The search for stronger welds
Welds made by Plasser’s APT 1500 R welding robot utilize a fully-automatic process.
forges research efforts by Mischa Wanek-Libman, editor
Rail welding service providers step up their research efforts to bring new products and stronger, longer lasting welds to North America’s railroads.
T
he life of rail steel has greatly improved over the years thanks to a committed research and development effort across the industry. A side effect of stronger steel is that the welds that use to last until the end of the rail’s expected life, aren’t always making it. Welding service providers, as well as researchers at Transportation Technology Center, Inc. (see page 11), are working diligently to increase the reliability of welds and extend service life.
Expanded mobile fleet
Chemetron Railway Products, a division of Progress Rail Services, says it continues to expand its fleet of mobile welding units with the addition of several new units that can be used for rail installation or portable welding applications. Chemetron is also adding rubber-tired units with cranes that will have a 30-foot reach. The company says these units are ideal for welding turnouts or other long-reach applications and, like Chemetron’s CAT track-hoe units, travel on the road and rail. On the fixed plant side of its busi26 Railway Track & Structures
July 2014
ness, Chemetron opened a new welding facility in Russell, Ky. According to Mark McLean, manager sales, this plant has many new features, including automated spot and end polishing, enhanced control and power systems that provide consistently high-quality welds. “Chemetron works closely with our customers and rail suppliers to extend the life of our welds. At our new Russell, Ky., facility, state-of-the-art control supervises every aspect of the welding process, ensuring repeatability of the operation. The fully-automated material handling includes a new rail end preparation system that polishes the rail head, rail base and the rail butt with no human interaction, resulting in a consistent and repeatable electrical contact while welding,” said McLean. “Chemetron continues to refine the uniformity and reduce the size of the heat affected zone (HAZ). The improved uniformity and reduction in size will extend the life of our welds.”
New welding head
E.O. Paton (Hong Kong) Ltd. has developed a ne w welding head
designed for crossing welding in close proximity to the adjacent rail. The company says the head also allows welding of third rail systems without removing the conductor rail, while the welding head’s design allows welding of tram rail, as well as conductor rail. E.O. Paton expects to have a production unit available later this year Dennis Shears, technical director with E.O. Paton, says with the advent of high-allotted rails, the company has been researching technology that allows for a narrow HAZ, as well as hardness restoration (quenched if required). Shears notes that the results so far show that the joint face heat control is critical and that even small deviations of this heat can have a marked effect on the strength of the joint. Shears also says customer requests regarding welding quality almost always call for greater wear resistance, better hardness and longer life of the parent rail. Additionally, Shears says narrow HAZ requests that are below the required specifications are also becoming the norm. www.rtands.com