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RESTRA OR DE

Bulging curtainsiders not only look amateurish, they'll attract the attention of the authorities because shifting loads can kill. Steve Banner has been taking expert advice on keeping your cargo where it belongs.

Curtainsiders bulging because the cargo has shifted present a potential hazard to other road users, but not everyone sees it that way. The attitude among some operators in the UK seems lobe that if the curtains are shut and you can't see what's going on, then everything must be OK," says Martin Relton,materials handling manager at SpanSet."As a consequence you end up with a pregnant eurtainsider wobbling down the motorway."

And if the curtains give way, and the vehicle's contents end up scattered allover the highway, the result could be a serious accident followed by some equally serious legal action.

Not that you need the accident to be on the wrong end of the prosecutionif a pallet-shaped bulge appears in a curtain that's starting to split,then by definition that pallet is being carried in an unsafe manner.

If the truck and its wayward cargo manage to evade the law and reach their destination. there's still the risk that somebody could be injured when the curtains are opened during unloading. That's likely to attract the attention of the Health and Safety Executive, which is currently taking a keen interest in workplace transport safety.

The fact is ordinary curtains should not be used as a means of load restraint," says Relton. As a trailer industry executive puts it:"They should be treated solely as a weather shield."

Load restraint in curtainsiders and other vehicles has long been an area of concern for the Department for Transport. In October 2002 it produced its Code of Practice for the Safety of Loads on Vehicles; in its third edition,it can be downloaded from the Dff's web site.

DfT officials have dismissed any suggestions that the code is about to be revised." It is not being reviewed, nor are there currently any plans to review it," says a spokeswoman. She admits the DfT is At Load restraint in curtainsiders and other vehicles helping to put together a European wide code has long been an area of concern .

of practice, which could result in changes to the UK's own code.-But the process is in its early stages. and some years away from being ratified." However, there are strong rumours that an 86-page guide entitled European Best Practice Guidelines on Cargo Securing for Road Transport is being circulated in draft form and will be published by the end of the year. One likely consequence of this would be changes to the ways cargo is held in place in curtainsiders. UK operators are used to restraining loads to the body's superstructure, relying on tracks running down the centre of the roof or along the cant rails. But standard practice in many Continental countries is to strap cargo down to the side raves, and that's the approach favoured by Germany's influential VDA 2700 standard.The draft guidelines are believed to suggest that this is the one British operators should follow.

Guidelines

These guidelines state that, for restraint purposes, cargo in a curtainsider should be treated as though it were travelling on a flatbed, so curtains should not be used to restrain loads unless they're specifically designed for the purpose.

Some load-restraint specialists argue that restraint to the side raves is a requirement of the DfT's existing code, and roof straps should only be used as a secondary means of holding tall, lightweight cargo in place.

The prospect of a wholesale change is causing some concern to Chris Curzon, sales director at Peterborough-based curtainsider specialist Lawrence David."But it's something the Germans seem to be pushing for," he agrees. "For our part we pointed out to the DfT some time ago that the roof strength of our trailers, not to mention the strength of the curtains and the straps we employ, mean that we more than meet the industry's requirements.We certainly meet the requirements of the present Dff code. "We fit load-bearing Armour Sheet curtains as standard, and they're designed to be strong enough to hold any cargo in place that isn't on wheels. They'll restrain up to 28 tonnes."

Curzon warns that a move to strap rave-torave would cause UK hauliers enormous difficulties, even though their Continental counterparts seem able to Cope.

"The loads our firms carry don't all come in neat 1x1 xlm packages," he points out. "They're all different shapes and sizes, which will cause strapping problems, and there's also the question as to where you're going to stow all the straps you'll need.

"Strap retention will end up being a big problem. Ferry type roller straps could be fitted,of course, but the cost would be considerable. What the Continentals don't appreciate is that the UK approach suits our logistics system, which is a lot more complex and sophisticated than the system they have on the other side of the Channel.They don't, for example, have RD Cs in the way that we do — in fact they're miles behind."

Load cube

Ingirnex MD Justin Gallen says: "If strapping across the top of a load is going to work then the straps have got to be at an angle. That means you may lose load cube."

Despite its reservations Lawrence David is offering operators cargo tie-down rings recessed into the side-raves,13 on each side of a standard trailer, in anticipation of a change in UK practice. It's an approach being adopted by several other British curtainsider specialists. including Don-Bur.

The side-raves it fits now have a vee-shaped groove in the top with lashing points shaped like goals, with two uprights and a crossbar, that drop down out of the way when not in use.

The restraints remain accessible when the curtains are closed.

It's an option that features on the latest batch of trailers supplied by the Stoke-onTrent firm to DHL and now appears on nearly half of all its new trailers.

Don-Bur also provides raves with restraint hooks mounted on a pivot that can face forwards or backwards. Stowage for rave-torave straps can be built into the front bulkhead.

SDCTrailers offers a standard vee-groove rave, with 2.5-tonne capacity tie-down rings at lm intervals (more can be fitted with no loss of capacity).

Cartwright Group has produced raves with lm-spaced 2.5-tonne rings for the past two years. "We're finding that British operators aren't all that enthusiastic about restraining to the raves though," says SDC general manager, Paul Bratton."They still like their roof straps."

