Reprinted from the December 2005 edition of the CNS Bulletin (Vol. 26, No. 4)


The Eldorado Radium Silver Express

by J.E. Arsenault

Ed. Note: A CNS member, Jim Arsenault, is a retired reliability engineer living in Stittsville, Ontario, who has developed an interest in the early days of Canada's involvement in radiation and nuclear energy.   As well as the following bit of history he has been pursuing the papers generated at the Montreal Laboratory during the Second World War.


Preserving cultural artifacts has a long tradition in Canada, especially with respect to the arts.   However, with few exceptions, science and technology have until recently received little attention in this regard.   The situation is improving and there are a number of efforts now underway, particularly related to the nuclear field, aimed at preserving the scientific and technical accomplishments of the past.

A case in point is the work of the Western Canada Aviation Museum (WCAM) at Winnipeg, Manitoba, which is engaged in the restoration of an aircraft, the Eldorado Radium Silver Express, owned originally by Eldorado Gold Mines Limited, that was linked directly to the mining of uranium.

Eldorado Gold Mines Limited

Eldorado Gold Mines Limited was incorporated in 1926 but with the doubtful value of its claims associated with its mine at Long Lake, Manitoba, and the discovery in 1930 of pitchblende (uranium oxide) at Great Bear Lake, Northwest Territories, the company changed direction completely.   The point of land where the discovery was made by the company's Managing Director, Gilbert A. LaBine (1890-1977), became known as Port Radium.   The ore consisted of both uranium oxide and silver in significant amounts.   At the time, the mining economies were driven by the world price of radium, which was extracted from uranium oxide and sold on the world market for US$ 50,000 per gram or, taking inflation into account, about US$ 500,000 today.

With these considerations in mind, Eldorado set plans in motion to bring in a mine and mill operation at Port Radium, and a refinery at Port Hope, Ontario for radium.   The refining of the silver concentrates was to be contracted out.   One of the stark challenges was the great distance between the mine and the Port Hope refinery; the route that evolved was a water and railway combination of nearly 4000 miles.   The uranium concentrates were ferried westward across Great Bear Lake and down the Great Bear River, up the Mackenzie River, eastward across Great Slave Lake, then southward up the Slave and Athabaska Rivers, to the railhead at Waterways, a short distance up the Clearwater River from Fort McMurray, Alberta - a total of about 1450 miles.

The waterborne segment of the route was limited in capacity and was restricted to the short open-water season at those latitudes.   Consequently, an additional all-season transportation mode was developed quite early on, to bridge the gap between mine and railhead, during the bulk of the year when the lakes and rivers were frozen.

The Eldorado Radium Silver Express

In the 1920s, exploration in the north began to open up rapidly with the use of bush planes, which were capable of flying great distances and landing on both water and ice.   It was the use of a bush plane by geologists and others, including Gilbert LaBine, that led to the Great Bear Lake mining rush around 1930, which seemed like the only game in town in the depths of the depression.   In the early days at Port Radium, the uranium oxide concentrates were sufficiently rich to justify the use of aircraft to supplement the water route, and to fly in personnel and supplies.   For this purpose the Bellanca Aircruiser was selected [see Table 1].

This aircraft was designed in 1928 by Giuseppe Bellanca, to fly non-stop from New York to Rome - which it never did - but the essential design survived as a passenger and freight aircraft.   A total of 23 aircraft were built.   It was originally powered by a water-cooled engine but this was changed to a more reliable, air-cooled engine.   The final version of the Aircruiser was the most efficient aircraft of its day and with the air-cooled, supercharged engine it could carry 4000 1b payloads at speeds up to 155 mph.   The version that likely came to the attention of Eldorado was the floatplane which operated around New York City, as a ferry service between Wall Street and the East River.

