The Slovak Tatravagónka company started a project two years ago aimed at developing lighter and ergonomically better railway goods wagons. The project has involved both the customer and the supplier, and it all hinged on high strength steels.
Entirely new opportunities are now opening up in an area in which limited scope was available for innovation. The successes of Tatravagónka have awakened the interest of the industry and the company won second prize in the 2003 Swedish Steel Prize for its work on the new railway wagons.
”This is a major breakthrough in a conservative industry steeped in tradition,” explains Ján Valigurski?, Technical Manager of Tatravagónka, which is one of the leading European manufacturers of railway goods wagons. ”Our designs can contribute to a new way of thinking for tomorrow’s wagons.”
Many of the wagons that the company produces are designed for carrying coils of steel strip for the Swiss Ahaus Alstätter Eisenbahn (AAE) Company. AAE has 17 000 railway goods wagons and is thus one of the biggest operators in Europe.
A working group consisting of representatives of AAE, Tatravagónka and the material supplier was convened two years ago to examine how extra-high strength steels could be used in a new goods wagon for steel strip coils that are transported all over Europe.
The group had a two-fold objective. One of these was to meet the demands of the loading personnel for improved working conditions, and the other was to lower the deadweight of the wagons in order to increase the payload.
Better working conditions
The first stage of the work consisted of taking a closer look at the pivoted load-securing arms fitted to the wagon. Every wagon is equipped with twelve arms that must be lifted manually during loading and unloading. This is hard work and can cause strain injuries.
The working group soon realised that the original 21- kilo securing arms could be modified by replacing conventional steel with extra-high strength steel. A new design and the stronger steel could cut the weight of every securing arm by 8 kilos. At almost 40 %, this reduction in weight is of great benefit to working conditions.
”In the past, we continually had a couple of men on sick leave because of the injuries they sustained when lifting the old, heavy securing arms. But the new arms have elim inated the problem,” comments Anders Berg, who is in charge of the Port of Oxelösund – one of the places in which the new wagons are frequently used. Anders Berg continues:
”Although the securing arms are lighter, they feel much more rigid and stronger than the earlier arms. They appear to be more durable, while allowing us to work faster, which is important as freight quantities are on the increase. The lifting operations are numerous, and the new arms have cut the weight that every team must lift by 3 600 kilos on each shift.” Favourable experience
The next stage was to take a closer look at the end walls of the wagons. Tatravagónka engineers have now discovered the advantage of the extra-high strength steels used. The anticipated shearing and welding difficulties did not materialise.
Having realised that the first stage performed satisfactorily, new end walls of the same material as the arms were introduced – extra-high strength, hot-rolled steel Domex 650 MC. From wagon No. 150 in the development project, they now all have end walls of high strength steel, which has reduced the deadweight of the wagon further.
One tonne lighter
The third stage has just been completed – now the cradles and frame of the wagons have been redesigned using the same extra high strength steel. The deadweight of the wagons has been cut by one tonne, which will lead to increased payload and thus reduced freight costs. The greater the number of journeys, the greater the savings will be.
Tatravagónka views the future with high strength steel favourably.
”This is new technology for us, so we must take one step at a time,” says Sales Manager Franticek Hudák. ”I’m convinced that high strength steels will be increasingly common in our future products.”
Pioneering projects
To the company’s 50 engineers, the development project means that new knowledge and experience have been acquired. ”We have now become accustomed to using extra-high strength steel in our design work,” says Franticek Hudák.
”We have acquired new knowledge and can offer customers around Europe features that they may never have considered. We already have new projects on the way and high strength steel in timber-carrying wagons is the next step, with other projects in the offing.”
The development of new wagons and structures will increase as customers realise the benefits. The 360 coil wagons that have now been produced will serve as an example to many European customers.
”Developing goods wagons is a difficult task,” considers Jakob Öhrström, Marketing Director at AAE. ”Little money is available for experimenting, and waiting until an order has been received will not allow sufficient development time. Tatravagónka’s example is interesting and exciting as they dared to go against conservative views and opinions by thinking along new lines, and these coil wagons are an interesting example.”
Text: Jan Tannefors News Magazine No 1, 2004