‘Dynathane’® central to innovative embedded slab rail track

Hyperlast Limited manufacture the ‘Dynathane’® polyurethane elastomer rail pad that is central to the innovative embedded slab track system, developed by Balfour Beatty.

This new track system is low maintenance, and far safer and quieter than traditional ballast systems. It is ideal for tunnels and under bridges where maintenance can be difficult, and where vibration control is ‘high priority’.

Integral to the increased safety, noise and vibration control is the Hyperlast Limited ‘Dynathane’ polyurethane elastomer rail pad, specially developed and moulded by Polyurethane Products Ltd. ‘Dynathane’ is a variable density microcellular two-component polyurethane elastomer, which is easily tuned to meet individual vibration and shock control issues in a variety of applications, with low cost tooling in many mould configurations.

Unlike a solid elastomer that ‘bolts and bulges’ under compression, ‘Dynathane’ absorbs the compression to a pre-determined stiffness that can be tailored to meet varying ‘on-site’ requirements, specific in this case to the control of rail vibration, noise and ride quality.

PPL worked over several years with Balfour Beatty and Hyperlast Limited in developing the mathematical models and formulations that finally evolved the final mould design and application techniques.

The Balfour Beatty rail is manufactured symmetric on its two axes sits in the ‘Dynathane’ pad which is held by a GRP shell fixed into the concrete slab. During maintenance, the ‘Dynathane’ pad is easily compressed allowing the rail to be easily removed and replaced.

By varying the density of the microcellular two-component elastomer at the design stage, ‘Dynathane’ moulded components can be tuned to meet a variety of specific vibration and shock control requirements. It can be moulded using low-cost tooling, which allows fast starts to projects with a reduced capital outlay.

‘Dynathane’ is a tough and durable microcellular polyurethane specifically designed to reduce vibration and minimise noise pollution in aggressive working environments, and contributes to Hyperlast’s policy of protecting our natural surroundings.

Hyperlast Limited shock, noise and vibration control department engineers, are always available to help and advise, and to customise materials to specific requirements.

Ref: 22-1437   September 2003