e locomotives are of the Bo-Bo type having a designed weight in working order
of 75 tons. Each locomotive is of the full width body type with a driving cab at each
end. It has multiple unit equipment enabling it to operate in multiple, not only with
locomotives of the same design but with all locomotives for the British Railways
modernisation scheme equipped with BTH, Crompton-Parkinson or English Electric
electrical equipment. is feature, the result of co-ordination with other rms, should
be a great aid to the exibility of British Railways operating arrangements.
The principal data of the locomotives
Wheel arrangement .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. Bo-Bo
Maximum weight in working order. .. .. .. .. .. .. .. .. .. .. .. 75 tons
Maximum axle load in working order. .. .. .. .. .. .. .. .. .. .. 18¾ tons
Diesel Engine HP at continuous rating .. .. .. .. .. .. .. .. .. .. 1,160 hp at 750 r.p.m.
Maximum tractive eort .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 40,000 lbs.
Continuous tractive eort.. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 21,300 lbs.
Speed at continuous tractive eort and full engine output .. .. 15 mph
Maximum speed.. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 75 mph
Driving wheel diameter.. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 45 inches
Length over buers. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 50 6 inches
Distance between bogie centres .. .. .. .. .. .. .. .. .. .. .. .. .. 28
Bogie wheel base . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 8 6 inches
Fuel oil capacity (engine and boiler) .. .. .. .. .. .. .. .. .. .. .. 630 galls.
Water capacity for boiler .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 600 galls.
Locomotive Structure
In order to achieve a light construction, the weight carrying properties of the vehicle
are shared between the underframe and a girder structure to which the body sides are
attached. Bung and draw loads, however, have not been neglected and the
underframe is designed for bung loads of 200 tons. In the rst place, the locomotives
are being tted with double buers and a central screw-link coupling. Provision,
however, has been made for the later addition of automatic central couplers.
e underframe consists of two longitudinals, each consisting of two standard
channel sections. ese channel sections are placed back to back and the intervening
space is covered top and bottom by plates, so forming ducts for the traction motor
ventilating air, thereby avoiding fragile sheet metal ducts and considerably simplifying
the underframe arrangement.
e longitudinals form the foundation for the four-point mounting of the engine
generator set. ey are tied together by the two main transoms which carry the bogie
pivots and by other substantial members. e side girder frames are axed to these
transoms and tied together at the top by steel sections which also form the roof
framing. Cables and pipework have been kept away from each other on opposite sides
of the locomotive. e cables are laid in a duct outside the main longitudinal member
and this duct is covered in on all sides. e pipework is tted in a similar manner.
Despite the presence of the side girder structures, access to the interior is
satisfactory. Due to the slim in-line engine, there is provision for moving from end to
end of the locomotive on both sides of the diesel engine, and inspection doors are
tted on each side of the engine room to facilitate handling of equipment at overhauls
such as exchange of fuel injectors, lter elements and so forth.
For major overhauls, there is a large removable section of the roof through which
a complete engine generator set can be installed and removed. is section has a
small hatch for removal of engine cylinder heads and pistons, and there are also
smaller hatches through which the boiler auxiliary equipment and control gear can
be installed or removed.
A sealing plate tted to the underframe receives any leakage from the engine
room or boiler compartment. is drains into a centrally placed spillage tank, which
may be emptied from time to time. In addition, clean fuel spillage is kept completely
separate and is ducted back to the main fuel tank.
All air coming into the engine room is ltered through 2-inch deep Air Maze
lters located in the body sides. e whole of the engine room therefore becomes
a clean air compartment from which air is drawn for the traction motor blowers,
engine, main generator and all auxiliary equipment. In addition to the engine
room ltration, which is of a type designed for low air resistance despite severe
contamination, the engine has its own high eciency lter of the Vokes oil wetted,
bonded hair type. In accordance with the usual method adopted by Sulzer, the hot air
exhausting from the generator is expelled downwards out of the engine room so that
SLW Class 24 Operating Manual Page 11Page 10 SLW Class 24 Operating Manual
