Description
SilentRail: Silentflex® floating slab for railway tracks
SilentRail is a concrete slab for the track that floats on metal dampers, each with a steel spring and a stainless steel mesh cushion. The track is separated from the ground, and the vibration generated by each passing train stays in the slab instead of reaching nearby buildings.
It is designed for the sections where that vibration is a problem: tracks next to homes and neighbourhoods, hospitals, laboratories, data centres, auditoriums or any sensitive equipment. It is suitable for metro, tram, commuter rail, high speed and freight, and also for bridges, tunnels and viaducts.
It is the railway version of our anti-vibration floating slab, a patented system we install in plant rooms, data centres and laboratories.
The problem: the vibration the train transmits to the ground
Every passing train makes the track vibrate, and that vibration travels through the ground to nearby structures. Inside buildings it is felt as a low rumble and constant structure-borne noise; over time cracks appear and neighbours complain. In laboratories, hospitals and data centres it also affects equipment that needs a stable environment.
How it works
The track’s concrete slab rests on metal dampers housed in containers embedded in the slab itself, which fully decouple it from the substructure:
- the steel spring isolates: the slab floats at a low frequency and the vibration doesn’t pass into the ground;
- the stainless steel mesh cushion damps: it dissipates energy through friction between the wires and curbs the slab’s rebound with each passing train.
The system works vertically, laterally and longitudinally, and is designed to isolate the frequencies that matter most in railway vibration, from 15 to 80 Hz.
Why spring + metal cushion
Compared with rubber solutions (under-sleeper pads, under-ballast mats, sleeper boots):
- rubber ages with water, oils, temperature and fatigue, and loses its properties over the years;
- replacing it means lifting the track or the slab;
- SilentRail is 100 % metal: it doesn’t degrade, needs no maintenance and is designed for a service life of more than 25 years.
Compared with spring-only systems:
- a spring alone isolates but hardly dissipates energy: the slab can rebound and high-frequency vibration gets through more easily;
- in SilentRail, the metal cushion inside each spring adds the missing damping. This hybrid behaviour adapts better to the real loads of railway traffic.
Advantages
- No maintenance and no elastomers: steel and stainless steel, recyclable
- Inspection without dismantling the slab: the containers give quick access
- Modular system: a damper can be replaced without demolishing the slab
- Resists moisture, oils, chemicals and extreme temperatures
- Compatible with different track gauges, standards and railway loads
- Anti-seismic version: it also absorbs the forces of earthquakes, ground settlement and impacts, protecting the track and the surrounding structures
Where it is used
- Metro, tram and commuter lines in urban areas
- High-speed and freight sections next to built-up areas
- Tracks near hospitals, laboratories, research centres and data centres
- Tracks next to auditoriums, theatres, recording studios and historic buildings
- Bridges, tunnels and viaducts
Frequently asked questions
How does it differ from the floating slab for buildings? The principle is the same: a concrete slab that floats on springs with metal cushions. SilentRail is sized for the dynamic loads of railway traffic and isolates the track instead of a plant room.
What maintenance does it need? None: the springs and cushions are made of steel and stainless steel and don’t age like rubber. The containers allow each damper to be inspected without dismantling the slab.
Custom design
Each SilentRail is calculated for its section: type of train and load, speed, ground and what needs protecting around it. We model it with our own dynamic simulation software. Send us the project data and we’ll prepare the proposal.
