Lion locomotive

The Sulzer 12LDA28-C engine. It was a further development of the 2500bhp 12LDA28-B model. The output was increased to 27500bhp by improved intercooling and raising the crankshaft sped to 800rpm with a slightly increased b.e.e.p. of 168 psi. The connecting rod and big end bearings were also redesigned.
The full load crankshaft speed of 800rpm was raised by a synchronizing gear step-up to 1150rpm on the output shaft driving the three tandem arranged AEI generators. The traction generator, incorporated a special field winding, and the heating generator were housed in a common frame from which was overhung the auxiliary generator. All three machines were insulated with silicone treated materials to BS 173 Class H.
This type of engine was built by Vickers-Armstrong (Engineers) Ltd., Barrow.

Auxiliary equipment such as the exhausters and blowers were as far as possible grouped in the form of self contained sub assemblies for ease of removal for overhaul. The first auxiliary group was situated at one end of the locomotive below the radiator unit and consists of the air compressor, a traction motor blower, the combined pump set, and the engine instrument panel. The second group of auxiliaries was at the other end of the locomotive and consisted of the other traction motor blower and two exhauster sets. Above both the auxiliary units were mounted the break equipment cubicles containing most of the break system components.

The control system was based on that successfully used on many B.R. Type 2 locomotives, but adapted for the Lion.
The 800 volt train heating generator supply was also used to power radiator fans, traction motor blowers, and provide traction generator excitation. In line with standard British Railways practice the diesel engine speed was controlled by variations of air pressure activated by the master controller power handle. To give extra power for acceleration the power used for train heating could be transferred to the traction motors.

A full width cab located at each end of the locomotive was fitted with large windows of gold film type glass, giving maximum forward vision. The tip-up crew seats were mounted on draught-screens forward of the inward opening doors. The layout of the driver's controls followed standard British Railways practice but with the addition of six ammeters - one in each motor circuit to detect wheel slip. The driver could select electric or steam train heating at will, and the same controls at the driving position applied to either system.

Above the engine was fitted a roof hatch with translucent fibre-glass panels. It could be raised under pneumatic control to ventilate the engine room before maintenance was carried out on the engine. An interlock safety system was fitted which automatically lowered the hatch before the locomotive could be moved and also prevent the hatch being raised when the locomotive was in motion. When raised the hatch could be rolled along the roof to improve access to the engine.

At the design stage, much attention was paid to detail regarding maintenance and operation. For example:

All electrical resistances were mounted on a completely removable unit and cooled by air drawn in through louvers and extracted by ventilators.

A door was provided in the body side and arranged so that the lower portion hinged down to form a platform upon which personnel could stand when using the water chute to the underslung water tank.

All pipe connections to the break units were flexible for ease of connecting and disconnecting during overhauls.

Steam for train heating was supplied by a Spanner MK IIIB boiler with a rated output of 2500lb. per hour. The boiler consisted of a cylindrical fire box surrounded by an annular water jacket, and the whole unit was surmounted by the header dome. The burner was fitted centrally to one end of the fire box and the hot gasses traveled to the other end through fire tubes in the water jacket before being discharged to the atmosphere. The supply of steam was controlled by demand and was only admitted to the train-pipe when normal working pressure had been reached. The boiler would automatically shut down in the event of low water level or flame failure.

LEADING PARTICULARS

A = 63' 6"
B = 8' 10"
C = 12' 95/16"
Gauge- 4ft 81/2 2
Wheel arrangement - Co-Co
Wheel dia - 45”
Length over buffer beams - 59ft 6” (18.135 m)
Weight in working order with full supplies - 114 tons
Maximum service speed - 100mph
Starting tractive effort - 55000 lb
Locomotive continuous rating - 30000 lb tractive effort at 25.5 mph (13.636 kg at 40.8 kph)
diesel engine type - Sulzer 12LDA28-C
Continuous rating - 2750 hp at 80rpm (crankshaft speed)