SIST EN 16432-4:2026

Railway applications - Ballastless track systems - Part 4: Special ballastless track systems for attenuation of vibration

This part of EN 16432 series specifies how to integrate the particular aspects of ballastless track systems for attenuation of vibration into the system and subsystem design and component configuration according to EN 16432-2:2017.
The general system and subsystem design requirements are assigned from EN 16432-1:2017.
Additional noise and vibration requirements can be project specific and are not provided by this document. Acoustic requirements are considered as input for the track design from the acoustic design. The acoustic design and the track design affect each other and may require an iterative overall design process.
The range of applicability covers all kind of rail systems including Urban Rail systems.

Bahnanwendungen - Feste Fahrbahn-Systeme - Teil 4: Spezielle Feste Fahrbahn-Systeme zur Vibrationsdämpfung

Dieser Teil der NormenreiheEN16432 legt fest, wie die besonderen Aspekte von FF-Systemen zur Schwingungsdämpfung in den System- und Teilsystementwurf und die Komponentenkonfiguration nach EN16432-2:2017 zu integrieren sind.
Die allgemeinen Anforderungen an den Entwurf von Systemen und Teilsystemen sind in EN16432-1:2017 festgelegt.
Zusätzliche Geräusch- und Schwingungsanforderungen können projektspezifisch sein und sind in dieser Norm nicht enthalten. Akustische Anforderungen werden als Eingabe für den Fahrbahnentwurf vom Akustikentwurf berücksichtigt. Der Akustikentwurf und der Gleisentwurf beeinflussen sich gegenseitig und können einen iterativen Gesamtentwurfsprozess erfordern.
Der Anwendungsbereich umfasst alle Arten von Bahnsystemen, einschließlich städtische Bahnsysteme.

Applications ferroviaires - Systèmes de voie sans ballast - Partie 4: Système spécial de voie sans ballast pour l'atténuation des vibrations

La présente partie de la série EN 16432 spécifie comment intégrer les aspects particuliers des systèmes de voie sans ballast pour l'atténuation des vibrations dans la conception du système et du sous-système et la configuration des composants selon l’EN 16432-2:2017.
Les exigences générales de conception du système et des sous-systèmes proviennent de l’EN 16432-1:2017.
Des exigences supplémentaires relatives au bruit et aux vibrations peuvent être spécifiques au projet et ne sont pas fournies par cette norme. Les exigences acoustiques sont prises en compte comme données d’entrée pour la conception de la voie à partir de la conception acoustique. La conception acoustique et la conception de la voie s'influencent mutuellement et peuvent nécessiter un processus de conception global itératif.
La portée d'application couvre tous les types de systèmes ferroviaires, y compris les systèmes ferroviaires urbains.

Železniške aplikacije - Sistemi brezbalastnih tirov - 4. del: Posebni brezbalastni tirni sistemi za dušenje vibracij

Ta del serije EN 16432 določa, kako vključiti posebne vidike sistemov tirov brez balasta za zmanjšanje vibracij v zasnovo sistema in podsistema ter konfiguracijo komponent v skladu z EN 16432-2:2017.
Splošne zahteve za zasnovo sistema in podsistema so določene v EN 16432-1:2017.
Dodatne zahteve glede hrupa in vibracij so lahko specifične za projekt in jih ta dokument ne zagotavlja. Akustične zahteve se obravnavajo kot vhod za zasnovo tirov iz akustične zasnove. Akustična zasnova in zasnova tirov vplivata druga na drugo in lahko zahtevata iterativen celoten proces načrtovanja.
Obseg uporabe zajema vse vrste železniških sistemov, vključno z mestnimi železniškimi sistemi.

General Information

• Status: Published
• Public Enquiry End Date: 31-Mar-2025
• Publication Date: 10-Jun-2026
• ICS: 17.160 - Vibrations, shock and vibration measurements
• ICS: 45.080 - Rails and railway components
• ICS: 93.100 - Construction of railways
• Technical Committee: IŽNP - Reilway applications
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 27-May-2026
• Due Date: 01-Aug-2026
• Completion Date: 11-Jun-2026
• Mandate: M/591 - Standardisation request to the European Committee for Standardisation and the European Committee for Electrotechnical Standardisation as regards railway products in support of Directive (EU) 2016/797
• Ref Project: EN 16432-4:2026 - Railway applications - Ballastless track systems - Part 4: Special ballastless track systems for attenuation of vibration

Overview

SIST EN 16432-4:2026 is a key European standard developed by the Slovenski inštitut za standardizacijo (SIST) that focuses on railway applications, specifically addressing special ballastless track systems for the attenuation of vibration. As Part 4 in the EN 16432 series, it provides guidelines for integrating vibration mitigation solutions into the overall system and component design of ballastless railway tracks, complementing existing general (EN 16432-1:2017) and detailed system (EN 16432-2:2017) design requirements.

