I saw the header and thought, what would anything have to do with pulling a train be in the Womens Issues forum.
Was started in 2009, and I still have never heard this term used. Except by Guinness World Records when some person wants to play Locomotive and attach themselves to a train and see if they can move it a little bit. Toot Toot.....
Pulling a train = Gang Bang..who woulda thunk.