With wartime restrictions on new locomotive designs imposed by the War Production Board the PRR was forced to borrow a design from another railroad. It chose the C&O's Class T-1 "Texas" type and the C&O loaned it a locomotive for evaluation. The PRR engineers prepared drawings based on the T-1 and the Altoona Shops built what would become North America's largest fleet of "Texas" type locomotives. In total the PRR's shops at Altoona, Pennsylvania would build 125 of these locomotives.
The Altoona Shops started delivering the new 2-10-4s in late 1942 with six out-shopped with road numbers 6450 through 6455.and designated as Class J-1. In1943, a total of 101 were built and put to work. Forty-one were given road numbers 6435 through 6449, 6456 through 6476 and 6150 through 6156. This group was designated as Class J-1, The other sixty were built with cast bed frame and were assigned road numbers 6401 through 6434 and 6475 through 6500 and they were designated as Class J-1a. In 1944, another eighteen were added to the roster as road numbers 6157 through 6174. These last eighteen were of the J-1 class.
All of the PRR "Texas" type locomotives had 69" diameter drivers, 29" x 34" cylinders, a 270 psi boiler pressure with a resultant tractive effort of 95,100 pounds. The J-1s weighed 589,975 pounds and the J-1a locomotives weighed 579,975 pounds. The firebox had an area of 575 square feet, the evaporating surface was 5,998 square feet and the superheater added 2,930 square feet giving the J-1 and J-1a a total of 9,498 square feet of combined heating surface. The boiler was of the radial stay design and the piston valve had a diameter of 14 inches. There was a trailing truck booster that added 15,000 pounds tractive effort.
The J1 and J1a locomotives spent the war years hauling freight on the railroad west of Altoona. Fifty five were assigned to the Central Region spread among the Western Pennsylvania Division-Pittsburgh Division, the Eastern Ohio Division-Eastern Division, the Eastern Ohio Divisions-Panhandle Division and the Lake Division-Cleveland Division. The other seventy were assigned to the Western Region spread among the Northwestern Division-Toledo Division, the Northwestern Division-Ft Wayne Division, the Northwestern Division-Logansport Division and the Southwestern Division-St. Louis Division
After the war they were displaced by diesels but the PRR found uses for them until they were retired in the late 1950s. There are no surviving examples of the PRR's 2-10-4s.
|Class||Qty.||Road Number||Year Built||Builder||Notes|
Altoona works numbers Month-Year Road numbers
4399-4404 December 1942 6450-6455
4405-4413 January 1943 6456-6464
4414-4425 February 6450-6474
4429-4435 March 6475-6479
4436-4447 April 6480-6489
4448-4457 May 6490-6498, 6401
4458-4468 June 6402-6411
4469-4478 July 6412-6421
4479-4486 August 6422-6429
4487-4493 September 6430-6434, 6499-6500
4509-4515 December 6150-6156
4516-4518 January 1944 6157-6159
4519-4521 February 6160-6162
4522-4526 March 6163-6167
4528-4531 September 6168-6171
4532-4534 October 6172-6174
Based on the Chessie's 40 T-1 class engines built in the 1930s (Locobase 95). Pennsy built 127 total, modifying them slightly internally and to a significant degree on the surface, including the addition of a much larger tender. J1as used different materials in their boilers, but were otherwise identical. Some sources claim that J1a had cast-steel, as opposed to built-up, locomotive beds, but others state that both classes had locomotives rolling on both kinds of beds.
Unlike most Pennsy engines, which had 12" piston valves, these imports sported 14" (356 mm) diameter piston valves. EHS, SHS dimensions were slightly smaller, but BP higher, resulting in higher TE.
J1s initially had serious issues with counterbalancing the drivers, possibly because they used the original specifications (suggested by a Railroad.net post by Les ("Desertdweller") and not ones developed by the C&O after confronting their own problems. The Pennsy did solve the problems and it's worth recalling that the Chessie did have continuing issues as noted in Locobase 95. Chris Trunk's comment led Locobase to compare the original diagram dated 8 January 1943 and Pennsylvania Railroad 1 September 1956 109-L Classification and Description of Locomotives and Tenders. Although the J-1s were delivered with 69" drivers, the road later adopted the 70", probably to alleviate the counterbalancing problems noted above.
Regardless, the J1s were considered very successful engines whose careers were severely curtailed by the system-wide conversion to diesel power beginning in the late 1940s. Occasionally reactivated in the mid-1950s in response to heavy traffic, the class was scrapped in 1957-1959.
|Specifications by Steve Llanso|
|Road Numbers||6401-6500, 6150-6174|
|Locomotive Length and Weight|
|Ratio of driving wheelbase to overall engine wheebase||0.49|
|Overall Wheelbase (engine & tender)||104.04'|
|Axle Loading (Maximum Weight per Axle)||76800 lbs|
|Weight on Drivers||377800 lbs|
|Engine Weight||572640 lbs|
|Tender Light Weight||411500 lbs|
|Total Engine and Tender Weight||984140 lbs|
|Tender Water Capacity||21000 gals|
|Tender Fuel Capacity (oil/coal)||29.9 tons|
|Minimum weight of rail (calculated) on which locomotive could run||126 lb/yard|
|Geometry Relating to Tractive Effort|
|Boiler Pressure||270 psi|
|Cylinders (dia x stroke)||29" x 34"|
|Tractive Effort||93747 lbs|
|Factor of Adhesion (Weight on Drivers/Tractive Effort)||4.03|
|Firebox Area||575 sq. ft|
|Grate Area||121.70 sq. ft|
|Evaporative Heating Surface||6568 sq. ft|
|Superheating Surface||2930 sq. ft|
|Combined Heating Surface||9498 sq. ft|
|Evaporative Heating Surface/Cylinder Volume||252.69|
|Computations Relating to Power Output (More Information)|
|Robert LeMassena's Power Computation||32859|
|Same as above plus superheater percentage||43045|
|Same as above but substitute firebox area for grate area||203378|