The Karangahake Gorge and its Industrial Archaeology.

Summertime in New Zealand means roadtrips and exploring all that our lovely country has to offer.  Me and mine decided to spend some time in the goldmining town of Waihi and of course as always this meant a lesson in history, in particular the area around the Karangahake Gorge.

The Karangahake Gorge is situated between the Coromandel and Kaimai ranges and was formed by the flow of the Ohinemuri River.  It’s steep sides are covered in native bush, a haven for those wanting to experience the great outdoors.  There are plenty of walks and cycle trails to enjoy or you can simply sit by the river and enjoy a picnic.  However not so long ago the visitor would have been greeted by an entirely different scene.

On this visit we did the Windows Walk which takes you past and through several of the stamping batterys and the many associated building ruins then into the old tramway tunnels along the Waitawheta Gorge (an offshoot of the Karangahake Gorge).  Unlike other goldmining areas, alluvial gold is rare in the gorge and almost all of the gold and silver recovered from here was done by deep quartz mining.  This meant only the large well funded companies could afford to operate in the gorge.  The three main players were the Talisman Mining Company, The Woodstock Mining Company and the Crown Mining Company.  (The latter will ring some bells with those of you interested in Cornish mining history as they were a major player in the mining industry of Cornwall.  In fact many of the miners came from Cornwall which was at the time undergoing a decline in mining.  Their skills in hard rock mining was in great demand in colonial lands).  Today so much of the ruins are covered in dense bush, their edges softened by vegetation and with the sound of either the Ohinemuri or Waitawheta rivers filling your ears it is hard to imagine this as a place of heavy industry.

A continous rythmic thumping once filled the air here, as stamper batteries (gold recovery plants) of the Talisman, Woodstock and Crown Mining Companies pulverised quartz rock to free the gold within.” (taken from an information board at the beginning of the walk)

Much of the ore came from the steep sided Waitwheta Gorge and was then transported via aerial tramway across the gorge to the tramway and delivered to the stamping battery where it would undergo a series of crushings to extract the gold and silver which was then smelted into bullion bars.  The Talisman and Crown Mines were two of the largest of their type in New Zealand and together produced in the region of four million ounces of gold bullion.

The following are some of the photographs taken during our time exploring the industrial archaeology of the Karangahake Gorge.

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All that remains of the Talisman powerhouse on the banks of the Ohinemuri River.
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Several phases of building are present at the Talisman powerhouse – here you would have found the boilers and air compressors that powered the machinery for the battery and mines.

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Remains of the Woodstock Battery, note the water wheel for powering the stamping machine.
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Woodstock battery.
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These can be found lying all along the route, heavy cast iron crushers for pulverising the quartz.
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Woodstock battery.
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To increase yields potassium cyanide was used to remove even the smallest particles of gold and silver from the ore.

Once the ore had been crushed in the upper levels of the battery the fine powder that resulted was subjected to the cyanide process.  This involved mixing potassium cyanide with the finely crushed ore in tanks for several days then drawing off the solution and passing it through wooden boxes where the dissolved gold and silver precipitated as a black sludge on zinc shavings.  The sludge was then treated with sulphuric acid to remove the zinc.  The residue was then smelted into bullion bars (of gold and silver)” – From the above information board.

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Remains of the tanks where the powdered ore would be treated with cyanide.

 

One of the main features of the Windows Walk is the tramway, part of which goes through the side of the gorge (a torch is a must if you do this walk).  In its heyday, the ore was transported via tram but because of the steep sides of the gorge a trail had to be cut out of  and through the rockface.

A bit further on from the modern suspension bridge is the remains of the Crown  Mine.

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The entrance to the Crown Mine
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Drawing showing the extent of the Crown Mine in the Waitawheta Gorge.
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Side view of the mine workings through the gorge.
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The now peaceful view which was once dominated by the Crown Mine operations.

Today goldmining in the area is representated by the large open cast mine in nearby Waihi with the now defunct Cornish Pumphouse from the earlier 19th Century Martha Mine standing ever watchful over.

 

For more information –

Department of Conservation – Karangahake Gorge

Ohinemure Regional History Journal – Historic Karangahake Gorge

Waihi – Gold Discovery Centre

Waihi –  History and Heritage

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