UP 4000 - Largest, heaviest (yes I know what Huddleston wrote and I think he was reaching), arguably most capable high speed super power articulated.
N&W Y6b - Masterpiece of evolutionary design. Easily the highest thermodynamic efficiency of any modern articulated. Best design for hauling dead freight up steep grades.
DM&IR M3 - Excellent modern and versatile heavy duty freight locomotives. D&RGW leased some M4’s for use over the Tennessee Pass in the 1940’s and raved about them.
B&O EM-1 - Another excellent late steam design that did everything the B&O wanted. Although on the small side, the EM-1’s were easily among the finest articulateds operating in the Eastern U.S.
SP AC-12 - Very versatile big power used all over the SP, including through the tunnels and snow sheds of the Sierra Nevada. The AC-12’s were the newest cab forwards in the SP’s large fleet.
The SP AC units were also consistently used on passenger runs as primary power for passenger schedules at several locations around the SP system, if I recall correctly.
I would agree with Peter and put up a Garratt for consideration, specifically NSWGR AD60 class 4-8-4+4-8-4’s. I believe that these were the largest Garratts ever built and provided big power for relatively light rail.
N&W Y6b because they were perfectly designed for the task they were most often assigned to: mineral service on heavy grades.
N&W Z1b simply because I like the look of them and maybe also because they were workhorses that didn’t get much glory. And where else besides on the N&W could you find big articulateds in yard and hump service.
UP Big Boy because as with N&W’s Y classes they were designed to do a specific job and they did it admirably.
C&O H-8 2-6-6-6 because I like 'em.
PRR T1 because who besides the Pennsy would try to streamline an articulated? [(-D]
Hey, THAT’S NOT FAIR. And you know better about the ‘real thing’ being articulated, even though some of the models kinda are…
And not even true: a perfectly good counter-example already having been mentioned here: the AC-12s were streamlined by most definitions that could be applied to nominally much “faster” steam power…
(What you need for full comic effect here is to put up a picture of a lash-up of TWO T1s here, which is an ‘eight-coupled articulated’ just as a brace of K4s is equivalent to a very fast 4-6-6-4…)
Powerful imagery all right. Makes me feel like I’m on the Bismarck and King George V and Rodney are coming to get me! British steel at it’s most awesome!
I guess it wouldn’t surprise anyone to know that I had been to Fassifern in that era, and photographed the double headed Garratts there, only still photos of course and mainly B&W. I remember one occasion in 1970 when I did have colour film, because Pacific 3822 was expected to haul the “Newcastle Flyer” after some time out of service for repairs, that nobody really expected to be completed. But to our relief, it appeared heading south as a “light engine” and returned on the “Flyer” as advised. we spent about half a day on a rocky outcrop north of the road bridge seen in some of the videos.
However, I also met the man who took the movies, Philip Belbin in August 1962 photographing trains on a rural branch on the southern edge of Sydney from Campbeltown to Camden. Phil gave me a lift to follow the train, but I had used the last frame of 35mm on the first shot of the branchline train. His eldest son is a magazine editor which I regularly contribute to, and is a close friend. But all wasn’t lost. The photo I took with that last frame is the best I ever took of that line, and I have a 10" x 12" enlargement handy. I should scan that some day…
If we’re talking about garratts, then the South African Railways class GL of 1929 has to be mentioned.
These were the most powerful garratts ever built with a tractive effort of 89,000 lbf. They originally hauled 1000 tonne trains up 1 in 66 gradients and 2000 tonne trains downhill, before electrification in 1938 transferred them to pulling 1200 tonne trains up 1 in 50 gradients. A truly remarkable feat for any loco, far eclipsing anything ever run in Europe.
The AD60 garratts were actually not that big nor powerful as far as garratts go. Their tractive effort was only 59,000 (later 63,000) lbf which was less than all later South African garratts besides the branch-line GO of 1954. The Algerian Railways BT, Rhodesian Railways 20th class, East African Railways class 59, Bengal Nagpur Railway class N, NM, and P were all also much more powerful.
The physically largest garratt ever built was the sole Soviet Ya.01 class of 1932. It had a tractive effort rivalling the GL of 89,000 lbf. It was 17 feet tall and the boiler (7ft 6in wide, same diameter as EAR 59) was so large it had to be transported by truck. It was designed to run in extremely cold conditions, but was retired only 5 years into service as the Soviets were unfamiliar with Garratt technology.
There were plans to build a 61 class for the East African Railways, which would have had a boiler 8 ft 6 in wide and a tractive effort of 115,000 lbf, which would have certainly have been the largest garratt and the largest locomotive to ever have run on a narrow gauge. Was never built as it was decided impractical, especially with diesels on the horizon.
Back to United States articulateds, I think the Great Northern
