James Cross and Co: White Raven
Note, this is a sub-section of James Cross and Co
The White Raven was built by James Cross, for the St. Helen's Railway, but before being placed in regular service, was tried on the North London Railway. It was completed in 1863, so the construction should probably by credited to the St Helens Railway rather than to James Cross and Co.
In addition to the radial axle-boxes, the engine was fitted with the Adams patented spring tires. Between the rim of the wheel and the tire, which was of Krupp steel, a steel hoop spring was placed round the wheel, with the object of making the tire fit the wheel elastically, being neither too loose, or too tight. Mr Adams considered this the safest form of tire, as it had no tendency to burst; it had sufficient yield to minimise the effect of blows, and was pliant enough to case better adhesion between tire and rail.
The radial axles were the locomotive's principal feature. In the White Raven each radial axle-box had a lateral movement of 4.5 in each side and the radii of curvature were struck from the centre of the nearest coupled axle; in this case 7ft distant.
The engine was too flexible, with a tendency to excessive lateral oscillation. It came into possession of the London and North Western Railway when the latter absorbed the St Helen's Railway in 1867, and a few years later, the radial axle-boxes were removed and the engine was converted into a 2-4-0 tender engine with rigid leading axle.[1]
Account from 'The Evolution of the Steam Locomotive (1803-1898)'
'We have on previous occasions referred to the improvements in locomotive construction introduced by Mr. W. Bridges Adams, and we now have again to record a successful employment of his design. [See James Cross and Co: White Raven ]. In the first week of November, 1863, Mr. James Cross, locomotive engineer of the St. Helens Railway, completed a tank locomotive, supported on eight wheels, the leading and trailing pairs of which were fitted with the radial axle boxes patented by Mr. W. B. Adams; whilst the four coupled wheels were fitted with spring tyres, which were another invention of the same engineer.
'The St. Helens Railway was famous or, from an, engineer's point of view, we should say, perhaps, infamous for the severe gradients, sharp curves, and numerous points, crossings, and junctions. The inclines were as steep as 1 in 35, 1 in 70, and 1 in 85, whilst the curves were constructed with radii of 300ft, and 500ft., and reverse or S curves were also more frequent than pleasant. The St. Helens Railway was only 30 miles long, but within two miles of the St. Helens Station no less than 12 miles of sidings were located. We do not mean to suggest that the whole line of railway was so thickly covered with siding connections, but such were distributed over the remaining mileage of the railway in too plentiful profusion. Here, then, was a length of railway containing the three great hindrances to smooth and quick running, but the locomotive about to be described was so constructed as to successfully overcome these impediments.
'This engine had inside cylinders, 15in. diameter and 20in. stroke. The coupled wheels were 5ft. 1in. in diameter, the rigid wheel base being 8ft., but as these wheels had spring tyres, each pair of wheels was practically as free to traverse the curves as uncoupled wheels. Other dimensions were: Heating surface, 687 sq. ft.; grate area, 16.25 sq. ft.; total wheel base, 22ft.; weight in working order, on leading wheels, 7 tons 15 cwt. ; on driving, 11¾ tons; on rear coupled, 11¼ tons; on trailing, 10 tons, including 4¼ tons water and 1¼ tons coal. Total weight, 40¾ tons.
'The boiler contained 121 tubes, 10ft. 11in. long, and 1½ in. diameter; steam pressure, 140lb. ; water capacity of tank, 950 gallons. The fire-grate was 5ft. long, and sloped from the door to the tube- plate. The springs of the coupled wheels were connected by means o a compensation lever. The dome was placed on the raised fire-box and fitted with a screw-down safety valve; a second valve of the same pattern was fixed on the boiler barrel. A roomy and well-enclosed cab, fitted with side windows, thoroughly protected the enginemen.' [2]