NETWORK RAIL INVESTS IN AUTOMATED WELDING EQUIPMENT FROM ESAB TO REDUCE TIME AND COST ASSOCIATED WITH REPAIRING WORN RAILS

Network Rail, the organisation that owns and operates Britain’s rail infrastructure, has purchased ten Railtrac BV 1000 units with Mobilemaster wire feeders from ESAB. A further six sets of equipment are on order and it is possible that additional sets may be purchased in the future. The Railtrac BV 1000 is a specialised set of equipment for repairing the surface of worn rails by laying down weld metal. As well as the equipment, Network Rail has also approved the use of ESAB's Tubrodur OK 15.43 welding wire.

Prior to the equipment and consumables being purchased, rigorous trials were undertaken to prove the efficacy and gain the necessary approvals. As well as formalised trials, three people from Network Rail visited the Swedish railway administration's training facility in Sundsvall, and ESAB demonstrated the equipment on site to a number of Network Rail's welding engineers.

Switch crossing components are costly and time-consuming to replace, and it is not easy to obtain track possessions of sufficient length to carry out extensive repairs using manual welding. Network Rail has therefore chosen to use an automated welding process which is considered to offer significant time savings over conventional arc welding techniques. Of the various systems available on the market, ESAB's Railtrac was found to be the most portable, with its compact dimensions and low weight. In addition, ESAB was able to adapt its equipment for use with Network Rail's existing generator-driven welding power supplies - which avoided the prohibitive cost that would have been associated with purchasing new power supplies. Another benefit was that the ESAB system does not require interpass grinding, which makes the repair process quicker, easier and safer.

Each ESAB Railtrac BV 1000 set consists of a control box, remote control unit, carriage, alignment rails and running tracks. The control box enables various welding programs to be selected for hard-facing or repairing rail ends, wheel burns, wing rails and crossing noses. During welding, the operator can make adjustments to the weaving pattern, travel speed and zero line, as well as the welding parameters.

ESAB has also supplied Mobilemaster IV wire feed units with the Railtracs, adapted so that the electrical connectors suit Network Rail's welding power supplies. The Mobilemaster benefits from a totally enclosed, metal-reinforced, impact-resistant case that protects the welding wire and feed system from dirt, moisture and other contaminants. Solid-state motor control and dual grooved, serrated feed rollers help to ensure that feeding is powerful, smooth and dependable.

The switch and crossing components currently repaired by the Railtrac system are manufactured from carbon-manganese steel and there can be some lipping occurring after a relatively short period of time. As a result, it is often necessary to revisit the site to grind away the lipping. In contrast, repairing worn components by welding with ESAB Tubrodur OK 15.43, a self-shielded, flux-cored wire, results in a rail surface that has a hardness of 30-40 HRC immediately. Consequently there is no need to revisit the repair to regrind it in similar timescales and the component is likely to last as long as - if not longer than - a new component.

Using the ESAB Railtrac system could result in substantial cost savings for Network Rail, with repair being very much quicker and cheaper than replacement and the repair lasting at least as long as a new component.

Derek Harvey, Sales and Marketing Manager for Welding Automation at ESAB, comments: "We worked hard with Network Rail to prove the process, equipment and welding wire, and to obtain the approvals. We are confident that the Railtrac units will bring considerable benefits to Network Rail's maintenance processes."

Bill Mosley, Network Rail's National Welding Engineer, adds: "I am convinced that repairing worn crossing components is, in many cases, a better option than replacement. In fact welding can be used to resurface rails that have suffered damage in a number of ways, and the Railtrac system can equally well be used to repair standard rails. We also have other weld-repair applications that we are investigating, so depending on the success of the machine, it is possible that we could be purchasing more Railtrac systems in the future."

To request more information about the Railtrac BV 1000, Mobilemaster wire feeder and Tubrodur OK 15.43 email info@esab.co.uk.