New York Central / Big Four 4-8-2 "Mountain" Type Locomotives

Introduction

The New York Central Railroad needed a successor for its 4-6-2 "Pacific" that it was using for fast freight and selected the 4-8-2 wheel arrangement for a trail. In 1916, it bought a single "Mountain" type locomotive (road number 2500) from the American Locomotive Company and put it to the test. Satisfied with its performance, the NYC decided that the name "Mountain" would not be appropriate for a river level railroad and chose to call the 4-8-2 wheel arrangement "Mohawk" on its railroad. Twenty-nine more "Mohawks" were delivered by the end of the year. These thirty, ALCO built, locomotives (road numbers 2500 through 2529) were designated Class L-1a and had 28 x 28 cylinders, 69" drivers, a 200 psi boiler pressure and exerted 54,084 lbs of tractive effort.

During 1917 and 1918, 55 "Mohawks" designated Class L-1b (road numbers 2530 through 2584) came from ALCO and in 1918, one hundred 4-8-2s would arrive from the Lima Locomotive Works. These Lima built locomotives, Class L-1c (road numbers 2585 through 2639) and Class L-1d (road numbers 2640 through 2684) were duplicates of the ALCO built Class L-1a locomotives.

Between 1925 and 1930, the NYC bought a total of three hundred more "Mohawks" and designated them Class L-2. All 300 of the L-2 Mohawks were eventually numbered 2700 through 2999. Those L-2 Mohawks originally numbered 2450 through 2499 were renumbered 2950 through 2999 in 1936.

In the 1940s, 115 more "Mohawks" were added to the roster making a total of 600 4-8-2s built for the New York Central. This last group included the 65 Class L-3 (road numbers 3000 through 3034 and 3050 through 3064 from ALCO and road numbers 3035 through 3049 from Lima) and the 50 Class L-4 (road numbers 3100 through 3149 from Lima).

The NYC performed heavy repairs on and did rebuilding of locomotives at shop complexes such as those at Beech Grove, IN and Collinwood, OH.

The L-3 and L-4 Mohawks were built without smoke deflectors, and were the only Mohawks retrofitted with them. The L-3a Mohawks were built with roller bearings on all axles, but the L-3b and L-3c Mohawks were built with roller bearings on all axles except those of the driving wheels. The L-4 Mohawks were built with roller bearings on all axles.

The L-3 Mohawks were built with Boxpok driving wheels and the L-4 Mohawks were built with either Boxpok or Scullin Disc driving wheels. These wheels had a nickel content of 2-3 percent, but no NYC engine was equipped with stainless steel drivers. According to Mr. Gerbracht, stainless steel has metallurgical properties which make it unsuitable for use in driving wheel centers or tires.

There are two surviving NYC "Mohawks": number 2933 at the Museum of Transportation in St. Louis, MO and number 3001 at the National NYC Railroad Museum in Elkhart, IN.

Class Details by Steve Llanso

Class L-1a (Locobase 4793)

Data from "NYC 4-8-4 Type Freight Locomotives", Railway Mechanical Engineer, Vol 92, No 2 (February 1916), pp. 77-80. Works numbers were 56000, 56027-56055 in 1916, 56910-56964 in 1917-1918 and Lima works numbers were 5499-5553, 5585-5629 in 1918.

The first of a numerous stud of Mountains (known as Mohawks on the NYC). Schenectady built the first two batches 2500-2584) and Lima finished off the class in 1918.

These were not the engines that made the 4-8-2 such a staple on the Water Level Route. For one thing, they were completed without automatic stokers. This meant, according to the New York Central Museum website (nycmuseum.railfan.net/MOHAWK.htm), that they couldn't use all the potential in their boilers. Moreover, they were hard on the track.

Although the proportions of boiler to cylinder and to grate were approximately the same and L-1s had the same 14" (356 mm) piston valves, later Mohawks had bigger grates and boilers as well as a longer stroke and higher boiler pressure.

Two L-1b--2568-2569--were converted to a three-cylinder design (25" x 28") in 1922 and 1924, respectively.

By the mid-1930s, 50 of the 185 L-1s had been scrapped.

