Truck and trailer body manufacturer Serco has collaborated with retail group Spar South Africa to develop a prototype of a new concept trailer, designed to help reduce fuel costs as well as carbon dioxide emissions, while simultaneously being highly practical to load.
Decisions about which features will become standard on future Spar trailer designs will be made this year.
The initial concept designs and research on the available technology and accessories for the Serco Green trailer started in May 2011. The concept was refined in early 2012 and production of the new prototype started in September last year, says Serco MD Clinton Holcroft.
Spar national transport manager Charles Davidson says the project, which Spar is very excited about, was born out of Spar’s com- panywide initiative to reduce its carbon footprint. “We approached Serco to come up with a green concept trailer, but one which would be practical and not have an adverse impact on our usual loading operations,” he says.
The key issue for Serco was to optimise the aerodynamic efficiency of the 15-m-long and 4.3-m-high trailer without compromising the interior loading volume, which can handle 30 t of perishable products using pallets and insulated lugs.
This was achieved by focusing on the three major sources of aerodynamic drag in the typical tractor-trailer application – the tractor-trailer gap, the trailer side and the trailer wake.
One of the improvements to the trailer is the tapered rear end of the roof to help maintain the airflow of the trailer body and to effectively reduce the trailer’s wake, which subsequently contributes to reduced drag and improved fuel economy.
Serco also installed a side aerodynamic kit from US-based aerodynamic trailer attachment developer Freightwing. These design changes significantly reduce wind drag and, in turn, improve the fuel consumption of the truck-trailer combination, says Holcroft.
The trailer is also fitted with an electronic braking system for improved road safety and electronically controlled air suspension, which reduces the overall height of the truck and trailer and enables the trailer to adjust to a normal dock height for loading and unloading.
The trailer also uses disc-braked axles for improved vehicle safety, single tyres with aluminium rims and high tensile steel in the chassis to reduce the truck’s weight and rolling resistance. Holcroft says the trailer weight was, as a result, reduced by just over 500 kg.
Further, the tractor is fitted with aero- dynamic truck fairings, provided by truck fairing specialist Aerotruck. This was fitted to improve airflow, notes Holcroft.
The trailer also features underbody side skirts, manufactured from a flexible and durable polypropylene plastic, which improves the trailer’s aerodynamics by reducing wind drag, particularly in the presence of crosswinds. This further results in improved fuel consumption.
Holcroft says the first trailer fitted with side skirts was delivered in October last year and the second trailer, fitted with side skirts and the roof taper, was delivered in November.
One of the main challenges in designing the green trailer was to ensure that the new features could be developed without significantly increasing the cost of the trailer, while ensuring a favourable return on investment for Spar, says Holcroft.
To do this, Serco’s design team, with more than 30 years’ experience, was employed to develop suitable solutions to meet Spar’s requirements.
Holcroft credits Spar – which has a fleet of more than 400 vehicles – for innovatively pushing the envelope and incorporating bold green features to reduce its carbon footprint through streamlining its vehicles.
“We have enjoyed working with Spar – a company prepared to actively work towards protecting the environment – as we are conscious about using green concepts in the manufacturing of our truck bodies and trailers,” he says.
Meanwhile, Serco recently acquired a 13.4 ha piece of land in Boksburg, Johan-nesburg, which will be used as a platform for further growth in the Gauteng region.
“We are drawing up plans for a new factory on the acquired land, which will further improve capacity and efficiencies. “This is a significant milestone for us and we are looking forward to this exciting project, which will take place over the next 12 months and lift our infrastructure to a new level,” concludes Holcroft.