The reference for locomotives and railcars
Great Western Railway class 3031 “Achilles” / “Dean Single”
Great Britain | 1894 | 30 produced
Nr. 3046 “Lord of the Isles”
Nr. 3046 “Lord of the Isles”
Locomotive Magazine, January 1899

The Class 3031 of the Great Western Railway, also known as the “Dean Single”, was created from the conversion of 30 examples of the Class 3001, which had been built by William Dean in the 7 feet 1/4 inch broad gauge and were converted to standard gauge a short time later. Since an increase in power through a wider boiler was impossible with the standard gauge due to the limited space between the large wheels, the boiler was extended to the front. After the leading axle derailed in the middle of the box tunnel due to the increased weight, it was replaced with a bogie, resulting in the class 3031. Since the cylinders were located below the smoke box in class 3001, a special bogie had to be constructed. This could be pulled out after loosening four screws and slightly lifting the front part of the locomotive to ensure uncomplicated maintenance of the smoke box and cylinders.

No. 3050 “Royal Sovereign”
No. 3050 “Royal Sovereign”
J.R. Howden, The Boys' Book of Locomotives

First, two class 3001 locomotives were converted in March 1894, the remaining 28 were converted between June and December of the same year. A total of 50 more were factory built between 1894 and 1899. In use, the class 3031, like other locomotives with a 4-2-2 wheel arrangement, excelled with high sustained speeds. On May 9, 1904, a mail train was able to travel the 117 miles from Bristol to London-Paddington in just under 100 minutes for the first time, which corresponds to an average speed of around 70 mph. However, since one driven axle was soon no longer sufficient, they were decommissioned between 1908 and 1915. Today there is a replica of No. 3041 “The Queen”, which was completed in 1982.

Axle config4-2-2 (Single) 
Gauge4 ft 8 1/2 in (Standard gauge)
Dimensions and Weights
Wheelbase23 ft 6 in
Fixed wheelbase9 ft
Service weight109,760 lbs
Adhesive weight40,320 lbs
Total weight182,560 lbs
Axle load40,320 lbs
Water capacity4,323 us gal
Fuel capacitycoal
Power sourcesteam
Estimated power725 hp (541 kW)
Optimal speed36 mph
Starting effort12,738 lbf
Power Plant
Driver diameter92.5 in
Boiler pressure160 psi
Expansion typesimple
Cylinderstwo, 19 x 24 in
Grate area20.8 sq ft
Firebox area127 sq ft
Tube heating area1,434 sq ft
Evaporative heating area1,561 sq ft
Total heating area1,561 sq ft
Calculated Values
steam locomotive
William Dean
last changed: 02/2022

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