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|Touring New Zealand 2015 - part 6|
We left Napier after 5 days of lovely weather to head North in the hope of some camping just as the weather started to break. We took the main road up to Taupo, or more precise round Taupo as there is a new bypass. Our only stop was at a viewpoint we had marked on the GPS which turned out to be of a rather magnificent waterfall. After a few minutes break and one of the Apples we had bought earlier it was on to Rotorua where we stopped at the Polynesian Pools for an ice-cream and to change drivers. We then continued on the Pyes Pa road, once a backroad but now sealed and busy. We bypassed Tauranga by going across to Bethlehem - unfortunately we were too late for lunch at Mills Reef, one of our favourite wineries both for the wine and the quality of food.
Athenree Hot Springs and Holiday Park We continued on to stay at a camp site we have visited before on the coast near Waihi which has Hot Springs and a thermal pool – the Athenree Hot Springs and Holiday Park - it is excellent. It has a limited number of cabins and although we had no problem in mid February it would be prudent to book ahead before 20th January or on Friday/Saturday nights. There is a large hot spring pool big enough to swim which has no chemical treatments but has the water changed every night and an even hotter smaller pool at about 38.5 degrees C which sits a dozen people. The water is not full of salts like in Rotorua and is like silk on the skin. On an earlier visit we spent a long time talking to Alan and his wife who also have an old wooden yacht that they have recently bought from Whangaparapara in Great Barrier and now have at Whitianga. - they used to be farmers up the Coromandel. We went into the hot pools in evening and in the morning decided to sit out the rain with another day, normally we would have had another session before leaving.
The next day Pauline spent most of her time making use of the NZ law Library Databases before she loses access and Pete made a bit more progress writing up. We also had a walk round the area and of course there was time in the hot pools.
Waihi: The next morning we left, after a final soak, and went up to Waihi for shopping. We we were disappointed that the excellent small Museum and Goldfields Centre has been commercialised and is now an "All New Gold Discovery Centre". It now has an expensive looking building, a couple of staff doing nothing as nobody seems to come in, an empty area and an expensive underground display which is hopefully much like the previous free one which was excellent. In the past one could by homespun knitting from the area and things like old gold assay crucibles but all that has gone. I think in the past there were volunteers involved but they have disappeared. They must hope to get on the tourist bus circuit as they offer a (currently) free toilet or am I being cynical.
Opoutere: We then went on to look at a camp site at Opoutere on the coast - it was marked on the GPS but we did not recognise it when we got there. The office was not open during the day which made it difficult. It had a few available tent spots marked on the map to help oneself to. We were less keen on a tent as the indications were we would get more heavy storms overnight and the only three cabins were occupied by a group who had come for a wedding over the weekend so we reluctantly looked elsewhere. There seemed to be a gravel road leading to the next possible at Pauanui which we rand and did have a kitchen cabin so we set out - the road terminated in a gate to the forest so it was back to the main road to Taitua and back in down an 11 km well sealed road.
Pauanui The whole town of Pauanui, which faces Tairua, seems to be holiday accommodation and it has a very expensive 'canalside' housing estate with every house facing it own moorings on the manmade network of waterways. There was even a small airstrip for access. The Glade Motor Park was also very different with a predominance of fixed caravans and semi-mobile homes built into big extensions. There are three kitchen cabins and a couple of motels and a big conference centre building. Our cabin seems very good and sensible value and the site seems almost deserted at this time of year. We went into the small but well stocked supermarket in the tiny shopping centre and cooked a butterfly lamb leg on the barbeque - the site seems to have lots of them and the kitchen and facilities block opposite us was huge and we never saw another person enter the kitchen and the fridges and freezers were likewise almost empty - it must be a very short season or maybe everyone just comes at weekends. We walked round the coast - there is a surf beach and then the Tairua harbour the other side is protected by a river bar. There is a ferry during the day to Tairua. A nice stop for a couple of days.
Broken Hills: The second day at Pauanui we drove to Broken Hills which is an old Goldmining area with a DOC camp site. We have stayed there and done many of the walks round the gold mining area in the past. We did not camp this time as the forecast included the possibility of heavy rain in the evening and we nearly got trapped by floods and bridges in the past. It seemed fine for the walks but as we got close to the furthest point the skies opened and we finally aborted as the paths were turning to slippery mud pools. By the afternoon it had cleared and we once more set out on a couple of the very short walks and discovered that there was small scale mining in operation and were invited back the following day for an underground tour. After return went over to Tairua to see if we could find the old boat which we could see cross the harbour entry. Turned out to be one of the last of the Auckland ferries which is now used a 'leisure complex' - they were setting up a marquee alongside for a wedding but let us in. It had a bar and the upper deck looked as if it was used for backpacker style dormitory accommodation.
