With level crossings, and level crossing safety, very much in the public eye, the rail engineer met with Richard Whatley, Managing Director of STRAIL (UK) Limited, to ask about the advantage of rubber crossing surfaces.
TRE: What made you interested in rubber level crossings in the first place?
RW: Speaking honestly, it was my father. He became involved over 25 years ago, and, if you think about it, rubber is an ideal material. It absorbs noise and vibration, it isolates the track from the hammering of heavy traffic, and so it protects track geometry and it makes for a quiet crossing.
TRE: We understand that STRAIL crossings are “green” and that recycled rubber is involved.
RW: That’s right. The German company which makes the crossings is part of a large group specialising in rubber. Re-treading tyres is one of its many activities. The process involves stripping off the worn treads and vulcanising fresh treads in their place. A great deal of rubber is left over and the company, already experts in the vulcanising field, decided to turn it into level crossings.
TRE: We believe that vulcanising is more expensive than gluing with modern elastomeric adhesives. Why do you do it?
RW: If you apply sufficient heat and pressure to a mass of rubber granules they will melt into each other to become a homogeneous mass. This is called vulcanising, and it is the way in which vehicle tyres are made.
The finished level crossings have the same properties of strength, flexibility and endurance, properties second to none. Yes, the tooling is expensive, involving massive heated and pressurised steel moulds, but we believe that the quality of the finished product justifies the expense.
TRE: Would you like to say a word about safety?
RW: There are three obvious safety hazards in the composition of the crossings themselves: loose panels, skidding and flangeway grooves.
Virtually all level crossings are made up of individual panels. A loose panel is a potential hazard.
Therefore STRAIL panels are shaped to inter-lock with each other and under the head of each rail.
Furthermore, high tensile steel tie rods run through the panels from end to end making it virtually impossible for a panel to break loose.
Mineral grit is embedded in the surface of each panel during the vulcanising process to guard against skidding.
Another hazard is presented by the flangeway groove beside each rail, particularly to cyclists. Strail have developed a replaceable honeycomb element to fill this groove. It is sufficiently strong to support a cycle, but it deforms under a tram wheel.
TRE: No two level crossing sites are identical. Do you make a new design for every site?
RW: Yes. We visit and survey every site, recommending the crossing type, quantities etc. Furthermore we have complete records of all the one thousand or so crossings which we have supplied.
TRE: You mentioned crossing type. Do you have a large range?
RW: Yes. They range from pedeSTRAIL, designed for pedestrians, through standard STRAIL, innoSTRAIL for lesser used crossings, pontiSTRAIL for very heavy traffic and veloSTRAIL for cyclists. Variations within each range are considerable and our engineers will recommend the right model for each application.
TRE: How about experience elsewhere?
RW: STRAIL claim to have made the first rubber level crossing. India was the fiftieth country to start using them and STRAIL have supplied about 40,000 world wide.