Ballastless track systems are essential for modern rail infrastructure, offering stability, reduced maintenance, and improved performance-especially in environments where controlling vibration is crucial for environmental protection and passenger comfort. This standard is applicable to all railway types, including mainlines and urban rail.

Key Topics

• Integration with Acoustic Design
  The standard requires that acoustic (noise and vibration) requirements, which are often project-specific, inform track design from the outset. Acoustic and track designers must collaborate iteratively, ensuring that the system meets both structural and vibration attenuation goals.

• Design Requirements for Vibration Attenuation
  The document outlines how to incorporate resilient elements and subsystem configurations (as defined in EN 16432-2:2017) that effectively reduce vibration. This includes considering the interaction between design elements, dynamic and static stiffness, and the overall mass-spring configuration.

• System and Component Verification
  Comprehensive verification procedures are described, covering acceptance of design, components, and completed works. These ensure that vibration mitigation measures are correctly installed and function as intended throughout the system's lifecycle.

• Types of Resilient Elements
  Descriptions and definitions for various resilient elements (longitudinal, lateral, full surface, strip, discrete) are provided, each tailored for managing movement and loads in specific directions and configurations.

• Mass Spring Systems (MSS)
  Special focus is placed on mass-spring systems, in which the mass and resilience of supporting elements are balanced to achieve targeted natural frequencies and insertion loss for optimal vibration attenuation.

Applications

SIST EN 16432-4:2026 is widely applicable wherever railway tracks are constructed without ballast and where vibration control is a priority:

• Urban Rail Systems
  Essential in city environments where controlling ground-borne vibration protects adjacent structures and improves quality of life for nearby residents.

• Mainline and High-Speed Rail
  Where noise and vibration requirements are imposed by regulations or sensitive land use near rail corridors.

• Underground Railways and Tunnels
  Critical for integrating vibration mitigation into compact, enclosed environments where structural interaction and acoustics are closely linked.

• Infrastructure Upgrades and New Projects
  Guiding system designers, civil engineers, and project managers in meeting contemporary standards for vibration reduction in newly constructed or modernized track systems.

Related Standards

For comprehensive compliance and optimized ballastless track design, SIST EN 16432-4:2026 should be used in conjunction with these related standards:

• EN 16432-1:2017
  General requirements for ballastless track systems, covering overarching principles.

• EN 16432-2:2017
  System design, subsystems, and components for ballastless tracks.

• EN 16432-3:2021
  Acceptance procedures to verify performance and installation quality.

• EN 17495:2022
  Methods to determine the dynamic stiffness of elastic track components with respect to noise and vibration.

• EN 17682
  Specifications for resilient elements in floating slab systems.

• EN 13481-5
  Requirements for fastening systems in ballastless tracks.

• EN 15461 / EN 15610
  Determination of track decay rate and roughness for evaluating noise performance.

Conclusion

By adhering to SIST EN 16432-4:2026, stakeholders can ensure that ballastless railway track systems are designed and implemented to meet stringent vibration mitigation requirements. The standard provides a structured, compliant approach for designers, engineers, and project managers, ultimately supporting quieter, more sustainable, and efficient railway infrastructure across diverse applications.

Standards Content (Sample)

SLOVENSKI STANDARD
01-julij-2026
Železniške naprave - Progovni sistemi z utrjenimi tirnicami - 4. del: Posebni
progovni sistemi z utrjenimi tirnicami za dušenje vibracij
Railway applications - Ballastless track systems - Part 4: Special ballastless track
systems for attenuation of vibration
Bahnanwendungen - Feste Fahrbahn-Systeme - Teil 4: Spezielle Feste Fahrbahn-
Systeme zur Vibrationsdämpfung
Applications ferroviaires - Systèmes de voie sans ballast - Partie 4: Système spécial de
voie sans ballast pour l'atténuation des vibrations
Ta slovenski standard je istoveten z: EN 16432-4:2026
ICS:
17.160 Vibracije, meritve udarcev in Vibrations, shock and
vibracij vibration measurements
45.080 Tračnice in železniški deli Rails and railway
components
93.100 Gradnja železnic Construction of railways
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN 16432-4
EUROPEAN STANDARD
NORME EUROPÉENNE
May 2026
EUROPÄISCHE NORM
ICS 45.080; 93.100
English Version
Railway applications - Ballastless track systems - Part 4:
Special ballastless track systems for attenuation of
vibration
Applications ferroviaires - Systèmes de voie sans Bahnanwendungen - Feste Fahrbahnsysteme - Teil 4:
ballast - Partie 4: Système spécial de voie sans ballast Spezielle Feste Fahrbahnsysteme zur
pour l'atténuation des vibrations Vibrationsdämpfung
This European Standard was approved by CEN on 13 April 2026.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by
translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2026 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 16432-4:2026 E
worldwide for CEN national Members.