We stayed an extra day to have our visit into the Broken Hills Historic Mine arranged for 1400. This left the morning free to explore a bit more of the Pauanui area. We went to the far end and did a couple of the shorter walks near Mount Pauanui. Not time for the three hour Mt Pauanui Trig Track which took one to the Trig point at just under 400m but did the Ocean View Loop Walk and the flat Rock Walk. Could not extend to Cave Bay as it looked as if the tide could cut us off leaving the 3 hour Trig Track the only return route. We also had a look at the new Pauanui Waterways Canal and Housing development.
Broken Hills Historic Mine: Our discussion and long underground visit was probably the highlight of our holiday this year. The following forms a major new section in our background page on Gold Mining in the Coromandel.
The Broken Hills Mines are of more interest to us because they continued longer with small scale production continuing until 1923 and parts have recently been open. The current mining is using purely historic methods and you are unlikely to notice it is taking place as there is no publicity and the external impact is very small. The area which was reopened as a historic mine was originally worked from 1899 to 1912, producing about 30,000 oz of gold from over 30 000 tonnes of ore during that time. It is a typical narrow-vein hard rock underground metalliferous mine, and was worked by shrinkage stoping methods. It is characterised among other things by good ground conditions. A family group led by Stuart and Miranda Rabone applied for a mineral exploration permit over the area in 1991 and in 2000 was granted a Special Purpose Mining Permit over the historic mine workings allowing mining to be carried out on a small scale using historical and traditional (essentially hand-held) techniques.
Over the last 15 years, the old section of the mine has been restored and made safe, and the vein system has been further developed. The mining utilises hand-held airleg drills and haulage by 24” gauge rail network in tunnels generally 1-1.5 metres wide and 2 metres high. The number of staff varies but is typically four and on occasion rises to a total of six persons. This is a an unusual and exceptional operation - there are currently only three underground hard rock metalliferous mining operations in New Zealand, namely Oceana at Macraes, Newmont at Waihi (Favona – Trio) and this historic mine at Broken Hills at Tairua. The first two are large scale highly mechanised modern operations. The Broken Hills Mine is unique in New Zealand as a small scale hard–rock underground mine utilising traditional, but nevertheless efficient, methods of extraction. The following pictures were taken the day before a visit underground and show how small the impact is. There is virtually nothing different from any other old adit entrances except for the few minutes when the train is unloading.
The success of the operation has been very dependent on the experience (and qualifications) of the family team led by Stuart Rabone, the General Manager. His qualifications and experience are to me exemplary and include an MSc and PhD in Geology and tertiary qualifications in Engineering Geology as well as membership of the appropriate professional bodies such as FAusIMM and T.IPENZ. I can safely say as I have plenty of alphabet soup of my own that paper qualifications count less to me than relevant practical experience and Stuart has 45 years’ experience in metalliferous mineral exploration and development, including Golden Cross, Waihi (Martha – Correnso and Favona – Moonlight) in addition to the 14 years’ experience restoring and operating Broken Hills Mine itself - it shows as soon as one talks to him.
At the time the mine was not in full operation as its licence is suspended until a second method of egress has been created. The mining regulations and how they are applied in practice has been changed recently and even a small mine is required to comply with the new regulations.
To understand the major changes in regulatory environment one has to know a little about the recent Pike River Mine disaster which was a major coal mining accident caused by a series of methane explosions in 2010. This accident killed 29 of the 32 miners underground at the time. It ranks as the worst mining disaster in New Zealand in a century. The resulting Royal commission concluded two years latter that the regulation and inspection of mining by the Department of Labour had failed to prevent the accident and shortly afterwards Prime Minister John Key said he would apologise in person to the families of the deceased, for the Government's weak regulations and inadequate inspection regime. Efforts were made to prosecute various directors with only minor success and little money reached the families. I do not want to go into many details of the disaster which contained a catalogue of short cuts and poor infrastructure but shortfalls identified included a lack of secondary egress and poor ventilation in an area known for methane problems, a classic risk in Coal mines but almost unknown in hard rock mines. The Pike River Mine was using a very new method of extraction (hydro-mining) over 4000 feet underground arguably without the owners having sound appreciation of the particular risks associated with technique and and how those risks differed from other forms of mechanical mining and there were a number of previous incidents with methane.
It is easy to understand why change is required in such a politically charged environment but to me it is less clear why regulations relevant to Coal Mining and need to be applied to Hard Rock mining where for example methane gas build up is almost unknown. But the new regulations are a fact and will undoubtedly avert some disasters in the future. To me regulations alone are not a total solution but it also depends on the regulators and they must have more experience available than those they are regulating and must be all seeing. I ran many projects and always insisted that most of the project meetings were on site so I could get a feel for what was going on rather than depend on presentations and regarded the ongoing quality and experience of staff to be extremely important - big firms tend to put an impressive team into project proposals which evaporates once work starts! Enough of my own biases and back to our underground visit other than to say that after talking to Stuart and Miranda I felt very safe in going into the old workings and very privileged to have the opportunity.
