The Old Ways: The monster gold dredges multi-story machines built in the first Half of the 1900s

Tuolumne Gold Dredge -- a.k.a. "Gray Goose" -- in La Grange, California @ Michael Holshouser

A gold dredge is a placer mining machine that extracts gold from sand, gravel, and dirt using water and mechanical methods.

The original gold dredges were large, multi-story machines built in the first half of the 1900s. Small suction machines are currently marketed as “gold dredges” to individuals seeking gold: just offshore from the beach of Nome, Alaska, for instance.

A large gold dredge uses a mechanical method to excavate material (sand, gravel, dirt, etc.) using steel “buckets” on a circular, continuous “bucketline” at the front end of the dredge.

The material is then sorted/sifted using water. On large gold dredges, the buckets dump the material into a steel rotating cylinder (a specific type of trommel called “the screen”) that is sloped downward toward a rubber belt (the stacker) that carries away oversize material (rocks) and dumps the rocks behind the dredge.

The cylinder has many holes in it to allow undersized material (including gold) to fall into a sluice box. The material that is washed or sorted away is called tailings. The rocks deposited behind the dredge (by the stacker) are called “tailing piles.” The holes in the screen were intended to screen out rocks (e.g., 3/4 inch holes in the screen sent anything larger than 3/4 inch to the stacker).

The basic concept of retrieving gold via placer mining has not changed since antiquity. The concept is that the gold in sand or soil will settle to the bottom because gold is heavy/dense, and dirt, sand and rock will wash away, leaving the gold behind. The original methods to perform placer mining involved gold panning, sluice boxes, and rockers. Each method involves washing sand, gravel and dirt in water. Gold then settles to the bottom of the pan, or into the bottom of the riffles of the sluice box.

The gold dredge is the same concept but on a much larger scale.Gold dredges are an important tool of gold miners around the world.They allow profitable mining at relatively low operational costs. Even though the concept is simple in principle, dredges can be engineered in different ways allowing to catch different sizes of gold specimen. Hence the efficiency of gold dredges differs greatly depending on its specifications.

By the mid to late 1850s the easily accessible placer gold in California was gone, but much gold remained. The challenge of retrieving the gold took a professional mining approach to make it pay: giant machines and giant companies. Massive floating dredges scooped up millions of tons of river gravels, as steam and electrical power became available in the early 1900s.

The last giant gold dredge in California was the Natomas Number 6 dredge operating in Folsom, California ceased operations on 12 Feb 1962 as cost of operation began exceeding the value of the gold recovered. Many of these large dredges still exist today in state-sponsored heritage areas (Sumpter Valley Gold Dredge, Dredge. No. 4 National Historic Site of Canada) or tourist attractions.

Lets have a look at some abandoned and neglected relics of the past:

Bucket Ladder Floating Gold Dredge

 

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Fairbanks Exploration Company, Goldstream Dredge No. 8, Fox, Fairbanks (North Star Borough, Alaska) As it is today – Fairbanks Exploration Company Goldstream Dredge No. 8

 

Gold Dredge diagram Gold Dredge #8, near Fairbanks, Alaska Photos: Historic Chatanika Gold Dredge No. 3 The historic Chatanika Gold Dredge No. 3, outside Fairbanks, burned in August 2013, destroying the wood and metal structure. But its story isn’t over yet. Courtesy Jane Haigh Gold Dredge at Sumpter Oregon. They weren’t exactly small

In the late 1990s and through today, dredging has returned as a popular form of gold mining. Advances in technology allow a small dredge to be carried by a single person to a remote location and profitably process gravel banks on streams that previously were inaccessible to the giant dredges of the 1930s. Today dredges are versatile and popular consisting of both floating surface dredges that use a vacuum to suck gravel from the bottom and submersible dredges. In 2015 goldminer Tony Beets is reconstructing a 70-year-old dredge (as seen in the popular TV series on Discovery channel ‘Gold Rush’).

Until September 2007 this gold dredge sat alongside the Taylor Highway between Dawson City, Yukon and Tok, Alaska. Due to its deteriorating condition and safety concerns, the Bureau of Land Management (BLM) had it removed. Some major parts were set up as an interpretive display near the Chicken post office, but the majority of it went to the Tok garbage dump. Jake Wade Dredge

 

3 story tall Gold Dredger near Lewiston, 1950. Photo courtesy of the Trinity County Historical Society. A photo of a dredge in operation may be the Josephine and was probably taken in the spring of 1900. Note the man standing on the roof. A disabled gold dredge near Nome, Alaska 1908.

 

An Australian dredge. It weighed over 1000 tons (.907 tonnes) and had 63 ten cubic foot (0.28 cubic metre) buckets, each capable of gouging the alluvial gravels at the rate of 23 buckets per minute, 24 hours a day. source A.F. Graeter Gold Dredge – Bannock, MT

 

Oregon has a long history of gold mining though it’s not discussed much anymore. Alva Day photographed this gold dredge in March, 1928, apparently up near the John Day river.

 

Gold Dredge operating in Nome, Alaska in 1993

 

The Sumpter Valley Gold Dredge is a historic gold dredge located in Sumpter, in the U.S. state of Oregon. Gold was discovered in Sumpter in 1862. Three gold dredges were put into service in the Sumpter Valley district between 1912 and 1934.

 

There were once three of these working the Powder River, this is Dredge #3. The remains of Dredge #2 can be seen on the North side of town in a pond it made, while the remains of Dredge #1 are in a pond about six miles south at what was once McEwen. Besides the tailing piles that line the river and make it look more like a series of ponds these days, one of the first sights in town is a collection of logging and mining equipment on the right side of town.

 

Lead image Michael Holshouser