Ohinemuri - One of the Largest Processing Batteries

Ohinemuri Regional History Journal 53, September 2009

One of the largest quartz crushing plants in Australasia, the Victoria Crushing plant at Waikino, at the eastern end of the Karangahake Gorge is being slowly restored and is attracting increasing interest from tourists and holiday makers.

Built by the Waihi Gold Company in 1897 the huge battery operated until its was closed in 1954, two years after the company's Martha Mine, once the richest gold mine in the world, closed down.

The location for the battery was chosen to take advantage of the water power available from both the Ohinemuri and Waitekauri Rivers, which joined about 1km further up the valley. However, the mining company drew up an agreement with the Government of day, to constructed Horahora hydro-electric scheme on the Waikato River and with a land-lines, use the electricity. The whole scheme was purchased by the Government in 1919.

By 1913 the whole battery was converted to electricity, which was brought from the generation plant by cables and pylons across country to Waikino.

When the battery reached its maximum production it had 200 stamper heads, pounding the quartz rock, brought by a special narrow-gauge railway (the rake line) from the company's mine in Waihi, a distance of 8kms. These stampers operated 24-hours a day, seven days a week, and were capable of handling 800 tons of ore per day.

Initially the ore was "roasted" in special kilns to oxidise the sulphides and other impurities. There were eight kilns dug into the hill above the battery site and lined with bricks. The wagons of ore were winched up to the top of the kilns and tipped into the kilns. Layers of ore alternated with layers of wood—one ton of firewood was required to roast one ton of ore.

Up to 1ha of timber was felled each day and brought from the Waitawheta Valley by tramline. Once roasted the ore was then crushed and processed.

With the wood supply diminishing a new process was introduced to the battery around 1900 which used cyanide to recover the ore and the kilns were abandoned [Victoria Battery used the cyanide process from the start; in 1901 dry crushing was replaced by wet crushing – E]. The ore came straight from the trucks and crushed wet and then processed. The new system enabled the company to improve the recovery rate of gold and silver from around 60-70 per cent to 95 per cent [this had already happened at the Waihi Battery in 1894 - E].

After the battery closed in 1954 the land and buildings were sold. The new owner demolished the buildings and burnt the timber, processing and extracting the gold dust from the ashes. The 15m high by 4m diameter steel cyanide tanks were cut down for scrap. The only building left standing was the concrete transformer house.

Today the transformer house is home to the Victoria Battery Tramway Society, which is working in conjunction with the Department of Conservation to develop the battery site into a place of historical interest.

The Society runs trains on the tramway that snakes around the site with audio description of the various areas. Guided tours of the kilns and their service tunnel are also undertaken. Five of these kilns have been cleaned out, and a roof placed over them. An interesting museum has been established in the power house.

The Society opens the museum, runs tours of the kilns and operates the train on Sundays and public holidays. Other times can be arranged for groups. Group bookings to phone 07 863 6169.

The site itself can be explored at any time with foot access from either the Waikino Railway Station carpark or from Waitawheta Road (left off the Owharoa Bridge).