New York Central class L-2 “Mohawk”
After the 185 “Mohawks” of the L-1 class, the New York Central developed the more powerful L-2 class. It was also intended purely for freight service, but had a larger boiler, a feedwater heater and a booster on the trailing axle. The driver diameter remained at 69 inches or 1,753 mm and allowed a maximum permitted speed of 60 mph or 97 km/h.
Production began in 1925 at ALCO in Schenectady with 100 locomotives of the subclass L-2a. Further subclasses up to the L-2d all also came from Schenectady and brought the number to a total of 300 by 1930. They differed in the boiler dimensions, wheelbases and the feedwater heater used, which could be of the Elasco, Worthington or Coffin types.
In 1939, two L-2d were converted as prototypes for the L-3 for mixed service. These were intended to achieve higher speeds without requiring larger drivers. Thanks to roller bearings on the axles, cylinders with a smaller diameter and a higher boiler pressure, they could be approved for speeds of 80 mph.
Technical data
General
| Property | L-2a | L-2b, d | L-2c | L-2d prototype for L-3 |
|---|---|---|---|---|
| Built | 1925-1925 | 1929-1930 | 1929 | 1939 |
| Manufacturers | ALCO | New York Central | ||
| Wheel arrangement | 4-8-2 (Mountain) | |||
| Gauge | 1,435 mm (Standard gauge) | |||
Dimensions and weights
| Property | L-2a | L-2b, d | L-2c | L-2d prototype for L-3 |
|---|---|---|---|---|
| Wheelbase | 12.80 m | 12.83 m | 12.80 m | |
| Total wheelbase | 25.78 m | 25.81 m | 25.78 m | |
| Service mass | 164.4 t | 167.1 t | 165.6 t | 174.7 t |
| Adhesion mass | 109.8 t | 112.3 t | 111.1 t | 116.6 t |
| Total mass | 293.1 t | 309 t | 306.2 t | 316.9 t |
| Rigid wheelbase | 5.49 m | |||
| Axle load | 27.4 t | 28.1 t | 27.8 t | 29.1 t |
| Water capacity | 56,781 l | |||
| Fuel capacity | 19.1 t (coal) | 25.4 t (coal) | 19.1 t (coal) | 25.4 t (coal) |
Boiler
| Property | L-2a | L-2b, d | L-2c | L-2d prototype for L-3 |
|---|---|---|---|---|
| Grate area | 7 m² | 6.996 m² | ||
| Firebox surface | 32.888 m² | 32.052 m² | 32.888 m² | |
| Tube heating surface | 380.81 m² | 391.215 m² | 390.379 m² | 398.74 m² |
| Evaporative heating surface | 413.698 m² | 423.267 m² | 431.628 m² | |
| Superheater surface | 180.046 m² | 179.396 m² | ||
| Total heating surface | 593.7 m² | 602.7 m² | 611.0 m² | |
Power plant
| Property | L-2a | L-2b, d | L-2c | L-2d prototype for L-3 |
|---|---|---|---|---|
| Driver diameter | 1,753 mm | |||
| Boiler pressure | 15.5 bar | 17.2 bar | ||
| Expansion type | simple expansion | |||
| Cylinders | two, 686 x 762 mm | two, 648 x 762 mm | ||
Power
| Property | L-2a | L-2b, d | L-2c | L-2d prototype for L-3 |
|---|---|---|---|---|
| Power source | steam | |||
| Estimated power | 2,834 kW (3,853 PS) | 3,207 kW (4,360 PS) | ||
| Top speed | 97 km/h | 129 km/h | ||
| Starting effort | 269.6 kN | 267.2 kN | ||
| Starting effort booster | 55.158 kN | 61.163 kN | ||
Calculated values
| Property | L-2a | L-2b, d | L-2c | L-2d prototype for L-3 |
|---|---|---|---|---|
| Factor of adhesion | 1 : 3.99 | 1 : 4.08 | 1 : 4.04 | 1 : 4.28 |
| Optimal speed | 64 km/h | 74 km/h | ||
| Power-to-weight ratio | 17.2 kW/t | 17.0 kW/t | 17.1 kW/t | 18.4 kW/t |
| Heating Surface Equivalent | 938.2 m² | 942.3 m² | 946.5 m² | 954.9 m² |
| Cylinder volume/HSE | 1 : 600.01 | 1 : 597.41 | 1 : 594.77 | 1 : 525.88 |
| Adhesive weight/Total | 1 : 1.50 | 1 : 1.49 | 1 : 1.50 | |
| Tractive force/Heating surface | 1 : 9.48 | 1 : 9.34 | 1 : 9.13 | |
| Grate area/Heating surface | 1 : 84.82 | 1 : 86.09 | 1 : 87.34 | |
| Firebox/Tube surface | 1 : 11.58 | 1 : 12.21 | 1 : 11.87 | 1 : 12.12 |
| Total/Superheater | 1 : 2.30 | 1 : 2.36 | 1 : 2.41 | |
