For railway operators

Our acoustic barriers make it possible to reduce noise levels for residents along railways without any noticeable impact on the residential environment. This is because our low acoustic barriers can be placed extremely close to trains. Placement in close proximity to the train gives a reduction in noise levels of 5-11 dB (depending on train type) despite a height above track level of only 73 cm.

The costs for a low acoustic barrier such as Soundblock can be up to three times lower that traditional high barriers, both in terms of purchasing price, assembly and construction as well as maintenance over a 50-year period.

The operator responsible for track maintenance will be provided with the most low-maintenance solution available. A low barrier, placed on the embankment on both sides of the track may result in somewhat higher maintenance-related costs. These may include additional routines, snow removal and sleeper replacement. In comparison with maintenance costs for high barriers, the total cost of Soundblock is still many times lower over a 50-year period as the barriers themselves are maintenance-free. In order to assist project managers in assessing the total cost of Soundblock in a particular project, we have summarised our experience in this regard further down the page, under the headline Project Management.

With regard to safety issues, there are emergency doors in the event that the track needs to be evacuated. In order to assist in the efficient evacuation of trains, the top area of Soundblock forms a platform. Aside from this there are also specific routines for stretches with low barriers on both sides of the track.


The Soundblock acoustic barrier utilises “free space” on the embankment, combatting noise at its source. The fibre-reinforced concrete construction effectively blocks soundwaves. This absorption has all the benefits of channel attenuation and suppression chambers as well as avoiding problems with reflection. The barrier provides a reduction of up to 11 dB.

• Channel attenuation
As the distance between the side of the train and the Soundblock is so small, a channel is formed in which the sound is repeatedly reflected against the side of the train and absorbed by the acoustic properties of the materials in the Soundblock barrier. Repeated reflections on high barriers without acoustic baffling at large distances from the track (e.g. 4 metres) can on the contrary be disastrous for noise damping.

• Suppression chamber:
Because the Soundblock acoustic barrier is located so close to the track and has a sound absorbent interior, a noise suppression chamber is formed in the bogie cavity. (Soundblock “seals” and “damps” the bogie cavity). Noise is partially trapped beneath the train as well as being absorbed by the Soundblock barrier and the track ballast.


Soundblock comes with the option of doors, steps or ladders at the desired and the top part of Soundblock is formed to assist in the evacuation of stationary trains.



1. Excavate 20 centimetres of embankment.
2. Line with geotextile fabric. (Foam if necessary)
3. Fill with crushed rock.


5. Assemble the seal and lift the Soundblock into place.


4. Tamp until the surface is even.


6. Check the distance from the track.
7. Complete

Footings example

Footings should be 270 mm below rail height. Geotextile fabric is placed 200m below the bottom plate of the Soundblock and covered with crushed rock, tamped down to an even surface.

Location on the embankment (Soundblock 250)

1,700 mm from the track centre, additional distance for curve track as per BVF.


Lifting is done using hoist hooks through two screwed eyelets and complemented with a balancing lift on the shelf. (Eyelets to be screwed into place and removed after assembly.) Soundblock are place in sequence along the embankment. No fixings are required either in the footings or to the next block. Soundblock will remain stable under its own weight. A seal is mounted between each block during assembly. It is also possible to remove a block from the middle of a row.


Soundblock is manufactured in fibre-reinforced concrete. This is partly to further improve adaptability and partly to completely avoid the use of conductive materials in the Soundblock unit.

Alternative combinations

Below you can see a variety of alternative combinations of Soundblock based on the nature of the location:

1. A single block where buildings are located at the same height or low in relation to the track. If buildings are located similarly on the opposite side of the track, a single block can also be installed there.

2. Two Soundblocks where buildings are high in relation to the track.

3. A single block on each side and a middle barrier/barriers, where buildings are high in relation to the track and on both sides.

Project Management

As Soundblock has a low total cost, does not block views and provides effective noise reduction, no other acoustic barrier would be in use worldwide if it were not for the wide variety of conditions affecting the choice of barrier. What I am able to do is to help those who are faced with implementing noise reduction measures to as effectively as possible judge whether a low acoustic barrier is the best alternative on a specific stretch of track.

