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Photos courtesy of Mike and Joan Sinnwell June 2008
Gold Dredge Number Eight Fairbanks Alaska
I have always wanted to see the inside of a dredge. This was a opportunity for me to experience first hand what it must have been like. I was able to wander through the dredge at my leisure and imaging the buckets scooping up the creek bed, the soil, the rocks, the trommels separating the gold and the waste being ejected out the back. Okay it wasn't operating but it sure let me see how they did work. I have been in numerous other dredges but none that were this complete and accessible. Here is the story of the dredge.
On July 22, 1902, Felix Pedro discovered gold on Pedro Creek, 16.5 miles northeast of Fairbanks. During the years following Pedro's discovery, numerous small mining ventures used placer and crude underground mining methods to extract nearly $7 million worth of gold. Mining operations were limited to the winter months when tunnels could be kept dry. By 1920, miners had exhausted the supply of readily accessible gold.
In that same year, Fairbanks Exploration Company entered the field north of Fairbanks and acquired large blocks of already-worked claims. The organization invested an additional $10 million in equipment and in construction of the Davidson Ditch which delivered water to the mine sites and allowed for the operation of eight giant dredges.
One of those eight dredges, Dredge No.8 was manufactured in 1927-28 by Bethlehem Steel Company, Ship Building Division. The equipment was shipped from Pennsylvania by transcontinental railroad and by ocean-going barge to the Alaskan Railroad to be assembled in early 1928 just west of Fox, Alaska at the head of the Goldstream Valley.
Gold Dredge No.8 has a 43 foot 9 inch high bow-gantry which supported the belt-driven bucket line, with its 68 manganese steel buckets, each with a capacity of 6 cubic feet and weight of 1,583 pounds. The buckets were mounted on a steel digging ladder which measured in excess of 84 feet. The bucket line discharged gravel in to a dump-hopper to a belt-driven trommel-screen, where perforations ranging in size from 3/8 to 1-5/8 inches, sized the gravel. During the process, an occasional large nugget would stick in the screens as the dredged material traveled down a gentle decline. In the trommel, the relatively heavy gold fell through the screens; the rocks and gravels passed onto a conveyor belt to be discharged. Nozzles inside the trommel drum were used to wash the gold from the gravel before it was carried by a steel-reinforced conveyor belt to the tailing pile behind the dredge. This process resulted in removal of approximately 97 percent of the gold from the rich gravels. It operated each year until 1959.