The next big steam locomotive project in the pipeline is a model of the FEF series. 

The Union Pacific's version of the Northerns were usually referred to by the company as the Four-Eight-Four or FEFs.  During the 1920s-1930s the main power used on UP passenger service was the mountain series or 4-8-2 locomotives with road numbers in the 7000s.  These locomotives had been adequate for their day, but as passenger traffic began to increase in the mid 1930s and the trains became longer and heavier the mountains were no longer suited for the job.  As the story goes, one day while William Jeffers, president of the UP was riding in his private passenger car behind one of the mountain series across the desert of Wyoming, it had to stop due to lack of steam.  At that very moment, Jeffers immediately telegraphed the UP headquarters and demanded that a new locomotive design be drafted that would pull 16 heavyweight passenger cars from Omaha to Cheyenne and be able to do it at speeds of 60-70 mph.  The result of this decision was the Union Pacific's version of the 4-8-4.  These were the first truly modern steam locomotives and often said to be the finest steam locomotives ever built.  They were engineered and designed to operate at speeds of 100 mph with max speeds of greater than 110mph.  This demand for high speeds required an enormous boiler and a 4 wheel trailing truck.  The drivers were 77 inches on the first series, the FEF-1s and 80 inches on the FEF-2 and FEF-3 series.  Special attention was paid to the design of the main and side rods and balancing of the drivers to eliminate as much vibration as possibly. Many other new and modern innovations were applied as well. 

The first FEF entered service in September of 1936 and the locomotive outperformed everyone's expectations. 

More to come about the story of the FEFs.

Update 1/20/08

The model is essentially done, but I am going to hold off on any further work at the moment and wait for the release of Trainz Classics 3.  There are rumors that the steam support is going to be enhanced and several changes and additions to steam locomotives in general.  Once this version is released I will finish the model and release it.