Being able to weave a vehicle more than 25 metres long between cones spaced only 14 metres apart is certainly a test of credulity, but this is what I am doing. Under the watchful eye of instructor Terry Rose, I am at the controls of Denby Eco-link Road Train.
A road feasible combination of a standard tractor unit, standard except for three minor modifications, a specially designed trailer, onto which is then attached an unmodified 44 foot trailer. Terry assures me that the same set of manoeuvres can be carried out with the cones set at just 12 metres apart. I’ll settle for his assurances on that point. I’m here to assess the vehicle from a driver’s point of view, and am immediately impressed by the nimbleness of the configuration. The ability to achieve this level of manoeuvrability is reliant upon the unique design of the counter-steering action of the axles on the Eco-link trailer, which effectively eliminates any ‘cut in’ when negotiating turns thereby permitting the second trailer to follow a path as though it were connected directly to the drawing unit. This is even more apparent when we move to the area set out to verify compliance with UK Construction & Use Regulations, which stipulate that the vehicle must have the ability to remain within the area between two concentric circles, the inner being 5.3 metres, and the outer being 12.5 metres. This requirement is met with ease as I loop the combination counter-clockwise. The position and path, of the rear of the Eco-Link trailer, and the position of the headboard of the second trailer, can be viewed via small rear facing CCTV cameras located on either side which feed the signal to flat screen displays mounted on the sun visor in the cab. Being essentially only necessary in tight situations or when in urban traffic, they can be folded away for general driving. And if another motorist should be foolish enough to place their vehicle in the path of the counter steering axles, the action of activating a switch on the dashboard immediately returns them to a neutral position. Having acquainted myself with driving the vehicle in a forward direction, I am now presented with what every novice artic driver fears, reversing! This vehicle, having two pivot points, equates best with a rigid connected to an “A” frame trailer, but in this instance, the pivot points are at much greater distances, and therefore any corrections need to be identified, and carried out, at a much earlier stage. First I plumb for reversing in a straight line, or, in my case, a not so straight line, as each correction results in the vehicle zigzagging until the oscillations reach an intensity where the only solution is to pull forward and start again. A second attempt, applying greater care, sees considerable improvement. Not perfect, but acceptable nonetheless. The next, and final, exercise is to reverse through an arc of 180 degrees, and requires a degree of mental gymnastics; simply to decide upon in which direction it is necessary to first turn the steering wheel. That overcome, it now becomes simply a matter of controlling the Eco-Link trailer in such a manner that it pushes the rearmost trailer in the desired direction. Further practice follows and the steering wheel inputs begin to become intuitive. With some 30 minutes or so practice under my belt, I’m now sufficiently confident to venture out onto the roads around the Newark and Notts Showground, except that I can’t. Unfortunately, at the time of writing, the vehicle has yet to gain approval for use on UK roads. Even with the limited amount of practice afforded, I would be more than happy to take the vehicle, not just on Motorways and Primary routes, but also on many of the Urban routes that I would normally expect to travel as part of a normal working day. Terry is of the opinion that for someone with five years experience of driving articulated vehicles, a minimum of two days training should be sufficient with up to 20% of that time being given over to ‘free practice’ reversing. FOR THE TECHNICALLY MINDED The steered axle on the Eco-Link trailer is disabled when reversing and when travelling forward at speeds greater than 40kph. Below that speed a potentiometer senses the angle at the ‘fifth wheel coupling’ and sends a signal to the electronic unit controlling the hydraulics powering the axle. Maximum lock is not achieved until the vehicle has slowed to below 15kph, and is progressive between those speeds. The three modifications to the tractor unit are the fitment of a switch to disable the Eco-Link steer axle, along with the fitment of connections for the CCTV signals, and the displays themselves. It was definitely an experience not to be missed and my thanks go out to Terry Rose and Dick Denby for the opportunity of exploring the characteristics of this unique vehicle combination. Kenneth Reeves AMSOE, AMIRTE