Yukon Gold Company Dredge No. 3, c1920
black and white image of Yukon No 3 dredge.
Inscription recto: Wolfe Photo Dawson Y.T. [ A date may also be inscribed but has been cut off and is indecipherable.]
Caption: Yukon No. 3 – A typical Yukon Gold Co. dredge operating near the mouth of Bonanza Creek. There were as many as seven of these dredges operating at one time, two on each of the richer creeks, beginning in 1907. By 1920 nearly all of the major creeks on which Yukon Gold Co. had property had been dredged and only one dredge was operating.
The dredge uses a line of 60 heavy manganese steel buckets of a cubic yard capacity each, the line suspended from a gantry at the right. The buckets dug 30 feet deep, taking up the gravel and also biting into the bedrock in the crevices and irregularities of which gold had lodged. The gravel conveyed to the top centre of the dredge fell into a series of slowly revolving sloping drums with perforated steel walls. Water sprayed the length of the drum washed small gravel, sand, dirt, gold through drums with constantly smaller openings. The fine material containing gold went with water through sluice boxes with transverse riffles to catch the gold. Behind the larger rocks went out the incline to the left as “tailings.” The sluices were cleaned at least once a week, yeilding [sic] at least $250,000 (with gold at $20 per ounce). On richer creeks and richer spots it was necessary to “clean up” twice a week.
The “navigation” of the dredge utilized either or both of the “spuds,” the large vertical pile driver like structures at the rear of the dredge. Typically one of the “spuds” would be lifted and dropped with force into the bottom of the pond. The dredge would then be pivoted from side to side in a semicircle as it dug. When the dredge had exhausted its reach, the spud would lift, the dredge winched forward and the spud dropped again. This accounts for the series of semicircular ridges of the tailings. The dredge “carried” it’s pond forward with it.
