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was rather outdated by 1940 but probably stems from the use of the stored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 https://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.
Above: 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.
Technical
information:
Steam
pressure: 180 lbs
Cylinders: 12in x 15in
Tractive effort:9,720 lbs (at
85% boiler pressure)
Wheel diameter: 2' 10"
Coupled wheelbase 6' 0"
Weight in working order: 26 tons
Water capacity: 450 gallons
Coal capacity: 15 cu ft
Above:
Below:
A well polished worksplate on RSH 0-4-0CT "Roker"
