(50) Portable 3-Stamp Mill Achieves Operability

There is a freshly restored stamp mill that has just been made “Operable” at the Jerome State Historic Park at the Douglas Mansion Museum in Jerome, Arizona! This adds one more mill to my list of operable stamp mills. We now have (16) "operable" stamp mills in the USA. The folks at the Douglas Mansion Museum, led by Wes Yeager, did an excellent job with his first stamp mill restoration. I only jumped in when there were questions. They owned the restoration and did an outstanding job.

The actual restoration started in July 2014 and completed in May 2016. The timeline was drawn out due to the lack of information on what the structure of the stamp mill looked like, since we only had (3) stamps, a camshaft and a mortar box. We finally found structural information through a stamp mill model maker, Western Scale Models. They had the structural information we needed to come up with the dimensions for the uprights and their configuration. The key to finding the correct configuration was the ability to disassemble the mortar box and the A-frame upright arrangement.

The following is a description of the 3-stamp mill in an article taken from “Supplying the Mining World 1850 – 1900” by Lynn R. Bailey. “The three-stamp mill, fabricated by Fulton Engineering & Shipbuilding Works, was handy for prospecting or when a larger and more pretentious plant could not be secured. The unit was designed to be operated by either horse, steam or water power. The frame could be taken apart and put together again with no cutting or refitting. The stamps were ninety-drop, and weighed 250 pounds each. The entire outfit as shown, including frame, weighed 4,500 pounds. The picture below shows the drawing of the model that Western Scale Models produced.

Without the above information we never would have come up with the correct stamp mill orientation.The picture below shows the parts we had to start the restoration.

The mill was assembled in a courtyard in the back of the museum since it was close to utilities and tools. After the mill had been assembled it was taken apart and the 4.500 pounds of stamp mill was transported to its final location above the entrance road to the museum. The museum crew took the stamp mill apart and lowered it down to its present location and reassembled the mill. The picture below shows the rigging of the mortar box down the hill on an improvised rail system.

 

The mill was set up at the present location, a sluice table added, a water sump and delivery piping and pump to complete the job. The mill has been tested and it works very well. This mill is capable of crushing 3 to 4 tons of ore a day. The picture below shows the completed 3-stamp mill setup.