Chesapeake & Ohio class L-2
The class L-2 Hudsons of the Chesapeake & Ohio were 4-6-4 express locomotives introduced in 1942 to haul the fastest trains on level routes. They had to haul 15-car trains at 90 mph or 145 km/h. Trains on mountainous routes were already hauled by the “Greenbrier” 4-8-4 which had been introduced in 1935.
Their features included 78 inch (1,981 mm) drivers and a large 255 psi (17.6 bars) boiler with thermic syphons and an Elesco feed water heater. All axles of the locomotive and even the side rods had roller bearings. The Franklin type E booster was a special express variant that allowed operation up to 33 mph or 53 km/h.
The original class L-2 consisted of eight locomotives built in December 1941 and the following January. In 1948, five more of a revised design followed as L-2a. They had Franklin rotary cam poppet valves instead of piston valves and were the last steam express locomotives any US railroad purchased. After only a short career, they were scrapped in 1953.
Technical data
General
| Property | L-2 | L-2a |
|---|---|---|
| Built | 1941-1942 | 1948 |
| Manufacturers | Baldwin | |
| Wheel arrangement | 4-6-4 (Hudson) | |
| Gauge | 1,435 mm (Standard gauge) | |
Dimensions and weights
| Property | L-2 | L-2a |
|---|---|---|
| Wheelbase | 12.64 m | |
| Total wheelbase | 27.95 m | |
| Service mass | 199.4 t | 200.9 t |
| Adhesion mass | 98.7 t | 99.6 t |
| Total mass | 377.6 t | 379.2 t |
| Rigid wheelbase | 4.27 m | |
| Axle load | 32.9 t | 33.2 t |
| Water capacity | 79,494 l | |
| Fuel capacity | 27.2 t (coal) | |
Boiler
| Property | L-2 | L-2a |
|---|---|---|
| Grate area | 8.361 m² | 8.38 m² |
| Firebox surface | 42.735 m² | 37.626 m² |
| Tube heating surface | 350.524 m² | |
| Evaporative heating surface | 393.259 m² | 388.149 m² |
| Superheater surface | 168.155 m² | 165.832 m² |
| Total heating surface | 561.4 m² | 554.0 m² |
Power plant
| Property | L-2 | L-2a |
|---|---|---|
| Driver diameter | 1,981 mm | |
| Boiler pressure | 17.6 bar | |
| Expansion type | simple expansion | |
| Cylinders | two, 635 x 762 mm | |
Power
| Property | L-2 | L-2a |
|---|---|---|
| Power source | steam | |
| Estimated power | 3,281 kW (4,461 PS) | 3,244 kW (4,411 PS) |
| Starting effort | 231.8 kN | |
| Starting effort booster | 56.048 kN | 63.165 kN |
Calculated values
| Property | L-2 | L-2a |
|---|---|---|
| Factor of adhesion | 1 : 4.18 | 1 : 4.21 |
| Optimal speed | 87 km/h | 85 km/h |
| Power-to-weight ratio | 16.5 kW/t | 16.1 kW/t |
| Heating Surface Equivalent | 943.2 m² | 907.9 m² |
| Cylinder volume/HSE | 1 : 511.68 | 1 : 531.57 |
| Adhesive weight/Total | 1 : 2.02 | |
| Tractive force/Heating surface | 1 : 8.62 | 1 : 8.74 |
| Grate area/Heating surface | 1 : 67.15 | 1 : 66.11 |
| Firebox/Tube surface | 1 : 8.20 | 1 : 9.32 |
| Total/Superheater | 1 : 2.34 | |