Canada Line Bridge Looking south from South Kent and Cambie street - January 13, 2008 - Vancouver BC.

The first span of the bridge extends to Mitchell Island's Western tip then touches down at Lulu Island covering the North Arm of the Fraser River. This bridge design is what engineers call an ‘extradosed’ structure. Extradosed is a new bridge form that is really a hybrid between a conventional cable-bridge and post-tension box girder bridge making the first bridge of its kind in North America.

The decision to opt for the extradosed method of construction was prompted by the new bridge’s location, which is near a flight path of incoming aircraft to Vancouver International Airport.

An extradosed bridge uses shorter towers to support, via cable, the bridge’s deck segments. The effect of these cables, placed at lower angles, is two-fold. Not only do they support the bridge’s segments, with the cables transferring the weight to the towers and into the footings but the lower angle of the cables from the shorter tower provides a pre-stressing cable for the bridge deck. In the case of the North Arm bridge, the towers are only 21.4 meters above the level of the deck.

Directly to the North of this location, iron workers scramble upon a huge "Span by Span" Launching Equipment apparatus that rides on top of the cement foundation towers of the raised Canada Line platform. The Launching Equipment built by DEAL installs precast box segments to create the track platform.

The rail-based rapid transit line will open in 2009. The 19.5 km line with 16 stations will link central Richmond, the Vancouver International Airport, and Vancouver along the Cambie corridor to central Broadway, the downtown business district and Waterfront Station. The Canada Line will provide a important expansion to the existing rapid transit network.