Wincanton: longer semi trial will ‘take two years’
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CM gets an exclusive first look at Wincanton’s longer semi-trailer, and discovers how the Don-Bur unit is ready to hit the road running
EXCLUSIVE
By Will Shiers DAVE ROWLANDS, director of technical services at Wincanton and the brains behind the company’s irst longer semi-trailer (LST), is optimistic that the Department for Transport’s (DfT) 10-year trial will be completed in just two years.
He is positive that in this time the DfT will have gathered all the information it needs.
“Let’s face it,” he says, “they will be crawling all over the indings every few months. If they can’t get the information they need in two years, then what are they playing at?” He’s also conident that the trials will prove to be a complete success. He says 80% of the monitoring will be around safety, and he strongly believes that LSTs will perform impeccably in this area. Walking us around the Don-Burbuilt curtain-sided trailer, (which is 2.05m longer than a standard one), Rowlands points out the numerous safety features that Wincanton has insisted on. These include integrated Knorr-Bremse I-Corner (see over) and I-Cargo, roll-over detection, cameras that scan the length of the trailer, bogie weight indicators that can link to the tractor’s dash display, LED lamps and Spraydown spray suppression guards.
No additional signs
Although there are no additional signs on the rear of the trailer to warn passing motorists of its length, Rowlands points out that they aren’t necessary, “after all, it’s shorter than a wagon and drag.” But while Rowlands is enthusiastic about LSTs, he’s the irst to acknowledge that in some respects “they are a bit of a compromise” . The biggest issue is the increase in tare weight. This one weighs 8,160kg, resulting in a payload of 27,503kg. Although the introduction of bonded loors will result in an opportunity to redesign the chassis and remove weight, their current design is still too heavy.
Watching the weight
However, engineers are already working on a lighter version. The heaviest additional component is the rear-steer axle – a requirement on every LST. In order to save weight, the one itted to Wincanton’s trailer is self-steer rather than command-steer. It acts like a caster and has 20-degree movement, which was the best available at the time of build. This unique axle has auto-reverse-lock and was developed with Mercedes-Benz.
Because of the current position of the steer-axle, it’s going to be all too easy to overload the rear bogie on all LSTs. On this particular example, this means that identical pallets weighing more than 860kg each can not be evenly spaced throughout the length of the trailer. For pallets weighing less than 860kg, there isn’t a problem. In order to achieve the full 44-tonne potential of the trailer, the rear axle would need to be located further back, but for this to happen it would need to steer by 33 degrees.
“As we sit here today,” says Rowlands, “this is the widest self-steer axle available. However, other manufacturers are now waking up to the need for a greater steering angle, which will allow additional rearward movement of the axle and assist with load apportionment.” He explains that a command-steer axle would have 45-degree movement, but they aren’t practical as they come with a signiicant weight penalty. “If we itted that we’d be taking away the beneit we are trying to get in the irst place,” he says.
But on the positive side, because of the location of the steering axle, overloading of the tractor as a result of diminishing loads is never going to be an issue.
“What we have here is the perfect design given the current constraints,” says Rowlands, “but we are only at the start of this engineering journey.” ■
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