Diesel of the Day 7/10: F-M H24-66

Today we have a rather curious and unusual diesel from the early days of dieselization: the Fairbanks-Morse H24-66 Train Master. When it was introduced in 1953, it was the most powerful diesel locomotive in the world, and its engine is what made it unique - it produced 2,400 horsepower using 12 cylinders and 24 pistons. Allow me to explain! The Fairbanks-Morse model 38D-8 1/8 two-stroke supercharged engine is of an opposed piston design. It is an inline 12-cylinder block, but instead of each cylinder containing a single piston pressing against a cylinder head, each cylinder holds two pistons facing each other. Each set of 12 pistons is driven by its own crankshaft, one on top of the engine and the other underneath. The reasoning behind this unusual design is to cram twice as much power into the space normally occupied by a single conventional engine design. It worked well, and the Train Masters were known for incredible pulling power and rapid acceleration. However, maintenance was a headache, due to the engine needing to be removed from the locomotive to service its lower half, and they also tended to consume cooling water at an alarming rate. Competing designs from EMD, Alco, and GE soon took over the H24-66’s market share as conventional engine designs caught up in the horsepower department. Of the original production of 127 units built between 1953 and 1957, only one was preserved, Canadian Pacific number 8905, cosmetically restored and on static display. The picture today is a Pennsylvania Railroad builder’s photo, with specifications.