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The New Zealand Railways Magazine, Volume 2, Issue 4 (August 1, 1927)

Main Particulars of Locomotive

Main Particulars of Locomotive.

Internal Combustion Engine, 8-cyls., 4-stroke Cycle.

Cyls: 13 1/2 in. dia. × 15 1/2 in. stroke.

Gear Ratio: 1.878 to 1.

Designed Engine Speed: 450 r. p. m.

Loco Speed at 450 r. p. m.: 45 m. p. h.

Max. i. h. p. on Combustion only: 1,000.

Max. i. p. h. available, 1,200.

Starting Tractive Force: 25,450 lb.

T. F. at 45 m. p. h.: 7,000 lb. (assuming 80 per cent. overall Mech. Efficy.).

Boiler and Tanks.

Heating Surfaces:-

119 Tubes 1 3/4 in. dia. outside × 9 ft. long; 490.6 sq. ft.

Firebox: 72.0 sq. ft.

Total Evaporating Surface: 562.6 sq. ft.

Regenerating Surface:-

36 Tubes 2 3/4 in. dia. outside × 17 ft. 4 in.: 448.7 sq. ft.

2 Tubes 6 1/2 in. dia. outside × 17 ft. 4 in.: 59.0 sq. ft.

Total Regenerative Surface: 507.7 sq. ft.

Firebox Volume: 39 cu. ft.

Water Capacity: 1,000 gallons.

Fuel Oil: 400 gallons.

Lubricating Oil: 85 gallons.

The boiler which supplies the steam is a simple structure. Its functions are to provide steam by oil firing for starting, to act as partner with the combustion-cylinder jacket in the regeneration of steam, by absorbing the heat of the exhaust gases, and at the same time to act as a silencer.

Dining car on the south island royal train

Dining car on the south island royal train

Full advantage has been taken of the loading gauge width for the cab and footplate, seats are provided for the operator and his assistant: the controls are so placed that the driver need not leave his seat to perform any of the manipulations required, and the fireman, having no arduous task in maintaining steam, can assist in any duties demanded by routine. Due to the absence of coal dust and firing tools, a neat, clean, well-lighted compartment for the crew is provided.

The small diameter of the boiler enables large windows to be provided in the cab front, whilst the disposition of the tanks permits a generous look-out for running in reverse.

Under normal conditions of load and grade the process of starting the engine is as follows:-Having put the steam gear over to full gear position (which ensures the combustion gear being set correctly) and having opened the oil regulator to “start” position, the steam regulator is opened and the engine moves away. Within a few revolutions of the driving wheels the oil side fires at a low power, the first combustions being also imperceptible because in the “start” position the spill valve returns most of the oil to the tank. As the speed increases, the steam gear is notched up, and the oil regulator is advanced to running position. At any speed above about 6 miles per hour the steam regulator may be closed entirely and the oil engine relied upon.

To stop, the oil regulator is moved round to the “off” position, and if steam is being used its regulator is closed and the brakes applied in the usual way. In case of emergency stops, the steam gear could be reversed and the steam regulator opened. In the case of special need for acceleration, steam will be used to judgment according to the circumstances.

For starting, brakes and train heating, steam is the source of energy. By its essential flexibility it replaces for starting and low-speed work a clutch and gear box, electric or fluid transmission, and enables a unit complete in itself to accomplish the extraordinary requirements demanded by rail traction. It enables also a staff trained for the maintenance of any ordinary reciprocating engines to adjust or repair or inspect the entire mechanism of the locomotive with very little special training. The controls and operations will be familiar to the driver of steam-locomotives and the general appearance reminiscent of his usual charge.

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Shunting, backing on to a train, or moving about the yard and sheds, can be done on steam alone by the controls familiar to all.

It is safe to assume that an overall figure including oil burnt whilst firing the boiler for starts, will not exceed 0.4 lb. per i. h. p.-hr.

The Kitson-Still locomotive, burning fuel at 80s. per ton, would cost roughly £500 per annum. For a comparative steam-locomotive, using coal at 21s. 6d. per ton the fuel bill would be approximately £1,000 per annum.

In a review of the various points in the design of this engine probably the most important is the symmetrical disposition of details about the central shaft and gears. By this means, accessibility is made very real, the main driving gears operate under the best conditions, a simple and stiff crank-shaft is possible, latitude for wheel position is obtained, and cam-shaft and pump operations are effectively synchronised.

Such is the engine which in a few months will be submitted to the chances and changes of the open road.

Trolleyways at Rewanui State Coal Mines, West Coast, South Island.

Trolleyways at Rewanui State Coal Mines, West Coast, South Island.