Caissons for Lions Gate Bridge
When it came to building foundation piers for the bridge’s two towers, physical conditions differed considerably on either side of the First Narrows channel. Stanley Park’s steep cliffs meant that the southern foundations had to be built in the water — not a simple feat, given the strong currents and tides. After the seabed was levelled off through blasting, caissons (watertight compartments) were put in place to enable underwater construction. These round structures reached down to bedrock and were 48 feet (15 m) in diameter and 41 feet (13 m) high. Made of steel, concrete and timber, they were built on the bank, then floated and sunk into place. Once the footings had been built inside them, handsome granite facing specified by the architects was placed around the portions of pier visible above the waterline.
Unlock history! Scroll down and click on thumbnails.
An early construction photograph. “Both caissons are in position and underwater operations are being pushed,” the photographer wrote of this scene.
This is on the south side of the First Narrows entry into Burrard Inlet, below the cliff and at the end of the Stanley Park causeway.
This picture was taken on October 6, 1937, a little over six months after construction had begun.
North Vancouver resident and amateur photographer David Loughnan took this photograph and many others documenting the bridge’s construction.
More Pictures Below