Preliminary findings from the Alberta road research initiative (ARRI), a five-year project that will end in 2009, are already resulting in changes to provincial trucking laws.

A public-private partnership involving the University of Calgary, Alberta Infrastructure and Transportation, Syncrude, Leduc County and the Alberta Crane Owners' Association, ARRI is examining the impact of heavy mobile cranes on the province's highways.

So far, officials have found that lengthening loads by using dollies (trailers to extend load weight over a larger section of road) does little to reduce strain on the roads in winter. As such, Alberta has eased its regulations requiring mobile cranes to use dollies since February.

The changes, they add, improve safety on roads that carry mobile cranes to and from jobsites, while also reducing the costs associated with moving them.

Photo courtesy of University of Calgary
University of Calgary civil engineering professor Lynne Cowe Falls watches an all-terrain crane navigate the Nisku test track.

The pavement structure for every highway in Alberta is designed for a 20-year life and an estimated number of loads, says Lynne Cowe Falls, a civil engineering professor in the Schulich School of Engineering.

The loads refer to single-axle loads, equivalent to 18,000 pounds or 4,000 cars. "Then the province, which is responsible for maintaining the highways, is approached by crane and other heavy-vehicle operators who ask for permission to use the roads," she adds.

The overload permitting system, employed around the world, is meant to recapture some of these damage costs through user fees, notes Cowe Falls. "One way companies can reduce their permitting fees (in Alberta) is to add on extra trailers or dollies."

But the results showed that in winter, when roads are actually frozen, extra dollies for the mobile cranes weren't necessary.

Until last month, Alberta had asked crane operators to configure the crane vehicles so that the boom was not positioned over the front of the cab - the way they were designed to be driven - but instead turned to the rear with extra dollies put in place to better distribute the weight over a larger amount of space.

"When they asked us to re-configure the crane, and add trailers to carry it, it really compromises the integrity of the crane. We didn't want to do that for safety reasons," says Terry Danderfer, president of the Alberta Crane Owners' Association.

"But in all fairness to Alberta Transportation, they're responsible for the safety of the public and are there to protect the infrastructure. Our comment - even though the vehicles are bigger and heavier - was that with new suspension and new technology, they weren't damaging the roads."

Danderfer says that when a dolly is added to the vehicle and the boom is over the back, driving the vehicle requires more skill, the vehicle is harder to manoeuvre and the operator is prone to more fatigue.

Cowe Falls says since these vehicles are not allowed to travel faster than 60 km/h, cars and trucks would be passing larger, longer vehicles - a potential safety issue.

Danderfer says the mobile cranes already meet the strict regulations concerning road-worthy equipment, but he believes the only way to resolve the issue was through a comprehensive study.

"What we want to find out is whether the rules and load limits that are in place are actually resulting in less strain on roadways and come up with real made-in-Alberta solutions that make sense for the oilpatch and the government," says Cowe Falls.

To do this, a 300-metre test track has been built south of Edmonton in Nisku. Sensoring devices have been built into the pavement structure that mimics both parts of the highway system these vehicles would use: Main highways and secondary roads. Year-round testing gathers readings on how the pavement reacts in all-season conditions and over five years to see if the impact changes as the asphalt wears down. The vehicles used include cranes with the boom over the front, and others with the dollies added.

"We were able to show that not much was different in winter time with dollies or without. As a result (Alberta Transportation) is allowing cranes to travel in winter without dollies and as a result, roads are safer," says Cowe Falls.

Despite lower costs for crane operators - without dollies, vehicles consume less gas, fewer tires are used and less time is employed to add and remove dollies - money was not the driving force in going ahead with the study, says Danderfer.

"The force driving the crane owners was not one of monetary consideration. It was more about safety."

(Laura Severs can be reached at laura@businessedge.ca)