A NEW concept for a railway turnout designed in the Netherlands for use in winter conditions without a point heater, offers the potential to avoid high energy bills while reducing CO2 emissions.
The impetus for the project stems from the problem of turnouts becoming clogged with snow and ice resulting in many train delays in the Netherlands during the last 15 winters.
As a mechanical design engineer working with 3D-CAD since 1990, designing all types of machinery for the defence, food, rail and off-shore industries, I became frustrated by the lack of progress in trying to find a solution to the problem. As a result, I spent the last three years developing a new mechanical working principal for railway turnouts which is neither high-tech nor expensive to build. By avoiding the use of horizontal movable tongues, I found that snow and ice has no impact on the correct working of the turnout which obviates the need for turnout heaters.
The problem with existing turnout designs, which are more than 100-years-old, lies with the horizontal movable tongues where snow and ice can accumulate between the tongue and the fixed rail. At present every turnout which needs to remain in use during the winter months requires an expensive and reliable high-power (10kW-15kW) heater, resulting in high energy and maintenance bills.
Instead of using open horizontal movable tongues, the new turnout is fitted with vertical movable tongues which can slide up and down between four guides to form a closed box around each tongue. This prevents snow and ice from penetrating the mechanical parts of the turnout.
The vertical movable tongues are locked by a set of 14 mechanical horizontal moving locking bars. The rail tongues (points) and the locking bars, which are linked by a connecting strip, can be driven simultaneously by three electro-mechanical or electro-hydraulic actuators.
The winter-proof turnout is 10.4m long, has a radius of 190m, weighs 15.2 tonnes and uses UIC 60E1 rails. Series production of the winterproof turnout should not be any more expensive than conventional turnouts because of its very simple mechanical setup.
To give an idea of the savings which could be achieved, there are 22,567 electric point heaters on the German rail network, each of which consumes10kW. On average in 2012 the point heaters in Germany were switched on for 1440 hours. The cost per kWh is €0.07 and 0.7kg of CO2 are emitted to produce 1kWh. So in 2012, German point heaters consumed 324,964,800kWh at a cost of €27.48m and emitted 227,475 tonnes of CO2. There would be additional savings from not having to inspect and maintain point heaters, plus the operational savings by avoiding train delays due to faulty point heaters or frozen points.
I have funded the project entirely from my own resources and carried out the development work in my own time. A 1/6th-scale working prototype has been built, which is made of stainless steel, and is driven by high-torque servos and digitally controlled from a laptop. The scale model is being used for technical presentations to universities and the railway industry, as well as at exhibitions.
A full-size prototype will need to be tested mechanically, checking for wear and correct functioning and operating mechanical forces. It will then need to be installed on a railway, to monitor the operation of trains over it at different speeds. Once these trials have been completed, the winter-proof turnout will require certification.
I have applied for two patents for the winter-proof railway turnout which is now being considered in the Netherlands by turnout manufacturers Vossloh and Voestalpine, infrastructure manager ProRail, and national operator Netherlands Railways (NS).
With the same turnout system in use unchanged for more than 100 years, it is very difficult for people to accept change. However, I have made several technical presentations during the last two years, and I am optimistic that my new design will eventually be taken seriously.