March 26, 2008

Occupational Health and Safety

ITC Construction Group and Metrocan Construction Ltd. employ Canada's first anti-collision safety system for tower cranes

JOHN NICKEL

Seven of the 12 cranes currently in use on Vancouver Olympic village will soon have a new anti-collision system in place.

RICHARD GILBERT

staff writer

The cranes used to build Vancouver’s Olympic village will be the first ever in the country to use a new anti-collision safety system.

The ITC Construction Group and Metrocan Construction Ltd. will use the system to prevent collisions between seven of the 12 tower cranes operating on the Millennium Water construction site in southeast False Creek.

Four of the cranes getting the collision prevention system belong to ITC and three belong to Metrocan. The cranes, which are all at similar heights and close together, are being fitted with a sensitive alarm system to warn operators if they are in danger of swinging into a neighbouring crane.

“When we looked at the scope of the Millennium Water project, we knew there would be a number of challenges,” said Jeffrey Lyth, the director of health and safety for the ITC Construction Group.

“There were a number of cranes on the site and one crane in the middle of the site was overlapping with five other cranes.”

After Lyth completed a job hazard analysis of the site, he asked Betty Ann Lee at WorkSafeBC about different safety systems. With Lee’s help, he selected the TAC-3000 Tower Crane LMI Safety System.

“Basically, how the system works is that we take a site plan and measure the distance between cranes. We identify the relative position of cranes between each other and program positions into the software system,” said Kendall Strysick, president and CEO of Persha Inc., the North American distributor of the TAC-3000.

“We calibrate this information into the cranes, so they can work together as a team. We can calibrate 252 cranes together at one time on the same job site.”

The TAC-3000 detects and anticipates the risk of collision when multiple tower cranes are in use.

“The key to the TAC 3000 is a guidance system, which works off the earth’s magnetic flux. The system has a similar style of navigation to commercial airplanes, military ships and cruise ships,” Strysick said.

Most of the tower cranes in B.C. were built in the 1980’s and early 1990’s and don’t have a Load Moment Indication (LMI) system.

“The LMI system brings old technology based cranes, like all the cranes at the Athlete’s Village, up to modern day technology.”

Strysick explained that an LMI system is the latest advancement in tower crane safety.

For example, when the risk of a collision is detected, the system calculates the relative distance in real-time between potential collision paths. It alerts the operator, on an LCD screen and audibly, with the collision information and sends a signal to the other cranes.

“The majority of crane cabs face forward and don’t have rear view mirrors. The monitor displays the colliding crane from front/back and left/right,” Strysick said. “The system gives the operators eyes in the back of their head and the ability to protect behind them.”

The system also allows the tower crane to remain in the operator’s control, if safe working distances are compromised.

“At all times the operator has the ability to steer away from a collision,” he said.

If a crane does get too close to another crane, alarms will sound and the system will monitor the operator’s response.

If the operator is unable to stop the crane’s movement, the system will apply the brakes and avoid a collision.

“The system is designed to prevent swing shock, which causes a load to fly around erratically and become a risk. If the crane is going fast, the system slows down the crane by half, then slows down again and cuts the power,” Strysick said. “This enables what is called a counterslew, which takes inertia away from the swing of the crane and then engages brakes to stop the cranes motion in that collision path.”

ITC began installing the TAC-3000 system on cranes at the Olympic Village construction site on March 17, by putting brackets in cranes and mounting hardware.

Persha Inc. has been marketing, selling and installing the TAC-3000 in the U.S. for more than two years. Currently, there are 35 units running in the US.

The TAC-3000 is manufactured by Singapore-based e-Build Innovations.

Persha was the second distributor in the world to get the rights to sell the TAC-3000.

South Korea was the first market in the world to use the product.

Print | Email | Comment