Contents
European foreword . 3
Introduction . 4
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 5
4 Abbreviations . 7
5 Design approach . 8
6 System design . 9
6.1 Establishing the interface between acoustic design and track design . 9
6.2 Design implications arising from the integration of resilient elements . 10
6.3 Control of vibrations using the rail fastening system alone . 11
6.4 Mass spring system (MSS) . 12
6.4.1 General. 12
6.4.2 System classification according to length . 13
6.4.3 Joints . 15
6.4.4 Transitions . 17
6.4.5 Lateral and longitudinal resilient elements . 17
6.5 MSS for switches and crossings . 22
6.6 Drainage . 22
6.7 Design requirements for maintenance and durability . 22
7 Acceptance. 23
7.1 Acceptance of design. 23
7.2 Acceptance of components . 23
7.3 Acceptance of works . 24
7.3.1 General. 24
7.3.2 Stage 1 – Before installation . 24
7.3.3 Stage 2 – Installation of resilient elements . 24
7.3.4 Stage 3 – Installed mitigation performance . 25
7.3.5 Stage 4 – Operational performance . 25
Annex A (informative) Typical workflow from design to installation of special ballastless
track systems for attenuation of vibration . 26
Annex B (informative) Simplified assessment of structural dynamics implications . 28
Bibliography . 32

