Wednesday 26th Oct 2016 - Logistics Manager

Why it’s good to lose your edge

It’s such a blindingly simple idea that you wonder why no-one thought of it before – chamfering the leading edge of a trailer to make it more aerodynamic. If you can’t use the space, then the fuel saving makes it worthwhile – and lots of people are now going down this route.

Don-Bur has gone a step further with its teardrop design which can cut fuel consumption by ten per cent, compared to a standard cab-trailer fleet operation.

As well as improving the aerodynamics, the shape gives up to 16 per cent more load space than a standard trailer.

In the Don-Bur design, the roof has a specially designed full-length curve and corners are rounded off to improve air flow, while the gap between the truck and trailer is minimised to reduce turbulence and skirts under the trailer further minimise the drag factor.

Marks & Spencer has ordered 140 trailers while PC World is replacing its entire 75 strong fleet with the trailers which it has dubbed “RoadMouse”. Keith Jones, managing director of PC World says: “The aerodynamic shape is much more efficient and, being mouse-shaped, it is also a great reminder of the technology that we provide.”

Cartwright reckons its Cheetah Aero System can give fuel savings of 16 per cent – with a 13 tonne reduction in annual carbon emissions based on 124,000 miles a year.

The system has been developed in conjunction with TNT Express, The Department of Energy and the Transport Research Laboratory.

The manufacturer says wind tunnel tests on the Cheetah’s cab roof fairing, cab extensions, trailer skirts and rear roof scoop showed a 42 per cent total reduction in drag coefficient.

TNT has taken delivery of 86 GRP van trailers and plans further orders for 2008. A key feature of the TNT trailer, is the tapered body.

Owing to the nature of the load, Cartwright was able to taper the body from bottom to top inwards, enhancing the aerodynamic effect, in line with the cab aerodynamic components.

TNT’s national engineering manager Steve Davis says: “We have found that this Aero System will play a huge role in the future in reducing our carbon footprint and fuel consumption – and that is something backed up by the official Department of Energy test trials.

“There are other trailers on the market but Cartwright’s aerodynamic system has proved it can save on carbon emissions and ultimately on fuel costs. That is why we have bought it.”

The Cheetah features specially-designed cab roof fairing and side collars which work together with the trailer’s front aerodynamic aluminium blimp, aerodynamic rear roof scoop, a large radius skirt, tapered rear skirt quarter panels and a circular rear under-run bar and open rear chassis design.

Using liquid nitrogen to keep trailers cool is not a new idea, but a new take on the concept is now being trialled by one of the major supermarkets.

ASDA is planning to replace the diesel-fuelled fridges in its transport fleet with the “ecoFridge” which is being trialled in seven vehicles at its Skelmersdale depot.

It reckons this could reduce the overall amount of carbon emitted by its fleet transport by around 860 tonnes, putting it on course to hit its commitment in reducing the amount of carbon produced by 80,000 metric tonnes by the end of 2008.

If the trial study is successful, the ecoFridge, which runs off liquid nitrogen rather than diesel, may be rolled out to its entire fleet of temperature controlled distribution trailers. By switching all of its fleet transport to nitrogen powered refrigeration, ASDA estimates it could reduce overall carbon emissions by 70,000 metric tonnes in the next five years.

The ecoFridge, designed by Ukram Industries, uses liquid nitrogen as the accelerant in the cooling process. It costs up to 30 per cent less to run, it can achieve pull-down to set temperature 70-80 per cent faster and it is virtually maintenance free. Added to this, it will not top freeze and for multi-temperature applications it requires half the investment cost of a mechanical system.