Long-term acoustics consultancy for ProRail

Managing the noise capacity of rail yards

Thijs van Bon: "Rail yards are used to work on railway material, for instance cleaning carriages internally and externally, checking their technical state and changing the composition. These yards are often sprawling pieces of land in the middle of an urban area. Since the nineties, railway yards are regarded as industrial terrains. Therefore, stricter sound norms are applied to yards than to trains when they are in operation on the tracks. Not surprisingly, the subject of noise and its occurrence is a hotly debated issue. We proudly look back on our many years as policy advisor for ProRail, manager of Dutch rail yards."

Different to regular railway noise

Yards produce a different kind of noise when compared to regular railway tracks. This is because localised activities take place, such as the running of diesel locomotives and ventilating carriages to preheat them. Moving materials from one process location to the other (shunting) produces a different kind of noise as well. The vehicle's speed, for instance, is much lower than on regular tracks. Yards furthermore contain a lot of switches to link the various process locations. Passing these switches can sometimes produce a curving noise (squeal) that is shrill and intense and can cause a lot of nuisance.

Tailor-made solutions

Over the past two decades, a lot of effort has been put into reducing noise pollution by railway yards. Big projects such as Project Industrielawaai emplacementen (PRIL, Project Yard Industrial Noise) and Uitvoeringsprogramma Geluid Emplacementen (UPGE, Implementation Yard Noise) have been put in place. As a result of these programmes, most yards have been fitted with continuous welded rail and systems to combat curving noise. The systems in question reduce noise by adding a thin layer of conditioning substance to the rail tracks. Trains have also been adjusted in order to reduce the noise of working installations when the trains are at a standstill. These measures are very costly. It is extremely important to know exactly what effect they have and which measures are the most effective in a certain situation.

Complex calculations

How much noise pollution does a yard produce? This question cannot be easily answered. It depends on the processes that are being carried out at a given moment, the materials that are in place and the route that is being used for shunting. Circumstances that vary from day to day. Yards are therefore one of the most complex problems our branch has to deal with. In order to get a better grip on the influence of the business layout, we developed the so called Dynamic Sound Models. They help us to calculate various business layouts in a flexible, efficient and fast way. ProRail has recently started working with our Dynamic Sound Models, which are being implemented nationwide. In order to do so, ProRail asked us to develop the necessary software.