European foreword
This document (EN 16432-4:2026) has been prepared by Technical Committee CEN/TC 256 “Railway
Applications”, the secretariat of which is held by DIN.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by November 2026, and conflicting national standards
shall be withdrawn at the latest by November 2026.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
Any feedback and questions on this document should be directed to the users’ national standards body.
A complete listing of these bodies can be found on the CEN website.
According to the CEN-CENELEC Internal Regulations, the national standards organisations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland,
Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of
North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and the
United Kingdom.
Introduction
Ballastless track systems can be affected by acoustic requirements for the protection of the
environment against noise and vibration.
This document covers the integration of additional acoustic requirements in the ballastless track
system design.
This part of the EN 16432 series is used in conjunction with the following parts:
— Part 1: General requirements;
— Part 2: System design, subsystems and components;
— Part 3: Acceptance.
1 Scope
This document specifies how to integrate the particular aspects of ballastless track systems for
attenuation of vibration into the system and subsystem design and component configuration according
to EN 16432-2:2017.
The general system and subsystem design requirements are assigned from EN 16432-1:2017.
Additional noise and vibration requirements can be project specific and are not provided by this
document. Acoustic requirements are considered as input for the track design from the acoustic design.
The acoustic design and the track design affect each other and may require an iterative overall design
process.
The range of applicability covers all kind of rail systems including Urban Rail systems.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
EN 1991 (all parts), Eurocode 1 — Actions on structures
EN 1992 (all parts), Eurocode 2 — Design of concrete structures
EN 16432-1:2017, Railway applications - Ballastless track systems - Part 1: General requirements
EN 16432-2:2017, Railway applications - Ballastless track systems - Part 2: System design, subsystems and
components
EN 16432-3:2021, Railway applications - Ballastless track systems - Part 3: Acceptance
EN 17495:2022, Railway Applications - Acoustics - Determination of the dynamic stiffness of elastic track
components related to noise and vibration: Rail pads and rail fastening assemblies
EN 17682, Railway applications - Infrastructure - Resilient element for floating slab system
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https://www.iso.org/obp/
— IEC Electropedia: available at https://www.electropedia.org/
3.1
mass spring system
ballastless track system using a specific mass in combination with its designed support stiffness
3.2
longitudinal resilient element
resilient element according to Figure 1 for MSS in order to constrain the longitudinal movement of the
mass
Note 1 to entry: It is installed perpendicular to the track axis.
3.3
lateral resilient element
resilient element placed according to Figure 1 for MSS in order to constrain the lateral movement of the
mass
Note 1 to entry: It is installed parallel to the track axis.
3.4
vertical resilient element
resilient element placed according to Figure 1 for MSS in order to provide the required support stiffness
3.5
full surface resilient element
full surface support (mat) between mass and its substructure to provide the required support stiffness
3.6
strip resilient element
linear support between mass and its substructure to provide the required support stiffness
3.7
discrete resilient element
point support between mass and its substructure to provide the required support stiffness
3.8
dynamic stiffness
force or stress per unit deflection measured under an uniaxial force which acts periodically at a given
frequency of 5 Hz to 20 Hz between specific force or stress levels
Note 1 to entry: This value is determined mainly for calculation of dynamic deformation of tracks.
3.9
acoustic stiffness
dynamic stiffness of a resilient track support element that is measured under a static preload and at
small amplitudes of displacement or velocity applied in the frequency range relevant to noise or
vibration perception
3.10
insertion loss
relative reduction [dB] of vibration in the transmission path as a function of frequency resulting from
the implementation of a subsystem
Key
X longitudinal direction
Y lateral direction
Z vertical direction
REx longitudinal resilient element
REy lateral resilient element
REz vertical resilient element
Figure 1 — Orientation of resilient elements (for example: arranged as discrete resilient
elements)
4 Abbreviations
For the purposes of this document, the abbreviations in Table 1 apply.
Table 1 — Abbreviations
Abbreviation Abbreviated term
CRCP Continuously Reinforced Concrete Pavement
FEM Finite Element Method
GB N&V Ground Borne Noise and Vibration
JPCP Jointed Plain Concrete Pavement
JRCP Jointed Reinforced Concrete Pavement
MSS Mass Spring System
MWCC Main Works Civil Contractor
S&C Switches and Crossings
5 Design approach
The physical behaviour of ballastless track systems influences vibrations transmitted to the sub-
structure and noise emitted from the track. In situations where such vibrations or noise are
unacceptable due to local or regional requirements, the ballastless track system may be designed to
control vibration transmission and may therefore, incorporate elements, layers or components which in
turn can affect the structural and functional performance of the ballastless track system (see Figure 1).
The general system and subsystem design requirements for ballastless tracks are set out in
EN 16432-1:2017. The static and dynamic performance of the entire ballastless track system, including
the interaction of different subsystems and subsystem configurations (e.g. use of resilient fastening
system or resilient mats supporting a ballastless track), shall be considered in the design requirements.
Though the additional noise and vibration requirements are project-specific and not provided by this
document, the eventual influence of the components for vibration or noise mitigation shall be
accounted for in the design verifications (for example, they can govern the track stiffness or affect the
degree of interlayer interaction). In this regard, ballastless track system configurations for noise and
vibration mitigation commonly consist of prefabricated elements and/or a pavement structurally
independent from the substructure. These can incorporate resilient elements which lead to subsystem