CF-AWR was built in 1935 by the Bellanca Aircraft Corporation of New Castle, Delaware, and was the first of five of its type used in Canada.   It was operated for Eldorado by Mackenzie Air Service Limited of Edmonton, Alberta, and it was the second largest aircraft operating in Canada at that time.   Mackenzie was formed in 1932 by Leigh Britnell (1895-1971), coincidentally the pilot who first landed Gilbert LaBine on Great Bear Lake in 1929.   The aircraft was named the Eldorado Radium Silver Express but it was nicknamed `The Big Bellanca' or `The Flying W'.   It was identified easily by the characteristic W appearance, derived from the aerodynamically shaped, triangular lifting struts, which extend down from the bottom of the fuselage then up to a point outboard of the main wing.

Table I: Some characteristics of CF-AWR Eldorado
Radium Silver Express (Bellanca Model 66-70, sn 719)

Wingspan19.81 m (65 feet)
Wing area61.32 sq.m (660 sq. feet )
Length13.16 m (43 feet 2 inches)
Height4.04 m (13 feet 3 inches)
Engine700 hp Wright Cyclone SGR 1820F-32
Maximum speed 216 km/h (135 mph);
Cruise: 200 km/h (125 mph)
Maximum range1690 km (1050 miles)

Typical Weight Schedules (all in lbs.)
 Land PlaneSeaplaneSki plane

Typical load (for ski plane):


Typical load1290 
Available cargo:3589 

The first load of concentrates was flown out on 19 March 1935 and was landed at Fort McMurray [see Figure 1].   In the winter of 1936 a rail carload of 34 tons of concentrates was airlifted to the railhead at Waterways from the Port Radium mine, a distance of 710 air miles, and an additional 20 tons was flown to Fort Rae, on Great Slave Lake to take advantage of the earlier ice break-up there.   Fort Rae, at that lime, was an important fuel stop for planes on the route between Waterways and Port Radium.

Based on the fact that 130 mg of radium is usually found in a single ton of pitchblende containing 50% uranium oxide, and assuming the Port Radium concentrates were such in 1935, it would take about 8 tons of concentrates to produce 1 g of radium.   Allowing for two flights a week and 50% cargo space, enough concentrates to produce 1 g of radium per month was feasible, theoretically.   Due to downtime caused by freeze-up and break-up, only 10 months would be available annually for flight operations, thus limiting radium production to about 10 g per year from concentrates carried over the air route.

The Port Hope refinery produced 2.8 g of radium in 1934, 8.5 g in 1935, 15.5 g in 1936 and 23.8 g in 1937.    As Eldorado was interested in producing a steadily increasing output of radium, the economics demanded improvements in the less expensive but slower water route.   Plans were implemented to stockpile enough uranium concentrates at Port Radium, which could be moved by the water and rail route to Port Hope, to keep the refinery going for a year.   In 1936 Eldorado created a water-based shipping subsidiary by purchasing the Northern Transportation Company, and by 1938 it had cut the 1934 shipping rate by half.

The Eldorado Uranium Silver Express with Leigh Britnell (left) and Stan McMillan (right). (WCAM photo)

The Eldorado and Bellanca Legacy

The Port Radium mine was closed in 1940 during radium market saturation and disruptions caused by the Second World War, then it was reopened in 1942 to supply uranium oxide for the Manhattan Project.   In 1943, Eldorado was renamed Eldorado Mining and Refining Limited, in recognition that gold mining was no longer the main business of the company.   Uranium had by this time become a strategic material and Eldorado Mining and Refining became a Crown Corporation in 1944 and it was renamed Eldorado Mining and Refining (1944) Limited in 1945.   The mine ceased production of uranium oxide in 1960 due to economic considerations and by that time Eldorado had gone on to other developments.   The company became Eldorado Nuclear Limited in 1968, Eldorado Resources Limited in 1982, and later still it was merged with the Saskatchewan Mining and Development Corporation (in 1988) to form Cameco, now the largest uranium producer in the world, headquartered in Saskatoon, Saskatchewan.

Today nothing much more than a plaque exists at the Port Radium mine site.   It says, in part, "In order to supply this remote northern community and to transport the mines products, the mining companies pioneered aviation, marine and winter road transportation in northern Canada. ...production from the Eldorado ... mines included 13,700,000 lbs [6850 tons] of uranium oxide."

