“Largest” steam locomotive
I was bouncing around one of my favorite websites, https://www.steamlocomotive.com/ , my quest still being details on CNor 2791 heavy pacific. I was trying to figure out when and how often Worthington Type SA feedwater systems were added to the heavy pacifics. The Mantua boiler casting has a molded detail at the front that resembles the heater from a Worthington Type SA system. When I originally didn’t recognize the detail (and threatened to grind it off), George mentioned that it was a common steam appliance – and I proceeded to find it’s resemblance to the feedwater system heater. …anyways, more on feedwater systems at some other date.
So in bouncing around the Steam Locomotive site, I ran into the “Largest” steam locomotive listing. Now I’ve accidentally posted some fake pictures of large steam in the past – so finding a legit listing caught my attention. It’s a bit of a trite topic, but still captivating for us steam lovers.
To start off, let’s define “large”. There’s two categories common to steam locomotive performance: tractive effort and power (horsepower). Then, there’s two size categories: length and weight.
Starting with TRACTIVE EFFORT, the locomotive with the most pulling force was the N&W #2300 “Jawn Henry”, listed as a C+C+C+C (steam turbine). Only one unit was built in 1954 with a tractive effort of 180,000. The Jawn Henry ran about 3 years before the diesels pushed it to the scrapyards. It was mainly used as a pusher.
Second (or possibly above the Jawn Henry) was the experimental Virginian #700, class X-A 2-8-8-8-4, built in 1916. It’s tractive effort is listed as 166,300 compound and 199,560 simple. (Please don’t ask me the difference between simple and compound tractive effort – I didn’t get a chance to look it up…yet!) The #700 never made a successful trip and was broken up into two separate locos.
Third on the list was the Virginian class AE 2-10-10-2, built in 1918 by Alco. We can get away from the experimental designation because (10) total units were built. It’s tractive effort is listed as 147,200 compound and 176,600 simple. There was an ATSF class 3000, 2-10-10-2, but they were built differently than the Virginians. I believe you can find videos of these operating.
Moving on to greatest horsepower – topping out the list at 7,498 hp @ 46 mph was the C&O H-8 “Allegheny”, 2-6-6-6. We can definitely call this a production unit – (60) engines were built from 1941 to 1948 by Lima Locomotive works.
Second on the power list was the Western Maryland class M-2 “Challenger”, 4-6-6-4, 6,345 hp @ 50 mph. (12) total units were built in 1940 & 1941 by Baldwin. A lot of Challengers were made by Alco, but the Baldwins win at horsepower.
Moving to the longest steam locomotive, we go back to the “Jawn Henry” – 161’-1” total (first two pics). Second on the list is the C&O M-1 4-8-0-4-8-4, another steam turbine like the “Jawn Henry”. Three units were built (by Baldwin) in 1947 & 1948 at 154’ long. The M-1’s were supposed to pull the “Chessie”, but the “Chessie” was discontinued before the M-1’s were delivered.
Third on the longest steam locomotive is the one everyone knows – the Big-Boy, UP 4-8-8-4, at 132’-10”. I skipped listing it above – it’s also third on the list under power at 6,298 hp @ 41.5 mph.
Alco built (25) locos from 1941 to 1944. Interestingly, 8 of the 25 still exist with UP #4014 still operational making it the longest and most powerful locomotive in existence today.
Finally, we get to the heaviest steam locomotive – The C&O M-1s (above second under longest) is the heaviest at 1,233,710 lbs.
Second under weight is the Erie class P-1 2-8-8-8-2 at 1,169,750 lbs. Here’s #5014, the “Matt Shay”
Three were built in 1914 by Baldwin. They were similar to the Virginian X-A (above), but while the X-A proved unsuccessful, the Erie P-1s were used in service until the last one was scrapped in 1933.
and #5016
The next two under heaviest (in order) were the Virginian X-A, and the N&W “Jawn Henry” (both above). To check out the full list under each category, go to the website listed above: https://www.steamlocomotive.com/
Oops! When I went to the Steam Locomotive website to find the “largest” locos, I looked at the articulated list and didn’t check back with the non-articulated list to see on how they ranked. For the most part, the articulated locos rank “larger” in most categories…except in power. There are two non-articulated locos that top out the power category: The PRR S-1, a 6-4-4-6 built in 1939, reaches 7,200 hp @ 100 mph. The PRR Q-2, a 4-4-6-4 built in 1945, generated 7,987 hp at 57.4 mph. There were (26) Q-2s built.
My apologies to all the PRR fans, and thanks to Bob Bartizek for pointing out the error (and thanks to George Roos for making the connection between Bob and me). Visit the website above and search for “largest locomotives” to see the complete list.