Here is the “little” 80-inch-drivered Santa Fe Baldwin 3751 in 2010.
It is about a 1 minute film.
https://www.youtube.com/watch?v=5eggYBVAYiI
And this one just for fun - paced down the middle of the I-10 Freeway - an 11-minute film.
Incredible. Not only can 3751 move, but it makes it look effortless!
Just imagine her bigger sister’s of the 2900s doing that routinely across Kansas hauling named trains like the Chief or Grand Canyon until replaced by diesel.
The “little” 3751 class were not that much smaller than the 3765, 3776 and 2900 classes.
Even as built with the smaller driving wheels, the 3751 had the same grate area of 108 square feet, the same maximum boiler diameter of just less than 100 inches and the same length between tubeplates of just under 21 feet…As rebuilt, the 3751 class were about three feet shorter than the later locomotives, due to the boiler having a shorter combustion chamber.
Of course the 3751 class had a lower boiler pressure (230 Lbf/sq in against 300 Lbf/sq in) but had larger cylinders to compensate for this.
Interestingly the 5001 class 2-10-4 and the 3760 class 4-6-4 also had boilers of around 21 feet between tubeplates, and both had grates of the same width, 108 inches, although the 4-6-4 grate was shorter and the 2-10-4 was longer than that on the 4-8-4. The 2-10-4 boiler was bigger in diameter, 104 inches compared to just under 100 inches for the 4-8-4, while the 4-6-4 boiler was 92 inches maximum diameter.
I recall that Bachmann made an HO scale model of the 2-10-4 using the existing boiler and cab moulding for the 4-8-4. It was relatively close to correct, given the small difference in dimensions when reduced to HO scale.
Peter
Agree M636C! The ATSF “little” 4-8-4s were not very little, just as the UP 800-814 were not very little.
Santa Fe’s mechanical department sure knew what they were doing when they rebuilt the 3751-3764.
And they rebuilt them beginning in 1938, which allowed the improved power at speed to improve the timings of all the passenger trains, just as the very first passenger diesels were arriving, and when the first 3765 class were just entering service.
The 3400 class Pacifics and 3450 class 4-6-4s were also rebuilt, and some of the new 3460 class 4-6-4s were held as reserve power for the diesel hauled trains.
There was a well organised process to provide faster service for passengers and freight.
Peter
M636C,
Thank you for such great historical information! Just as a follow up to that I linked to a couple of photos of 3751-class locomotives for comparison.
Here is a builder’s photo of ATSF 3764 as built in 1927:
https://www.railpictures.net/photo/628000/
Here is ATSF 3761 as rebuilt in 1946:
https://www.kshs.org/km/items/view/61553
This shows how extensive the rebuilding of the 3751 class was - my goodness, they almost don’t look like the same class of locomotive!
Amazing. In a way, it reminds me of the change of appearance of the battleships salvaged from Pearl Harbor and repaired and refitted.
They called them “The Pearl Harbor Ghosts.” They got their revenge at Suragao Strait in 1944, but that’s another story.
Roger that, '76! Crossing the “T”!
It wasn’t quite that much revenge after the PT-boats, destroyers and some cruisers pounded the Japanese force pretty severely before it got within range of the battle line.
We will take the “W”!
Meanwhile, a question popped in to my head regarding the rebuilding of the 73-inch-drivered 3751 class in to 80-inch drivered locomotives.
Might they have needed a small insert to the boiler and perhaps a new frame or extended frame to fit four 80-inch drivers where 73-inch drivers used to be?
I know the Missouri Pacific needed to do an insert when they converted their 63-inch-drivered Berkshires to 75-inch-delivered Northerns.
The rebuild in '41 involved a new cast engine bed with roller bearings. To my knowledge the boiler was not enlarged.
3751 was the last to be rebuilt for an interesting reason. She was modified with a Batz high-speed lead truck (with larger wheels), improvements to valve motion, etc. as protect power for the Super Chief in 1936. Consequently by the time of the ‘second’ rebuild she got the benefit of all the revealed wisdom from both the first and second ‘batches’.
I believe there are contemporary accounts of the detail rebuilding in the trade press, as there is for the late-Forties second rebuilding of the awesome C&NW H locomotives, but I cannot find it on a phone. Here is a modeler’s reference which pointedly says nothing about boiler mods:
http://sfrhms.org/files/ThompsonJohn/4-8-4%20Clinic/4-8-4%20Clinic.pdf
That Thompson paper is a good resource for individual 3751 class locomotives.
While the boiler wasn’t lengthened, the smokbox was lengthened. Sadly I can’t quote a number of inches, because while the rebuilt locomotive drawing shows a distance from the tubeplate to the centre of the blastpipe, the original locomotive does not quote that figure.
However, on the original locomotive, the access hatch for the superheater header takes up most of the space between the stack and the tubeplate, while on the rebuild, it occupies only about
The rebuilding of the battleships from Pearl Harbor is an interesting comparison, having occurred only a short time after the rebuilding of the second batch of 3751 class.
A good reference to these is Battlships and Battlecruisers 1905-1970 by Siegfried Breyer. This is illustrated by line drawings to a constant scale and illustrates ships at various stages of their lives, in both side elevation and in plan view. One of the best examples was California, which looked like a WWI battlship before Pearl Harbor but looked more like a contempoary South Dakota class after rebuilding. The replacement of the secondary armament with twin 5"/38 turrets provided a useful anti-aircraft capability on many of the rebuilds, including California.
Peter