configurations eventually distinct from those considered in EN 16432-2:2017. The consequence is that
design-relevant parameters (stresses and/or displacements) resulting from the pavement design
approach of EN 16432-2:2017 can be significantly affected due to the low support stiffness.
In case that such design parameters do not fulfil the limits of EN 16432-2:2017, a pavement-based
design may not be sufficient and structural design methods shall in this case be used. Furthermore,
specific dynamic analysis may be required in addition to the design methods specified in
EN 16432-2:2017 when e.g. simplified dynamic amplification factors are not sufficient.
For track systems where acoustic, noise and vibration requirements apply, the relevant criteria for
performance shall have been established. These criteria shall detail how this performance can be
demonstrated in design and following construction, for acceptance. The criteria may include one or
more of the following for ground borne noise and vibration requirements:
— the insertion loss for the track system with respect to a reference track form;
— the natural frequency and/or full frequency spectra of the track system;
— maximum or weighted level of accelerations at the track or at specific locations next to the track.
For airborne noise requirements influenced by the track system the criteria may include:
— track decay rate (see EN 15461);
— track roughness (see EN 15610), for the relevant wavelength range.
6 System design
6.1 Establishing the interface between acoustic design and track design
Special ballastless track systems for attenuation of vibration are custom-fitted solutions requiring a
specific design. The design of mitigation systems includes activities for both an acoustic designer and a
track designer. These may be conducted by different parties. The interface between the different
designers requires an information exchange to establish the parameters the track designer shall use. An
example of the process for the exchange of information is provided in Annex A (see Figure A.1).
The natural frequency and the insertion loss are usually determined by the acoustic designer in the
ground-borne noise and vibration prediction assessment. However, both the natural frequency and the
insertion loss are often determined based on simple assessments in early project stages.
When progressing the design of the mitigation system, more detailed modelling of the mitigation
system is required, including the assessment for different loading conditions, the nonlinear behaviour
of resilient elements, and the stiffness characteristics and finally assessments of the system under
service conditions.
NOTE Service conditions are the traffic loading and other actions, such as environmental conditions that will
act on the track system through its design life.
The main aim of the acoustic designer is to provide a mitigation concept fulfilling the applicable limit
values at the sensitive receptor, for example:
— determination of locations requiring resilient track forms as a mitigation system;
— preliminary schematic cross-section (principally for the civil design phase);
— determination of the stiffness of the fastening system;
— determination of mitigation system’s natural frequency and required mass of the system;
— determination of the required insertion loss.
The main aim of the track designer is to provide a design of the resilient track form able to fulfil the
required vibration mitigation performance including:
— the predetermined natural frequency;
— the predetermined insertion loss;
— fulfilling the requirements set in EN 16432-1:2017 and EN 16432-2:2017.
The determination and assurance of the system’s natural frequency and insertion loss is usually an
iterative process for which both the acoustic designer and the track designer are responsible. It is
therefore essential to specify the following assumptions on which the assessment has been based in the
information exchange between the acoustic and track designers:
— applied load assumptions, which can be:
o self-weight only;
o self-weight including parts of the vehicle’s load (undamped wheel-set masses of the train/s);
o entire vehicles’ axle load configuration (e.g. operating vehicle, design vehicle) and operating
conditions (e.g. speed).
— assumptions for determination of natural frequency or insertion loss, which can:
o include the vehicle’s load;
o include only parts of the vehicle’s load (e.g. undamped wheel-set mass);
o exclude the vehicle’s load (or parts of it).
— assumptions for the resilient elements, which can consider:
o static, dynamic and/or acoustic stiffness;
o linear or nonlinear behaviour of the resilient element.
The track designer is responsible for the final selection of the resilient element to satisfy all the
functional track performance characteristics established. The assurance of the system natural
frequency and insertion loss shall be set out in a System Assurance Plan (see also EN 16432-2:2017).
The track design may optimize the cross-section, select a resilient element, and adapt masses during the
concept design phase to fine-tune the resilient track form. Such modifications and adaptions of the
system may have an impact on the natural frequency or the insertion loss, and therefore shall be
verified against the acoustic requirements.
6.2 Design implications arising from the integration of resilient elements
The overall system design including the integration of resilient elements shall be in accordance with
EN 16432-2:2017, 6.1. The traffic load models required to check the structural performance may be
different from the loads required to check the acoustic functionality. In particular, the acoustic proof of
ballastless track systems incorporating resilient elements for vibration attenuation requires the
application of realistic operational loads.
In the design, special attention should be paid at the eventual change of the subsystems interaction
caused by the introduction of intermediate resilient elements: ballastless track systems designed as
monolithic multi-layered structures in terms of EN 16432-2:2017, 10.1 will behave as independent
layers after the integration of intermediate elements. In the terminology of EN 16432-2:2017, Annex B,
design Variants III may behave as Variants II, which may require a consistent adaptation of the design
analysis.
The integration of the resilient element in the system design calculation should use relevant stiffness
properties such as those obtained by tests in accordance with EN 17495:2022 and EN 17682.
The system design methods in EN 16432-2:2017 or acoustic models needed may require input on noise
and vibration parameters, which should include:
— static vertical stiffness. The static vertical stiffness determines the vertical displacements of the
track under quasi-static loads and is a result of the contribution of the vertical stiffness of all
