Great Western Railway class 2601 and 2602 “Kruger”
In 1899, Swindon built two mixed-traffic prototypes designed by William Dean. While number 2601 was a 4-6-0, number 2602 was a 2-6-0. Their rugged design was likely influenced by Churchward and their main feature were the large outside plate frames, concealing part of the driving wheels which measured four feet and seven and a half inches. The cylinders had a small diameter of 19 inches and a long stroke of 28 inches to fit between the frames. Their boilers had a Belpaire firebox with a combustion chamber and were pressed to 180 psi. Above the front part of the boiler, there was a saddle-shaped sandbox.
Eight more locomotives were built with a 2-6-0 wheel arrangement and were numbered 2603 to 2610. They were nicknamed the Kruger class, after the South African Boer War leader Paul Kruger. Altogether the class was not very successful, with unsatisfying boiler performance and frequent fractures in the crank axles due to the long stroke. 2601 was already scrapped in 1904 as its wheel arrangement differed from the others. Most of the 2-6-0 locomotives had been withdrawn by 1906. At the same time, Dean had designed its Aberdare class and he re-used the numbers of the withdrawn locomotives for this class, possibly while re-using some parts of these locomotives.
Technical data
General
| Property | 2601 | 2602-2610 |
|---|---|---|
| Built | 1899 | 1899-1903 |
| Manufacturers | Swindon | |
| Wheel arrangement | 4-6-0 (Ten-wheeler) | 2-6-0 (Mogul) |
| Gauge | 1,435 mm (Standard gauge) | |
Dimensions and weights
| Property | 2601 | 2602-2610 |
|---|---|---|
| Wheelbase | 7.62 m | 6.86 m |
| Total wheelbase | 15.24 m | 13.92 m |
| Service mass | 64.8 t | 61.4 t |
| Adhesion mass | 52.3 t | 52.6 t |
| Total mass | 102.2 t | 98.7 t |
| Rigid wheelbase | 4.57 m | |
| Axle load | 18.3 t | 17.8 t |
| Water capacity | 13,639 l | |
| Empty mass | 56.1 t | |
Boiler
| Property | 2601 | 2602-2610 |
|---|---|---|
| Grate area | 2.991 m² | 2.903 m² |
| Firebox surface | 15.496 m² | 11.882 m² |
| Tube heating surface | 159.162 m² | 167.699 m² |
| Evaporative heating surface | 174.658 m² | 179.582 m² |
| Total heating surface | 174.7 m² | 179.6 m² |
Power plant
| Property | 2601 | 2602-2610 |
|---|---|---|
| Driver diameter | 1,410 mm | |
| Boiler pressure | 12.4 bar | |
| Expansion type | simple expansion | |
| Cylinders | two, 483 x 711 mm | |
Power
| Property | 2601 | 2602-2610 |
|---|---|---|
| Power source | steam | |
| Estimated power | 708 kW (963 PS) | |
| Starting effort | 123.9 kN | |
Calculated values
| Property | 2601 | 2602-2610 |
|---|---|---|
| Factor of adhesion | 1 : 4.14 | 1 : 4.17 |
| Optimal speed | 35 km/h | |
| Power-to-weight ratio | 10.9 kW/t | 11.5 kW/t |
| Heating Surface Equivalent | 252.1 m² | 239.0 m² |
| Cylinder volume/HSE | 1 : 1,031.92 | 1 : 1,088.69 |
| Adhesive weight/Total | 1 : 1.24 | 1 : 1.17 |
| Tractive force/Heating surface | 1 : 14.82 | 1 : 14.42 |
| Grate area/Heating surface | 1 : 58.39 | 1 : 61.86 |
| Firebox/Tube surface | 1 : 10.27 | 1 : 14.11 |