Lehigh Valley 4-8-4 "Northern" Locomotives of the USA

The Lehigh Valley Railroad took delivery of two 4-8-4s in 1931. Road number 5100 was built by the Baldwin Locomotive Works and was designated Class T-1a. It had 70" drivers, 27 x 30 cylinders, a boiler pressure of 250 psi, a tractive effort of 66,400 lbs and weighed 413,170 pounds. Road number 5200 came from the American Locomotive Company and was designated Class T-2a. It had 70" drivers, 26 x 32 cylinders, a boiler pressure of 255 psi, a tractive effort of 66,700 lbs and weighed 424,000 pounds. These two locomotives were delivered for trials, with 10 more of the Class T-1a 4-8-4s delivered from Baldwin in 1932, and 10 more of the Class T-2a 4-8-4s delivered from ALCO, also in 1932.

The Lehigh Valley gave its 4-8-4 type locomotives a local name, rather than the "Northern" designation. The name "Wyoming" was selected. The Wyoming Valley is a historic section of the Susquehanna Valley that is served by the railroad.

In 1934, five heavier 4-8-4s were delivered by Baldwin as dual purpose locomotives. They were designated Class T-3 and assigned road numbers 5125 through 5129. They had 77" drivers, 27 x 30 cylinders, a boiler pressure of 275 lbs, a tractive effort of 66,500 lbs and weighed 441,400 pounds.

During World War II, the Lehigh Valley needed additional motive power but because of wartime restrictions, it could not build newly designed locomotives. Therefore, 10 duplicates of the Class T-2a Wyomings were ordered from ALCO and delivered in 1943. They were very similar to the older Class T-2a locomotives except they were 17,000 lbs heavier.

There are no surviving LV "Wyomings".

Roster by Richard Duley

ClassRoad NumbersBuilderYear Built
T-1a5100 - 5110BLW1931, 32
T-2a5200 - 5210ALCO1931, 32
T-2b5211 - 5220ALCO1943
T-35125 - 5129BLW1934, 35

Class Details by Steve Llanso of Sweat House Media

Class T-1 (Locobase 263)

Data from LV 3-1934 locomotive diagram book supplied in May 2005 by Allen Stanley from his extensive Raildata collection. See also DeGolyer, Vol 82, pp. 87+. (Thanks to Chris Hohl for 10 April 2015 spotting and reporting the differences between the 5100 and the other ten locomotives; see below.) Works numbers were 61615 in March 1931, 61672-61674 in April 1932, and 61675-61681 in May.

Known as "Wyomings" in Lehigh Valley service and intended for heavy fast trains over maximum grades of 1 1/2%. When fitted, an unusually powerful trailing-truck booster added 18,000 lb (8,165 kg) to the starting tractive effort.

Chris Hohl noted some differences between the 1931 loner and the ten engines supplied a year later: "5100 had Walschaert valve gear, and an Elesco K-50 feed water heater at the top/crown of smokebox ... her tender weighed 363,000 lbs. Her tender capacities were 28 tons [25.45 metric tons] & 18,000 gallons [68,130 litres]." The Baldwin specs estimated a total engine weight for the 5100 of 425,000 lb (192,777 kg), but the LV diagrams report 408,000 lb (185,066 kg).

Production T-1s used a Worthington feed water heater and actuated the 12" (305 mm) piston valves with Baker gear. In all, the firebox's heating surface area included 143 sq ft (13.3 sq m) in Nicholson thermic syphons, three in the firebox and one in the combustion chamber. An additional 92 sq ft (8.5 sq m) came from the shell of the chamber. A Standard BK stoker fed the coal. The front truck (bogie) axles turned in Timken roller bearings; it weighed 5,070 lb (2,300 kg) more than the one under the 5100.

