Goldstream Dredge No. 8
(Posted August 26, 2000, Herbert E. Lindberg)


After those of us who successfully panned gold with Andy Wescott (I wasn't one of them) had it weighed and bottled, we hopped back onto our motor coach and proceeded to Goldstream Dredge No. 8, where we had cafeteria-style lunch in the old mess hall. Then we watched a short video on gold dredging and met Bob in front of a tin shed where he explained the operation of No. 8, on which he had served as crane operator for many years.

Bob explains the operation of his river dredge


In a better view (below) of the chart behind Bob you can see the main elements of the dredge. Operation begins with the Pivot Spuds at the upstream end of the dredge (on the left in the chart). There are two of these tall, heavy stakes, one on each side, which the captain can raise and lower into the river bed. He jockeys the dredge into position by anchoring one spud and letting the barge swing around it. Then he lowers the other spud, raises the first spud, and lets the barge swing around the second spud. In this way he waddles the barge across the river to the exact location he wants for dredging. With both spuds lowered the dredge is firmly anchored.

Key elements of the No. 8 dredge


Most of the rest of the operation is clear from the chart. The bucketline scoops gold-bearing gravel from the river and drops it into the washing trommel, which is a large, rotating barrel with holes all around it. As the gravel passes through the trommel in a shower of water, the fines fall through the holes and into sluice boxes below. The coarse material continues on through the trommel and falls onto a conveyor belt that dumps these tailings back into the river behind the dredge. Gold falls with the fines into the sluice boxes where further washing takes place. Gold (specific gravity 19.32), being much more dense than rock, falls into gaps between slats across the bottom of the sluice box. About once a day digging operations are stopped and the material caught by the slats is scraped into containers for final extraction of pure gold.

The picture below gives a feel for the size and shape of the actual dredge. This dredge was built in 1928 and was in operation until 1959. Some upgrading of the wooden structure was done more recently, to make it suitable for visitor viewing.

Dredge No. 8 viewed from the downstream (bucketline) end


With the sun behind me instead of into the camera as in the picture above, I got a much better view of the bucketline and support structure. This and two more pictures below it put into reality some of what was involved in operating the dredge.

Bucketline viewed from operator's room

Washing trommel viewed from operator's room
Take-up reels and machinery on lower level

Continue to Fun at Alaskaland - - - Return to Alaska hub page - - - Return to Home Page Top