View all newsletters
Receive our newsletter - data, insights and analysis delivered to you


Flexible Rail Fixing Materials for Direct Fixation Systems

Email Address
Postfach 400760,
D-70407 Stuttgart,

Sika Deutschland GmbH has been the key supplier of the German Railways for a range of coatings, sealants and adhesives for more than 100 years. The flexible grouts of the Icosit® KC 300 range have won worldwide renown for tailor made, long lasting direct fixation of rails to solid substrates, i.e. concrete and steel. They are incorporated in a variety of trackwork designs, in discrete and continuous fixation, embedded/floating rail, lawn track, for railway, light rail, tram and crane track installations.

Sika provides design and technical assistance to consultants, operators and contractors for optimum and innovative trackwork solutions under a wide variety of conditions of exposure, for wheel loads ranging from 4 to 75 metric tons.


These load-bearing, flexible polyurethane grouts of the Icosit® KC 330/Icosit® KC 340 range fulfil 4 main requirements for direct fixation:

  • Levelling out inevitable tolerances between rail and concrete or steel substrate
  • Highly efficient electrical insulation for prevention of stray current leakage as a safeguarding against signalling malfunction, electrochemical corrosion and data transfer interference
  • Resilient intermediate layer for optimum reduction of noise and vibration transmission, i.e. vibration damping, cast-in-situ after alignment to eliminate any point loads
  • Powerful adhesive for added safety and maximum performance


Successful dynamic performance tests with minimum 3 to 4 million cycles are a prerequisite for market introduction. Field tests with the German Railways proved that during 28 years of exposure to dynamic stress and weathering, with virtually no maintenance, the reduction in flexibility of the Icosit® KC 330 flexible grout was only marginal. The University of Calgary confirmed suitability for service temperatures from -40°C (-40°F) to +70°C (+158°F). Field test reports confirm reduction of structure borne sound transmission of up to 18 dbA. The high performance is also governed by the fact that these flexible grouts – contrary to pure elastomers – are all somewhat compressible which is absolutely essential to compensate for the unfavourable shape factor in practice and to retard the "bouncing back" effect.

In Erfurt, Germany continuous undersealing of rails with Icosit® KC 340 reduced vibration by 40%.
In 1986, the baseplates of the lawn track in Fellbach, Germany were supported by Icosit® KC 330, resulting in an extremely quiet and aesthetically attractive system.
The baseplates of the crossover of the Heathrow Express in London were undersealed with Icosit® KC 330 in situ for maximum precision and riding comfort.
In Memphis, Tennessee, the very basic suspension of heritage trolleys necessitated maximum vibration absorption through an embedded rail design with Icosit® KC 330.
In Tuen Mun, Hongkong, the light rail vehicles have run on vibration-absorbing Icosit® KC 330 since 1987.

Discrete fixation – Regardless of the type and size of the baseplates, the pourable or injectable flexible grouts can be adopted to all situations of direct fixation, particularly for special trackwork, in tunnels and on bridges, with or without sleepers/ties/gauge bars, under certain circumstances even without anchor bolts.

Floating rail (Embedded rail) – Various options are mainly based on designs with a recess (trough) in the concrete which may be produced with a slipform paver. The rail is then suspended in the trough and cast-in-situ all aroud with Icosit® KC 340 without any mechanical fixation. Other alternatives use a flat concrete slab with prefabricated sound-dampening filler blocks attached to the web of the rail and the flexible Icosit® KC 340 grout cast around the foot of the rail only.

Lawn track – Lawn track designs are becoming very popular as they are aesthetically and ecologically attractive. Various design options include embedded rail, discrete fixation with baseplates and specially adapted concrete sleepers/concrete ties on continuous, slipform-cast concrete beams with Icosit® KC 340 as vibration-reducing intermediate layer cast-in-situ after alignment of the track.


Whether you are involved in the design, construction or maintenance of railway tracks, light rail tracks or heavy crane tracks, Sika can assist you with its long-term experience with field-tested Icosit® KC 330/340 resilient grouts for a multitude of design variations with optimum cost/performance relation.

Docklands Light Railway Capacity Upgrade

Since opening in 1987, the Docklands Light Railway (DLR) has been central to the regeneration of east London. Now its significance is far greater than originally envisaged.

Bremen Light Rail System

Bremen in north-west Germany is one of the two urban subdivisions, the other being Bremerhaven, that make up the country's smallest land (state), Freie Hansestadt Bremen.


The largest-ever public works project in the US state of New Jersey, Hudson-Bergen Light Rail opened in April 2000 (the name relates to the two-state counties covered in the initial plan).

Portland MAX Light Rail

Expansion of the Portland MAX (Metropolitan Area Express) light rail system continues apace. The next phase, due to open in 2009, will add a fourth route.

Vancouver SkyTrain

Vancouver is Canada's third city, the metropolitan area having a population approaching 2.3 million and projected for 3

Heathrow Express

The Heathrow Express is a high-speed service link offering the fastest journey time between Heathrow Airport and central London of 16 minutes and 21 minutes to Terminal 5.

Karlsruhe Light / Heavy Rail

Close to the French border in south-west Germany, Karlsruhe in Baden-Württemberg was the first European city to implement track-sharing for light and heavy rail vehicles.

London Underground Jubilee Line

Construction of the extension of London Underground's Jubilee Line from Green Park, through south London and Docklands to Stratford, proved a troublesome project.

Potsdam Light Rail

Potsdam, in the former East Germany, is the first European city to adopt the standard new tram design by that country's

Finland Pendolino Tilting Trains

Finland's rail administration underwent a substantial reorganisation in 1995, when the Ratahallintokeskus (RHK), or Finnish Rail Administration, was created as a civil service department, under the aegis of the country's Ministry of Transport and Communications.

Grenoble Light Rail System, Rhône-Alpes

Grenoble opened its first tramway in 1987. With the opening of Line D in October 2007, the system had grown to four lines with a combined length of 34.2km (21.4 miles).

Kuala Lumpur

Light Rail came to Kuala Lumpur in 1998 with the creation of the first section of an automatic mass transit system, runn

Sika Deutschland GmbH

Postfach 400760
D-70407 Stuttgart

NEWSLETTER Sign up Tick the boxes of the newsletters you would like to receive. The top stories of the day delivered to you every weekday. A weekly roundup of the latest news and analysis, sent every Friday. The railway industry's most comprehensive news and information delivered every month.
I consent to GlobalData UK Limited collecting my details provided via this form in accordance with the Privacy Policy


Thank you for subscribing to Railway Technology