Longer truck combinations bring a promise of significant improvements in efficiency for the logistics sector, but can the UK’s infrastructure cope?
Professor David Cebon certainly thinks so, and reckons technology needed to make it possible could be put to wider use.
David Cebon’s views are unlikely to win him many friends among those whose unthinking hostility towards trucks remains undiminished. There is no denying however that his opinions are authoritative given that he is Professor of Mechanical Engineering at the University of Cambridge and Director of the Centre for Sustainable Road Freight.
Cebon believes that there is a strong case in favour of using much longer tractor-unit-and-semi-trailer combinations on trunking work in the UK than are used at present. What he has in mind are combinations that are far bigger than those created by the current government-backed trial of 14.6m and 15.65m semi-trailers.
He contends that it is a case that can be made on grounds of less fuel being consumed per unit of payload transported.
On this basis an operator that switches from running two standard artics to the sort of B-double – a tractor unit plus two semi-trailers – that Cebon envisages will see fuel usage tumble by at least 25%. That only works however he stresses if the B-double is running full.
Surely the judicious use of aerodynamic aids such as boat-tail fairings that can be attached to a semi-trailer’s rear can bring just as big a fuel economy benefit? Not so, says Cebon.
“If you cut your fuel usage by between 3% and 5% on long-haul work as a consequence of better aerodynamics then you are doing really well,” he observes.
Critics warn that B-doubles are bound to present road safety hazards but it is a claim that he rejects.
“Bigger, heavier trucks are not only more efficient on long-haul work, they can be just as safe as smaller vehicles if not safer if operated under closely-regulated conditions with properly-trained drivers,” Cebon contends. “That is certainly the case with B-doubles in countries such as Australia where they have a good safety record.”
Even larger combinations are of course deployed Down Under, with big-capacity road trains used on long-haul work.
Longer trucks do face manoeuvrability challenges however and that is something he has been addressing.
As director of the Cambridge Vehicle Dynamics Consortium he has played a pivotal role in the development of the Path Following Steering System. Using computer-controlled electro-hydraulic actuators that precisely control the steering of each of the semi-trailer’s axles, it ensures the trailer faithfully follows the path of the tractor unit with minimal cut-in and tail-swing.
The first commercially-viable prototype semi-trailer fitted with the system has now been constructed by SDC in conjunction with Tridec, Haldex and Goodyear.
At 15.65m long it fits in neatly with the aforementioned government trial and will go into service with Wincanton, which has been closely involved in its development, later in the year. Wincanton already has considerable experience of the operation of longer semis.
This type of steering could benefit semi-trailers used on city centre work as well as those on long-distance duties Cebon believes because of the increased manoeuvrability it brings and may boost the popularity of the urban artic. “It could enable you to for example use larger urban artics to handle deliveries to city convenience stores,” he observes.
It could even result in a radical rethink about the design of RCVs – Refuse Collection Vehicles – he suggests.
