There are some things in this mechanical world that we take for granted and just kind of know. One of them is that skinny tires on a heavy truck in the mud is not exactly the best way to make progress. We’re reasonably sure that the US Army knew that in 1966 as well but just how bad were they as compared to other styles of tires? Being that the country was getting ever more involved in Vietnam at this point and its vehicles were proving to be less than ideal for wet jungle conditions, some research and ideas were needed. In this film we see some of that as a couple of Army trucks are used in Thailand to both illustrate and document the efficacy of different tire combos.
As was to be expected, the standard NDT (non directional tires) rollers on the truck were the worst and they did not even get the truck to the testing area before getting stuck. The rig was mired down and going nowhere in a hurry. One can only imagine how bad things were for the guys stuck with those crummy tires. The second idea was to double up the tires on all four corners and that seemed to have some promise. The third and best way was to bolt a very wide terra style tires that not only made the truck look awesome but they were by far the best performers.
The trucks in the video are interesting. If you look close, they are not exactly Dodge M37 rigs. Upon further reading, Toyota apparently manufactured trucks for the US Military after the war and these could have been some of the Toyota variants of the M37. The noses are a little narrower and there are some other little things but they are definitely not standard M37.
Also, this test was conducted by ARPA, the Advanced Projects Research Agency, no known as DARPA. The guys who test stuff like fighting robots and self driving tanks were testing tires 50 years ago.
Fun stuff!
