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Robert Stephenson & Hawthorn 0-4-0 side tank with crane, number 7006 "Roker"
Above: "Roker" in steam at Foxfield Colliery in the 1970s
A fleet of crane tank locomotives was used at the shipbuilding yard of William Doxford & Sons Ltd in Sunderland, and four of the later survivors still exist in preservation. This unusual locomotive makes an interesting contrast with the Dubs 0-4-0 crane tank number 4101 from Shelton Steelworks.
"Roker" followed the design of a much earlier locomotive built by Hawthorn Leslie in 1902, number 2517 "Pallion", and was delivered to the yard in June 1940 at a time when shipbuilding was in great demand. An identical locomotive named "Hendon" was delivered at the same time, and it is believed that the pair were constructed by Robert Stephenson & Hawthorn using unassembled parts that had been in store for 22 years following a cancelled order from overseas. The crane tanks were designed for lifting steel plate and other materials as well as shunting wagons around the shipyard. The hooks on the steam crane jib are fixed and not attached to a rope; indeed the design uses no cables or gearing at all. There are three hooks attached to the jib at different radii which allow the crane to lift varying weights: 1 ton at 20' radius, 1.5 tons at 15' radius and 2 tons at 12' radius. A vertical lifting cylinder is incorporated into the crane structure and its piston is connected to the end of the jib. Steam at full pressure is always maintained on the upper side of the piston, and pressure on the underside is controlled from the cab. The jib is pivoted at a point on the forward end of the crane structure and, with full pressure on the underside, the piston is in equilibrium and the weight on the jib causes it to drop. When steam is exhausted from the underside, the full boiler pressure on the top of the piston causes it to rise. A two-cylinder engine is provided to slew the jib through 360 degrees. The crane jib fits neatly over the locomotives long tapered chimney when not in use, although it substantially overhangs the front of the locomotive. Very large dumb buffers and a modified version of Joy's valve gear are other characteristic features of the design. The choice of Joy valvegear was rather outdated by 1940 but probably stems from the use of the stored parts mentioned above.
"Roker" and its stablemates were housed in a five road locomotive shed and all carried a mid green livery lined in black, edged in yellow with fluted corners. The buffer beams and valvegear were red. For some colour pictures of "Roker" and "Hendon" at work at Doxford's yard see http://www.cirsel.freeserve.co.uk/Doxford.htm. They worked in the yard until replaced by road cranes in 1971, "Roker" being withdrawn in January. "Roker" was bought from a scrap merchant in Surrey for a private railway collection at the JCB works at Rocester in February 1974 in the company of the much older example "Pallion". They did not stay long as fortunately "Roker" was sold on, travelling by road to the Foxfield Railway in mid July 1974, while "Pallion" was unfortunately scrapped a few weeks later.
"Roker" has been steamed at Foxfield and proved useful for small lifting
jobs. It was particularly useful during a relaying of Cresswell Ford level
crossing in 1976, but now awaits a major overhaul. "Roker" is on permanent
static display in the museum building at Caverswall Road station but is
occasionally hauled outside for special events. In summer 2004 "Roker"
left the railway for a couple of weeks to take part in a filming assignment
in Liverpool, returning to Foxfield on 24 August. The loco was repainted
in lined maroon livery during winter 2004/05.
Repainting of "Roker" underway in the museum at Caverswall Road, 3 April 2005
"Roker"s sister engine "Hendon" (7007/1940) is preserved at the Tanfield Railway.
The other two Doxford crane tanks which survive in preservation are "Southwick" (7069/1942) at the Keighley & Worth Valley Railway and "Millfield" (7070/1942) at Bressingham Steam Museum.
pressure: 180 lbs
A comparison of "Roker" and "Dubsy" at Caverswall Road station
Below: A well polished worksplate on RSH 0-4-0CT "Roker"
|For more information on the Foxfield Steam Railway, its passenger services and special events please see the official website at http://www.foxfieldrailway.co.uk.|