Locomotive 4012 as it arrived in 2000.
4012 was acquired from the Yakima.
The cooling fan is an important part of any diesel engine. On the 4012, it is powered with the diesel engine by coupling a universal joint to the end of the engine driveshaft. The universal transmits power to an angle drive and the cast aluminum blades are mounted directly on top. The speed of the fan is directly proportional to the speed of the diesel engine.
After the fan drive was disassembled, the problem was evident: a number of gear teeth had stripped off one of the miter gears. So each rotation of the shaft caused the gear to slip, which also damaged the universal joint. If left unchecked, continued use would have stripped all the teeth off the gear and resulted in an overheated diesel.
Broaching a keyway.
Gear mounted on shaft.
A test run of the 4012 quickly established that everything was correctly fitted. Now locomotive 4012 is ready to pull nine days of regular Santa Train 2014 to North Bend, and to support steam locomotive SCPC 2 on the special Friday, December 19 Steam Santa Train.