MD Steven Cartwright says: "Strapping across a trailer can be impractical if you're dealing with a load that's maybe 8ft high. Remember that a lot of European hauliers don't use overhead restraints because many of their curtainsider trailers have sliding roofs — remember that some still run tilt trailers."

One cynical haulier warns:"Something you've got to bear in mind is whether drivers and warehousemen will bother to use a crossways strapping system, even if the straps and restraint rings are provided.There's a fair chance that some of them won't."

Not surprisingly, Continental curtainsider manufacturers marketing their products in the UK are wholeheartedly in favour of side-rave restraint because it's what they're used to. Kogel and Krone are among these companies: Kogel fits 13x2-tonne rave rings along each side of a standard length trailer; Krone also provides 2.0-tonne lashing points and guarantees its side rave will hold 8 tonnes per metre.

Krone UK sales director Ged Kirwan says: "We believe we're the only curtainsider trailer maker in Europe to have our restraint arrangements certified by TOV in Germany." The problem with restraining to the roof is that you always get some movement in relation to the floor of the trailer,he adds.That means the lashings are likely to be compromised.

System

"In Britain we're used to operating in a different way to the Continentals, but that doesn't mean to say it's the right way," Kirwan suggests. "It's merely the easy way—and when you think about it, it can't make sense to have a restraint system that operates at a different level to where the load actually is."

However you use your load restraint straps, they should conform to BS EN 12195,says Phil Maltby. He's a director of cargo restraint specialist Pritchard Tyrite, which is a member of the Association of Webbing Load Restraint Equipment Manufacturers.

BS EN 12195 covers all types of restraint — chains and wire ropes as well as webbing — and includes a method of calculating the forces likely to affect a load during transportation. Much of it is based on the VDA standard.

Maltby's advice is simple: "Don't exceed the capacity of the anchorage point and don't exceed the capacity of the strap you are using. Both anchorage point and strap should have their ratings displayed; so should the strap's end-fittings."

Lashing capacity is expressed in DecaNewtons (daN);it is equal to half the breaking strength.A daN is equivalent to lkg.

"Each time you use a strap you should give it a visual inspection — don't use it if it's cut or frayed — and it makes sense to check it thoroughly when the vehicle itself receives its regular statutory safety check," says Relton. If the strap needs washing then use clean water, a mild detergent, and drip-dry.

"The end fittings and ratchets should be inspected every so often for signs of wear and damage too."

Extension levers should never be used to over-tension ratchets, he stresses. Lashings should never be knotted together, and use sleeves to protect them from sharp edges.

Standard straps can damage some fragile loads when they're ratcheted tight."However, you can obtain straps with PVC panels in the middle that are around 2-3ft long and 10ins or so wide," says Cartwight.

"They spread the pressure imposed on the load.Restraining nets can also be used to protect loads, hut even this is too harsh for certain types of vulnerable cargo. and in those circumstances the authorities seem willing to accept arrangements other than crossstrapping if they will keep loads firmly in place.

Cartwright Group, among others, can supply drop-in bars that go behind the curtains and between the pillars. They can be placed across the width of the trailer too.

"Some of the supermarkets have straps running lengthways along the sides of vehicles, behind the curtains, along with other straps running crossways, to keep the load where it should be," Cartwright explains.

Difference

"The design of the trailer bed can, of course, help hold loads likely to move in place Building it so that it angles inwards slightly from the sides to the centre can make a considerable difference."

Krone offers a restraint system designed to restrain items weighing up to 30 tonnes. It involves bars that can be placed transversely so the load can be strapped front-to-back or side-to-side.

Kirwan reckons anybody considering cargo restraint should find out how substantial the bulkhead is in case the load slides forwards. "We provide a corrugated steel bulkhead," he says. "When tested at up to 16 tonnes by TiiV it moved no more than 300mm. It's interesting to note that there is no legislation on bulkhead strength in the UK, so the bulkheads provided by many British curtainsider builders tend to be more lightly constructed than those found in the rest of Europe. All you may get on a lot of trailers is a GRP air-deflector backed by a bit of plywood."

That's a problem because roof restraints do little to stop the fore-and-aft movement of cargo, says Relton."Loads are affected by the forces imposed when a truck moves away' from rest, which forces them to the rear. Make an emergency stop and you typically impose a force of lg, which forces them forwards.

"At the same time you've got centrifugal forces created when the truck goes round a sharp corner or a roundabout." On top of all that you need to take account of the friction between the cargo and the vehicle's floor.' In some circumstance the load may have to be chocked," he remarks.

Will tougher load restraint requirements spell the end of curtainsider bodies in Britain? Bratton is among those who strongly doubt it, pointing to some significant differences in front end prices.

"A box van trailer typically costs £4,000 more than a curtainsider,while one with sliding side doors costs up to 16,500 more," he points out. "As well as being less expensive, curtainsiders offer you unrestricted side loading and unloading.

Ron Cantheld, sales and marketing director at Schmitz Cargobull UK, sums it up nicely. "Curtainsiders have been around in Britain since the 1960s," he says." They're here to stay -don't forget that a lot of places need side access because they don't have loading docks but the loads they carry will have to be better secured."