This thing arrived fresh from eBay the other day, and all I can say is it is GORGEOUS! What a great model - incredibly detailed. It's a Piggy Packer, which was used to load trailers and containers onto flat cars.

The model comes fully assembled from Wheels of Time (although mine arrived from eBay with both real wheels broken off - a quick fix with superglue and kicker).

I don't know much about the prototype. This is from the web site:

The PC-90 is a big machine. The front tires alone stand seven feet tall. The operator sits over 13 feet off the ground with an excellent view of the loading and unloading operation. Hydraulically operated boom and lift mechanisms make this machine very durable and robust. The Piggy-Packer typically loads an average of 12 trailers or containers per hour on to piggyback flat cars.# They come equipped with a spreader and bottom pick that handle both trailers and containers. In top-pick mode, they're able to stack containers three-high. The PC-90s could optionally be equipped with a spreader for lifting containers only.The PC-90 is powered by a Cummins NH-855C-250 6-cylinder diesel engine located under the operator’s cab. The Cummins engines have a four-speed transmission designed for maximum torque. They have a maximum rating of 250 HP at 2100 RPM. The PC-90 weighs over 80 tons and has a maximum speed of 27 mph ... not exactly swift.

It says that the machine was in operation from 1968 to the present, so it is chronologically correct for my 1984 time period. Alas, the MKT did not have any of them. But I'm invoking "Rule 1", and will place this model at the pig ramp (now a TOFC facility!) at the New Franklin Industrial Park. It will get some weathering and the "Norfolk and Western" marking must go, but generally, she is good to go for the layout!