Woodstock Pumping Chamber

Ohinemuri Regional History Journal 21, June 1977

This large excavation is situated at Karangahake under the "Plum Pudding Hill" with the entrance from the Waitawheta Gorge.

Prior to 1900, the Woodstock Company had worked its claim from adit levels but in 1901 a small chamber was excavated in the No. 5 level and a shaft sunk from it reaching a depth of 252ft. The No. 6 level, which was below river level was driven out from the bottom of the shaft. At this stage, the chamber and shaft were quite small.

After the Woodstock claim was taken over by the Talisman Consolidated Company in 1904, it decided to greatly enlarge the chamber and shaft and sink it to a greater depth. A large winding engine and pump engine was also to be installed. To accommodate all this machinery including the pump capstan, the chamber had to be enlarged to a length of 100 feet, 40 feet wide and 25 feet high. Because of the dangerous nature of the rock the whole of the drilling was done by hand.

The method of excavation was to first extend a drive the full length of the proposed chamber and this was met by a crosscut driven in from just above river level. A stope was then put up and widened until the height of the roof was reached. Sufficient rock was left in the stope for the men to stand on and easily reach the roof. The working space in the stope was reached by an inclined rise. Before the chamber was completely excavated the timbers for the roof were put in position. It was far easier to winch the heavy timbers up the rise and put them in position whilst standing on the broken rock. After the roof was in place the loose rock in the stope was removed and the sides excavated back.

Woodstock Pumping Chamber, Karangahake – Photo 1970.

The pump installed was a Cornish pump driven by steam supplied from steam boilers situated in the Waitawheta Gorge. The pump flywheel was 17 feet 6" in diameter and weighed 40 tons. The pump could handle 50,000 gallons per hour. The Woodstock shaft was used to provide access to the lower workings of the Talisman mine.

The WOODSTOCK Pumping Chamber is still accessible today, although it is in a dangerous state. The photograph in the Journal shows the pumping chamber in 1970. This photograph was taken by Mr. Allan Beck with the assistance of Mr. Phil Jones. Since the photograph was taken most of the large roof rafters have fallen. Their fall was probably caused by explosive blasting, by the Southern Cross Exploration Company, in the Talisman No. 8 level during the early 1970's. The large pump capstan can be seen in the photo. The figure standing in background gives a perspective to the size of this excavation.