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

Class L-1a (Locobase 4793)

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" piston valves, later Mohawks had bigger grates and boilers as well as a longer stroke and higher boiler pressure. By the mid-1930s, 50 of the 185 L-1s had been scrapped.

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

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.

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.

Class L-2b, d (Locobase 213)

Boiler had feedwater heater, valve motion

limited cutoff. 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.

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

Class L-3a (Locobase 214)

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. 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." .

Class L-4b (Locobase 215)

Firebox heating surface included 35 sq ft of arch tubes. They were identical to the L-3s (Locobase 214) but had 3"-taller drivers and slightly larger cylinders to compensate.

Farrington (1976), who didn't particularly like the J-class Hudsons, says these L-4s could climb Albany Hill with 7 cars in tow without a helper.

Specifications
Class	L-1a	L-2a/L-2c	L-2b, d	L-3a	L-4b
Locobase ID	4793	444	213	214	215
Railroad	New York Central (NYC)	New York Central (NYC)	Big Four (NYC)	New York Central (NYC)	New York Central (NYC)
Whyte	4-8-2	4-8-2	4-8-2	4-8-2	4-8-2
Road Numbers	2500-2684	2700-2899	2900-2999	3000-3064	3100-3149
Gauge	Std	Std	Std	Std	Std
Builder	several	Alco	Alco	Alco	Lima
Year	1916	1925	1929	1940	1943
Valve Gear	Baker	Baker	Baker	Baker	Baker
	Locomotive Length and Weight
Driver Wheelbase	18'	18'	18'	19'	19'
Engine Wheelbase	39.33'	42'	42.08'	43.08'	43.08'
Ratio of driving wheelbase to overall engine wheebase	0.46	0.43	0.43	0.44	0.44
Overall Wheelbase (engine & tender)	82.54'	84.58'	84.67'	95.96'	95.96'
Axle Loading (Maximum Weight per Axle)
Weight on Drivers	234000 lbs	242000 lbs	247500 lbs	264440 lbs	266500 lbs
Engine Weight	343000 lbs	362500 lbs	368500 lbs	398000 lbs	401100 lbs
Tender Light Weight	166500 lbs	283700 lbs	312700 lbs		309400 lbs
Total Engine and Tender Weight	509500 lbs	646200 lbs	681200 lbs	0	710500 lbs
Tender Water Capacity	15000 gals	15000 gals	15000 gals	15500 gals	15200 gals
Tender Fuel Capacity (oil/coal)	18 tons	21 tons	28 tons	43 tons	42 tons
Minimum weight per yard of rail on which locomotive could run	97.50 lb rail	100.83 lb rail	103.12 lb rail	110.18 lb rail	111.04 lb rail
	Geometry Relating to Tractive Effort
Driver Diameter	69"	69"	69"	69"	72"
Boiler Pressure	190 psi	225 psi	225 psi	250 psi	250 psi
Cylinders (dia x stroke)	28" x 28"	27" x 30"	27" x 30"	25.5" x 30"	26" x 30"
Tractive Effort	51380 lbs	60618 lbs	60618 lbs	60077 lbs	59854 lbs
Factor of Adhesion (Weight on Drivers/Tractive Effort)	4.55	3.99	4.08	4.40	4.45
	Heating Ability
Firebox Area	320 sq. ft	354 sq. ft	345 sq. ft	373 sq. ft	373 sq. ft
Grate Area	66.80 sq. ft	75.35 sq. ft	75.30 sq. ft	75.30 sq. ft	75.30 sq. ft
Evaporative Heating Surface	4430	4646	4556	4676	4676
Superheating Surface	1212	1938	1931	2082	2082
Combined Heating Surface	5642	6584	6487	6758	6758
Evaporative Heating Surface/Cylinder Volume	222.00	233.70	229.17	263.69	253.65
	Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation	12692	16953.75	16942.50	18825	18825
Same as above plus superheater percentage	15418.46	21944.09	21985.81	24624.59	24624.59
Same as above but substitute firebox area for grate area	73860.90	103094.97	100731.81	121978.40	121978.40
Power L1	18546.56	31051.99	30794.29	40984.53	41137.42
Power MT	698.94	1131.53	1097.21	1366.74	1361.24