The tender in the Athearn RTR derrick (crane) sucks though. VERY light weight and while some north east roads had light tenders for their derricks, for a 250 ton derrick, you want something more beefy. The Athearn crane tender would be more suitable for the Tichy derrick. UP's derricks usually had six axle long tenders, utilizing old passenger car trucks, but the WPMW 37 (Industrial Brownhoist stem, converted to diesel which the Athearn are loosly based from) uses an old 50' gondola with the end of a boxcar welded into one end for cables and slings. The WP cut steps into the ends to get up into the car and what amounts to a caboose style platform into one end for access. The WPMW 37 is currently operative at the Western Pacific Railroad Museum in Portola California and is a joy to operate. We use the heck out of it, and I am now the 2nd generation in my family to operate it. My Dad is very proud of his old Derrick being used to this day for its intended purpose with its original owner, the WP.