Nelson Historical Society Journal, Volume 3, Issue 5, October 1979
5. Onekaka Iron Works
5. Onekaka Iron Works.
Notwithstanding the strenuous efforts which were made a smelting industry had not been established prior to the outbreak of war in 1914 with the result that little further was done until a new company, under the name of Onakaka Iron and Steel Company Limited, was incorporated in 1920 to acquire the leases of the earlier companies and set up works at Onekaka (please note difference in spelling of name. J.N.). A blast furnace was brought down from the North Island and re-erected. This had been in use at New Plymouth to smelt ironsands but the process had not been successful as the sand settled down too tight and air could not get through it and there was too much slag. (The only possibility would have been to make the sand into bricks before loading. Modern plants pellet the sand before loading the blast furnace.) Although the smelter was old it was able to be used at Onekaka after very little modification and was very efficient.
When the company was formed in 1920 with a capital of 80,000 pounds ($160,000) the price of pig iron was 14 pounds ($28) per ton but after having erected the blast furnace and plant the price dropped to 9 pounds ($18) per ton and the directors were faced with a loss in producing the first 100 tons of pig iron. In 1922 the company capital was raised to 150,000 pounds ($300,000) and the plant was extended. Meanwhile the price had declined to 7 pounds 10 shillings ($15) per ton, and later to 6 pound 2 shillings and 6 pence ($12.25) per ton. A mysterious fire occurred at the plant which caused serious damage and held up production with the result that it was 1924 before the plant was fully operational. The furnace capacity was 10,000 tons per year but as the local demand was only 4,000 tons of pig iron the company had to export to make the plant a business proposition. (Spasmodic production was maintained until 1935.) By October 1925 2670 tons had been produced but as the market was saturated the company could not sell its page 16iron. Six hundred tons of pig iron was shipped to Australia and orders from there were coming in when the Australian Customs Duty was increased from! pound to 3 pounds ($2 to $6) per ton. With this setback and the fact that Indian iron was being dumped on the New Zealand market the future was a little gloomy. The Australian situation was unfortunate as the small furnace at Onekaka could turn out a variety of irons which could be used for various purposes whereas the Australian plants with their bigger furnaces could not vary their product. The Onekaka product was a soft iron which was very suitable for making stoves. Two of the satisfied users were Metters (N.Z.) Ltd and the Sunshine Harvester Company of Australia.
Good pig iron was produced during the early trials in 1922 and future prospects appeared bright. Before the company built its own wharf Skilton's wharf on the Onekaka channel was used to land much of the machinery and requirements for the works including one or two loads of coke from Wellington, by the Kohi, for trial workings prior to the building of coke ovens. When a weight of 40 tons was stacked on the wharf it was too heavy for the structure and a stringer broke. The Anchor Foundry at Port Nelson made castings from the first iron produced and in the Marsden Church House (now a Funeral Chapel) in Nile Street, can be seen a steel support carrying the wording "First Casting from Onakaka Iron, A.S. & F. Co., 1922."
Early in 1923 the Onakaka Iron and Steel Company Ltd applied for permission to erect a wharf at Onekaka beach. This was to be on the western side of the Onekaka Inlet running out into the open sea whereas the existing wharf was in the narrow channel leading to the inlet. Meanwhile the company was requesting the Collingwood County Council to make improvements to the road from the beach as they planned to convey at least 450 tons from the inlet to their works. This required that the road be properly formed and gravelled. Developments moved on apace and early in 1924 the company was applying for permission to cross the main road with the tramline. The accompanying map showing the tramline and wharf was signed by John A. Heskett, A.M.I.M.E., M.I.S.I., who was manager of the works until the final closure in 1935.
page 17 page 18The raw materials, both iron-ore and limestone, were obtained from a quarry 1500 feet (457 m) above sea-level and transported down to the works on an aerial tramway one and a half miles (2.4 km) long. The angle was about 26 degrees and the buckets, each carrying one hundredweight (51 kg) spaced 365 feet (111 m) apart travelled at a speed of 337 feet (102 m) per minute. This was controlled by a 25 horsepower motor. When the iron ore was sent down the buckets were filled with the material as it was quarried. It went straight into a rotating washing and crushing plant and the waste material was washed away.