Canadian Klondyke Mining Company Dredge No. 4

Where: Bonanza Creek, YT.

Date of construction: 1913

Canadian Klondyke Mining Company Dredge No. 4 (Source: Wikipedia)

Site Location: Lat.: 63° – 56’ – 36” N.; Long.: 139° – 20’ – 6” W. (GPS: 63.9433452, -139.3350078). From Whitehorse, take Yukon Highway 2 north 515 km towards Dawson City. Just before crossing the Klondike River, turn left (south) on Upper Bonanza Creek Road, and proceed 12.1 km to the dredge.

Plaque Location: The plaque is temporarily in storage while site work is done at Dredge No. 4. It is envisaged that the plaque will be mounted on a boulder at the dredge when the site work is complete.

Description: After the Klondike Gold Rush (1896-1899), 19 bucket dredges mined placer gold in Yukon between 1900 and 1966. Dredge No. 4, purchased from the Marion Steam Shovel Co. of Ohio, was shipped dismantled from Vancouver to Skagway, carried on to Whitehorse on the White Pass and Yukon Route Railway, and carried on to Dawson by sternwheeler. Teams of horses hauled the last hundred tons of dredge machinery to the dredge assembly site in February 1913 after the last sternwheeler was frozen about 40 km (25 mi.) south of Dawson in October 1912.

Longitudinal section through bucket dredge (Source: Historic American Engineering Record)

Gold dredges float on a moving pond of water, picking up gold-bearing gravel using a chain of buckets at one end and discarding the waste gravel through the discharge stacker at the other. Inside the dredge, the buckets empty into a hopper that feed an inclined revolving circular screen, or trommel, where large volumes of water wash the fine material into the distributor, where it is directed to the sluice boxes.

Dredge No. 4, eight storeys high and two-thirds the size of a football field, has a displacement weight of over 2700 tonnes (3000 tons). It could dig material from 14.6 m (47 ft.) below water level to 5.2 m (17 ft.) above water level using iron buckets with 0.45 m3 (16 cu. ft.) capacities, processing 14,000 m3 (18,000 cu. yds.) per day. The Canadian Klondyke Mining Company operated Dredge No. 5 on the Klondike River from May 1913 to October 1940. The Yukon Consolidated Gold Corporation rebuilt the dredge, using the original machinery with new timber, at a Bonanza Creek site, operating it from 1941 to 1959. It is now a National Historic Site.

Dredge No. 4 in operation in 1916. (Source: Wikipedia)
Satellite view of tailings created by dredges east of Dawson City. The sweeping motion of the tailings stacker created the arc-shaped pattern of the tailings. (Source: Google Street View)

Historic Significance: Dredge No. 4 is the largest placer gold dredge in North America and the only remaining intact dredge that operated in Yukon. It symbolises the evolution of gold mining from a labour-intensive activity to a mechanical process. This large-scale mining era in the north, after the Klondike Gold Rush, pioneered cold-regions engineering techniques in northern planning, northern transportation, northern water resource development, northern mining. This era also pioneered northern construction techniques that address the challenges of cold weather, permafrost, and geographical isolation.

Plaque detail. (Source: K. Johnson)

Plaque Wording: Historic Civil Engineering Site. CSCE. CANADIAN KLONDYKE MINING COMPANY DREDGE NO. 4. A tribute to the engineers, and contractors who designed, built, and operated “Canadian Klondyke Mining Company” Dredge No. 4 from 1912 to 1959. The all wood dredge was designed to float and support 3000 tons, including a chain of 68 large iron excavating buckets. Gold dredging operations in the Klondyke from 1900 to 1966 also included large hydro electric, water supply and machine shop facilities. Dredge No. 4 produced 300,000 ounces of gold and mined 65 million cubic yards of gravel. Canadian Society for Civil Engineering 2012.

SCGC. Site Historique de Génie Civil. DRAGUE NO 4 DE LA COMPAGNIE MINIÈRE CANADIENNE KLONDYKE. Un homage aux ingénieurs et entrepreneurs qui on conçu, construit et utilise la drague no 4 de «la Companie minière canadienne Klondyke» de 1912 à 1959. Construite entièrement en bois, la drague fut conçue pour flotter et supporter un poids de 3 000 tonnes ainsi qu’une chaîne de 68 grands godets d’excavation en fer. Les operations de dragage d’or menées de 1900 à 1966 dans le Klondyke ont aussi inclus des installations hydro électriques, d’adduction d’eau et d’un atelier de machines. La drague no 4 a produit 300,00 onces d’or et extrait 65 millions de yards cubes de gravier. 2012. Société canadienne de genie civil.

Plaque Unveiling Ceremony: The plaque was unveiled at Hanger 14, the Alberta Aviation Museum, as part of the 2012 CSCE Annual Conference in Edmonton.

The plaque was subsequently unveiled on site on June 30, 2012, by Patrick Habiluk, former Dredge #4 Recovery Project Manager, and Carrie Docken, former Parks Canada Visitor Services Manager. Mr. Habiluk presented a brief description of the historical significance of the dredge on behalf of CSCE National History Committee member Ken Johnson, who co-ordinated the nomination, to an audience of 150.

Plaque unveiling at Dredge No. 4. From left: Sandy Silver, Klondike Region M.L.A.; Patrick Habiluk; Carrie Docken; Hugh Copland, former Parks Canada Asset Management Advisor; David Rohatensky, former Parks Canada Superintendent, Klondike National Historic Sites. (Source: P. Habiluk)

Links to Online Documentation:

Canada’s Historic Places, “Dredge No. 4 National Historic Site of Canada”.
Yukoninfo, “Dredge No. 4”.
Kathleen Murphy and Alex Barbour, “Dances with Wires: An Unusual Rigging Project”, San Francisco Maritime National Park Association, 1997.
Ken Johnson, “Gold Dredging in the Klondike and Number 4”, CSCE Edmonton Conference Proceedings, 2012.

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