Class L-2a/L-2c (Locobase 444)

Data from the 1930 guide to Dimensions and Classifications of Locomotives seen on http://www.rr-fallenflags.org/nyc/nyc-lb30.html (May 2003) and the 1946 guide from the same site. The tube count is from the 1946 version. Works numbers for the L-2a were 66281 in March 1925, 66578-66647 in March 1926, 66648-66676 in May and for the L-2c 67821

-67835 in April 1929, 67850 in May, 67851-67875 in April, 67876-67899 in June, 67900-67905 in July, 67906-67914 in August, 67915-67920 in September

Boiler had Elesco feedwater heater, valve motion limited cutoff. NY, O & W 459-460 similar. Like the L-1s, these Mohawks were limited to a 60-mph maximum speed. But their bigger boiler and grate set the standard for later NYC 4-8-2s.

Class L-2b (Locobase 213)

Data from tables in 1930 Locomotive Cyclopedia. Works numbers were 67742-67757 in February 1929, 67758-67766 in March, 68118-68142 in October.

Known as Mohawks in NYC service (Locobase 15900), 50 of this class went to the Cleveland, Cincinnati, Chicago & St Louis.

Boiler had feedwater heater, valve motion with limited cutoff operating 14" (356 mm) piston valves.

Slightly larger boilers than the earlier L-2as. More important, their cast-steel engine beds, roller bearings, lightweight main and side rods meant the NYC could raise the maximum speed to 80 mph, thus making them truly dual-purpose locomotives. According to nycmuseum.railfan.net/MOHAWK.htm, L-3s developed 4,100 hp at 57 mph, which was a 23 1/2% increase over the L-2ds.

Class L-2d (Locobase 15900)

Data from tables in 1930 Locomotive Cyclopedia. Works numbers were 68118-68142 in October 1929, 68093-68103 in February 1930, 68104-68117 in March.

Boiler had feedwater heater, valve motion with limited cutoff.

Slightly larger boilers than the earlier L-2as (Locobase 444). More important, their cast-steel engine beds, roller bearings, lightweight main and side rods meant the NYC could raise the maximum speed to 80 mph, thus making them truly dual-purpose locomotives. According to nycmuseum.railfan.net/MOHAWK.htm, L-3s developed 4,100 hp at 57 mph, which was a 23 1/2% increase over the L-2ds.

Known as Mohawks in NYC service, 50 of this class went to the Big Four (CCC&StL); see Locobase 213.

Class L-3a, b, c (Locobase 214)

Data from tables in 1947 Locomotive Cyclopedia and NYC 1-1944 Locomotive Diagrams supplied in August 2013 by Allen Stanley from his extensive collection. Schenectady works numbers were 69337-69361 (L-3a) in 1940 and 69362-69371 in 1940-1941 (L-3b). Lima supplied another 25 in the same years as works numbers 7779-7793. Schenectady finished the class with works numbers 69745-69759 in 1942.

The first 25 of these dual-service engines were assigned to passenger trains and fitted with roller bearings for lower resistance and faster running. Pressing the boiler at 250 psi meant smaller cylinders to fill and still greater power. The L-3b and c had boosters that added 14,000 lb (6,350 kg) to starting tractive effort. L-3a had Worthington feed water heaters while L-3b and L-3c had Elescos.

Drury (1993) claims they were the equal of the better-known Hudsons at passenger running while the 4-6-4s couldn't haul freight. The L-4s that followed the L-3 class (Locobase 215) had drivers that were 3" taller.

The nycmuseum.railfan.net/MOHAWK.htm website puts it more strongly about both the L-3s and L-4: "[Their] performance was almost beyond belief. It was nothing for them to bring in a heavy freight drag, be serviced, and leave a few hours later at the head of one of the "Great Steel Fleet' passenger trains.".

In the latter service, their huge PT tenders ensured endurance. Although tank capacity seemed almost modest, track pans between the rails on the Water Level Route meant the engine could take on water while scarcely slowing down. 86,000 lb (39,009 kg) of coal cut the number of stops for refuelling considerably.

Class L-4b (Locobase 215)

Data from tables in 1947 Locomotive Cyclopedia and NYC 1 - 1946 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive collection. Works numbers were 7978-7988 in December 1942, 7989-7994 in January 1943, 7995-7999 in February, 8000-8002 in March, 8292-8298 in October, 8299-8307 in November, 8308-8316 in December.

Firebox heating surface included 35 sq ft of arch tubes as well as a sizable combustion chamber. They were identical to the L-3s (Locobase 214) but had 3"-taller drivers and slightly larger cylinders to compensate. Piston valves measured 14" (356 mm) in diameter and the boiler accommodated a Worthington feed water heater.

