Looks like they don't like hotlinking. Whatever. Cut'n'paste: http://1.bp.blogspot.com/_CXF5WqwPWlc/SiCaKQ5JEOI/AAAAAAAAFb4/4bADXc8-Yog/s1600/100_1503.JPG
Oh now I see it. Grand Trunk built a series of transfer cabooses out of old boxcars. The body is a cut down section of the boxcar, and the boxcar frame is also utilized. Our friendly neighborhood tourist RR has one left on the property, and I know of at least 2 more besides the one shown. Used by GTW for the crew when moving cars for interchange with other RRs or transfer runs to other yards. Very basic accommodations. Yard crews don't need all the amenities that over the road crews do.
It's a transfer caboose. A transfer caboose looks more like a flat car with a shed bolted to the middle of it than it does a standard caboose. It is used in transfer service between rail yards or short switching runs, and as such lacks sleeping, cooking or restroom facilities. The ends of a transfer caboose are left open, with safety railings surrounding the area between the crew compartment and the end of the car. http://en.wikipedia.org/wiki/Caboose Ed .