The Waterways dock and railhead property has been rehabilitated and forms part of the Fort McMurray public park system.   Along the edge of the Clearwater River only a few piles provide a physical link to an era long past but nearby at the Heritage Park in Fort McMurray, a 48-foot yard vessel built in 1946, the MV Radium Scout has been preserved and is on display in the open.

The Port Hope refinery now produces fuel for heavy water CANDU reactors and products for the export market, which are used to manufacture fuel for light water reactors.

By the late 1930s, Eldorado became less dependent on the Bellanca and increasingly dependent on the water route to move concentrates to the Port Hope refinery.   In August 1939, ownership of the Eldorado Radium Silver Express passed to Canadian Airways Ltd. of Winnipeg, Manitoba.   It remained in the service of Eldorado until the mine was closed in 1940.   CF-AWR served on floats and skis with Canadian Pacific Airlines, after it was formed in 1942 and took over the bush-plane operations of Canadian Airways Limited.

In January 1947, CF-AWR crashed and was damaged beyond economic repair, at the edge of Upturned Root Lake, about 130 miles northeast of Sioux Lookout, Ontario, as a result of fuel starvation.   It lay abandoned until 1973, when it was retrieved by the WCAM.

WCAM Restoration Project

After 26 years, volunteers from WCAM, assisted by a helicopter from the Canadian Forces, recovered the remains of CF-AWR from the bush.   At that time, most of the woodwork had rotted away, steel parts were badly rusted and trees had grown up through the skeletal remains.

The restoration was initially contracted out to an experienced mechanic who had worked on Bellancas for many years.   The fuselage frame was rebuilt from scratch, which required making everything back from the rear of the cabin, including much of the floor and wood framing, before it was brought back to the museum for completion.   New wooden spars were fabricated for the wings and all the stainless steel ribs were rebuilt one by one.   From 1990 to 1998 restoration work was limited but since then steady progress has been made.   All major structures have been rebuilt and a trial erection was made in 1998.   At present work is concentrated on the instrument panel, the engine and powerplant controls, the propeller and its controls, and fabric work [see Figure 2].

CF-AWR is one of only two aircraft of this type known to exist today.   The second aircraft, CF-BTW, also of Canadian registry, served into the 1970s and is presently located in a museum in the United States.

CF-AWR undergoing restoration at WCAM (author photo)


The Canadian nuclear legacy is only emerging slowly in the nations' museums and archives but there is the appearance of an accelerating trend.   The Bellanca Restoration Project by the Western Canadian Aircraft Museum is part of that trend and Canadians can undoubtedly look forward to other fine examples of historical preservation.

Western Canada Aviation Museum
Hangar T-2, 958 Ferry Road, Winnipeg, NIB R311 OY8
Tel (204) 786-0003 Fax (204) 775-4761
web site:   email:


Thanks are due to John Clearwater for drawing my attention to the WCAM, to Fred Boyd for encouragement with this article, to Carl and Elizabeth Vincent for Bellanca background material and to Brian Watson of WCAM for restoration details.


  1. Bellanca Airbus Aircruiser C-27 homepage: (accessed 050915).
  2. Bothwell, Robert. Eldorado: Canada's National Uranium Company. Toronto: University of Toronto Press, 1984.
  3. Gardiner, Paddy. "Bellanca's Flying in Canada," The Journal of The Canadian Aviation Historical Society 9, 1 (1971): 7-15.
  4. Jenkins, Robert G. The Port Radium Story. Summerland, BC: Valley Publishing, 1999.
  5. Liddell, Donald M., ed. Handbook of Nonferrous Metallurgy. Vol.2 - Recovery of the Metals. New York: McGraw-Hill Book Company, 1945.
  6. McNiven, J.G., "History of the Eldorado Mine, Port Radium," Canadian Institute of Mining and Metallurgy 60, 667 (November 1967): 1247-1207 and 60, 668 (December 1967): 1387-1395.

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