The Lehigh Valley laid out the schedule it expected this engine to keep from Frontier (near Niagara Falls, NY) to Tidewater (Jersey City, NJ) while hauling 3,000 short tons:

Suspension Bridge to Manchester 3 hours 30 minutes

Buffalo to Manchester 3 hours 0 minutes

Manchester to Sayre (Pa) 3 hours 0 minutes

Sayre to Coxton 2 hours 15 minutes

Coxton to Mahoning (Pa) 3 hours 0 minutes

Mahoning to Jersey City (NJ) 4 hours 0 minutes

Class T-2, T-2b (Locobase 265)

Data from 1947 Locomotive Cyclopedia and from Data from LV 3 -1934 Locomotive Diagrams, the latter supplied in May 2005 by Allen Stanley from his extensive Raildata collection. Works numbers were 68546 in March 1931, 68610-68611 in April 1932, 68612-68619 in May (T-2) and 70839-70848 in October 1943.

These engines were built in two batches --10 in 1932 and 10 in 1943. The T-2a were delivered at the same time Baldwin supplied its T-1s (Locobase 263). Compared to the Baldwins, these Alcos had less cylinder volume, longer combustion chambers, slightly less adhesion weight but almost six tons more engine weight. 5200-5205 carried the Elesco feed water heater in its customary position above the smokebox; 5206-5210 used Worthingtons.

Firebox heating surface included 131 sq ft (12.7 sq m) of arch tubes in the firebox and Nicholson thermic syphons in the firebox and combustion chamber.

T-2bs came a decade later and repeated the design with some detail differences and a small gain in adhesion weight (to 274,500 lb/124511 kg) and a larger rise in engine weight (to 451,000 lb/204,570 kg).

Class T-3 (Locobase 264)

Data from LV 3-1934 locomotive diagram book supplied in May 2005 by Allen Stanley from his extensive Raildata collection. Works numbers ran 61808-61810 in December 1934 and 61811-61812 in January 1935.

Obviously based on Baldwin's T-1s of 1931-1932, this quintet had taller drivers, boiler pressed to a higher PSI, and a larger grate. Firebox had thermic syphons and the boiler had a Worthington feed water heater.

Drury (1993) says that these Wyomings weren't passenger engines, but "occasionally pulled milk trains, where their high drivers were useful -- a slow milk train can quickly become a yogurt train." They would also head up the famous Black Diamond express train.

Specifications by Steve Llanso of Sweat House Media
ClassT-1T-2, T-2bT-3
Locobase ID263 265 264
RailroadLehigh Valley (LV)Lehigh Valley (LV)Lehigh Valley (LV)
Number in Class11205
Road Numbers5100-51105201-52205125-5129
Number Built11205
Valve GearBakerBakerBaker
Locomotive Length and Weight
Driver Wheelbase (ft)19.2519.2520
Engine Wheelbase (ft)44.9245.5845.92
Ratio of driving wheelbase to overall engine wheebase 0.43 0.42 0.44
Overall Wheelbase (engine & tender) (ft)94.879595.17
Axle Loading (Maximum Weight per Axle) (lbs)67,50068,300
Weight on Drivers (lbs)270,000269,000272,200
Engine Weight (lbs)413,170424,000435,000
Tender Loaded Weight (lbs)398,300389,100389,000
Total Engine and Tender Weight (lbs)811,470813,100824,000
Tender Water Capacity (gals)20,00020,00020,000
Tender Fuel Capacity (oil/coal) (gals/tons)303030
Minimum weight of rail (calculated) (lb/yd)113112113
Geometry Relating to Tractive Effort
Driver Diameter (in)707077
Boiler Pressure (psi)250255275
High Pressure Cylinders (dia x stroke) (in)27" x 30"26" x 32"27" x 30"
Tractive Effort (lbs)66,39166,98266,391
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.07 4.02 4.10
Heating Ability
Firebox Area (sq ft)490494507
Grate Area (sq ft)88.3088.3096.50
Evaporative Heating Surface (sq ft)542253765439
Superheating Surface (sq ft)225620952056
Combined Heating Surface (sq ft)767874717495
Evaporative Heating Surface/Cylinder Volume272.73273.39273.59
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation22,07522,51726,538
Same as above plus superheater percentage28,47728,82133,703
Same as above but substitute firebox area for grate area158,025161,242177,070
Power L141,33740,39647,004
Power MT1350.111324.281522.79



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