This diorama depicts a log loader and winch on top of a steam-powered turntable. Sonny Wizelman, a lifelong master of live steam models, built this diorama from plans and did all of the building, weathering, and rusting himself.
The piece with the roof is the log loader. This was used in the logging industry to lift logs onto separate cars so they could be taken to a mill. The car is on a separate track so that when one car was loaded, they could move the log loader to the next car and continue loading it.
The other piece is called a winch, also known as a steam donkey, which is sitting on a flat car. The winch was used to tow the logs from where they were cut to the place, they were being loaded so the log loader could put them on the cars. This is used to move the locomotive or cars from one track to another. All of these highly detailed parts add to the fact that loggers had to carry everything they needed as they were so far from any supplies.