We are cutting train noise in half by 2020
Making an active contribution to reducing noise emissions is part of our corporate philosophy.
Transport services are vital in a collaborative and globally networked economy and are therefore a prerequisite for our prosperity. Rail freight traffic is the most environmentally friendly transport option here, but it needs to be quieter to maintain social acceptance. DB and DB Cargo have taken on this challenge.
As an eco-pioneer, Deutsche Bahn has set itself the objective of halving rail traffic noise by 2020, compared to the values from the year 2000. This can only be attained by applying different measures on the track and on vehicles.
With the support of the federal government, Deutsche Bahn has already accomplished a great deal where infrastructure is concerned, and further comprehensive measures are planned. Approximately 1,800 of a total of 3,700 kilometres of track requiring noise mitigation have already been treated within the scope of the federal government’s voluntary noise abatement programme. Under this programme, some 740 kilometres of noise barriers have been erected (as at end of 2018) and around 60,650 residential units have been equipped with noise control features. By 2020, noise abatement measures will have been rolled out for some 2,000 kilometres in total.
We are pursuing this noise abatement programme intensively, employing innovative technologies to reduce noise from the rail infrastructure.
About 80 per cent of DB Cargo's freight wagons were already quiet by the end of 2018
DB Cargo has been conscientiously pursuing the retrofitting of whisper brakes for the past five years. The company already had almost 8,500 new quiet freight wagons in use at the end of 2018. By the end of 2020, approximately 10,000 new quiet wagons with K brake blocks will be operational.
In addition to the procurement of new wagons, upgrading the existing freight wagons poses a great challenge. The LL-type quiet composite brake block, which can be fitted without the costly conversion of the brake system, was approved in June 2013. All of DB Cargo's 53,000 freight wagons currently awaiting conversion (which will not be taken out of service) will be retrofitted with whisper brakes by 2020.
DB Cargo started the systematic upgrading of its existing freight wagons in January 2014, just half a year after the LL blocks were approved. More than 42,000 wagons had already been converted by the end of 2018, meaning that, including the newly acquired wagons, DB Cargo had over 50,400 quiet freight wagons active at this time.
Thus, approximately 80 per cent of DB Cargo's active wagon fleet was equipped with whisper brakes at the end of 2018. All of DB Cargo's wagons in Germany will be quiet by the end of 2020.
Retrofitting is and remains a feat of strength
In order for noise reduction to be achieved across the board, however, all freight wagons operating in Germany, including the 120,000 freight wagons currently owned by other wagon keepers (domestic and foreign wagon lessors and railways), need to be retrofitted with quiet brake blocks or be replaced by new quiet wagons.
The federal government is providing funds of around EUR 150 million to support the retrofitting of the freight wagons operating in Germany.
Furthermore, in 2013 DB Netz AG introduced the noise-differentiated track access charges system (NDTAC) as a financial incentive for retrofitting quiet brake blocks. Since June of that year, railway undertakings (RUs) have been paying a surcharge on top of the track access charge for loud freight trains. This has been billed at 5.54 per cent since December 2018 and must be paid unless the train is made up of at least 90 per cent quiet wagons. By the same token, RUs receive a bonus for using quiet wagons. This part of the incentive system is therefore financed by the railway sector itself.
In addition to the national funding, there is also limited support available from the EU's Connecting Europe Facility (CEF) funding instrument.
Upgrading wagons is a strenuous economic challenge for the railway sector facing fierce intermodal competition with very narrow margins. While the actual retrofitting of quiet brakes is 50 per cent publicly funded, the increased operating costs of retrofitted wagons are not. Brakes and wheelsets, for instance, need to be inspected at shorter intervals, wheelsets wear more quickly and need to be reprofiled more frequently, and LL brake blocks are considerably more expensive to replace than the old cast-iron brake blocks. These increased operating costs will amount to approximately EUR 700 million for the entire railway sector by 2020, weakening rail freight transport as it competes with other, less eco-friendly modes of transport.
REASONS: Acoustic, technical and operational
Rolling sounds dominate the noise
Railway noise has several causes. The most significant source of noise is the contact between wheel and rail. Freight wagons are traditionally braked when brake blocks made of grey cast iron bear down on the surface of the wheel. Repeated braking roughens the wheel tread over time, which results in noise when the wagon rolls.
Composite brake blocks halve the noise emitted by freight wagons
The solution is to have smooth wheels on smooth rails. Driven by the railways' requirements, industry has developed composite brake blocks. Known as whisper brakes, these prevent corrugation of the wheel tread. Whisper brakes ensure smooth wheels during the journey by actively smoothing the wheel tread when braking. Noise exposure from a train as it passes by is reduced by about 10 dB(A) if the wagons are equipped with composite brake blocks, and the rolling noise level perceived by humans is just half of what it would otherwise be.
The composite brake block known as the K brake block has been internationally approved without restrictions since 2003. DB Cargo has been procuring new freight wagons with these brake blocks since their provisional approval in 2001. About 8,300 new quiet wagons were in use at DB Cargo at the end of 2017.
A freight wagon's brake system must be specially designed to accommodate the K brake block, which is simple to accomplish on new wagons. Retrofitting older freight wagons with K brake blocks, however, means the brake system must be upgraded and re-approved at great expense. The LL brake block was developed to address this problem, as it can be installed in existing freight wagons without converting the brake system, apart from in exceptional cases.
Comprehensive retrofitting of freight wagons necessary
The conversion of all freight wagons from cast-iron brake blocks to composite brake blocks is necessary if the whisper brake is to be fully effective along the rails. Retrofitting across the board must be the objective for achieving comprehensive noise reduction.
For rail freight in Germany, this means that approximately 180,000 wagons need to be upgraded or replaced with new wagons. Of these, approximately one third are at DB Cargo and a further 120,000 wagons belong to private domestic and foreign wagon keepers and other railways that cover considerable distances operating on the German rail network.