components and subsystems. In addition, the vertical stiffness of each component governs the
bending performance and load distribution within the ballastless track system. Therefore, the static
vertical stiffness or bedding modulus of all the components of the system shall be integrated in the
design verifications of EN 16432-2:2017. Appropriate testing methods are necessary for each
component or sub-system (refer to particular solutions in the subclauses of this document).
— dynamic vertical stiffness. The dynamic vertical stiffness determines the vertical displacements of
the track under dynamically varying loads (e.g. train loads). It is also a result of the contribution of
the different components and subsystems of the track. The dynamic vertical stiffness or bedding
modulus of all the components shall be integrated in the design methods of EN 16432-2:2017 when
determining the effects of train loads. Appropriate testing methods are necessary to determine the
dynamic stiffness of each component in the relevant frequency range (refer to particular solutions
in the subclauses of this document).
A track design solution to achieve the required acoustic performance (e.g. introduction of resilient
elements or definition of the required mass) usually makes use of the conceptual criterion that the
lower the natural frequency of the ballastless track system is, the better the performance of the
vibration mitigation, which implies a reduction of the system’s natural frequency. The resulting
adaptation of a reference track design not fulfilling acoustic requirements to an acoustically-acceptable
ballastless track system design can, therefore, lead to a dynamic amplification of the system’s response
at excitation frequencies around the system’s natural frequency, see Annex B. In case that specific
dynamic analysis is required for appropriate design verification, the following input parameters are to
be taken into account:
— mass (in case of discrete elements) or density (in case of distributed elements) of the system or
subsystem components;
— damping coefficients of the system or subsystem components. An alternative way to determine
experimentally the damping coefficient of resilient materials is the loss factor, which can be
measured by the energy dissipated by damping against harmonic vibrations (e.g. EN 17682,
EN 17495:2022);
— operational train loads and axle configurations including running speeds;
— track roughness;
— natural frequency.
Where applicable, existing subsystem or component requirements from other documents are to be
referenced.
Noise absorbers, rail dampers etc. can be handled as equipment in the ballastless track system design
(see EN 16432-2:2017), while the acoustic design may require their full integration into the design
process.
6.3 Control of vibrations using the rail fastening system alone
Where it is proposed to mitigate vibration with the application of rail fastening systems with a reduced
vertical stiffness, rail stresses are a key consideration. Since the rail bending stress due to vertical
loading will increase as the support stiffness is decreased, a proof of rail stresses shall be made
following EN 16432-2:2017, Clause A.2, as part of the structural track design.
The performance of rail fastening systems with respect to vibration shall be tested according to the
relevant cases of EN 17495:2022, Table 2 (“Rolling noise” and “Ground vibration/ground borne noise”).
For the calculation, estimation, or prediction of the effects on noise and vibrations, the acoustic stiffness
of the rail fastening system or the resilient pad shall be determined in accordance with EN 17495:2022.
Additionally, a Track decay rate test in accordance with EN 15461 may be required for the
consideration of airborne noise requirements.
NOTE 1 The requirements for fastening systems for ballastless track, including discrete supports and
embedded rail systems are covered by EN 13481-5 and EN 17319 (for grooved rail).
NOTE 2 The airborne noise emissions can increase as a consequence of using a lower stiffness.
6.4 Mass spring system (MSS)
6.4.1 General
For input to the track design, the acoustic designer shall have defined the MSS in terms of mass and
dynamic supporting stiffness (in accordance with EN 17682), per unit length (see Annex B).
This mass shall encompass all the project specific ballastless track subsystems (see EN 16432-2:2017,
Figure 1) and all the imposed track equipment.
The project specific combination of mass and the dynamic supporting stiffness shall be selected in such
a way that the safe functionality of the track is demonstrated to be achievable for the planned design life
and service conditions (see EN 16432-2:2017).
To achieve the required mass, the density, and/or the thickness and the width of the track system can
be increased forming a pavement or structure (beam, slab) to distribute the loads (permanent and
traffic loads) via the designed support stiffness to the supporting system, e.g. tunnel.
Typically, the MSS requires more space between rail and tunnel compared to a ballastless track system
designed according to EN 16432-2:2017. It is recommended to synchronize the tunnel design with the
track design.
The load distributing subsystem (e.g. the slab) can be designed using the pavement design approach
according to EN 16432-2:2017. If the bending capacity of the slab according to EN 16432-2:2017 cannot
demonstrate the required safety level, then a structural design approach according to EN 1991 and
EN 1992 series is required.
NOTE 1 The pavement design approach is limited to CRCP, JPCP and JRCP with continuous support (see
EN 16432-2:2017, 10.2). As bending stresses obtained in the slab of MSS are typically higher than those of
conventional ballastless track systems, the concrete tensile strength might not be sufficient to resist the applied
loads. In such cases, two-layered reinforced concrete slabs alternative to CRCP and JRCP with a single centred
reinforcement layer can be designed following structural design methods.
NOTE 2 Typically, the required additional mass designed as a load distributing structure and the ballastless
track system are forming a monolithic track system.
The track may be designed with track cant that is different to the lateral inclination of the mass
supporting resilient elements. In this case the lateral load acting on the resilient element is the
centrifugal force dependent on train speed, radius and the lateral inclination of the mass supporting
resilient elements (superelevation of the substructure).
6.4.2 System classification according to length
6.4.2.1 General
MSS can be classified according to the length of the load distributing subsystem as listed in Table 2.
Table 2 — General concept of mini, short and long slab
Longitudinal section Cross-section

