GWR Dean experimental locomotives

During the 1880s William Dean constructed a series of experimental locomotives to test various new ideas in locomotive construction for the Great Western Railway.

Locomotives

No. 1

This locomotive appeared in 1880 as a 4-4-0T, but was rebuilt in 1882 as a 2-4-0T. It was withdrawn in 1924.

No. 7

Number 7 was built in 1886 as a compound 2-4-0 and later rebuilt as a 4-4-0.

No. 8

Number 8 was built in 1886 as a broad gauge 2-4-0 compound, the low- and high-pressure cylinders sharing a common crosshead. It had 7 ft 0½ in driving wheels and a high-pressure boiler rated at 180 lbf/in² (1.24 MPa). Unsuccessful in its trials, it was never taken into stock. In 1894 it reappeared as a conventional standard gauge 4-4-0.

No. 9

This number started out in 1881 on a 4-2-4T, the only tank locomotive built by the Great Western Railway with single driving wheels (though not the only tank locomotive operated by the Great Western, which inherited some from the Bristol and Exeter Railway), these being 7 ft 8 in diameter and had unusually large 18 in × 26 in cylinders. It did little work as it was prone to derailing, indeed it did this in front of William Dean on its first trial move out of the shed.

In 1884 it was rebuilt as a strange-looking 2-2-2 tender locomotive with outside Stephenson's valve gear. In 1890 it was rebuilt with more conventional double frames and inside valve gear similar in style to the Queen Class. In this guise it was named "Victoria" in honour of Queen Victoria.

No. 10

A 2-2-2 locomotive that, as with number 9, was eventually rebuilt to be similar to the Queen class. In this latter guise it was named "Royal Albert" in honour of Price Albert, husband of Queen Victoria.

No. 13

Tank locomotive number 13 first appeared in 1886 as a 2-4-2WT. In this form it worked on the St Ives branch and also on the Watlington branch.

In 1897 it was rebuilt. The large bunker and rear water tank was reduced which allowed the rear carrying wheels to be removed, instead a saddle tank was fitted and the front of the frames extended to allow the fitting of a bogie truck, thus becoming a 4-4-0ST. It continued to work on various branch lines, being loaned to the Liskeard and Looe Railway and later continuing to work on the Looe branch. It was also recorded on the Highworth and Brixham branches, and working in the Plymouth area, before finally moving to Swindon from where it as withdrawn in 1926.

No.s 14 and 16

Two rather more conventional 2-4-0 express locomotives were turned out in 1888 and ran on the broad gauge. They were similar to the standard gauge 3206 Class "Barnum"'s turned out in 1889 but with large 7 ft 0½ in driving wheels.

Following the abolition of the broad gauge in 1892 they were renewed, reappearing as standard gauge 4-4-0 locomotives in 1894.

References

*
*
*