Midland class 1000
London, Midland & Scottish class 4P
In 1902, the Midland Railway had five express locomotives built, numbered 2631 to 2635, designed by Samuel Waite Johnson. The special feature was the power plant, which consisted of three cylinders with compound action. The high-pressure cylinder was below the smoke box, while the low-pressure cylinders were on the outside and got their steam from a common receiver. All three cylinders acted on the first driving axle.
From 1905, Johnson's successor Richard Deeley had 30 more built, which were initially numbered 1000 to 1029. They had some simplifications, especially in the area of valve gear. In 1907, the first five were renumbered 1000 through 1004, while the locomotives from the second batch were numbered 1005 through 1029. Ten more followed in 1908 and 1909, bringing the total to 45.
With train weights typically ranging from 250 to 300 long tons, the locomotives reached average speeds in excess of 50 mph. On the incline between Settle and Carlisle, it was now possible to do without double-heading in some cases, while speeds of up to 85 mph could be run downhill. They were superheated from 1914, saving 25.9 and 22.3 percent on coal and water, respectively. All 45 survived the formation of British Railways, but by 1953 all were gone.
Technical data
General
| Property | No. 2631-2635 | No. 1000 etc. | superheated |
|---|---|---|---|
| Built | 1902 | 1902-1909 | 1914 |
| Manufacturers | Derby | ||
| Wheel arrangement | 4-4-0 (American) | ||
| Gauge | 1,435 mm (Standard gauge) | ||
Dimensions and weights
| Property | No. 2631-2635 | No. 1000 etc. | superheated |
|---|---|---|---|
| Length | 18.54 m | ||
| Wheelbase | 7.39 m | ||
| Total wheelbase | 14.71 m | ||
| Empty mass | 55.2 t | ||
| Service mass | 59.5 t | 60.9 t | |
| Adhesion mass | 38.9 t | 39.7 t | |
| Total mass | 113.5 t | 104 t | |
| Rigid wheelbase | 2.92 m | ||
| Water capacity | 15,910 l | ||
| Fuel capacity | 7.8 t (coal) | 6.1 t (coal) | |
Boiler
| Property | No. 2631-2635 | No. 1000 etc. | superheated |
|---|---|---|---|
| Grate area | 2.638 m² | 2.64 m² | |
| Firebox surface | 14.196 m² | 14.2 m² | 14.03 m² |
| Tube heating surface | 121.257 m² | 132 m² | 108.7 m² |
| Evaporative heating surface | 135.453 m² | 146.2 m² | 122.73 m² |
| Total heating surface | 135.5 m² | 146.2 m² | 149.7 m² |
| Superheater surface | 26.94 m² | ||
Power plant
| Property | No. 2631-2635 | No. 1000 etc. | superheated |
|---|---|---|---|
| Driver diameter | 2,134 mm | ||
| Boiler pressure | 13.4 bar | 15.2 bar | |
| Expansion type | compound | ||
| Cylinders | three, HP: 483 x 660 mm and LP: 533 x 660 mm | ||
Power
| Property | No. 2631-2635 | No. 1000 etc. | superheated |
|---|---|---|---|
| Power source | steam | ||
| Estimated power | 671 kW (912 PS) | 708 kW (963 PS) | 932 kW (1,267 PS) |
| Starting effort | 68.0 kN | 76.7 kN | |
| Starting effort simple | 81.5 kN | 92.0 kN | |
Calculated values
| Property | No. 2631-2635 | No. 1000 etc. | superheated |
|---|---|---|---|
| Factor of adhesion | 1 : 5.61 | 1 : 4.97 | 1 : 5.08 |
| Optimal speed | 61 km/h | 56 km/h | 74 km/h |
| Power-to-weight ratio | 11.3 kW/t | 11.9 kW/t | 15.3 kW/t |
| Heating Surface Equivalent | 206.4 m² | 217.2 m² | 246.8 m² |
| Cylinder volume/HSE | 1 : 1,413.92 | 1 : 1,343.83 | 1 : 1,182.85 |
| Adhesive weight/Total | 1 : 1.53 | ||
| Tractive force/Heating surface | 1 : 10.48 | 1 : 10.95 | 1 : 10.70 |
| Grate area/Heating surface | 1 : 51.35 | 1 : 55.38 | 1 : 56.69 |
| Firebox/Tube surface | 1 : 8.54 | 1 : 9.30 | 1 : 7.75 |
| Total/Superheater | 1 : 4.56 | ||