track segments with an alternating pattern: standard width track and cast track with extension. 

In 1950, the second framework showed progress with the development of attachable track extensions on the prototype Object 730 (T-10). The assembly included blades with a 3 layered spring, these parts were attached to each track using a bolt and clam. 

Object 730 with detachable track extensions

Comparison trials were conducted and showed that track extensions offered better mobility on soft terrain compared to standard tracks. Extended tracks also reduced the sinking rate of the vehicle in mud/swamp terrain by 30% and offered 11% better traction. Further trials showed the surprising durability of the assembly during a 500km route snow march.

T-10A trials with extended tracks

The same idea was continued and trialled on the 38th Research and Testing Institute (38-й НИИБТ) with an improved design using a T-54, utilizing a much more rigid and flexible extension assembly. This prototype track differed from the standard caterpillar assembly, due to it having an additional membrane with an integrated hole to mount an extension piece using a bolt. 

Comparison trials showed that tracks with resilient extensions improved mobility in swamp locations compared to traditional tracks. In addition to the improved mobility, the sinking depth of the tracks was reduced by 1,8 times.

In 1961 the idea of track extensions was suggested to be integrated onto T-55 tanks, with the same core idea as on the T-54. The design was similar to the previous iterations, weighed 11,4kg per blade extension and had a ground pressure reduction from 80,4kPa to 54,9kPa. The new design had low-reliability ratings. It was recommended each track segment would receive an extension. 

Serial production track (top), prototype track with extension (bottom)

T-55 track with detachable extension

Through 1965-66, a similar design was developed and to be used on the tracks of Object 432. The extensions were to be mounted between each individual track on special brackets on the linking segments. Trials were conducted but in the end, it was noted that such extensions did not fit the set requirements and would not be used as a widespread solution to improve mobility on soft terrain. 

Object 432 track extensions

T-54A equipped with detachable extensions (1961)

Taken from: M.V. Pavlov I.V. Pavlov; Soviet Armoured Vehicles 1945-1965, Part 1 Light, medium and heavy tanks

----------------------------------------------------------------------------------------------------------------------------

Discord 

----------------------------------------------------------------------------------------------------------------------------