Firefly tank

[Bob Cohoon]

I was reading the comments about "live" track and found exactly how it`s done in the M4 manual. Apparently the track blocks consist of two steel tubes with steel end plates attached to them. the rubber block is molded around that. The connecting pins have rubber "doughnuts" ( description in manual), or sleeves , vulcanised to them and are pressed in , into the tubes in the block assemblies.The connecting pins have grooves in them at their ends ,and the pins are pressed in so that these grooves are 90 degrees to the track surface. When the block assemblies are connected to each other with the main track connectors/ guide horns, they are locked in place with a wedge which has a 7 1/2 degree angle on each end of it and this engages the grooves in the pins. the two 7 1/2 degree angles then force a 15 degree angle between each block assembly.This is why the track wants not to lay flat when loose, but wants to curl up slightly, if the pin rubbers are still in good shape. Sometimes the pin rubbers will shear and this results in a loose pin and what the book calls a "dead" block, which usually requires replacing asap, as it can affect the action of the track. I think even later types of track, like M48 tank track, uses this idea