St. Andrew's Lock and Dam

St. Andrew's Lock and Dam

Completed in 1910, this engineering system is comprised of three elements; a dam, a lock, and a bridge. The design employed a Camere style dam and, at 240 metres long, it is the largest dam of this type ever built. It is also considered to be the only one still in existence in the world. It continues to operate to this day, regulating the water level of the Red River. It also allows river traffic to operate between Winnipeg and points downstream, while providing a link for road traffic across the river.

Quick Facts

• Dam constructed 1907-10.

• Bridge constructed 1912-13.

• Modifications in 1949 to increase loading capacity.

• Frame and curtain replacement in 1967. (1)

• Metallized in 1999 (2)

Location

Lockport, Manitoba

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Why

Prior to it's construction, there wasn't a singular mode of transportation between areas downstream of Selkirk (including all of Lake Winnipeg) and areas upstream of St. Andrew's. At the time, there were no rail lines connecting Winnipeg with areas North of it. The elevation drop of the Red River (approximately 13 feet between between Middle Church and Lister Rapids) also prevented freighter ships from navigating through the area currently known as Lockport.

Immediately after the opening of the locks and dam, freighter ships as large as the "Winnitoba", which could carry 2,000 passengers and thirty-five carloads of freight, could provide a viable link. These passenger and freighter ships ensured economically sustainable development of fisheries, farming land, and mineral resources. (3)

With the competition of rail lines and road transportation, the use of the locks for river travel waned considerably by the middle of the 20th Century. However, the dam continues to provide a key role in flood mitigation as a control structure.

How

The St. Andrew's Dam is a unique “Camere” style dam using moveable curtains consisting of horizontal sections of wood hinged together, which are raised or lowered to control water flows. Invented by French engineer M. Camere, this type of dam was popular in western Europe in the late nineteenth century.

The structure consists of:

• Seven 15 m high concrete piers

• Steel trusses approximately 40 m long that span between the piers

• A 6 m high by 11 m wide concrete sill or fixed dam that joins the bottom of the piers.

• 15 steel frames per span which are hung from the trusses, and

• 89 wood curtains

The design consists of a repeating series of two movable components. The first is a steel frame that is stored horizontally when the dam is not restricting flow. These frames are hung from the upper structure and are rotated down from an axis that is transverse to the flow of the river and located at the top end of the frame.

Attached to these frames are curtains, 4 m long and 2.1 m wide and consisting of 50 individually sized Douglas Fir laths held together with brass hinges and pins. During the navigation season the curtains are individually rolled up to increase flow, or rolled down to restrict flow, depending on daily water flow rates in the river.

Fun Facts

• The Canadian government constructed the dam and lock as part of a proposed river steamboat navigation system extending from Winnipeg to Edmonton.

• The total cost of construction was $3.5 million by 1913.

• It was opened by the Honorable Wilfred Laurier, the Prime Minister of Canada, from the deck of the Winnitoba, which was built in Winnipeg.

• During construction, organizations prearranged excursions to see the work in progress. A special trail for visitors was created from Winnipeg and Back. The cost was 45 cents return, allowing them two hours to inspect the project.

Also See

Camere dam, curtain dam (US) (it was invented by Camere and introduced in 1876-1880 at Port Villez on the lower Seine. In it wooden curtains that can be rolled up from the bottom were substituted for the needles in the Poiree weir) Camerewehr, Rolladenwehr, Jalousiewehr, Rollvorhangwehr

Key Player

Mr. A.R. Dufresne - Construction Engineer. Mr. A. St. Laurent and H.E .Vautelet, Design Engineers

References

1. http://www.historicplaces.ca/en/rep-reg/place-lieu.aspx?id=4441
2. http://www.tac-atc.ca/english/resourcecentre/readingroom/conference/conf2004/docs/s5/bowen.pdf
3. http://www.mhs.mb.ca/docs/pageant/11/locks.shtml
4. http://www.historicplaces.ca/en/rep-reg/place-lieu.aspx?id=4441
5. http://lockportmanitoba.ca/history.swf
6. http://www.stclementsheritage.com/index.php/heritage-articles/transportation/influence-of-the-river/st-andrews-lock-and-dam/