Work on Port Mann bridge delayed after crane mishap

The gantry crane used to place pre-cast concrete segments for the new Port Mann Bridge in Greater Vancouver collapsed and dropped a massive section of the deck into the Fraser River.

“The yellow and blue gantry crane we use to install the pre-cast concrete sections of the north approach to the bridge experienced a malfunction this morning and is now leaning to the south,” said Max Logan, spokesperson for the Transportation Investment Corporation.

“At the time of the malfunction, one of the pre-cast concrete sections fell into the river. This section of the river was already closed due to overhead construction work,” said Logan. “There were no injuries and no impact on the travelling public.”

The incident happened at about 8:30 a.m. on Feb. 10.

“The site was cleared and secured immediately, while crews were sent home and are not working today,” said Logan.

According to Logan, the 90 tonne section is still in the water.

It will be removed, but he doesn’t know when this will happen.

A gantry is a horizontal crane, which fits objects in a large trolley and lifts them with a hoist. The objects are moved horizontally on a rail or pair of rails. There is no cabin for an operator, like a traditional crane. The gantry is operated by remote control.

“The decision about when they return to work will depend on the contractor and WorkSafeBC, who is carrying out an investigation,” he said. “The general contractor is also carrying out their own investigation to determine what happened.”

These investigations will determine how the malfunction occurred and the impact this incident will have on the construction schedule.

Initial reports indicate that one of the supports for the gantry was crushed and the whole apparatus pitched forward.

The gantry being used on the new Port Mann Bridge is 19 metres wide, 13 metres tall, 155 metres long and weighs 720 tonnes.

The crane is being used to place the pre-cast segments for the new bridge deck. The work started on the south approach in Surrey and then moved to Coquitlam to install the north approach segments.

The newly placed segments become a platform for the crane as the bridge installation moves forward.

“To date, the gantry has been used to install 1,000 concrete segments,” said Logan. “This is the first incident of this kind.”

There are 1,158 new bridge deck segments being fabricated in Coquitlam.

Out of this total, 327 pre-cast segments will have been trucked from the pre-cast yard in Coquitlam across the existing bridge to the south bridge construction site and 831 pre-cast segments will be trucked to the north bridge construction site.

Peter Kiewit Sons Co. and Flatiron Constructors Canada Limited were awarded a $2.46 billion fixed-price contract by the B.C. government to design and build the new bridge and to widen Highway 1 for 37 kilometres on the east and west sides of the Fraser River.

The project includes the construction of a new 10 lane bridge, upgrading interchanges and improving safety and access between McGill Street in Vancouver and 216th Street in Langley.

Construction of the new bridge is expected to create about 8000 jobs and is scheduled for completion by 2013.