NEW RAIL MOTOR

Hokitika Guardian, 24 July 1928, Page 4

NEW RAIL MOTOR

TOWER WAGGON FOR OTIRA

An interesting type ■of rail motor vehicle has just been completed by Hardy Railmotors, Limited, of Slough. Bucks, lor service on the New Zealand Government Railways, says the “New ■Zealand Railways Magazine.” This vehicle, which is to he used as a tower waggon for the inspection and repair of overhead babies, will bo used by the signal and electric branch on the electrified section of the New Zealand Government Railways between Christchurch and Grcymouth, ami will thus operate through the longest tunnol in the British Empire —the Otirn, tunnel. The tunnel is about 5J miles in length, and the lino through it is a single one on a gradient of 1 (in 33. The shunting yard at Arthur’s Pass is 2420 feet above sea level, and snow is fairly constant during the winter months. SUPERSTRUCTURE.

The superstructure of the vehicle,, consisting of a tower and accommodation at each end for the driver, has been designed by the chief mechanical engineer of the railways (Mr G. S. Lvnde) and will he constructed in the New Zealand Government Railway workshops. It will be approximately 15ft long and Bft wide and will house tho driver, the engine, and repair material for the overhead cable. The gauge of the car is 3ft Gin and the wheel-base 10ft, and it will be required to operate on- a 3 per cent upgrade with a total load of 90001 b on the chassis and a. gross training load of 14,000 Tb at a- speed of 15 miles an hour. All controls arc duplicated at each end to allow tho vehicle to be operated in both directions with the full training load. The car has a G-eyliridor engine with cylinders lOOmm. bore hy 1-Xlnmi. stroke, developing 80 b.li.p. at 2000 r.p.m. The valves are placed on one side, and are of large diameter—inlet valve of nickel steel and exhaust valves of stainless steel. Tile crankerase is of valves of stainless steel. Tho crank-case is of aluminium,- and tho capacity of the sump is three gallons. Lubrication is by gear pump through a large strainer to the main and camshaft hearings, and through .the crank-shaft to the big end bearings, efficient relief valves being fitted to the whole system. Ignition is by high tension magneto, and an electric starter and lighting are also fitted. Efficient cooling is secured by two gilled tube radiators with cast tanks and side brackets mounted one at each end of the vehicle circulation being carried through tho engine and tl}o two radiators in series by a large capacity rotary pump. A fan is also mounted at the engine end.

SPEEDS AND BRAKES. All gears and shafts run in oil on ball or roller bearings, and are totally enclosed. Tlie gears are of the constant mesh type, engaging hy dogs. Four speeds in both directions aro provided, namely, 16 m.p.h. at normal engine revolutions on top gear; 8 m.p.h. on third, 4 m.p.h. on second; and 2 1-3 m.p.h. on low. Reverse is effected by la subsidiary gearbox placed between the clutch and main gearbox, giving direct drive through the box or reverse through intermediate gears. The drive if taken from the gearbox centre drive by cardan shafts with universal joints to both axles independently, which are of the f.ull floating bevel typo, and arc fitted with tapered roller bearings. Springs are of the laminated type hardened in oil. The wheels are of Boin diameter on tread, aiid aro of disc type with rolled steel tyres. Two brakes are provided, one acting on, a drum at tho back of the gearbox, and so through the transmission on all four wheels, the other being a screw-down hand-brake acting through brake-blocks on all four wheels. Sand boxes are fitted at each end, aiid the petrol-tank has a capacity of 17 gallons. In order to enable the vehicle to lie tested under working conditions, special temporary axles of standard (4ft S.)in) gauge were employed, with the f.ull load on the chassis and a trailing load Utons in excess of what was specified. With this gross load, tho vehicle -climbed a gradient of 1 in 24 without difficulty at 18 miles per hour with the engine accelerating on the steepest part of the gradient. Moreover, the load was securely held on the gradient by . the foot-brake alone.