Low loaders face approval peril

Low loaders, for long the workhorse of plant transport, are undergoing something of a transformation. For many years they were big, heavy, low-tech items that remained in the fleet forever - but not anymore. Instead they are becoming more hi-tech and moving from general purpose designs, to individually tailored items. "Our customers' jobs are getting more and more difficult and they are turning to us for more bespoke solutions," says Mark Carrington, managing director of King Trailers.

One of the major movers is an increase in transporting crushers as the recycling market expands. While most crushers can easily be accommodated on low loaders, they are heavy and often occupy the entire deck length, giving little, if any, latitude on weight distribution, meaning they can easily overload the truck's drive axle. To overcome this there has been an increase in the use of extendable trailers and moving the crusher rearwards to bring the drive axle within the weight limit. This is particularly the case with detachable neck trailers which, even unladen, impose a considerable weight on the truck.

The increase in high-reach demolition rigs also means heavy excavators are now moving more frequently than in the past and low trough trailers have also become more common. Such designs, especially if extendable, are finding additional use transporting wind turbine sections.

Manufacturers of such ultra-long extendables can struggle to meet the maximum allowable delay between hitting the brake pedal in the tractive unit, and shoes contacting the drums in the trailer's axles. Increasingly, this is being overcome by using electronic braking and, of course, anti-lock braking is now mandatory for all vehicles over 3.5t, so the days of low-tech low loaders are well and truly over.

Health and safety

The other main driver at the moment is health and safety, but there is a lot of confusion about which regulations apply: work at height or the Road Traffic Act. Carrington believes there is a clear distinction between the two: "Outside the cones you are on the highway and the Road Traffic Act applies; inside you are on a site and its Health and Safety at Work."

One of the biggest considerations is the potential for low loader drivers to fall off the trailer when exiting a machine they have just loaded. Such problems have led to bespoke innovations such as Tinsley's removable fall arrest system and a fold-out walkway from King. Others are offering, or working on, a variety of designs to increase the safety of workers.

However, in a few years' time, heavy transport operators may consider this to be something of a 'golden age' for low loaders because Whole Vehicle Type Approval could well limit the scope of trailer manufacturers to deliver such bespoke solutions. Len Fuller, technical director at Andover Trailers, says the move will suit manufacturers producing large numbers of identical products as they won't have to type-approve their products in each country, but it will hamper the production of smaller-run and more bespoke products such as low loaders. "We will have to approve a few trailers comprising a braking module, a steering module, an electrics module, the removable neck and so on. Then, when we tailor a trailer for a customer, we can put together all the necessary type-approved modules and leave the customisation to the less complicated areas such as deck length, width extensions and the like."

Type approval becomes mandatory from 29 October 2012 and will divide into three types: full type approval acceptable throughout the EU; national small series approval for yearly production runs of less than 250 for heavy trailers (or 500 for trailers below 3500kg gross weight) - which may or may not be acceptable in other EU countries and; individual vehicle approval (IVA), which is less likely to be accepted by other countries. The legislation also allows exemptions from certain requirements for 'special purpose' vehicles (although the qualification criteria is currently being worked out) and for a 'model report' where a full conformity check is carried out and only areas that deviate from the approved model will need individually checking.

While it is early days and many of the details are still being worked out, it is clear that only a small number of items have to be checked on a trailer to gain type approval. These include braking, steering (if applicable), lighting, side under-run, electro-magnetic compatibility, tyres, design weight, and the plate.

It is likely that the manufacturers will build 'worse case' trailers to represent the longest, heaviest unit with the maximum number of steering axles they offer in their ranges. These units will then be tested for conformity and approved either under the small series or a model report. That documentation can then be used in the individual approval of subsequent trailers (as they will be shorter, lighter and so on) and the individual inspection will only need to cover aspects impacted by the variations from the 'standard' design. These could include general construction, side under-run, axle weights (if fewer axles) and so on. In some cases, the small series route could even be used for these subsequent trailers.

Individual approval

While this will minimise the on-cost, it will still mean each trailer is likely to have to undergo individual approval and this can only be done at selected test stations. Currently only five of the UK's HGV 89 test stations are earmarked to issue IVA certificates. They are Gillingham, Glasgow, Derby, Manchester and Avonmouth. Taking a trailer to one of these stations will require a suitably plated tractive unit, which most trailer builders don't have in their yards.

While approved trailers should be able to run across the EU, according to Andover's technical director Len Fuller, each state has its own foibles that may exclude their use. "While we in the UK can run axle loads of up to 16t on Special Types, countries like Germany and France have a maximum of 10t per axle," he says.

"Also Germany stipulates turning circles and axle spacing for trailers depending on the axle load, which adds complication as it involves a tractive unit that is itself a big variable," he adds. For these reasons, it is vital that STGO operators specify where they want to operate when ordering a trailer.

When the dust finally settles on the regulations, the best guess is that the on-cost will be in the region of £1,000 per trailer and that figure is likely to rise sharply as the design moves further away from the approved 'standard'.

Red tape

By October 2009 in the EU all new 'heavy and long vehicles and their trailers' will be required to have reflective tape along the sides (and in some cases the back) to comply with ECE104.

The rules specify that special retro-reflective marking tape 50mm to 60mm wide must be applied to the outmost edge of the rear of trucks and trailers along a minimum of 80% of the perimeter. This tape must be between 250mm and 1,500mm above the ground, but can be stretched to 2,100mm if there are technical difficulties. Andover's Len Fuller said meeting such conditions could be extremely difficult, if not impossible, with low loaders and talks are ongoing at a European level to resolve these problems.