The world’s lightest and toughest container? Manufactured entirely from one of the most  advanced high strength steels available on the market and with ultra thin walls. The material used and the new design significantly increases the useful life of the container. The container became the winner of Swedish Steel Prize 2005.

CMT – the company that specialises in hooklift containers – has been closely following the development of new high strength steels. This has enabled CMT to develop containers that are lightweight, have high strength and offer major cost benefits to its customers. A decisive factor is that CMT has used the new materials to produce economically beneficial solutions.

“Some of our customers can pay off their investment in a container in only a few months of operation and this is a powerful sales argument,” states Martin Wåhlin, Managing Director of CMT.

CMT has three models in its product range, the lightest two of them are of the design now awarded. These are ultra-thin containers for wood chip and forestry materials, whilst the somewhat sturdier, all-round model is intended for a variety of materials.

Horizontal ridges

The difference between the models is mainly the material thickness and the design of the walls.

“In the lightest model, the walls are very thin and are folded into horizontal ridges both on the inside and on the outside, whereas the walls of the all-round model are smooth on the inside in order to withstand the wear caused by metal scrap, for instance,” explains Martin Wåhlin.

The horizontal ridges add strength and eliminate the need for the reinforcing beams that are normally visible on the outside of other containers. Another feature of the design that arouses interest is the rounded transition between the bottom and sides, which is achieved by folding up the bottom plate on the sides and welding it to the wall plates. This results in fewer joints and increased strength. In addition to lowering the weight, the removal of the side beams also provides significant environmental benefits.

Free flow of air

“A container of traditional design has a number of horizontal beams on each side, which jointly form a wide wall since they project by about 100 mm and restrict the free flow of air,” explains Martin Wåhlin. “By removing these beams – of which there are often ten – we have eliminated about one metre of wall width on each side of our container design. The result is a reduction of at least 5 percent in the fuel consumption of the truck carrying the container, which has both economic and environmental benefits!”

The containers also have a new design of hook bracket used for loading the container onto a truck. Instead of two heavy vertical beams serving as reinforcement on one short side, CMT uses a Y-shaped design in which the beams are angled half-way up and are run to the top corners of the short side.

Thin walls

An advanced, cold-rolled high strength steel with a minimum tensile strength of 1400 N/mm2 is the predominant material used for CMT containers. In the ultra-thin wood chip container, the walls are 1 mm thick and the floor is 2 mm thick. The same grade of steel, but 2 mm thick, is used for the walls of the all-round model. In this container, the floor is made of 3 mm thick hot-rolled steel with a minimum yield strength of 650 N/mm2.

“We have found out how to handle these materials effectively and we are confident that we will be able to step up our production rate.” New ideas are already on the drawing board at CMT.

“We are considering a number of different options , including one in which the container will be delivered ‘semi-finished’ for the customer to carry out part of the final assembly,” reveals Martin Wåhlin.