Despite Britain having, officially, a temperate climate, it can still get pretty parky at times. And although it snows somewhere in the country every winter, it still catches us by surprise. Countries such as Sweden and Russia cope with snow metres deep on a regular basis. In the UK, just one centimetre brings everything to a grinding halt.
When the roads close down due to drifting snow, black ice, spinning cars and stranded lorries, it is the railways that keep going – most of the time. Infrastructure engineers have developed various pieces of kit to help keep the railway open.
One of these is the points heater. E lectric heating elements, clipped to the rails which make up a set of points, prevent ice forming and keep the switch blades moving. However, they are not very efficient and a lot of the heat is lost to the atmosphere.
That’s where Scotland’s A Proctor Group comes in. For nearly 80 years, the company has been developing and supplying product solutions to the agriculture, building and construction industries, including a 50-year pedigree of providing leading edge thermal and acoustic product solutions.
Working with Network Rail and its contractors, the A Proctor Group developed the Spacetherm® Point Heat Retainer Strip. This offers improved performance by directing the heat towards and into the rail, reducing the energy consumed in heating the points system and improving response times.
The Spacetherm Point Heat Retainer Strip is clipped into place over the rail and heating electrode. It helps reduce heat loss and the energy from the electrode (typically 200W/m) is dissipated quickly and effectively into the rail.
Energy consumption is generally 25-30% improved and response to temperature can be up to 60% faster. As a result, rail infrastructure managers can now choose a lower power-rated heating electrode to reduce the energy consumption where supply is limited or to save energy.
There are other advantages too. The response time to heat a standard set of points reduces from around two hours to approximately 50 minutes. This has a big impact on the performance of the whole points heating system and saves energy costs. In the same installation, a 200W/m heating strip would consume more than 0.5kWhr/m to heat and subsequently maintain the system at a temperature of about 3 ̊C. With the heat retainer fitted, the energy required to heat and similarly maintain the system reduces by more than 25%.
Once the advantages of Spacetherm were fully realised, it found other applications as well. One of these was on Network Rail’s latest de-icing train.
The A Proctor Group was asked to develop a thermal solution that would ensure pre-heated air was blasted at the rail from the de-icing train at the original temperature generated by the on-board systems. Bespoke Spacetherm sections were cut at the company’s fabrication facility and supplied ready for wrapping into the ducting work designed to carry the heated air to the rail. This simple and cost-effective solution significantly improved the retention of heat in the system and therefore its performance.
No doubt there are other applications both for the Spacetherm material and for A Proctor Group’s expertise. Being based in Scotland, the company is perfectly placed to understand Britain’s winter weather.