Black Hills Mallet #110

Black Hills Mallet #110 is directly related to Big Boy!

Pronounced (“Ma-lay”), BHCR’s Mallet 2-6-6-2T is using an articulated designed to allow for heavy loads in tight turns. Both locomotives have an articulated design whereby they use two wheeled trucks under one mail frame. The main difference between the two locomotives in that one uses compounded steam (BHCR’s 2-6-6-2T) and the other uses simple expansion steam (Big Boy).

Compounded steam utilizes the steam twice. Once at high pressure from the boiler at the rear cylinders and then again at the larger cylinders in at the front truck at lower pressure.

The simple expansion steam method uses steam generated from the boiler to both rear and forward pistons at the same time generating more power for larger loads.

BHCR’s #110 was built in 1928 and is considered a Pannier Tank Mallet with the water jacket straddling both sides of the boiler. It was used as a logging locomotive for Weyerhaeuser Timber Company at one time.

Let us know if you have ever taken an excursion on Black Hills Central Railroad in South Dakota. We would love to hear about your experience!