Aluminium tipper body options

Aluminium tipper bodies offer weight savings compared to steel plate, but often require reinforcement to obtain the required durability. Steve Banner explores the available options

Haul grain or other agricultural produce by road and there is every chance you will be doing so with a triaxle tipping trailer with a plank-sided alloy bulk body. “It will give you a capacity of from 65 to 71 cubic yards, and when you’re not on grain work you can use it to move other products such as sand or salt,” says Weightlifter Bodies managing director, Nigel Butler.

“We’ve built plank-sides at up to 80 cubic yards,” says Chris Bartlett, sales and engineering director at Wilcox Commercial Vehicles. It forms part of the TVS Interfleet group, which also includes McPhee Mixers, Priden Engineering and SB Components.

Transporting aggregates in a trailer of this size, however, is problematic because the load will weigh out before it bulks out. The body will be grossly overloaded if you fill it to the brim.

As a consequence, businesses that have sufficient aggregate work to keep them busy year-round without carrying farm produce tend to favour half-barrel triaxle alloy tipping trailers at 35 to 40 cu yd. They can make full use of their capacity without running overweight. As well as being up to 300kg lighter than their plank-sided stable-mates, half-barrels have the advantage of being shorter and lower, says Butler. That gives them an edge if they are entering construction sites where access is problematic.

Weightlifter Bodies typically produces around 150 tipping trailers annually. Hauling aggregates wears the body, so Weightlifter makes use of an especially tough aluminium called Endural, sourced from Alcoa, says Butler.

Wilcox can supply its Megalite 40 cu yd alloy trailer to customers who need to haul aggregates, but its flat floor means it is not a true half-barrel, says Bartlett. “A trailer fitted with it can come in at around 5,800kg though, and we have one customer who hauls one with a lightweight DAF CF tractor unit who is achieving a payload of over 30 tonnes at 44 tonnes gross,” he says.

The triaxle trailer concerned features a chassis made from high-strength steel which cuts its weight by around 250kg, compared with one built out of conventional steel, Bartlett says. Wilcox builds from 270 to 300 trailers annually and all the chassis it uses are sourced from Montracon.

The choice of tractor unit can have a major impact on the combination’s payload, points out Butler. Units can differ in weight by as much as a tonne depending on the make, model and specifications chosen, he says. Opting for a lighter unit – assuming operational efficiency is not compromised – can make more sense than trying to save weight by specifying thinner gauges of alloy for the trailer body, because that can affect the latter’s durability. This matters, says Butler, because the customer may want to run a trailer for nine years or more, longer than the tractor unit hauling it is likely to remain.

“We can reduce the gauge of metal we use from, say, 3mm to 2mm, and initially everything will be fine, but that may not be the case after two or three years in service,” he observes.

Some customers still favour monocoque rib-sided bulk bodies over plank-sides, but rib-sided models have their disadvantages, says Bartlett. “Plank-sided bodies are more fuel efficient than rib-sides and can potentially offer a 1mpg benefit,” he says. “They’re also easier to sign-write, and to keep clean,” adds Butler. “However, they can be perhaps 100kg to 150kg heavier than rib-sides on a triaxle chassis and can be more expensive to repair if they’re damaged,” Bartlett continues. “You may end up having to replace an entire side. With a rib-side all you may need to do is cut out one of the uprights, and weld another one in,” he says. “Furthermore, you can beef up a rib-side so it can carry scrap metal by putting in extra uprights and specifying thicker sides.”

“A rib-side might cost you £500 to £600 to repair while replacing an outer panel on a plank-side could cost you £1,000 to £1,200,” says STAS Trailers UK managing director, Graham Macmillan.

He argues strongly in favour of alloy rather than steel chassis, spotlighting their resistance to corrosion and their all-round durability. “We build wide chassis, and they’re very stable,” he comments. “They flex, but they won’t break. They’ve got 11 cross-members, front to back, and they’ll last three times longer than a steel chassis,” he contends. The sturdy construction means that they lose some of the weight advantage alloy would otherwise enjoy, he admits, but that does not make them overweight. A 70 cu yd Agrostar alloy plank-side with a triaxle alloy chassis weighs 6,200kg, he points out. “And it should last you 15 years if you’re carrying grain,” Macmillan predicts.

The foregoing are by no means the only players in the alloy tipping trailer market, with global trailer building giant Schmitz Cargobull anxious to make inroads with a 70 cu yd bulker on a 9.6m frame. The scale of its activities means that it can build some components in-house that other manufacturers usually have to purchase from third-party suppliers, including its Rotos axles.

“We’re putting a lot of effort into tippers at present,” says UK head of sales, Stephen Mallett. Schmitz builds 4,000 a year and has the capacity to produce 10,000 annually, he adds.

Fruehauf, too, is increasingly busy in the sector after its September 2021 acquisition by MV Commercial, which is now implementing a £30m investment programme.

Colson Trailers is eager to make the case for high-strength steel as a viable alternative to aluminium in the aggregates sector. It has not long launched its Agglite 35 cu yd aggregate triaxle trailer with extensive use made of 3mm-thick Hardox 500 Tuf said to be 30% stronger than the 4mm Hardox 450 previously used. Going for a thinner gauge has taken a tonne out of the trailer’s weight, it reports.


Much the same principles apply to rigid tippers as they do to trailers when it comes to alloy body choice, says Bartlett. “Our Megalite trailer body was in fact developed from our Wilcolite body for rigids, which we build to transport aggregates and asphalt,” he says. “Bulk bodies on rigid chassis are few and far between these days.”

Fit a Wilcolite to a 32-tonne eight-wheeler chassis and you should be able to achieve a 20-tonne payload, he says. “That’s become more and more of a challenge though, because truck chassis are getting heavier,” he adds.

Says Weightlifter’s Butler: “Ninety percent of the alloy bodies we build on eight-wheelers are insulated so they can carry asphalt while the rest are aggregate bodies plus a few plank-sided bulkers. Remember that eight-wheelers with bulk bodies have a tighter turning circle than artics, and that can give them an advantage if they’re delivering animal feeds to some farms.”

He adds: “Twenty tonnes on an eight-wheeler is the magic number, but if you want to achieve it you need to look carefully at the engine and chassis specifications.”

Is a 13-litre engine truly necessary for the work you are on? Maybe you should specify an 11-litre instead – and save yourself about 180kg.

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