AT THE HEART OF THE ROAD TRANSPORT INDUSTRY.

Call our Sales Team on 0208 912 2120

LEGS GOOD

20th January 2000
Page 34
Page 35
Page 34, 20th January 2000 — LEGS GOOD
Close
Noticed an error?
If you've noticed an error in this article please click here to report it so we can fix it.

Which of the following most accurately describes the problem?

cY LEGS sir-) BETTER?

Engineers who specialise in retrofitting lift axles to tractive units might not be lighting their cigars with Lao notes, but many of them enjoyed a significant increase in demand last year. "Our turnover doubled and we were kept busy throughout the year," says Keith Hughes, managing director of Bury St Edmunds, Suffolk-based Inter UK Engineering.

Demand was boosted by the introduction of the six-axle/41-tonne GCW limit. Many operators with triaxle trailers decided to have their 4x2s converted to 6x2s to take advantage of the new limit, while others opted for extra axles while staying at 38 tonnes to qualify for the V ED benefits of running a 3+3 rig.

"They were also conscious that a Gicz unit would be much easier to sell in two or three years' time," says Hughes.

Other converters report that while they've had plenty of inquiries, the possibility of saving on VED by re-registering trucks in another European Union country has clouded the issue. "Some hauliers have looked at the advantages of flagging out rather than putting on midlift or lifting tag axles," says Brian Mather, engineering manager at The Vehicle Application Centre (TVAC), which is based in Leyland. Although improved manoeuvrability and traction are among the benefits claimed for a tag, those who elect to add an axle tend to choose a mid-lift. "A second steer axle is in many respects the ideal solution, but they're very expensive to retrofit," Mather explains.

Put a tag on and you may have to shorten the wheelbase, moving the drive axle forwards and adding up to LL000 to the final bill, he points out, unless you want to risk ending up with an over-length unit. It's also easy to get the fifth wheel in the wrong position, and finish up with an overloaded tag axle. Mather warns, "and there's always the risk that when the tag is raised you'll foul the trailer", He adds that this is more of a risk with a box trailer, with a typical 1,600mm front overhang, than it is with the average L000rrirn overhang of a tipping trailer.

Nor does a lifting tag do much for the appearance of your unit; it can make it look unbalanced when the axle is raised.

By contrast, it's often possible to install a mid-lift without modifying the wheelbase or lengthening the chassis, says Mather. And Hughes points out: "You can squeeze it into a 3.8m wheelbase, but you'll have to lengthen a 3.6m chassis because you won't have enough room."

Mid-lift

A mid-lift takes up space normally occupied by the battery, fuel tank and exhaust. The battery will have to be repositioned, and you may have to fit a vertical exhaust stack.

You won't necessarily lose fuel carry ing capacity, Mather claims, and this view is shared by Truk Tec. However, you might find yourself replacing a single large tank with two smaller tanks on either side of the chassis, which means further expenditure. "Do that, and it's still possible to carry 850 litres of diesel," Mather contends. But if you want to fit really big tanks, a 4x2 will always give you more scope than a 6x2, says Hughes.

International operators travelling through France should also be aware that the French impose a 40-tonne limit on six-axle rigs, so British hauliers grossing at 41 tonnes risk being fined.

A mid-lift weighs from 750kg to 85okg, including wheels and tyres, and anything that increases a vehicle's unladen weight has implications for fuel consumption as well as payload.

"The driver can either raise and lower a mid-lift manually by using a switch on the dashboard, or it can be raised manually but lowered automatically, which is the route the OEMs favour," says Mather. It drops when the drive axle is about to become overloaded.

Running with a mid-lift down when

your truck is empty or only lightly laden can reduce traction because less of a load is being imposed on the drive axle. Mather points out that you can have a device fitted which dumps the air from the lowered mid-lift's air bag for about 90 seconds. This transfers more weight onto the drive axle, which allows the driver to pull away. The air bag is subsequently reinflated.

One drawback of running with a midlift down is that the tyres can suffer from scrub. It makes sense to instruct drivers to raise it when they are manoeuvring at low speeds in depots. Mid-lift or tag, it's important to remember that an extra axle demands extra maintenance with more tyres to replace. It's also another axle that can I become misaligned, which would lead to higher fuel bills.

Lifting tag

So how much does a mid-lift cost? TVAC will charge you £5,580 including suitable wheels and tyres. It charges the same for a lifting tag. If you've already got suitable wheels and tyres, the job will cost you less. Truk Tee for instance, will hand you a bill for around £4,600. Inevitably, that bill will rise if extensive chassis mods are needed.

Don't forget to ensure that any quote includes all the extras you'll require: additional wings and spray suppression gear, for instance.

A sloppily installed mid-lift can bash the underside of the tractor's chassis when it is raised, and even the most ingenious engineer might find it impossible to fit a mid-lift to a low-height chassis. In this case one option could be to have a full-width refuse-collection-type mid-lift installed with 19.5in wheels. This will be about the same price as a standard mid-lift, but the wheels and tyres will be cheaper.

Adding an axle constitutes a notifiable alteration, even if the chassis itself isn't modified. A VTGto form must be completed, and the truck must be submitted for test.

Another point to bear in mind is that conversion is not a task that can be completed overnight; a converter might need your vehicle for up to to days.

Several manufacturers will fit midlifts or tags to new chassis on-line for an

extra £5,000 or so, and twin steers are a common option. Eleven of the tractors run by Knapwell, Cambs haulier Mark Doel are 6x2s—a mixture of ERF, Foden, and MAN—and he's had Granning and Hendrickson mid-lifts installed. "We prefer Grannings because they're noticeably lighter than Hendricksons," Doel explains.

He runs his vehicles at 41 and 44 tonnes, and reckons its better if the mid-lift drops to the ground automatically the minute the driver takes his key out of the ignition. "That way there's less risk of your wheels being stolen," he points out.

Inter UK Engineering is Doe's favoured converter, and it's also handled a lot of work for Leggetts Transport which runs 70 tractors out of Wolpit, not far from Inter UK's Bury St Edmunds base.

Managing director Dick Leggett has had to 4-Series Scanias equipped with mid-lifts for 41 tonne operation. "I might have another five done early in 2000 unless I decide to flag them out instead," he says. Mid-lifts offer a much better ride than tags, he adds, and as his Scanias only have small tanks, no fuel capacity was lost.

Doel has had several problems with air bags blowing, a problem also highlighted by Colin Treagus, transport manager at Totternhoe Lime & Stone, near Bedford. He's had eight of the company's units, all Volvo FLtos, equipped with mid-lifts by Truk Tee so that they can run at 41 tonnes, and one managed to get through three Firestone bags. "It turned out that they were a faulty batch, and since then we've had no further trouble," says Treagus.

Asking Truk Tec to turn a 1992-vintage Mercedes-Benz 1733 4x2 tractor plated at 34 tonnes into a 6x2 gave it a new lease of life when the alternative might have been the scrap heap, says Colin Hayward, a partner in FES Hayward & Sons of Chilworth, near Guildford. "We thought about swapping the Mercedes for a new 6x2, but we were told we wouldn't get anything for it second-hand, despite the fact that it was a blooming good motor," he recalls. "So we had a mid-lift fitted (it's a long-wheelbase unit, so there was plenty of room) and the truck replated at 38 tonnes.

"That gave us a higher payload plus the ability to have a Hiab crane installed without having to worry about the weight," he says. "We carry a lot of glass fibre tanks and sewage treatment plants. They're bulky rather than heavy, but we need the additional payload to cope with backloads."

II by Steve Banner


comments powered by Disqus