Corus Rail Products Sil Silent Track™ T k™ Rail a noise red Railway reduction ction ssystem stem Mayy 2009
Corus Rail Products - An Introduction ¾ Corus Rail designs, g , manufactures and supplies steel rail, sleepers and rail products and related services such as welding. welding ¾ Corus has two rail manufacturing sites, Scunthorpe UK and Hayange, Scunthorpe, Hayange France. France ¾ Corus products are evident in rail networks in every continent and Corus has been supplying products to the rail industry for over 125 years. ¾Corus is market leader in the supply of rail dampers, marketed under the brand name “Silent “Sil t Track”. T k” Business Development
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Silent Track™ - Introduction •
Corus Rail’s Rail s Silent Track developed out of a E E.U. U part-funded part funded research project to reduce noise generated by railways. On track testing gave up to 6dB(A) noise reduction.
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Silent Track reduces noise generated by rails as train wheels pass over them. The system employs patented “tuned dampers” which are attached to either side of the rail.
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The dampers are designed to suit a particular track-form, and are tailored to meet Clients size requirements requirements. They are retro-fitted to existing tracks in-situ by a specifically designed clip.
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Dampers can also be pre-attached onto rail at one of our rail mills before the rail is delivered directly onto track. track
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SilentTrack™ - How does it work? Silent Track reduces the noise generated by the rails as train wheels pass over them. th The Tuned Rail Damper System y absorbs the vibrations efficiently from the rail –wheel interface and prevents noise from being generated by the rail. A contact paste is applied between the rail and the damper to ensure correct transference of vibrations.
El Elastomer “Springs” “S i ”
Rail vibration causes the masses to oscillate. The energy of movement is absorbed by the elastomer material material. The Tuned Rail Damper is q y band tuned to the frequency with the highest noise level. Steel Masses
SILENT TRACK is a unique q 2 mass design g developed jointly with the University of Southampton Business Development
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Rail as a Noise Source •
Roughness of the rail and the wheel gives rise to vibration energy from rail wheel contact
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50 0 to 5000 000 H Hz
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Wheel, rail and sleepers all radiate
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Modern, elastic tracks leave most of vibration in rail
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Vertical modes dominate
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Vibrating Length of track is important size of source
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Noise depends on decay of vibration with distance – the lower the decay rate, the greater the vibrating length of rail rail.
1.0E+4 0.E+0 -1.0E+4 -2.0E+4 -3.0E+4 Force e (N)
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-4.0E+4 -5.0E+4
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Effect of Damping on Rail Vibration
1.0E+4
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Decay rate can be increased by the addition of rail damping
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This reduces the displacement of the vibration waves along the rail, and therefore reduces the vibrating l length th off the th rail, il and dh hence th the noise i emitted itt d
0.E+0 -1.0E+4 -2.0E+4 -3.0E+4 Force e (N)
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-4.0E+4
Vibration waves are diminished if th rail the il is i damped d d
-5.0E+4
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Effect of Tuned Rail Dampers on Decay Rate •
The green line shows the increased decay rate on a track fitted with Silent Track tuned rail dampers, compared with the undamped track in blue Tjornap Comparative Decay Rates July 2008
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Decay Rate dB/ t dB/metre
Decay rate e (dB/m)
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0
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-1 1
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Reference Corus Damper
Frequency q y Hz
-2 2
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10 One third-octave band centre frequency (Hz)
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Silent Track™ – Damper design The design of a damper is a two stage process. Firstly, the Clients requirements define the shape of the damper and fixing method Second, the track characteristics enables Corus to design g the internal arrangement (steel size and spacing) of the damper to give the most effective noise reduction Stage 1 - Clients St Cli t requirements i t defining the shape of the damper Rail type
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Profile
Clearance constraints
Stage 2 – Corus St C d design i off internal i t l arrangementt to give effective noise reduction Track measurement to confirm acoustic characteristics of the track. Factors include: •
Fastening type (Pandrol fastclip, Vossloh etc)
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Pad stiffness (expressed as kN per mm deflection) Sleeper type (mono or twin bloc concrete, steel, timber) Slab or ballasted track
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Rail head
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height
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Rail fastening
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length
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Edge of rail foot foot.
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width
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Fixing constraints •
“removable” damper
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Clip-on
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“permanent” damper
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Glue-on
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Computor modelling then used to define most effective ff ti steel t l sizes i and d spacing i
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Silent Track™ – Market Development As of May 09
• Holland – First country with product approval – Apr 2004. Now installed onto a total of 35km of track.
Fully approved product
• Germany – Corus dampers in DB track since June 2006. First large scale projects currently underway.
Urban Network interested
Trial in progress Trial proposed National Networks interested
• Australia – New commuter line, 16km to be fitted with Corus rail dampers, Sept 09 • France – Product approval pp g granted April p 2007. • UK, Network Rail – approval exp. June 09. First installation planned for late 2009 as part of Thameslink project. • Several trials also in progress Sweden (July 08) Austria 08), A t i (Sept (S t 08), 08) Finland Fi l d (Oct (O t 08) Business Development
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Silent Track™ – Summary of Test Results Country
Track type
Damper
Fixing
Noise Reduction
UIC test centre
UIC 60, Pandrol E 500mm “continuous”
Cast onto rail Up to 6dB overall
Holland
UIC 54, Vossloh + 500mm “continuous” hard pad
Glued
Holland
UIC 54, Vossloh + 360mm between sleepers hard pad (600mm c/c)
Single sided 3.1 dB overall average clip
Pierrelatte, France
UIC 60, Nabla + hard pad
300mm, between sleepers (600mm c/c)
“U” Clip
Sweden
UIC 60, 60 Pandrol E
400mm, between sleepers p (650mm c/c), low height
Spring clip
2 - 6dB overall (depending p g
Germany
UIC 60, Vossloh
360mm between sleepers ((600mm c/c))
Spring clip
3.2 - 4.1dB (overall)
UK
UIC 60, Pandrol fastclip
360mm between sleepers (600mm c/c)
Single sided 4.7dB(A) to 6.2dB(A) – clip predicted overall
3.0 – 3.4dB overall
5.8dB (rail) 3-4dB (overall)
on train type)
Denmark, D k Fi Finland, l d C Czech hR Rep - discussions di i underway d - awaiting iti confirmation of test sites! Business Development
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Track maintenance activities Track where Corus dampers have been fitted can be maintained using normal machinery.
Rigorous trials have been carried out by the SNCF and ProRail as part of the product homologation process. The presence of Corus dampers had no effect on the normal functioning of tamping machines, rail grinders or ballast ploughs.
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Installation developments (1) Corus works in partnership with Volker Rail to improve rail damper installation techniques. Recent changes have been made to the clipping system in order to increase the rate at which Corus rail dampers can be installed installed. ¾ Single sided clip design ¾ Mechanised installation requiring possession i off single i l ttrack k only l ¾ High speed – target 250 metres/hr
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9 Reduced possession times 9 Lower overall cost 9 Increased scope for installation
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Installation developments (2) Volker Rail RDM (Rail Damper Machine) capable of installing dampers onto 250m of track per hour. Financial investment in the machine is in the region of € 1 million.
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SilentTrack™ - Advantages 9 Proven system 9 High noise reduction capability - at source. source 9 Maintenance-free. 9 Can be re-used when rails are changed. 9 No interference with track maintenance operations. 9 Visually unobtrusive (unlike noise barriers!). barriers!)
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