Objectives and content
Exterior noise caused by rail traffic is a major source of noise pollution in Europe. A large number of people living in the vicinity of railway routes are affected by rolling noise from trains, in particular from goods trains running through densely populated areas at night.
Rolling noise of goods and passenger trains is generated by wheel and rail roughness (form irregularity). This roughness leads to wheel and rail vibration and noise radiation. The cast-iron block braking system usually applied on goods trains and still widely found on passenger stock causes a significant increase in wheel roughness in the wavelength range 1-25 cm, which is of most importance for noise generation. This gives rise to high rolling noise levels, compared to a wheel with no brake blocks acting on the wheel tread. Where disc brakes are used, the wheel roughness is found to be much lower and the rolling noise is significantly reduced.
In many situations conventional tread brakes are preferred, for both technical and commercial reasons. Alternative materials to the conventional cast-iron brake block material have been tried and it appears possible to develop materials which do not roughen the wheel surface in the wavelength region of importance for noise generation. A number of practical problems have to be overcome, such as thermal build-up in the wheel, excessive wheel wear, wheel cracks, undesirable hollow wear of the wheel profile, lack of efficiency in wet conditions etc.
The objective of this project is to develop suitable brake block materials, which prevent the build-up of periodic roughness on the wheel running surface. This should be readily applicable to existing freight rolling stock and locomotives without significant extra costs. The aim is to achieve reductions in rolling noise of 5-12 dB compared to traditional cast-iron block brake stock. This acoustical improvement would affect millions of people living around railway tracks. An important aspect of the development is the retrofit potential of the novel brake block. This means that in a relatively short time all freight wagons can be acoustically improved.
The consortium consists of 13 organisations, which are complementary in the development of the novel brake blocks: end-users like railway companies, manufactures of goods wagons, bogies and locomotives, suppliers of brake blocks, scientific institutions which appropriate knowledge of tribilogy and acoustics. Together they constitute an ideal consortium to tackle the present problem. The time frame is about 3 years and the total budget is around 5.3 MECU.
Funding SchemeCSC - Cost-sharing contracts
SK12 6JP Chapel-en-le-frith
10129 Torino (Turin)
100 44 Stockholm
3526 AB Utrecht