NEW TYPE LOCOMOTIVE FOR MAIN TRUNK LINE

Manawatu Times, Volume LIV, Issue 6806, 9 January 1929, Page 8

NEW TYPE LOCOMOTIVE FOR MAIN TRUNK LINE

Safety on Curves

TWO ENGINES IN ONE • OF SUPERIOR POWER

MECHANICAL FIRING.

Times Special. AUCKLAND, Last Night. The first of threo new locomotives, of the Garratt type, for the New Zealand Railways arrived from England by s.s. Northumberland, now at Auckland, having been shipped in accordance with, an order placed 12 months ago with Messrs Beyer, Peacock, and Co., Ltd., Manchester. The engine will be taken to Wellington for assembly at the Hutt Valley workshops. Theso engines will be used on the Main Trunk line fiom Taihape northward as general utility engines, and will be employed on both goods and passenger trains. Their power is two and a half times that of tho ordinary express engine now in use. The main reason for importing the engines, is their adaptability for curves on hilly runs, and they arc so constructed that they can negotiate any of tho curves on the Main Trunk line with ease. It is not intended to speed up the present time-table for trains.

The principle of the Garratt type of locomotive is to obtain the greatest power wjtk the minimum of axle load, the total weight of the engine being distributed over a greater length. The new engines are therefore much longer than engines now in use, the total length over-all being 77 feet. The fact that each will develop a tractive effort tJ 51,5801 b. as compared with 20,0001 b developed by the AB class of locomotive at present in principal use in New Zealand, and that the weight in working order will be 146 tons, as against 84 tons 15cwt in the case of the AB, gives a good idea of the superior power and size of tho more up-to-date engine. The Garratt is in realitv a combination of engines, and in those of tho design under order is equivalent to two locomotives working with one boiler. In Thre'e Sections. Another interesting fact is that tho locomotive is in three separate sections. The boiler section in tho middle has a pivot point at each end, sitting over the respective leading and trailing engines. No turntable ,is required for reversing at termini, as the engine will run equally well in either direction. Water tanks. aro carried at each end, one containing 2500 gallons and the other .1500 gallons, a total of 500 gallons more than tho AB. The coal bunker will have a capacitv for six tons of coal, as against 4-i tons in the AB. In the new engines there is a radical departure from the usual practice in New Zealand as regards firing, for they are mechanically stoked. The coal is fed from the bottom of the tender to tho face-plate of the boiler, and is then lifted to nozzles and sprayed into the fire-box. A further new departure is that they will be of the three-cylinder simple type at each end.. They will also have super-heated boilers and a working pressure of 2001 bto tne square inch. The grate area will bo 58 square feet, this being the largest grate on any locomotive in New Zealand. _ , For Heavy Haulage.

One of the great advantages of the new engiue so far as the New Zealand railways are concerned will he m the creator powdr provided without the necessity for increasing the size ot bridges to take the weight or heavier engines of the type at present in use. If it were decided to a'tquire engines of the same power as the Garratt, but not of the articulated type, the axle load would be increased to such an extent that enormous expenditure would be necessitated in the strengthening of bridges. The new engines will also obviate the necessity of putting two engines, as is the present practice, on heavy trains travelling across the diflicult countrv between Frankton and Tuihapc. The purpose of the three new locomotives is heavy haulage rather than speed, but they are capable of a speed of 75 miles an hour. It is not likelv, however, that, they will be called upon to exceed 50 miles per hour ou the narrow New Zealand gauge. On heavy gradients and sharp curves Garratt locomotives arc far more efficient than orthodox types, but as additional advantages it has been proved that they are the means of enabling train loads to be increased, reducing running time, increasing the capacity of the line, and reducing the cost per ton-mile. It is not in the haul* ing of heavy freight trains alone that such economics can be effected; experience on muitv railways has fully demonstrated that Garratt locomotives are suitable for operating any class of traffic, from shunting to fast passenger trains. The standard utility locomotive in New Zealand has 12 wheels; the Garratt has 24 in two bogeys of 12 wheels each. Each locomotive of the Garratt typo costs about £II,OOO in the shop, exclusive of reassembling anil transport costs.

In connection with the installation of the Garrett engines, the “Times’' is informed that the X and XA loemotives, which the new type will replace on the difficult “spiral" section of the Main Trunk line from. Taihapo to Taulnarunui, will bn drafted to the Palmerston North yards. These engines will be used for goods haulage and are capable of pulling a load of 1000 tons. This will be an important consideration in Palmerston North’s tranport problems.