Body and trailer manufacturer Cartwright Group has started using computational fluid dynamics (CFD), a technology more usually associated with Formula 1 car design, to improve the aerodynamics of its products.
The Cheshire-based company has struck a partnership with Manchester Metropolitan University to develop low-carbon trailers using CFD through a knowledge-transfer scheme.
Director Steven Cartwright says: "CFD has replaced the wind tunnel. All the Formula 1 teams use it. By using particles, which you can alter in size, it shows up where the aerodynamic deficiencies are on the product."
He adds: "We have a guy working here doing his doctorate through the knowledge transfer. He is working with CFD on road transport products, such as Cheetah [Cartwright's aero trailer]."
Taking the desktop approach to aerodynamics also cuts costs, explains Cartwright. "When we first undertook the Department for Energy testing on the Cheetah in 1990, using a wind tunnel was the cheapest way to do this. At the time, CFD was getting there, but it was very expensive; now it's the other way around, the wind tunnel is the high-cost option."
He adds: "We have been using it to see where we can keep improving designs. It's all to do with lightweight designs and aerodynamics to come up with the ultimate shape."
New product
The first result of the use of CFD is the new Cheetah Fastback trailer design, which is due for launch soon. It adopts a variable-air suspension system that lowers the running height of the trailer to reduce drag.
"We have put the Fastback though CFD. It is a straight-frame trailer with a valve to lower the chassis, this is where we have been a bit unusual," he says. "It uses a wedge-shaped chassis and the roof line drops down to suit the shape of chassis."
Cartwright is also in the process of putting its first two 4m-high Cheetah Fastback trailers into operation for TNT in Germany and Holland. This reinforces Cartwright's belief that Europe represents a big opportunity.
"We have done a lot of products that have gone into Europe, but it's a market where we get France and Germany coming over here and having a go, but we never see UK manufacturers having a go at Europe.
"We think the Cheetah Fastback is the product for Europe," he says.
New markets: retail and home delivery
Cartwright Group builds, maintains, refurbishes and rents products for retail and home-delivery operations, and it is at these sectors it is aiming its latest range of products.
Cartwright will unveil a new product for the home-delivery market in the summer, but in the meantime it is launching a new moving-floor double-deck fridge trailer. Supermarket chain Asda, which is already improving productivity with double-deck trailers on grocery store deliveries, is taking on the new design for its fresh and chilled deliveries.
"The Asda ones have a swept-front, three-quarter moving-deck, step-frame chassis, as well as four direct-drive ram-lifts - one in each corner of the moving deck. We have several designs - pulley, under floor, or rams at the front and the back - but the most popular is the four rams," Steven Cartwright adds.
He says double-deck units will continue to gain popularity in the UK, reducing the number of standard trailers in the sector.
For delivery over the last mile, Cartwright sees specialist urban trailers as the solution, as well as larger rigids. "We sell a lot of 7.5-tonners, but the grandfather licence is disappearing and the new drivers coming through have to sit tests.
"We are supplying 38 home-delivery rigids for Homebase and they are 14-tonne vehicles. The heavier GVW means you are not scratching around for the [competitive] kerbweight," he adds.