Sounds like the recoil spades.
They are fitted to the end of the trail legs and when the gun fires, they dig in and help to reduce the recoil.
Self-propelled guns also have them, they usually look like bulldozer blades...
HTH
Chris
>
> On the 155mm heavy artillery piece "Long Tom" it is laid using a
> split trail. On the upper mid point of each trail leg is a fence like
> structure that seems to have no function. On model displays, and
> maybe even photos of the gun these fences are ;posed in their original
> places on the trail legs. So what is their function?