Dry Gulch Bridge on BC Highway 5 is a steel arch bridge.
According to the dictionary, a bridge is: “a structure carrying a road, path, railroad or canal across a river, ravine, road, railroad or other obstacle”.
That’s a basic and accurate description of a bridge to be sure, but here at the Ministry of Transportation and Infrastructure, we think of bridges as something more than just a structure crossing a span. We think of bridges as a special type of infrastructure. Bridges inspire. Bridges open possibilities. Bridges connect. To us, bridges are a pretty big deal.
Because British Columbia is so geographically diverse and because bridge engineering evolves over time, you will see a variety of bridge types being used in BC. In order to span a crossing, a bridge must have support. That support system can be above or below the bridge deck. Bridges can be constructed out of steel, wood, metal or concrete or a combination of these materials. With these basic ideas in mind, we would like to introduce you to some general types of bridges used in BC.
This is a type of bridge in which the weight of the deck is supported by vertical cables suspended from larger cables that run between towers and are anchored in abutments at each end.
Hudson’s Hope Bridge is a beautiful example of a suspension style bridge. Built in 1964, this bridge is located on Highway 29 west of Fort St. John. Suspension bridges use cables to support the bridge deck along the span.
Built in 1938, the iconic Lions Gate Bridge is the most recognizable bridge in BC and another excellent example of a suspension bridge.
A truss is a structure built out of tension and compression sections. These sections are arranged in triangular patterns to provide strength and stability. A truss bridge is a bridge with a load carrying superstructure made of trusses. Truss bridges are generally made from either steel or timber or a combination of both. Trusses can be presented on top of the bridge deck (a “through” truss) or under the bridge deck (an “under” truss).
The Oyster River Bridge near Campbell River on Vancouver Island is a timber “through” truss bridge. Basically, this is a bridge with a timber truss which you drive through.
The Bell Irving River Bridge is a steel truss bridge. Like the Oyster River Bridge, you drive through the trusses, but in this example, those trusses are constructed of steel instead of timber. If you look closely at this image, you will notice that this bridge has a metal deck used to reduce the weight of the bridge. The Bell Irving River Bridge was constructed in 1967 and is located about 100 km north of Cranberry Junction on Highway 37.
The Simon Fraser Bridge, built in 1963, is a deck over steel truss bridge which with an arch shaped bottom profile spans the Fraser River in Prince George. It was twinned with a second bridge in 2009.
An interesting and artistic perspective of the steel “under” truss of the Simon Fraser Bridge.
St. Mary’s Wycliffe Bridge, built in 1931, is a lovely example of a timber bridge with trestle spans and a deck over a timber truss support.
3. Arch Bridges
Are steel or concrete bridges constructed in the form of an arch or arches, typically with concrete abutments.
Big Qualicum Bridge is concrete arch bridge with concrete girders located along Highway 19 on Vancouver Island.
Dry Gulch Bridge on Highway 5 is a steel arch bridge.
Chilcotin BridgeLike the Dry Gulch Bridge featured above, the Chilcotin Bridge (located in the Cariboo region) is another classic example of a steel arch bridge. Unlike Dry Gulch Bridge, this arch uses a truss configuration.
The Culliton Bridge is a tied steel arch with the arch above the bridge deck. Built in 1983 it is located on Highway 99, also known as the Sea to Sky.
4. Cable Stayed Bridges
A cable stayed bridge has one or more towers from which cables support the deck.
The Pitt River Bridge, constructed in 2010, is an elegant example of a cable stayed bridge. Other examples of cable stayed bridges in B.C. include the new Port Mann Bridge and the Alex Fraser Bridge. All three are located in the lower mainland.
5. Girder Bridge
A bridge constructed with wood, steel or concrete girders.
The Park Bridge (the inspiration for our TranBC logo) is a curved steel girder bridge on concrete piers. Constructed in 2007, it is located on BC highway 1 between Field and Golden.
Another type of bridge which often goes unnoticed but is actually a very common bridge type in BC is the overpass. This is the Bostock Road Overpass, located on the Trans-Canada Highway in Kamloops. This bridge is made up of pre-stressed concrete box beams and supported on mechanically stabilized earth wall abutments.
This stunning structure is called Kiskatinaw Bridge. Located in the Peace region, it is a steel frame bridge built in 1978.
Built in 2010 on Vancouver Island, Large Creek Bridge is constructed out of glulam timber girders. Glulam is glue laminated timber, a structural timber made out of a number of layers of timber bonded together with durable, moisture-resistant adhesive.
6. Floating Bridge
These bridges are sometimes called pontoon bridges and they really do float.
The William R. Bennett Bridge on Highway 97 across Okanagan Lake was completed in 2008 and is one of only a few floating bridges in the world. The crossing is about 1060m long of which 700m are on floating concrete pontoons. The structure has five lanes plus an elevated span to allow passage of marine traffic.
So, now you know some of the basic types of bridges in British Columbia, you can amaze your friends and family with your new found knowledge on your next road trip. Looking for more information on a bridge, or type of bridge which we didn’t cover here? Let us know in the comments below.