Longer tractor B-trains outperform standard semis: CTA

OTTAWA The use of 6.2 metre (244”) wheelbase tractors for B-trains would not exceed RTAC and NAFTA standards for turning performance, the Canadian Trucking Alliance (CTA) said in a submission to the National Task Force on vehicle weights and dimensions.

Currently, tractors used in B-Trains configurations are typically 2 to 3 feet shorter then those on normal tractor semi-trailer configurations due to the 25-metre overall length limit and the need to maintain the 20 metre box length for productivity.

"What often happens because of these two key dimensional restrictions is the sacrifice in tractor length," said Geoff Wood, VP of Operations and Safety.

"This severely restricts a carrier’s ability to provide greater driver comfort in the form of sleeper berths."

He said that carriers who operate B-trains want to spec larger tractors, but cannot with adequate sleeper berths because of the current restriction.

CTA was asked by the National Task Force to conduct an analysis of the effect a longer tractor in use with B-Train would have on RTAC and NAFTA performance measure — low speed off-track (the amount of lateral space a vehicle takes to negotiate a turn).

Vehicles with too much off-track have the potential to come into contact with curbs and other objects at intersections.

"The proposed configuration actually out-performed standard tractor trailers in the low speed off-track measure," Wood said. "The results are encouraging, because it is one major unknown element explained for industry and governments."

CTA expects a decision at some point this year.