The New Zealand Railways Magazine, Volume 2, Issue 12 (April 1, 1928.)
On locomotive and other rolling stock the elliptical and spiral springs are indispensable factors. Each type of spring has a more or less severe duty to perform. The springs are subjected in service to heavy strains and stresses, and it sometimes happens that failure to withstand the demands of everyday operation results in derailment.
The Department having been faced with the problem of fractured springs and various other failures due to the many irregularities in treatment and handling, has given this particular subject very thorough study.
The treatment of spring steel in our workshops has, as a result of the reorganisation of the plant, been greatly modernised. The new plant will enable us not only to produce a class of spring that will be superior to the old (thus lessening spring failures) but the cost of production will be considerably reduced. Hitherto, the plant for dealing with the work of spring manufacture at Hillside consisted of a spring furnace (in which coal was used), an oil bath, two forges, a steam hammer, and a testing machine.