Go trough skeletal mesh

Hi!

I have a train in my scene and some of the carts are just hanging in the air. I would like these to have either an swingin animation or better yet, physical simulation. Problem is that I dont know how to do the collision in this kinda go trough skeletal mesh is handeled. Polygonal collision does not work with simulation so how should I approach this if I wanted it to be simulated?

Thanks!