In 1947, to help meet the demands of the post war coal boom, the Clinchfield purchased 6 used 4-6-6-4 Challenger-type locomotives from the Denver, Rio Grande, and Western. Despite being very big power and good haulers of coal, the units struggled at first because they simply could not operate on the high BTU coal. After being completely redrafted by the shop forces in Erwin, they were better, but the large locomotives still did not meet expectations and constantly found defects in the wyes at Spartanburg, SC and Elkhorn City, KY. Despite the late acquisition, they were not immune to the dieselization that the CRR underwent, and in lieu of ponying up the cash for the 15 year trust at once, officials decided to park the Challengers in Erwin, TN on the dead line until the trust was up. Less than 3 years from the time of the photo, 662 and the others were marched down to Tampa, FL and met their end at the scrapper's torch, marking a sad end to revenue freight steam on the Clinchfield Railroad. 35mm slide from my collection, photographer unknown.