There's a lot of railroad history in this scene. The diamond that's abandoned on the near side is the former East Tennessee & Western North Carolina (a.k.a. "Tweetsie") main that once extended all the way to Boone, NC. Built as a narrow gauge carrier (three foot), the diamond was once three-railed when the ET&WNC added standard gauge rails as far as Elizabethton (11 miles). The "bi-focal" was converted to standard gauge only in the late '40s, and operated until October 12, 2003, most recently as the East Tennessee Railway. The ET still runs, however, using a nifty pair of SW1200s painted in a Southern Railway-inspired green scheme. Today, the short line handles all contract switching for itself, as well as NS and CSX within Johnson City. The red wooden engine house dates to the line's narrow gauge beginnings, and it once sheltered the ET&WNC's small fleet of both narrow and standard gauge engines. The ET's two green EMDs are berthed there today. Finally--the in-service line (left to right) is the Carnegie Spur, which linked the old Clinchfield main (out of the picture to the left) with the former Southern main to the north. The spur got its name from an early 20th century iron furnace near the Southern's end of the line.