For rail and mass supporting stiffness, see
Annex B
Demonstration of load transfer at slab joint
required.
For rail and mass supporting stiffness, see

Annex B
For rail and mass supporting stiffness. see
Annex B
6.4.2.2 Mini slab
Mini slabs are slabs supporting one rail seat per rail and distributing the load to the supporting
structure mainly by vertical displacement without significant bending of the slab.
If mini slabs are supported by discrete resilient elements the arrangement of the resilient elements
shall be done in a way that stable support of the slab (e.g. 3-point support) and identical support
stiffness to both rails is achieved.
Because of the lack of longitudinal bending stiffness provided by the mass structure, the rail bending is
typically much higher than the rail bending of a normal ballastless track system. A proof of the rail
bending moment / the rail flexural stress is required following the calculation procedure of
EN 16432-2:2017, Clause A.2. The total spring coefficient of the rail support is provided at least by the
fastening system and the support of the slab.
Long slab Short slab Mini slab

NOTE Rail deflection along a mini slab system is typically significantly higher compared to the rail deflection
along a normal ballastless track system.
A check of the geometric situation of loaded and unloaded rail at rail fracture is recommended to
evaluate the risk of derailment in the event of rail fracture.
The mass structure of the mini slab does not contribute to the lateral track bending stiffness. A proof of
the following criteria shall be considered:
— lateral track stiffness (see EN 16432-2:2017);
— lateral track movement activated by all lateral forces;
— lateral elastic shear deformation of the resilient element (see EN 17682);
— risk of lateral displacements between mass, resilient element and support in case the lateral
fixation is based on friction.
For control of the lateral track stability in both curves and straight track, lateral resilient elements
should be considered.
Train braking and acceleration requires proof of:
— longitudinal track movement;
— longitudinal elastic shear deformation of the resilient element (see EN 17682);
— longitudinal displacements between mass, resilient element and support in case of relying only on
friction.
As mini slabs are more prone to excitation frequencies stemming from axle configurations and train
speeds, special attention shall be paid to avoiding resonance cases, see 7.1.
6.4.2.3 Short slab
Short slabs are slabs supporting more than one rail seat per rail and distributing the load to the
supporting structure through the resilient supports with no significant recourse to the bending strength
of the suspended slab. A single axle load applied to slab centre will cause a vertical slab displacement at
the joint of approximately the same dimension.
With the help of modelling and simulation tools (e.g. FEM) the situation of a moving load shall be
demonstrated to identify additional vertical slab motion (typically slab rocking) and slab loading at
critical locations (typically at the joints). Loading of the rail and the fasteners next to the joints shall be
demonstrated to decide on the need for and, if required, the design of, shear connectors at the joints. An
example for a shear connector is given in Figure 2.
A check of the geometric situation of loaded and unloaded rail at rail fracture is recommended to
evaluate the risk of derailment in the event of rail fracture next to a joint.
6.4.2.4 Long slab
6.4.2.4.1 General
A long slab is defined when its configuration is based on a continuous load-distributing subsystem
(slab) in which its longitudinal bending stiffness is activated upon application of vertical loads.
Long slabs acting as a mass can for example be built on site using the tunnel or other sub-structure as a
formwork and be lifted into place with resilient elements inserted afterwards, or built using
prefabricated elements connected to each other, set on pre-installed resilient elements.
With respect to the functionality of the track, the slab bending shall be limited as well as the angle of
rotation at the joints or the end of the slab. Unless otherwise specified the limits set in
EN 16432-1:2017, 5.2.3 bridges shall be applied.
NOTE 1 Stricter limits may apply to limit the slab bending to x/L ≤ 1/2000 and to limit the angle of rotation at
the end of the slab or at joints to x/L ≤ 1/3333.
NOTE 2 L is the length of the slab between inflection points and x the maximum deflection in between,
considering all applicable vertical load combinations.
Horizontal displacements of the slab under constant loading (e.g. temperature, shrinkage) and under
traffic loading shall be limited according to the performance characteristics of the resilient element.
By calculation, it shall be demonstrated that the resilient elements can support all longitudinal and
lateral load introduced by the traffic and distributed by the track and the slab forming the mass.
The joints at the end of the slabs and intermediate joints shall be designed according to 6.4.3.
A check of the geometric situation of loaded and unloaded rail at rail fracture is recommended to
evaluate the risk of derailment in the event of rail fracture next to a joint.
6.4.2.4.2 Long slabs cast on site
Long slab systems cast on site may be designed with a full surface resilient element, with strip resilient
elements or with discrete resilient elements supporting the slab.
In the latter case, if the tunnel floor is used to temporarily act as a formwork for the mass-slab following
requirements shall be applied:
— provisions to lift the slab (e.g. using hydraulic jacks) and to introduce the resilient elements to
support the slabs (e.g. openings) shall be integrated into the slab design. The same provisions may
be used to renew the slab support if needed;
— the openings shall avoid ingress of pollution that may block the dynamic displacement behaviour of
the slab (e.g. using covers to protect from pollution);
— to achieve a uniform loading on the support element a specified flatness of the supporting structure
may be required.
6.4.2.4.3 Long slabs using monolithically connected precast elements
The joints between the precast elements forming the long slab are construction joints providing the
continuity of slab bending.
NOTE Joints with different functionality can be placed at the ends of the slab or elsewhere in accordance with
the system design principles.
The base for the resilient element shall be capable of compensating vertical tolerances between tunnel
and prefabricated element and to provide the final level of the track.
6.4.3 Joints
6.4.3.1 Transverse slab joints in the track
Transverse joints may be required to enable longitudinal track movements due to temperature and
concrete shrinkage effects. Such joints should be designed to be orthogonal to the track axis to minimize
risk of twist and torsion of MSS. Without additional measures providing vertical load transfer at the
joint, higher vertical deflection could be either a structural issue for the rails as well as an issue for the
vibration mitigation effect happening when trains passing those joints. The track designer shall check
load transfer means at transverse track joints to cater for vertical and lateral force transfer.
The choice of such measure is a matter of the track design, loading assumptions and economic options
catering for dynamic and fatigue effects acting in railway tracks. The choice of measures shall be made
based on requirements of deflection, vibration and durability. Various types of measures and materials
are available, though dowels on the neutral axis are commonly used. For example, some shear dowels
solutions allow a degree of longitudinal movement and employ some rebar hooks and steel cages to
improve the force-transfer and provide a durable embedding into the concrete slab end (see Figure 2.)
The required number of measures (e.g.: shear dowels) depends on the loads, the track design and the
choice of dowel type. The designer shall set out the means of load transfer at joints and demonstrate the
resistance to dynamic loading to verify the intended solution for force transmission at track
connections against requirements. The track designer shall take into account the maintainability of the
joints.
A typical dowel type is displayed in Figure 2.

