Railway Tram car bodies built to last

Vossloh España finds a solution for further sustainability in tram car bodies from Outokumpu’s lean duplex stainless steel.

Light rail transit systems are developed and expanded intensively in many cities throughout the world. These systems are an efficient and viable solution for public transport, and even mature cities in developed countries are installing new tramways and other urban rail transit networks. Among other leading manufacturers of rail transport equipment, the Vossloh Group is tapping into the trend. This major European manufacturer of locomotives and passenger trains places an expanding focus on tramways, train-trams, metro trains and commuter trains at its Valencia-based subsidiary Vossloh España, S.A. Stainless steel has for long been a key part of Vossloh España’s production programme in suburban trains. Stainless provides the corrosion resistance and strength in structural sections of car bodies to meet the company’s commitment to build sustainable public transport equipment. Up until today Vossloh España’s stainless steel reference grade in structural sections has been ferritic EN 1.4003. This is a chromium stainless steel that offers a superior alternative to mild (carbon) steel in structural applications in moderately corrosive operating environments. On a new commission from a major metropolitan customer, Vossloh now seeks to develop a tram with longer design life and lower maintenance needs compared to conventional designs. During the early R&D phase of the new tram, Vossloh España was introduced by Outokumpu to duplex LDX 2101®, a lean duplex stainless grade developed and produced by the stainless steel company. After a review of the properties of this duplex grade against the customer requirements, Vossloh replaced ferritic 1.4003 with duplex LDX 2101® despite the substantially higher cost of the latter material. “We chose duplex LDX 2101® because of its strength and corrosion resistance,” says a representative of Vossloh España’s engineering department. He elaborates, “First, the duplex grade’s yield strength is 60% and tensile strength 45% higher than the values presented by the ferritic grade. “Second, duplex LDX 2101® has corrosion resistance similar to that of the austenitic stainless steel grade EN 1.4404 (ASTM 316L). This is much higher compared to ferritic 1.4003.” LDX 2101® (EN 1.4162) is a low-alloyed, general-purpose duplex stainless steel. It features high proof strength, similar to that of other duplex grades. Duplex LDX 2101® is one of the high-strength stainless steel options offered by Outokumpu for rail transport. High-strength stainless steel grades help to reduce vehicle weight, reduce maintenance and improve energy efficiency. They can be applied to arrive at designs optimised with respect to strength, maintenance, durability and long-term cost efficiency. Some of their benefits are safety-related and include high energy absorption at impact and a greater level of fire resistance, in addition to less likelihood of weakened structures owing to corrosion. Outokumpu supplies a comprehensive range of stainless steel grades, dimensions and finishes. They provide designers and engineers with exceptional possibilities to create innovative, light-weight railway vehicles of the future.

A metro train car body under construction at the plant of Vossloh España. Photo courtesy of same. A metro train supplied by Vossloh España. Photo courtesy of same.