The Broken Hills Mine was worked on a number of levels and a number of maps of the old workings which extend for nearly a kilometre from the entry portal still exist. I only managed to get a picture of the level we were visiting but the coloured multiple level one made the complexity more obvious. We only went into the workings on the entry level and that has been largely cleared of any old spoil and falls from the stopes. The mine adits are entirely in hard rock apart from the entries which have a massive timber support frames - the rest of the tunnels need very little support and I only noticed a single area with rock bolts in the adits. The tunnels are all high enough to easily walk through although we obviously had hard hats (and all the proper kit including helmet lamps and big power packs and were fully briefed). Most of the adits have narrow track (24 inch) rails laid for the trucks which remove the ore (rock with gold for processing) and tailings (the rock not containing any gold or too little to be worth processing). Ventilation was good and there was an obvious and very cold flow of air in our faces. As we went further there were big plastic tubes hanging to give forced ventilation into areas where there was work going on and to clear fumes from the workings, the train engine and other equipment. The compressed air and power cables were also hanging above us. The was little problem with drainage with a very small channel beside the rails carrying it out. We were fascinated to see there were some small fish which has adapted to the underground existence and even a small eel sometimes appears.
The mine was worked as adits which were searching for or following the veins of quartz which contained the gold. We saw the veins which were only quite narrow in the roof - they appeared to be 5-10cms wide. The veins were near vertical and the richer areas were mined as a series of near vertical stopes. Stoping is the mining term for extracting the ore, leaving behind an open space known as a stope. Stoping is used when the local rock is sufficiently strong not to cave into the stope, although in most cases artificial support is also provided. In the case of the Broken Hills mine a large number of timber supports known as stulls have been placed between the hanging wall of the vein and footwall. These 6 inch or so square timbers stabilised the stope and supported a number of working platforms for the miners to work from and drop the ore onto before it was lowered down to the adit level for removal. They had a small square cut out in the rock at one end and were angled and jammed so they would only get stronger as loads were applied on the platforms they supported. These structures have been renewed in in places but most are still in perfect condition after best part of a century. Good timber was one of the major requirements for historic methods of mining.
We could look up into several of the stopes from below and also down into one which probably extended to a lower level. They were very difficult to photograph in a way which makes they easy to understand as flash obviously only penetrated a short distance. The video using an LED torch gives a better impression and I have taken a few stills from it. In the life they were extremely impressive rising or falling some 50 ft or more and extending similar distances horizontally. They were however the minimum width to allow the miners access, around 2 feet with the massive stulls crossing and supporting various platforms. Some of the old iron and wooden access ladders were still visible with the wooden ones looking in much better condition. As I said earlier there was a very strong flow of cold air through much of the workings and enquires elicited the information that some of the stopes on the upper levels had shafts up to the surface which still provide some of this ventilation but have been covered to prevent anything falling down through to the working levels. In a dire emergency it seems to me that they could be an additional escape or entry route.
As said earlier the majority of the old workings had been cleared and made safe before the new adits have been driven for mining and we went into some of the new areas and saw one of the small stopes they had been working. We could not go into the area where a new adit is being driven to link to an existing adit with a portal further the track to provide the secondary egress route. This required a drive of 70 metres at about 2 metres a day and there was to be no production until that was completed. It was apparently quite a task to find the old adit entry as there had been a rock fall and the combination of convention metrology from the old drawings, modern satellite GPS measurements and real photographs before and after the slip were utilised. The extra entry is about 220 metres from the portal used for working. We had seen the train with its tipper trucks outside the previous day and we passed it on our way through the workings. The loading at the workface is by a bogger which is a special design of front loader for mines which loads in front and deposits the load behind it into the tipper trucks. We saw one during a previous visit into an Australian Mine. There have been a number of television programs covering the mine and there is a video of the train and blogger working by TVNZ at http://tvnz.co.nz/national-news/file-video-inside-broken-hills-gold-mine-4728919
Some of the other old equipment is still in place including an original winch used compressed air rather than steam. It looks in surprisingly good condition although dry rot had got into the woodwork. The ore is taken out by train and tipped into a small lorry and stored until there is sufficient for processing. It is not processed by Broken Hills Historic Mine themselves as that would not be economic.
Overall we spent a fascinating hour and a bit underground. They are remaking history in a way that static displays and written text can never do. The underground working we have seen previously were sanitised and artificial and the difference was even more noticeable than we expected. There is obviously some new equipment used such as modern compressors but they are not of the essence and the ventilation piping is different but it still feels like history being remade. Existing readers will already know our views on museums full of videos and plastic copies of artifacts and structures however well done.It will be an opportunity for future engineers from throughout the world to feel and learn from history as well as demonstrating the opportunities for small scale activities activities to complement the large and with far less impact.
The next part will continue in the Coromandel Peninsular, we were getting keen to get back under canvas and what better place than Colville.
| Copyright © Peter and Pauline Curtis
Spelling corrections: 8th January, 2016