Here is what you need. It says “Bridge Crane” on the side, all though it looks like some thing to pull rails up on to the ties. Notice the hooks by which it grabs the rails so the operator doesn’t pull the crane off the rails.
That looks like a rail pincher on the end of the boom.
If you want some thing very similar without scratchbuilding, you can get a Kershaw tie crane model kit from Custom Finishing. Picture as shown on the Walther’s website: http://www.walthers.com/exec/productinfo/247-7083
I forgot to ad that I believe it was used to get around the CN Rail yard in Edmonton, but I am not sure. My sister took the pic for me on a trip as it was RR related in a museum.
a Model T Ford with an add on half track kit. Back in the day there were a number of aftermarket kits that would convert the Ford to a tractor, or, like this one, an early snowmobile type vehicle.