Railway Technology for the Long Haul

Keeping Trains Running With Durable Railway Technology

Railways around the world need smarter solutions, like rail pads that combine long-term endurance with a minimum of maintenance.

Trains are vital to economies around the world, and so is railway technology that can help keep them moving more reliably. DuPont materials are helping rail pads and track systems withstand heavy loads and harsh conditions longer.  And DuPont engineers are collaborating with equipment-makers to help find smart solutions for local challenges.

Building in Reliability

The reliability of a rail system is only as good as the reliability of its tracks. So developing high-performance rail components is an industry-wide priority. One area of focus for DuPont railway technology is the rail pad, the assembly that anchors the rail to the ties or rail bed.

DuPont™ Hytrel® thermoplastic polyester elastomer is one material used, offering:

  • Excellent flex fatigue and broad temperature use.
  • Resistance to tearing, flex-cut growth, creep and abrasion.
  • Outstanding strength and toughness.
  • Superior durability vs. rubber

Managing Heavy Loads and Steep Grades

Reliable rail pads are especially critical in difficult terrain. When the South African engineering company, Pandrol, specified Hytrel® for a new rail pad assembly, we built a solution with a focus on strength. The goal: providing stability for tracks used again and again by long, heavy trains loaded with coal over a mountainous 300-mile route.

Creating a Multi-Material Solution

The existing rail pads were made from a standard ethylene, and weren’t sturdy enough for the taxing conditions. Pandrol’s new assembly design ultimately used both DuPont Hytrel® and Zytel® to help decrease shock, absorb vibration and reduce wear to the rail. Using these ultra-durable materials also tripled the longevity of the pads, so maintenance and production downtime were considerably reduced.

Pandrol integrated the Hytrel® railpads into a proprietary rail fastening system, called “Fastclip®”, which also included insulators made of high-viscosity, unfilled DuPontTM Zytel® nylon resin, selected for its strength and abrasion resistance.

Supporting High-Speed Systems

Other rail systems that put a high value on rail stability are high-speed trains. These trains require that rails be mounted on rigid concrete with rail fastening systems that are resilient and able to absorb vibrations. The rail fastening system of the German Federal Railways (Deutsche Bahn) uses foamed DuPont Hytrel® for this purpose. Engineers at Paul Muller Technische Produkte GmbH chose Hytrel® because it retains its resilience without hardening, whatever the temperature in the environment.

It also stands up to grease and other chemicals. As a result, the trains can travel around right bends at relatively high speeds, while their low maintenance and noise absorption make for an improved solution.

Making Parts Lighter and More Efficient

DuPont materials also can provide strength and durability,while making parts lighter in weight. This can allow for lower handling costs during the manufacturing process,and can also reduce shipping costs (and energy use) throughout the supply chain.

CASE STUDIES

  • Durable Rail Pads for Freight Lines

    How Pandrol collaborated with DuPont, specifying Hytrel® for rail pads that have endured over 10 years of use by heavy coal trains without replacement.

INFORMATION & IDEAS