Key
1 sleeve
2 steel cage
3 shear dowel
Figure 2 — Shear dowel with steel cage and sliding sleeve
Introduction of joints and connecting measures such as dowels shall be taken into account in the
earthing concept. Requirements to provide either electric continuity or gaps within the track system
shall be considered. Additional measures such as bonding, or insulated materials within the measures
may be required. Where electric continuity of the track system is to be provided or excluded through
the joints this needs to be ensured and demonstrated.
Additional provisions may be required with respect to electric interfaces (see EN 16432-1:2017, 6.9 and
EN 16432-2:2017, 6.1).
6.4.3.2 Longitudinal joints along the tracks
The slab of the MSS shall be separated from adjacent structures (e.g. walkways, tracks) by using
longitudinal joints. The longitudinal joint design shall allow the designed deflection under live loads and
shall provide the designed vibration mitigation functionality. Longitudinal joints in that sense can be:
— joints equipped with a separation layer (elastomer mat/resilient element, mineral fibre mat,
vertical drain mat). The acoustic designer shall check the effect on the acoustic performance of MSS
activated by the materials introduced in the joint;
— joints equipped with a joint sealant;
— just an empty space.
The track designer shall take into account the maintainability of the joints.
6.4.4 Transitions
Transition between track forms designed as MSS with different tuning frequencies and transition to
track forms designed according to EN 16432-2:2017 without additional vibration mitigation
requirements shall avoid abrupt stiffness changes.
The stiffness change along the track should be done gradually in defined stages to ensure that the
transition is as smooth as possible to minimize dynamic effects. Each stage requires a defined stiffness
and length related to line speed.
When determining the number of stiffness stages, the following aspects should be considered in
addition to 6.8 of EN 16432-2:2017:
— track forms designed as MSS with low natural frequency may require more stages than track forms
with high natural frequency;
— changes of the stiffness have an effect on the vertical and lateral forces that shall be considered in
the slab design. More stages of the stiffness may be needed to minimize these impacts, but may be
difficult to implement. It can therefore be more efficient to strengthen the MSS track system
structure instead of increasing the number of stages.
The transition from track forms designed as MSS to ballasted track is recommended to be designed as
two transitions. Following this recommendation, the first transition should be designed from the track
form designed as MSS to track forms designed according to EN 16432-2:2017 without additional
vibration mitigation requirements. The second transition to ballasted track should be designed
according to EN 16432-2:2017, 6.8.
6.4.5 Lateral and longitudinal resilient elements
6.4.5.1 General
The achievement of the vibration mitigating effect of a MSS requires ability of movement of the
elastically supported mass, slab or block in vertical direction. This can cause displacements of the MSS
slab in the lateral and/or longitudinal directions (see Figure 1), originating from the following actions:
— braking and acceleration forces;
— centrifugal forces;
— nosing force;
— forces due to thermal effects, shrinking etc;
— exceptional forces, e.g. derailment.
NOTE 1 Vertical forces are transferred onto the supporting structure (e.g. tunnel invert) via the vertical
resilient elements of the elastically supported mass. Vertical movements are limited by the vertical resilient
elements, horizontal movements by the longitudinal and lateral resilient elements.
In case a track section is receiving a combination of lateral and longitudinal forces then the resulting
shear stress τres can be calculated using:
2 2
ττ +τ
res lateral longitudinal
where
τ is the resulting shear stress
res
τ is the lateral shear stress
lateral
τ is the longitudinal shear stress
longitudinal
Lateral forces may be transferred into the supporting structure (e.g. walkway or tunnel invert) via
lateral resilient elements. Lateral resilient elements can be vertically-oriented discrete resilient
elements or vertical full-surface mats or layers acting as resilient elements.
Longitudinal forces may be transferred into the supporting structure (e.g. tunnel invert) via additional
longitudinal resilient elements. Longitudinal resilient elements can be vertically oriented discrete
resilient elements.
NOTE 2 There are exis
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