April 9, 2014
Every time I visit a mill I record and write up a report that night. Following are my notes on the Golden Point battery near Macraes Flat, New Zealand:
We drove over to Macares Flat and found the 5-stamper, Kevin Pearce and Helen Jones who work for the Department of Conservation, similar to the Forest Service in the States. We got there at about 10:30 and they were in the middle of heating up the engine. The engine is a kerosene engine that has to be heated up hot enough to make the kerosene injection flash and run the engine. The engine is a Tangye Type, AA oil engine. It took about 2 hours to heat it up properly. The mill is a 5-stamper with a feeder that works. There was also a shaker table that they had just restored back to operations. The entire setup was original including the engine that the Department of Conservation restored back to operations. This cost them $30,000 to complete. I was a little disappointed that the stamps were not dropped, but at least I got some good still pictures and video for my files.
There is a 5 minute You Tube video that I have and will put it in this file of the engine and stamps being dropped. Just click on the address blow and paste into the Internet and it will play.
The picture above shows the stamper battery with the screen removed, exposing the stamper shoes. You can see the middle 3 shoes have fallen off their bosses. That is one of the reasons why we did not drop the stamps today. The picture below shows Kevin removing material from the mercury slots. This sluice table is unlike anything in the States, since it has grooves across the table in about one foot intervals. He uses a special spoon to get down into the slots to remove the concentrates.
The picture above shows the engine warming up and all of the smoke from the kerosene pre-heater. The large container on top of the engine is the fuel tank. The picture also shows the many engine controls on the side towards the back of the cylinder. The picture below shows you the kerosene pre-heater fire inside the shroud. This took 2 hours to warm the engine cylinder enough to start the engine.
Kevin showed me some original tools including a key, and two tools for removing shoes and tappets.
Kevin set the 5 stamps on jackstands using a chain fall. This was done since they could not drop the stamps since three of the shoes had fallen off the stamps. Setting the stamps on the jackstands is a typical operation performed on the stamper batteries.
The feeder device on this machine still works. The feeders are very important since they control the level of material in the mortar boxes. If you do not feed enough the stamps will damage the mortar box by the metal on metal action between the stamps and the dies in the mortar box. If you feed too much material you do not get proper crushing action, so it is very important to maintain the correct feed rates. The feeder does this very effectively. The picture below shows the feeder friction wheel.
There were several parts to a Huntington Mill in the area. It had been re-assembled to show what it looked like originally. The quartz mill crusher was driven with a pelton wheel.
We went into the town of Macraes Flat and found a 3-stamper that was in pretty good shape. It was made by A & C Price, Thames, NZ, 1896. It did not have a feeder and there was no driver in sight.