How did the Erie Triplex compare to the Challenger and Big Boy engines? Also are there any Triplexes preserved today or were they all scrapped?
The Triplex was a purpose built engine used in pusher service by the Erie. There were 3 of them. They worked well in pusher service, but could not keep up a full head of steam for road service. They were built in 1914 and out of service by 1927. They were ‘compound’ engines. The Virginian also had a single copy of a Triplex design. As far as I know, there are no preserved copies of these engines.
The Challenger and Big Boy were built in much greater numbers and were modern steam engines that operated in ‘simple’ mode due to the fact that they could produce enough steam at road service speed. The UP had over 100 Challengers, and they were also purchased by several other railroads. A very sucessful design. The Big Boy was a UP only design and 25 engines were built. Dieselization ended any thoughts of more, but they did last until the late 50’s in road service.
Jim
Thank you for your reply Jim, I didn’t know the Triplexes were that much older than the Challengers and Big Boys.
The Triplex compared to the Challenger and Big Boy about the same way that a John Deere farm tractor with a 5-gallon fuel capacity compares to a Volvo highway tractor with extended-range tanks.
The Triplex was meant to be, and was used as, a pusher - and was only marginally successful due to the undersize firebox and losing half the draft generating capabilty of the exhaust steam (which was dumped to atmosphere at the rear of the tender instead of routed through the blast pipe and stack.) Due to driver size, it was incapable of running at any reasonable speed without risking damage to the track and the locomotive. The size of the bunker and water cistern were somewhat restricted by being carried over the rear engine.
By way of contrast, a Challenger (with only half the tractive effort of the Triplex) could bring its train up to 60+ MPH and sustain that speed until the cistern ran dry. It had the steam generating capacity to develop full horsepower at speeds the Triplex couldn’t dream of achieving. (The Big Boy, a Challenger on steroids, could handle heavier trains and run at similar speeds.)
All in all, the Triplex is one of those things we look back on and think, It looked like a good idea…
Chuck (modeling Central Japan in September, 1964)
The Erie engines were designed for a particular job (as were the Challengers, for that matter). They lasted 13 years. I wonder what the Erie thought of these engines. Were they quite happy and satisfied, or were they disappointed that they didn’t achieve anything near what was expected. We have opinions about these locos, but the opinions that counted were the ones from the people who operated them and the people who paid for them. I wonder what they were. Ed
Since actions speak louder than words:
Erie bought three (total) at a time when tractive effort was KING! and speed wasn’t a consideration. Ten years later, when speed had become a consideration, they were sidetracked (at a time when railroad business was expanding.) They languished for a while, then were scrapped.
Virginian took delivery of one, tested it and immediately sent it back to Baldwin! It ended up as a normal Mallet and a 2-8-2, both of which served the Virginian until the end of steam operation.
Of the two railroads, I think the Virginian got their money’s worth.
Chuck (modeling Central Japan in September, 1964)
The majority opinion is that Triplexes were a failure. They weren’t able to produce enough steam (power) to make them effective in most applications. (Talk about being slow and ponderous.) A mere thirteen-year life span during the height of steam locomotive activity is not a good return on investment. They are positively fascinating to the railfan and modeler, but not to a railroad accountant or investor. I’ll limit myself to four-cylinder duplexes (that’s weird enough) and articulateds/Mallets. Besides, I want every driver to be powered: the mass-produced model has only two-thirds of the drivers contributing to tractive effort.
Mark
Does anyone know what the Erie did to tame their hills once they decided the Triplexes weren’t going to cut it anymore?
I decided to skip this model when I learned that only the front two engines would be powered and that the “articulation” would be of the “diesel-truck” variety. Knowing how common it is for non-brass articulated makers to use this method, I was hoping MTH would choose to apply it to the middle and rear engine and let the front engine be unpowered and swivel as it was designed. I thought that if the tank were cast in metal with very thick walls, the tractive effort would be quite high. I thought also that it would be nice to use a motor for each of the two rear engines–thus there would likely be a minimum of unsightly drive components. Didn’t happen. Ed
Once they retired the triplexes, the Erie steered clear of mallets. They had a relatively flat mainline from Ney York to Chicago except for the grades on either side of the Delaware Water Gap. They relied on really heavy Mikes, Berkshires and Santa-Fe types and did a lot of double-heading often with two more engines pushing. The center of this action was Port Jervis as there were stiff grades in both directions and the town itself was situated at the bottom of the Delaware River Valley. Bert Pennypacker’s “Eastern Steam Pictorial” depicts some of this action.