The road to reduction

The second article on weight reduction looks at how truck manufacturers and end users find ways to maximise capacity by reducing transport weight. Laura Hatton reports.

Customers are looking for equipment with increased payload and that is easy to use, all while still meeting axle-load regulations. Manufacturers of transport equipment are developing clever designs using high grade materials to help meet these demands.

For end users lightweight designs are increasingly important, as Joe Burton, Van der Vlist group marketing co-ordinator explains, “Reducing the overall weight is one of our priorities. As many things have to move on land, it means that we can not only move heavier cargo under restrictions, but it gives us more options on routes, reduces fuel consumption and takes some cargo below the thresholds for escorting or levels of permits in certain countries. This gives us a great opportunity to save money for our clients and be as efficient as possible, helping the environment as we go, and even helping to preserve the roads with less weight.”

To keep weight down Van der Vlist is replacing a lot of its trailers with lightweight versions. “We work very closely with our trailer manufacturers in order to make sure we take advantage of the latest developments in materials, design and standards to get the most efficient trailer design for general use, or specific cargo use,” Burton adds. “Our fleet of extra light semi-low trailers is on the road now, but we also have now two rail trailers which have been recently developed and low loaders.”

The low loader was designed through collaboration between transport company Zwaar Transport Twente, transport engineering company Vehicle Systems Engineering (VSE) and manufacturer Recker. The new 2-axle narrow bed low loader was engineered to transport combine harvesters. To keep the weight of the loader down it was designed to have rear electrical steering so to eliminate the need for steering beams. In addition, because no turntable is needed the height of the gooseneck is reduced as well. “The turning radius is fully programmable depending on the length of the trailer and it’s driveable at any height without additional tyre wear,” Joe Burton, Van der Vlist group marketing manager, adds.

Another way to keep weight down on transport equipment is by using high yield strength fine grain steel. German trailer manufacturer Goldhofer, for example, uses high grade steel in its trailer designs. “Customers are looking for an optimum deadweight to payload ratio,” Horst Häfele, Goldhofer project manager, says. “To reduce deadweight and deliver the optimum ratio, we employ high-grade steels in combination with finite-element methods (FEM) for the design engineering. In this context it is important to find intelligent solutions for the load-bearing structure so that the steel parts can be kept as thin as possible.

“Our vehicles today are up to 20 % lighter, depending on the product group, than similar models produced ten years ago. Less dead weight means more payload based on restricted maximum axle load, which is one of the most important factors for our customers these days,” Häfele adds.

To keep the weight of transport equipment down specialized trailer manufacturer TII Group use a number of designs, including using high strength steel to help reduce plate thickness. “We developed special light weight modules in order to reduce gross combination weight,” the manufacturer explains. “We even developed light bogies in order to reduce weight. We even drill out hydraulic cylinders to remove material.”

Trailer manufacturer Doll adopts a number of techniques to help save weight, as Nadja Paulus, Doll marketing explains, “The panther technology enables us to design extremely high frames with very high moments of resistance which is another gain in weight saving. Furthermore, we equip our trailers with aluminium rims or other light components, such as plastic tool boxes, etc to reach the least possible dead weight. In general, one can say that – depending on the extension steps – panther trailers are between 10 to 30 % lighter than trailers which were built 10 years ago.”

Truck manufacturers are also looking at ways to keep transport weight down. Manufacturer MAN, for example, uses high strength steel in its chassis, which helps minimise kerb weight without compromising the structural integrity of the truck frame, the German manufacturer says. Martin Pickering, MAN marketing communications manager, says, “Customer-specific options, such as aluminium wheels and air reservoirs and different fifth wheel specification can also reduce kerb weight and therefore allow maximum productivity. In some sector specific applications, a 19.5 inch [495.3 mm] pusher axle can be specified instead of the standard 22.5 inch [571.5 mm], saving 375 kg of weight without compromising the gross combination capacity of the truck.”

Truck manufacturer Scania is also working with weight reduction designs, as Örjan Åslund, Scania product affairs says. “We always try to tailor make each truck we deliver for its specific application and task. The challenge is, of course, to do the weight savings in the right places to the right costs – there must always be a positive calculation involved. The use of high-grade steel and clever constructions are the most effective ways of saving weight, but they can of course be accompanied by hundreds of other arrangements such as the choice of axles, chassis set up, body building preparation, cab specification etc that also contributes to keeping the weight down.”

Other ways to keep the weight down of transport vehicles is to reduce the weight of any additional accessories that might need to be carried, such as ground mats. Ground mats are used to spread the weight of a load over a larger surface area and are usually made of metal. To help reduce the amount of extra weight they add to vehicle loads, Zigma Ground Solutions, a developer of temporary access and ground protection solutions, has developed its TuffTrak range. The latest addition is the TuffTrak XT, which has a foam filled cellular core, a 200 mm overlap and a cam lock connection system. It is manufactured using a high molecular strength glass reinforced nylon composite and has multiple fixing points. The mats are 4 metres long, 2 m wide and 0.9 m deep. They each weigh 350 kg and are rated to carry 150 tonnes per square metre.

Saving fuel
One of the publicised advantages of weight saving is fuel saving. It is, however, difficult to give a reliable figure in terms of litres saved per kilogramme lost. This is because many variables can affect fuel consumption, including how a person drives, Pickering points out.

Åslund adds, “It very much depends on the type of application and operation. The most weight sensitive applications can be found within distribution and, or, long-haulage of course, typically fuel transports or similar. As a rule of thumb, 1 kilo less under such circumstances could mean €6 extra revenue per year. It’s very hard though to break down what a kilo less in weight could mean in fuel consumption, although the law of physics tells us that less weight always means less fuel consumption (all other things being equal).

Although manufacturers are finding new ways to keep the weight of transport equipment down, as Pickering explains, the increasing legislation regarding exhaust emissions have inevitably increased truck mass over the past decade with the additional of both exhaust gas recirculation (EGR) and selective catalytic reduction (SCR) technologies, and most recently, diesel particulate filters (DPF) for Euro 6. With this in mind, future legislation is likely to affect the way that manufacturers focus on weight reduction in the transport industry. With Stage V legislation stated for January 2019 (see IC July 2015 page 21), the focus on saving weight is something that will continue.