The sound radiation of railway wheels mainly takes place in the area of resonant frequencies. All absorbers are constructed as multi-layer resonators. Single metallic plates are followed by layers of elastomer.
Schrey & Veit specialises in the fields of vibration technology. Our team has years of experience in shock and vibration isolation, vibration damping, acoustic and production engineering in the railway, aviation / aerospace and automotive industries.
For vibration damping and noise control on railway vehicles, we took over the department INCT from DaimlerChrysler Aerospace in 1995. The dampers developed and patented by INCT are in use on railway wheels and rails, from the ICE up to tramways, on curved and tangent tracks, steel bridges, general engineering and ship building.
The manufacturing of prototypes, our well-equipped laboratory and state-of-the art simulation tools guarantee a very fast and low-cost development of the products.
High performance – low costs
We place great value on adapting our products to ‘real-life conditions’. For the railway sector, this is visible in the robust constructive approach for rough condition at the running gear areas at vehicles on the trackside area close to the railhead.
Schrey & Veit
The acoustic performance can be quantified by additional offered measurements but also by accredited measurement offices according the national standards.
Wheel vibration absorber
VICON RASA wheel dampers are tuned to reduce curve squealing and / or rolling noise. A broad experience of existing dampers at different operative and environmental boundaries guarantees a high performance.
The development includes an individual tuning process to each wheel type. Due to different mounting approaches the dampers are suitable for nearly all resilient and monobloc wheels. Since 1995, more than 100,000 VICON AMSA wheel dampers have been implemented in trams, coaches and locomotives in various operation conditions.
Today, vehicles for narrow curved networks are usually prepared for wheel dampers due to the high probability of curve squealing. Furthermore, trackside devices for applications such as rail head conditioning (with ongoing operational costs) can be avoided by wheel dampers.
Latest success is the European wide TSI conformity statement of a combination by wheel damper on a lightly adjusted regular wheel type for usage in standard freight wagons. Pass-by noise reductions by up to 3.5dB for rolling noise have been gained under standardised measurement conditions.
To accelerate local noise abatement, VICON AMSA rail dampers are an international, commonly used measure. They are suitable for all rail profiles and track construction. Easy and quick to install, minimised inspection afford and compatible with most of the track maintenance actions are main objectives. Homologation processes have successfully finalised for different networks and can be used for further cross acceptances. More than 400,000 VICON AMSA rail dampers are in use all over the world.
Continuously research and development has led to an innovative rail damper type VICON AMSA VS with a beneficial fastening system.
It can be stated, that this rail damper:
- Does not influence common train control systems such as ETCS, ATP EG, ATB NG, PZB, LZB, Crocodile
- Has no impact on existing TSI Infra conformity (no change on the rail itself)
- Shows no outgassing of polluting substances
- Requires for installation only short track closings due to a reduced number of damper components
- Can also be installed during train operation when train following times are at least 10min
- Is only mechanically fastened without using any type of contact adhesive
- Is free from consumable materials such as liquids
- Causes no fouling of the track
- Complies with REACH standards (Europe)
- Is non-visible from the surrounding sites
- Has no shielding effect on the track neighbouring areas such as noise protection walls
- Is not susceptible to vandalism
- Is combinable with further noise reducing measures
- Shows a significantly increased acoustic noise reduction compared to rail shielding, especially at freight trains
- Is set up as a solid construction for long lifetime, proven by laboratory testing
Similar to wheel dampers each track construction is analysed to choose the most beneficial rail damper type.
Vibration damper for steel bridges
From a series of the rail vibration damper, Schrey & Veit developed the VICON SYSA damper system to reduce additional noise of steel bridges. Due to the direct placing of the track on the bridge construction, a nearly undamped vibration impact causes highly annoying low-frequently noise.
Due to constructive differences each bridge has to be individually analysed to specify the most beneficial damper characteristic and installation position. Experience shows that in most cases it is possible to adjust standard dampers for keeping the price low. The installation can usually be executed without closing the track by working from underneath the bridge.
Compared with alternative measures these vibration dampers are ‘defeating’ the vibration instead of bypassing it as by isolating measures. The bypassing effect includes the risk that any other bridge structure start to vibrates with a subsequently noise emission.
Different applications of the vibration damper VICON SYSA has proven the noise reduction effect. We are also supporting the legal approval of the reduction effect by measurements according the national specification. If required, we also offer support for accredited measurement offices.
For applications where standard products (rubber-metal parts, cable mounts, etc.) are sufficient, we work together with producers who come up with essential requirements on quality and price.
- Vibration measurements
- Vibration analysis on electrodynamic shakers
- Acoustic measurements
- Modal analysis
- Analysis of operating mode shapes
- Fatigue test
- Endurance limit
Although Deutsche Bundesbahn raised speeds and passenger standards with Class 103 hauled InterCity services from 1971, even with extensive track upgrading, 200km/h (124mph) would be the ceiling for reducing journey times.