Nicklas Erlandsson
Sales Manager
+46 (0) 708 321 680

Questions when faced with the choice of whether to use low acoustic barriers


1. Acoustic requirements – calculation data is available for various train types
2. Calculation of construction cost for Soundblock (possible widening of the embankment, access to the track area etc.)
3. Calculation of additional costs, for example over a 50-year period (track works requiring the removal of blocks, snow clearance and other additional routines etc. These calculations are often only required when low barriers are located on both sides of the track. Soundblock in itself is completely maintenance-free).

These points are discussed further below;

1. The first step is of course to ensure that Soundblock meets the acoustic requirements for the affected stretch of track. The evaluation of the acoustic properties of low barriers has always been problematic. Therefore, in collaboration with Tyréns AB we have developed a basis on which this can easily be judged. This basis can be ordered from We can also collaborate with an acoustics company to make a preliminary calculation of whether the use of low barriers is feasible. Soundblock provides stable noise reduction of between 5-7 dB (depending on train type) irrespective of where the receiver is placed. Depending on the type of train, a reduction of 10-11 dB may be achieved on certain stretches. It may be of interest to consider the height a traditional high barrier below the embankment needs to be on a specific stretch in comparison to a trackside barrier 73 cm above rail height.

2. When we know that acoustically a low barrier is a viable option, the next step is review construction costs. We have a great deal of experience in this area and will be only too pleased to assist you. Examples of issues are whether the embankment needs to be widened, ease-of-access to the track and how long it is possible to work track-side on any given construction opportunity. We are happy to accept photographs or drawings of the site in order to identify any adjustments that might be required. This might be a matter of running cable ducts through Soundblocks or altering the mould of certain blocks that need to fit existing installations along the track.

3. Finally, the maintenance costs during the relevant period need to be taken into account. The convenient thing about Soundblock in this context is that it is always simple to remove. However, this does come with a cost of around SEK 2,000 per metre for removal and replacing (depending on the ease-of-access to the site). When Soundblock is installed on both sides of the track, there may for example be problems with ballast cleaning and sleeper replacement. Those tasks that require the removal of Soundblocks are often carried out at intervals of many years (perhaps only every 30-40 years) and it is a good idea to see if any maintenance tasks can be carried out in conjunction with the construction of the barrier in order to avoid any major track maintenance after only 5-10 years. More regular maintenance, such as the use of a ballast plough, does not appreciably affect maintenance costs. Possibly one may need to exercise a little more caution. Conditions are precisely the same as for platforms in that they are the same distance and height. With regard to snow clearing it is recommended that when putting the service out to tender, a contractor is chosen who has access to a track-mounted snow blower. In the interests of fairness to the contractor, the tender documentation should contain a description of how snow clearance involving low barriers is to be carried out. The production of routines for snow removal, as well as for safety routines etc. of course entails costs in the form of extra time (in comparison to traditional barriers). However, there is a good deal of experience in these matters to be called on. Special transports are also something that are affected by acoustic barriers along the track. Put simply, if one is able to pass a platform then it is no problem to pass Soundblock. On stretches with large amounts of special transports, in all likelihood low barriers are not a cost-effective solution. Track access can also be affected but in common with traditional barriers where access to the track must be gained through openings, Soundblock is also equipped with doors at regular intervals.

For more detailed information and support, please contact Nicklas Erlandsson on +46 (0) 708 321 680


Below you will find a selection of reference routes

Z-bloc Norden AB have been supplying trackside acoustic barriers since 1999 to customers including: Karlstad, Karlskrona, 
, Gustavsvik, 
Umeå central, 
Gimonäs (Umeå), 
Åby (Norrköping)
, Kristinehamns kommun
, Annedal, 
, Bro (Stockholm),
Sya (Mjölby kommun), 
Ritorp (Stockholm
), Sollentuna Station, 
Täby kyrkby, 
Norra Järnvägsgatan (Boden)
, Skogås (Stockholm),Gimonäs, Umeå Åby, Norrköping, Roslagsbanan, Saltsjöbanan och Sundsvall.