Truck News


D-trains safe, stable: Curry

BURLINGTON, Ont. - Decision makers and concept architects in the trucking industry are always in search of improving productivity and ultimately increasing profitability, and Royce Curry, of National ...

BURLINGTON, Ont. – Decision makers and concept architects in the trucking industry are always in search of improving productivity and ultimately increasing profitability, and Royce Curry, of National Zephyr Research Corporation, is one of those architects.

The industry presently has its major freight distribution tool – the semi trailer, but according to Curry, double and triple trailer configurations have the potential to increase profitability, improve maneuverability and give the driver more confidence.

“I am convinced that doubles and triples will do a better job adding more money to the bottom line,” says Curry.

“They are the future, they will guarantee profitability even in a fuel crisis.”

Curry recently patented his D-train configuration in Canada and the U.S. The D-train is designed to remove articulation between the tractor and the lead trailer, essentially becoming a long wheel-base tractor.

With the trailer sitting within six inches of the cab, turbulence is limited which constitutes a 20 per cent improvement in fuel economy.

Ride quality, directional stability and driver comfort are all advantages to a long wheel-base tractor, says Curry, and with no articulation point between the cab and the trailer, wiggle is reduced and the possibility of jackknifing is eliminated.

Double and triple trailer sets have not developed to the popularity of the semi-trailer, says Curry, for some pretty obvious reasons.

In order to pull this kind of trailer within the overall length limit set by the Department of Transportation, a short wheel-base tractor is required.

These tractors are susceptible to trailer wiggle, a bumpy ride and jackknifing, so drivers tend to stay away from them, says Curry.

Also, it is very difficult to back these trailer sets into a loading dock – another reason drivers tend to avoid pulling them.

“If we can solve these problems, we can begin to compete against the use of semis while improving the productivity, and the D-train configuration does just that,” says Curry.

There is not much difference in the way the D-train is manufactured, he says.

The fifth wheel holds the trailer in the same manner, controls the braking, pulling and load distribution in the same way it does any other trailer but the afterframe of the truck chassis fits between the landing gear on the trailer so there is no articulation, and it is still demountable just the same as any other trailer.

According to Curry, there will be a 50 per cent improvement in maneuverability over the semi, an 18 per cent improvement in cargo space and double trailer sets will increase profit by 20 per cent while triple trailer sets will see a 40 per cent increase in profit.

“This is a major step forward for the trucking industry,” Curry says.

“Every time a driver turns the key, they are not going to be able to drive out of the yard without losing money, so we need a way to improve productivity and the D-train will do it.”

The D-train configuration will enhance the use of long combination vehicles (LCVs) and may allow their use on 400-series highways, says Curry, as the inherent stability and the elimination of jackknifing or trailer wiggle will allow the driver and the travelling public to be more comfortable with their use.

Another notable safety feature of the D-train configuration is the ability to use fender skirts to prevent splash and spray.

Because the trailer is rigidly coupled to the tractor a driver can operate the vehicle with skirting on the side of the trailer to eliminate the danger of passing a truck on the highway on a rainy day.

“This isn’t something that will happen overnight,” says Curry.

“I think it is a five to 10 year project, but we need fleets to be thinking ahead by starting to slowly integrate them into their yards.”

But trucking companies have to start thinking now, says Curry.

“The industry will continue to go through its ups and downs, but a conscientious fleet will think about what kind of equipment it will need 10 years down the road, and the D-train is an option that just wasn’t there before,” Curry says.

The D-train configuration is now being tested, and anyone wishing for more information can contact Curry at 905-569-0061 or e-mail him at

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