Persons having occasion to climb the many flights of stairs to the head–feeder floor at the Ahmeek Mill has noticed a change of scene there in recent months. In addition to the regular lighting system, there are now rows of blinking lights, both white and colored, which appear to be flashing on and off as far as the eye can see. Closer inspection will reveal that considerable other electrical equipment has been added–counters, relays, more lights and a maze of wiring. The installation looks complicated, but has a very simple assignment.
The eight Nordberg compound stamps in the mill, which now handle our entire mine rock production, were designed and built to operate with a stamp shaft stroke of about 24″. Operation with a shorter stroke prevents stamping at full capacity, and wastes large quantities of steam. Since each stamp consumes about $100 worth of steam per day, we cannot afford to throw a very large fraction of this away.
For the first 37 years of mill op-eration there was no way of determining definitely how much of the time the stamps were operating in the proper range of stroke. The elec-trical equipment was installed to get this information.
The unobtrusive but ever-watchful operator of this assortment of equipment is a small photo-electric” eye, suspended from the upper floor near one leg of the main frame of each stamp. In a corresponding posi-tion near- the opposite leg is a light source; which directs a narrow beam of light at the eye. When the head–feeder feeds rock into the mortar in such a manner as to allow the stamp to make a full stroke, the stamp shaft obstructs the light beam at the bottom this stroke, thus enabling the eye to “see” it.
Whenever the eye observes that such a low stroke has been made, it immediately flash-es a signal through “blinker” lights, to let the head feeder and mill run-ner know that the stamp is operat-ing in the proper range. Since the eye itself doesn’t have a good mem-ory, it needs assistance in remember-ing how many low strokes were made during each shift. This assis-tance is supplied by a small counter which “kicks” over a number every time the blinker flashes. Thus, the total number of low strokes for any period can be determined by obtain-ing the counter reading at the begin-ning and end of that period. Also, a pen recording set in the mill pump house shows the time distribution of all low strokes made on every shift, by “writing” on a moving chart.
To date, the information obtained by this equipment has been very en-couraging, indicating that a large majority of the head-feeders are op-erating their stamps in the full stroke range. The headfeeders on Foreman A.W.Grief’s shift have maintained an exceptionally high average stroke score, and the other shifts are improving steadily. The information also indicates that on those shifts which have high average “count” the steam consumption is less than on those with a low aver-age. This and other information in-dicates that the equipment will be a very valuable aid in following mill performance and maintaining top efficiency.

I had heard rumors that the park is very interested in this baby, and has written up plans for its removal and rehabilitation. But I guess its very expensive (that stamp is very heavy I’m sure) and is waiting on funding. Why it had survived relatively intact however, is still a mystery.

Really funny that you posted it when you did.

John