Farrington (1976), who didn't particularly like the J-class Hudsons, says these L-4s could climb Albany Hill with seven cars in tow without a helper.

The nycmuseum.railfan.net/MOHAWK.htm website puts it more strongly about both the L-3s and L-4: "[Their] performance was almost beyond belief. It was nothing for them to bring in a heavy freight drag, be serviced, and leave a few hours later at the head of one of the "Great Steel Fleet' passenger trains." 50 L-4s ran up about 5.5 million miles (8.55 million km) in their first four years--an average of 27,500 miles (44,275 km) per locomotive per year. 4.5 million (7.25 million km) of that distance was covered hauling passenger trains.


Specifications by Steve Llanso
ClassL-1aL-2a/L-2cL-2bL-2dL-3a, b, cL-4b
Locobase ID4793 444 213 15900 214 215
RailroadNew York Central (NYC)New York Central (NYC)Big Four (NYC)New York Central (NYC)New York Central (NYC)New York Central (NYC)
CountryUSAUSAUSAUSAUSAUSA
Whyte4-8-24-8-24-8-24-8-24-8-24-8-2
Road Numbers2500-26842700-28496200-6249/2900-29492450-2499/2950-29993000-30643100-3149
GaugeStdStdStdStdStdStd
BuilderseveralAlco-SchenectadyAlco-SchenectadyAlco-SchenectadyAlcoLima
Year191619251929192919401942
Valve GearBakerBakerBakerBakerBakerBaker
Locomotive Length and Weight
Driver Wheelbase18'18'18'18'19'19'
Engine Wheelbase39.33'42'42.08'42.08'43.08'43.08'
Ratio of driving wheelbase to overall engine wheebase 0.46 0.43 0.43 0.43 0.44 0.44
Overall Wheelbase (engine & tender)82.54'84.58'84.67'84.67'95.96'95.96'
Axle Loading (Maximum Weight per Axle)
Weight on Drivers234000 lbs242000 lbs247500 lbs247500 lbs264440 lbs266500 lbs
Engine Weight343000 lbs362500 lbs368500 lbs368500 lbs398000 lbs401100 lbs
Tender Light Weight166500 lbs283700 lbs312700 lbs312700 lbs374200 lbs379700 lbs
Total Engine and Tender Weight509500 lbs646200 lbs681200 lbs681200 lbs772200 lbs780800 lbs
Tender Water Capacity15000 gals15000 gals15000 gals15000 gals15500 gals15200 gals
Tender Fuel Capacity (oil/coal)18 tons21 tons28 tons28 tons43 tons42 tons
Minimum weight of rail (calculated) on which locomotive could run98 lb/yard101 lb/yard103 lb/yard103 lb/yard110 lb/yard111 lb/yard
Geometry Relating to Tractive Effort
Driver Diameter69"69"69"69"69"72"
Boiler Pressure190 psi225 psi225 psi225 psi250 psi250 psi
Cylinders (dia x stroke)28" x 28"27" x 30"27" x 30"27" x 30"25.5" x 30"26" x 30"
Tractive Effort51380 lbs60618 lbs60618 lbs60618 lbs60077 lbs59854 lbs
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.55 3.99 4.08 4.08 4.40 4.45
Heating Ability
Firebox Area320 sq. ft354 sq. ft345 sq. ft345 sq. ft373 sq. ft373 sq. ft
Grate Area66.80 sq. ft75.35 sq. ft75.30 sq. ft75.30 sq. ft75.30 sq. ft75.30 sq. ft
Evaporative Heating Surface4430 sq. ft4646 sq. ft4556 sq. ft4556 sq. ft4676 sq. ft4676 sq. ft
Superheating Surface1212 sq. ft1938 sq. ft1931 sq. ft1931 sq. ft2082 sq. ft2082 sq. ft
Combined Heating Surface5642 sq. ft6584 sq. ft6487 sq. ft6487 sq. ft6758 sq. ft6758 sq. ft
Evaporative Heating Surface/Cylinder Volume222.00233.70229.17229.17263.69253.65
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation126921695416943169431882518825
Same as above plus superheater percentage153572187022025220252466124661
Same as above but substitute firebox area for grate area73568102749100913100913122158122158
Power L1185473105230794307944098541137
Power MT698.961131.531097.201097.201366.761361.22

Photos

Reference

Credits

Introduction and roster provided by Richard Duley. Class details and specifications provided by Steve Llanso of Sweat House Media.