A tipper for the worst conditions
“It’s the worst material you can ever load. It comes in all sorts of sizes and weights. It’s hard, heavy and sharp but full of air too.”
John Bayley is talking about steel scrap. His company, Trent MF, has now developed a scrap trailer designed to withstand all the damage steel scrap can cause when it’s loaded over and over again in the same tipper body.
The trailer is designed for one of the leading recycling companies in Britain, European Metal Recycling, EMR. On paper the order from EMR was simple: build a trailer that can load as much as possible and that will hold.
That would be easy if it wasn’t for the demand that the trailer also has to carry as many tonnes as possible. The result is shown at SSAB’s stand at the Tip-ex exhibition: a 44-ton trailer that can carry 24 tons of steel scrap. The entire body is made from high strength steels.
“It can take a 2-tonne heavier payload compared to one made in conventional mild steels”, John Bayley says.
The tipper has an imposing volume of 68 cubic metres and with its body in royal blue, it literally darkens the corner of the hall. It is designed with a combination of high strength steels to withstand different kinds of stress factors. The side panels which have to withstand wear are made of Domex Wear and the floor plate which also has to carry heavy loads is of Hardox 450. The side rails are made of Domex.
”EMR has told us the problem. And SSAB knows about the materials”, says John Bayley.
Trent MF has designed all kinds of tippers and scrap-tippers. But to move forward John Bayley decided to get to the bottom of the problem. He started by visiting scrapyards to see what really happens when lorries are loaded and unloaded. David Want who works within Heay Transport at SSAB’s UK sales office went along to see just what the material was exposed to.
“Abuse” is regular use
“All truck bodybuilders hate crane drivers”, John says. The sparkle in his eyes indicates a touch of British humour, but the problem he points out is a serious one:
“Crane drivers work fast with a 5-tonne magnet that hits the walls of the body. They finish loading by banging on the top of the scrap material to get the full tonnage.”
First the scrap-iron of all sizes and weights is dropped into the trailer. When the lorry is full the 24 tonnes are pounded out against the sides.
“Even if you are gentle, these are tough conditions. Some would call this abuse, but it’s regular use”, John sums up.
Domex with good memory
The solution is not to build a rigid panel. It would only get damaged.
The long and high side panels on the custom-built scrap-tipper are designed using a combination of Domex Wear and Domex 700. Domex has a good memory. The panels manage time and again to regain their original shape after the lateral pressure they are exposed to during loading.
There is an enormous strain on the rear-end of the body when the load is tipped. The whole floor plate of the scrap-tipper is made of Hardox, a highstrength wear-resistant steel that is especially good for high impact loads.
Fewer reinforcements are needed with high-strength steel. The sides are smooth with one longitudinal mid-rail and two verticals. The conventional solution when using mild steels is to build a grid of longitudinal and vertical rails. Smooth sides reduce air-resistance which improves fuel consumption.
Enormous experience
John Bayley has been in the tipper industry for 45 years and has enormous experience of construction and materials. Among many other things he was a British pioneer in welding aluminium in the 60s. He built over 70 vehicles in aluminium and hollow work. When the material became too expensive he decided to try to build as light as possible in steel.
“I have built “steellite”, based on the awareness that all steel has the same weight. So as thin and as strong as you can make it …”
In the beginning of the 90s he came across the high-strength steels from SSAB for the first time.
“Since then we have been able to move forward. I follow every step and want to know about everything they do. I say: make it lighter, thinner, stronger! Always with the power to weight ratio in mind.”
Domex 1200 at the top
The next development for Trent MF is to design a new scrap trailer utilizing Domex 1200 in the top and mid rail. The ultrahigh-strength steel has been developed for use in slender structures which must be capable of withstanding very high stresses. Domex 1200 was introduced on the market as late as in March this year and creates the possibility for stronger structures in applications such as cranes, containers and heavy vehicles.
“We are in a continuing process to reduce weight and make stronger and even more competitive tippers”, John Bayley says.
“The benefits for the user are obvious. Let’s say you can make 5 trips a day with a scrap-tipper and you can load another 2 tonnes. That makes 10 tonnes extra a day, 50 tonnes a week and 2 400 tonnes a year based on 48 operating weeks.”