I agree. We had one like that in a dairy barn. The barrel device that was suspended from the track had a chain hoist mounted on one end of it. You lowered it to the floor to scoop crap from the gutters into the barrel. Then raised the hoist & directed it outside to dump. It had rail switching devices like railroad rails so you could direct it to different stalls, or to outside. 

Our barn hay-fork trollies were much larger & heavier. Carried 8 full-size bales at a time. Trip rope operated by someone standing outside the barn listening for the "TRIP-IT" command from stackers inside the barn.  Pull-back tractor operator then drove ahead & gave slack to the pull up rope so the trip operator guy could pull the now empty forks back out of the barn door & make it catch properly in the trolley. Took some well-timed jerks on the rope to make sure everything was latched.

That's how it worked "here" anyway.