John, I am using AnyRail (anyrail.com). The free trial version will allow you to examine a file of any size, but only allow you to save layouts of 50 track sections or less. I have also worked with Scarm and RR-track, but I find AnyRail to be easier (for me) to put together layout plans quickly. Biggest drawback of AnyRail (IMO) is that it does not generate a usable 3-D view.
After adding another whisker track off of the turntable (encroaching into the aisle space a bit more), I produced this pic of the engine terminal, with lengths of the engine tracks marked.
