SCHWIHAG was set up in Switzerland in 1971 as a supplier of track and switch components, which 47 years later remain the company’s main specialities. However, it was not until 2007 that the decision was made to build a factory near Leipzig, Germany, to manufacture track fastenings.
Mr Karl-H Schwiede, who is chairman and CEO of Schwihag, says he chose a site in Radefeld near Leipzig in Germany, because after German
re-unification a production site in eastern Germany offered attractive opportunities like a well-educated workforce. “We began construction of the first building in January 2008 and production started in July,” Schwiede says. “We produced the SKL1 clip at first, and the SKL14 clip a year later.”
The SKL1 fastening was originally designed by a German Federal Railway (DB) engineer in order to have an alternative to Vossloh’s double-spring washer. “We had a long relationship with DB regarding turnout fastening systems, and DB was looking for a strong second supplier of rail fastening systems to foster competitiveness, and we were keen to get into the fastening market,” Schwiede explains. “When you have the technical expertise, so that you know how to make a perfect clip for stock rails or turnouts, you know how to make a clip for rails in the track as well.
“The SKL14 clip was under patent, so we had to start with the SKL1. We obtained approval for our clip and received an order to supply 50% of DB’s needs. The SKL14 has a pre-mounting position on the sleeper before it is pushed laterally up to the rail foot, which is an innovation compared with the SKL1.”
Schwihag currently produces 25 different types of fastening for ballasted track with timber, concrete or steel sleepers for heavy-haul railways up to 30-tonne axleloads, high-speed lines up to 22.5-tonne axleloads, and for metros and light rail lines. The company can also supply fastenings for ballastless track and girders on steel bridges.
“Today, we are able to use modern design tools to produce a clip more efficiently than before and at the same time with less material,” Schwiede says. “We are also very flexible, and we can make any type of clip. We currently produce 15 million clips per annum, but we will probably increase output on a continuous basis to 20 million in 2018 as we have received approval to supply rail fastenings to several new customers.
“We have a joint venture with Progress Rail in the United States whereby we have system responsibility and produce clips and dowels while Progress Rail assumes responsibility for the sales. In North America, the SKL ME 1 is the Schwihag/Progress Rail solution for concrete bearers with W-fixation, which is used mainly on BNSF and Kansas City Southern of Mexico lines. Excluding China, which is our third largest market for turnout components, we have a world market share for track fastenings of probably 10-15%.”
Schwiede says Schwihag aims to maintain a high standard of quality during the sales effort, production process, supply and installation. “We always have complete system responsibility rather than the railways buying single items,” he explains. “Our clips are pre-mounted on the sleeper so there are no separate materials on site.
“During the production process we conduct cold soft bending. Bending is achieved by rolling rather than pressing which reduces the radius and thickness of the clip which can lead to deformation. We are talking about a system which should last for 25 years.”
Schwihag’s production process is designed to avoid surface decarburisation - reducing the carbon content of the steel. This is achieved using a special heat treatment process which allows a fine auricular, martensitic microstructure to form after heating. “With decarburisation, you can lose 0.2-0.3mm or up to 0.5mm which renders part of the clip useless,” Schwiede explains.
In addition, the hardening process takes place in an oil rather than a water bath, which Schwiede says is unique to Schwihag. “We have made a huge investment in this process, but we know that one of our competitors is following us,” Schwiede says. “We are discussing with some railways about reducing the cross-section of our clips while maintaining the same performance. We have demonstrated it and we now need to follow the approval process.”
Forging and bending of Schwihag’s SSb 2, 3 and 4 clips for slide baseplates for the inner bracing of stock rails is carried out in Switzerland, as Schwiede explains: “We couldn’t find anyone to forge and bend metal on one production line so this pushed us to do it ourselves.”
Single control centre
Schwihag has two production lines at its factory in Leipzig which are completely automated from a single control centre. One produces SKL21 fastenings, for example, which have more elasticity than other types, while the other line, which was rebuilt recently, produces fastenings such as the SKL15, which are often used on unballasted high-speed lines.
Once the fastenings have been bent into shape, they move through pre-heating ovens and final-heating stoves before moving on to the oil bath for hardening, cleaning and final temping. The fastenings always pass through the production process in the same order, which Schwiede says is important for quality control. The clips are then put into specially-designed crates for transport.
Schwihag has a test laboratory at the Leipzig plant which has a photographic digital measuring system to check the dimensions of the fastenings. The lab is also able to measure hardness, and one item from each delivery of raw material is cut to test for tensile strength. “The current production process is the result of 10 years of experience and development, and is at a very high level now,” Schwiede says.
Schwihag does not manufacture its own coach screws, but it does make its own dowels to reduce the risk of cracks in concrete sleepers. “We found that the dowels being used transferred stresses to the concrete sleeper, with a risk that the stresses would be too high,” Schwiede explains. “Our dowel is bit more expensive than those produced by other companies, but it reduces the risk of concrete bearer breakages.” Schwihag also has injection moulding machines which produce other track fastening parts such as gauge plates.
Looking to the future, Schwiede says he wants Schwihag to be “a real partner” for railways. He says this is particularly important today with the paradigm shift of knowledge and expertise from the railways to the suppliers. “In the past, all major railway suppliers were not used to thinking on their own - they just did what they were told,” Schwiede reminisces. “The railways used to have large technical organisations, whereas now there are fewer and fewer people in the railways with technical expertise. Due to this shift, we are increasingly solving problems for railways. For example, DB had a problem with the track transitions from bridges to normal track. We were able to solve the problem, and produce and certify a new product within 18 months.”
Schwiede adds that he has always been astonished at how little each railway knows about its neighbours. This is why he believes that Schwihag as a global operator is well-placed to bridge the knowledge gap between railways in Europe as well as internationally.
“Today some railways don’t even want to buy patented products, but patents are designed to protect inventions and thereby stimulate new developments by giving protection to inventors,” he says. “Ideas come from communication with customers. That is why we have technical sales staff rather than commercial sales people, to discover what needs and problems customers have and how we can resolve them.”
Schwihag has patently come a long way since the company was set up almost half a century ago. Schwihag will move into its new headquarters in Switzerland this October, consolidating six buildings into one purpose-built facility, including a laboratory, prototyping and testing facilities, and a training centre. Schwiede and Danneberg hope this will position the company to serve the railway industry for another half century.