The reorganisation of the New Zealand Railway Workshops has resulted in many marked improvements, not the least of which is the method of renewing tyres, both for locomotives and other rolling stock.

Under the old method, tyres, after they had been bored to suit the wheel centres, were taken outside, and stacked, ten or more high, in a position adjacent to a hand crane. Usually they were rolled out of the shop by man power. If a suitable line was available they would be loaded on a trolly, and pushed out to the crane. Much time was occupied gathering pieces of wood with which to heat the tyres. The wood was piled in the centre of the stack of tyres, and ignited. Then ensued a wait of several hours, until the tyres were hot enough to slip over the wheel centres, which had been placed in a vertical position, with the aid of the hand-crane.

For the benefit of the uninitiated, it should be explained that the tyres are always bored so many thousands of an inch less than the wheel centres, the allowance, in each case, being determined by the diameter of the centres. When heated, the tyres expand sufficiently to drop over the wheel centres. In cooling, the tyres contract, and grip the wheel centres very firmly. Suitable grabs, connected with short chains were used to lift the hot tyres from the stack.

An improvement was effected when the hand operated crane was altered by the addition of an air cylinder, and operated pneumatically. This system, with slight modifications has been in use for years. After the heated tyres had been applied to all the top wheel centres, it was necessary to wait until the tyres, by cooling, had gripped the centres tightly enough to remain in position while the wheels and axle were reversed. The remaining tyres in the stack were now applied to the wheel centres.