London & North Eastern class P1
The LNER originally planned a locomotive with a 2-10-0 wheel arrangement as a more powerful successor to the GNR Class O2. Ultimately, the two class P1 locomotives were built in 1925 and had the wheel arrangement 2-8-2. To increase tractive power, they had three cylinders and an additional booster on the trailing axle. The tractive power was sufficient for trains with 100 coal cars, but due to their length they caused problems in the operational process and meant that there was no series production. Because the boosters consumed too much coal and steam was leaking into the cab, they were removed in 1937 and 1938. In 1942 both locomotives were rebuilt to class P1/2, with smaller cylinders and higher boiler pressure. Immediately after the end of the Second World War, they were scrapped because the decline in freight traffic meant that there couldn't be found another area of use.
Technical data
General
| Property | P1/1 with booster | P1/2 |
|---|---|---|
| Built | 1925 | 1942, 1943 |
| Manufacturers | Doncaster | |
| Wheel arrangement | 2-8-2 (Mikado) | |
| Gauge | 1,435 mm (Standard gauge) | |
Dimensions and weights
| Property | P1/1 with booster | P1/2 |
|---|---|---|
| Wheelbase | 11.02 m | |
| Service mass | 101.6 t | |
| Adhesion mass | 72.6 t | |
| Total mass | 153.9 t | |
| Rigid wheelbase | 5.64 m | |
| Axle load | 18.7 t | |
| Water capacity | 21,365 l | |
| Fuel capacity | 7.1 t (coal) | |
Boiler
| Property | P1/1 with booster | P1/2 |
|---|---|---|
| Grate area | 3.832 m² | |
| Firebox surface | 19.974 m² | |
| Tube heating surface | 252.232 m² | |
| Evaporative heating surface | 272.206 m² | |
| Superheater surface | 48.774 m² | |
| Total heating surface | 321.0 m² | |
Power plant
| Property | P1/1 with booster | P1/2 |
|---|---|---|
| Driver diameter | 1,575 mm | |
| Boiler pressure | 12.4 bar | 15.2 bar |
| Expansion type | simple expansion | |
| Cylinders | three, 508 x 660 mm | three, 483 x 660 mm |
Power
| Property | P1/1 with booster | P1/2 |
|---|---|---|
| Power source | steam | |
| Estimated power | 1,193 kW (1,622 PS) | 1,491 kW (2,027 PS) |
| Starting effort | 171.2 kN | 188.9 kN |
| Starting effort booster | 42.258 kN | |
Calculated values
| Property | P1/1 with booster | P1/2 |
|---|---|---|
| Factor of adhesion | 1 : 4.16 | 1 : 3.77 |
| Optimal speed | 42 km/h | 48 km/h |
| Power-to-weight ratio | 11.7 kW/t | 14.7 kW/t |
| Heating Surface Equivalent | 469.6 m² | |
| Cylinder volume/HSE | 1 : 855.06 | 1 : 771.69 |
| Adhesive weight/Total | 1 : 1.40 | |
| Tractive force/Heating surface | 1 : 11.14 | 1 : 12.29 |
| Grate area/Heating surface | 1 : 83.76 | |
| Firebox/Tube surface | 1 : 12.63 | |
| Total/Superheater | 1 : 5.58 | |