On the metalworking industries fell the main brunt of the rising demand for locally produced munitions.2 General engineering factories had to increase their staffs by two-thirds in the five years 1938–39 to 1943–44. This staff increase was facilitated by the high priority for manpower purposes always given to munitions making, which was one of the first industries to be declared essential,3 making it possible to direct labour to it.
New Zealand munitions making was predominantly small arms; for example, New Zealand industry carried out all stages of the manufacture and filling of five and a half million hand grenades and of one and a quarter million trench-mortar bombs with fuses.4 Small-arms ammunition had been made before the war. Production was stepped up and the total wartime output of £303 ammunition was over 250 million rounds. This necessitated a considerable expansion of the peacetime plant. Capacity was expanded to provide for a nominal production figure of 60 million rounds a year, but in 1943, with overtime and shift-work, a peak output of 74 million rounds was achieved from this plant.
Over 9500 trench mortars, with parts for maintenance spares, were manufactured during the war, and in addition over 10,000 Sten guns, 1000 grenade mortars, 3750 rifle grenade dischargers, and 1500 automatic rifles were made.
As an example of munitions manufactured for an allied country, the production of well over a million special shell fuses was undertaken on behalf of the United Kingdom Government. Automatic machinery and other necessary equipment and materials had to be imported for the purpose.page 160
Motor assembly plants, with drastically reduced private motor-car imports to handle, played a variety of parts in the production of munitions and war stores. Most nearly allied to their normal peacetime production was the assembly of armoured machine-gun carriers. Twelve hundred carriers were produced, complete with maintenance spares. Sub-contracts for parts were spread throughout the country.
These examples are illustrative of the variety of munitions work undertaken by New Zealand manufacturers. Other war stores, such as water valves, concrete mixers, hospital beds, stoves for heating tents, jungle knives and the like were made for the New Zealand Forces, the United States Forces, or to the order of the Eastern Group Supply Council.
The impact of munitions work on New Zealand metalworking industries forcibly brought about a rapid expansion in their capacity for precision work. To ensure that munitions components for fuses, bombs, and grenades complied with rigid specifications, it was necessary for manufacturing machine-shops to be provided with special production gauges and for inspectors to have inspection gauges. The Dominion Physical Laboratory of the Department of Scientific and Industrial Research was expanded and annexes were established in the four main centres, each of which was equipped with machinery for making and testing gauges and precision tools.
Approximately three hundred machine tools of the latest types were procured for war production purposes, and the use of these, in addition to existing equipment, on munitions and allied stores production gave an impetus in the metal industries to more efficient methods.
Pressure on most manufacturing industries continued throughout the war period and, as late as December 1944, there was a call from Great Britain for an urgent increase in production of some classes of munitions.1 Immediately following the defeat of Germany in May 1945, the munitions programme was curtailed and, in August 1945, the capitulation of Japan brought the production of munitions to a halt.
2 The need for New Zealand made munitions is discussed on pp. 134–7.
3 In January 1942.
4 This and much of the following information on munitions making is derived from Parliamentary Paper H-44, Report of Department of Industries and Commerce, 1946.