TSN DRIVER CPC SPECIAL
Issue 322 SPRING 2014
KEEPING CONTROL
Think the Driver CPC is a waste of time? This course begs to differ – it teaches drivers how to properly control a skid and reduce the risk of rolling a truck on the road, and By Andy Stewart PHOTOGRAPHY MERCEDES-BENZ could very well save lives
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here’s a huge number of DCPC courses available to drivers looking to brush up their professional skills and achieve the required 35 hours of periodic training ahead of next September’s deadline. Some courses, like those which shore up understanding of working time regulations, tachograph use, or eco-driving are of obvious benefit; while other subjects can vary widely and should be carefully assessed before a driver exchanges his hard-earned money for a spot in the classroom. But one practical course, offered by CRYdel with the support of Mercedes-Benz Driver Training, is particularly beneficial for all drivers (though we admit it’s not cheap, with places costing upwards of £430 +VAT). It not only demonstrates how to properly control a truck in the event of a skid, but also offers drivers the rare chance to safely roll over a tanker, demonstrating just how easy it is to cause a potentially fatal and hugely expensive accident – and more importantly, how to avoid it.
Steer or stop? The course takes place at the MIRA Proving Ground on the outskirts of Nuneaton, Warwickshire and begins with a classroombased discussion of what to do and what not to do when approaching an unforeseen obstacle in the road. According to course leader Dean Jordan, a driver’s natural inclination to jam on the brakes and swerve around the hazard can do more harm than good. The laws of physics dictate a vehicle’s tyres have a finite amount of grip. If a driver brakes and steers at the same time, that grip is split between the two actions – so if 80 per cent of grip is used for braking, then there’s only 20 per cent left for steering, which is most likely not enough to get you out of trouble. The Skid & play: Negotiating MIRA’s wet-handling track is great fun, but the lessons learnt are vital
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Training tanker is fitted with special outriggers to prevent vehicle tipping completely
advice, therefore, is that in extreme situations, a driver should either brake OR steer, and not try both at the same time. “It’s counter-intuitive, but safer,” says Dean. Of course, some situations require a driver to do both – and in those circumstances, brakes should be released a few seconds before steering is attempted, to give the wheels time to spin up. Also of vital importance is declutching during emergency manoeuvres (if you’re running with an automated ’box, it should be flicked into neutral to guarantee disengagement of drive). Otherwise, the truck is still being told to move forwards, which will further reduce the amount of grip available for braking or steering. Brakes should not be feathered either, as it can confuse ABS/EBS systems. “If you need to brake, keep your brake on and let the technology do the work for you,” says Dean. Regaining control when negotiating bends is also covered. The procedure to
correct oversteer is to declutch/engage neutral, then if necessary counter-steer into the skid. To correct understeer, decelerate (lift foot of accelerator, rather than engage braking) and if necessary alter steering. The theory set out, it’s time to put it into practice on the skid pan. MIRA has a specialist low-friction circuit and MercedesBenz provided us with New Actros tractor units to use for the exercises. During the session, course members are encouraged to create a skid by entering the pan at speed, then applying some steer until the tyres lose their grip. Once skidding, the driver has to regain control of the vehicle and successfully avoid an obstacle (in our case, traffic cones). It’s certainly entertaining – but at the same time, the skills course members develop during the exercise will increase their chances of avoiding an skid accident when back out on the road.
Tipping point Once we’re done on the wet-handling course, it’s back to the classroom for some eye-opening lessons on how to avoid rolling a truck on the road. In the UK, there are 12,000 rollover accidents each year involving vehicles over 3.5 tonnes, and on average each accident costs a staggering £1 million to clear up. There are three contributing factors in a rollover incident: speed, centre of gravity, and the radius of the turn. If a vehicle’s centre of gravity is high (for example, if the load is top-heavy), then it will require less speed to roll over. There’s also no way for the driver to know his trailer is tipping over until it’s too late, as there’s no sensation of the movement inside the cab. “This is because rollovers start from the rear of the vehicle, and the last wheel to leave the ground is usually the one under the driver,” says Dean.
Most tanker rollovers occur just after a driver has negotiated a roundabout and starts to accelerate away, which can increase the movement of product that has already been set in motion during the previous turns. “Traffic lights on roundabouts are also a contributing factor,” says Dean, “as drivers are tempted to accelerate into a bend in order to beat the lights. You’d never accelerate into a bend under normal circumstances.” So what can be done to prevent a rollover from happening? The most important thing is to make sure roundabouts are approached slowly. If you’re coming in too fast, it’s better to stay straight and jam on the brakes to provide maximum grip for slowing the vehicle. It might mean the truck goes straight over the roundabout, but this, says Dean, is preferable (and safer) to rolling over. “And if a rollover is going to happen anyway, braking will reduce the chance of things on the street entering the cab and killing you,” he points out. A sobering thought, indeed. The theory is sound, and it becomes crystal clear once a driver initiates a rollover on the test track. Using a specially kittedout artic tanker with outriggers, Dean asks us to put the truck into a turn to simulate a roundabout. Travelling at what feels like a comfortable and safe speed (around 18 kmh), all appears fine. But when Dean instructs us to give it just a bit more gas, we’re shocked to look in the mirror and see the rollover occur at around 23 kmh – and the first feeling we have that the vehicle has rolled is the thump of the outrigger as it hits tarmac. It’s not often a driver gets the chance to roll a truck in absolute safety, and this course serves to highlight the value and relevance of quality DCPC training. ■
Course leader Dean Jordan explains the theory behind rollover prevention