IFC Railway: Strategies of Companies in the Rail Sector

The digitalization of the railway sector represents a priority for companies, institutions, and infrastructure operators worldwide. The increasing complexity of networks, along with the need to ensure sustainability, safety, and operational continuity in the long term, makes the adoption of advanced digital models based on open and truly interoperable standards indispensable.

IFC Railway is the extension of the IFC standard dedicated to openBIM modeling of railway infrastructures. It is part of IFC 4.3, the version of the standard developed by buildingSMART for linear infrastructures, and enables the interoperable exchange of data throughout the entire lifecycle of railway assets.

An approach that finds its maximum expression in the use of digital twin software capable of efficiently and consistently managing the IFC models of railways throughout the entire lifecycle of the assets.

What is IFC railway and why is it important?

IFC railway is the extension of the IFC (Industry Foundation Classes) standard dedicated to railway infrastructures. The standard is developed and promoted by buildingSMART International, the organization that globally coordinates the evolution of openBIM standards to improve the sharing and interoperability of data in the construction and infrastructure sector.

IFC Railway is part of the development of IFC 4.3, the version of the standard dedicated to linear infrastructures. IFC 4.3 introduces new entities and concepts for the modeling of roads, railways, bridges, and tunnels, allowing for the representation of elements based on alignments, kilometer references, and positioning systems along the track. The railway domain represents one of the main specializations of this infrastructural extension.

IFC Railway allows for the modeling, exchange, and management of BIM data related to complex railway networks through an open, non-proprietary, and software-independent format. Its importance lies in its ability to support coherent and interoperable digital processes for the entire lifecycle of railway assets, from design to construction, through to operational management and decommissioning.

IFC Rail is one of the application areas of BIM for linear infrastructures: there are also extensions dedicated to roads and tunnels, such as IFC Road and IFC Tunnel.

Standardized data schema

IFC Railway defines a standardized data schema that facilitates the coherent and structured representation of the main components of a railway infrastructure, such as tracks, rails, stations, civil works, technological plants, and support systems.

This informational structure relies on the frameworks introduced by IFC 4.3, which include entities such as IfcAlignment and mechanisms of linear referencing, essential for modeling infrastructures developed along extensive tracks. With these tools, it is possible to accurately describe linear geometries and spatial relationships typical of the railway domain.

The model defines common rules for organization, classification, and correlation of data, ensuring semantic consistency and interpretative clarity among models produced by different parties, including those derived from point clouds.

The adoption of an open standard allows designers, builders, and managers to exchange complete and reliable BIM models during various phases of the project, reducing information loss and the ambiguities typical of proprietary formats. This results in greater integration among technical disciplines and a more effective management of infrastructural data, even in complex contexts characterized by very long life cycles.

IFC extensions specific to the railway sector

Starting from the general IFC schema, IFC Railway introduces extensions dedicated to the railway sector, necessary for accurately representing linear assets, distributed systems, and infrastructural references developed over long distances. These extensions respond to the needs of a domain characterized by complex geometries, articulated spatial relationships, and strong interdependencies between civil, technological, and systems components.

The IFC Railway extensions allow for modeling that includes geometric, informational, and functional aspects, enabling a more accurate description of the relationships between the different elements of the infrastructure. This level of informational detail supports more informed decision-making processes during the design, construction, operation, and maintenance phases of the work and contributes to improving the overall quality of railway BIM models, which thus become reliable tools for managing the entire railway system.

Navigation of the digital twin railway model

How IFC Railway Supports openBIM and Interoperability

IFC Railway is an essential tool for the implementation of openBIM principles in the railway sector, as it allows data sharing through an open format that is independent of specific software. This approach promotes effective collaboration among all stakeholders involved in the process throughout the entire lifecycle of the infrastructure.

In particular, IFC Railway supports interoperability through:

• data exchange between different software, avoiding technological constraints and dependencies on specific platforms;
• integration of the disciplines involved in railway projects, such as civil works, structures, signaling, electrical supply, telecommunications, and technological systems;
• uniform access to information, which reduces errors, inconsistencies, and data duplication;
• collaboration among multidisciplinary and distributed teams, even at an international level;
• information continuity over time, essential for the management, maintenance, and evolution of railway assets.

Thanks to IFC Railway, BIM models become shared and reliable tools, capable of supporting coordinated decision-making processes and ensuring more efficient and transparent management of railway infrastructures.

Benefits for Companies, Governments, and End Users

The adoption of BIM and openBIM principles, supported by the IFC Railway standard, generates concrete benefits for all actors involved in the railway supply chain:

• railway companies: improve productivity and competitiveness through faster and more accurate processes, reduction of errors and inconsistencies, savings in time and costs, consistent data management, and greater reliability of digital models;
• governments and institutions: achieve more effective, safe, and sustainable infrastructures, with transparent data management that promotes decisions based on reliable information and comparable across different projects and territories;
• citizens and end users: benefit from more efficient and safer services, from infrastructures designed and maintained with high quality standards, and from a reduction in environmental impact due to optimized and sustainable processes.

Unlike other BIM applications, the railway sector deals with complex linear infrastructures and highly heterogeneous data. The use of open standards like IFC Railway reduces risks related to software obsolescence and file incompatibility, ensuring that valuable and detailed information remains always accessible and reliable, regardless of the technology used.

Digital Twin and Complete Lifecycle of Railway Assets

The use of BIM in the railway sector allows for the creation of digital models of the infrastructures that are fully consistent with the actual work, commonly referred to as digital twin railway. These models constitute a structured informational basis that accompanies the asset throughout its entire lifecycle, from design to construction, to operational management, maintenance, and decommissioning.

The lifecycle of a railway asset is structured into the following phases:

• Development: definition of requirements, planning, and feasibility evaluation of the project;
• Design: creation of detailed models of the infrastructure and technological systems, integrating all the involved disciplines;
• Construction: realization of the infrastructure based on the BIM models, with accurate transfer of design information to the construction site;
• Operation: use of the digital model as a reference for performance monitoring, planning of maintenance interventions, and defining requirements according to the railway operator’s needs.

In all phases, IFC Railway ensures a consistent flow of data that is readable by any software and free of information loss. The standard keeps contents reliable and updated for all stakeholders.

IFC railway assets life cycle

The digital twin integrates geometric, technical, and functional data related to the infrastructure. The model captures all the changes that occur over time and ensures alignment with the actual state of the work, offering traceability and reliability of data. Thanks to this integrated management, the digital twin provides railway companies with a unique reference for performance monitoring, intervention planning, impact analysis, and operational decision support. The digital twin thus assumes the role of an operational and strategic tool, capable of improving the management, control, and optimization of railway infrastructures.

The main challenges of railway digitalization (and how IFC solves them)

The digitalization of the railway sector presents complex challenges, related to the multidisciplinary nature of the infrastructures, the long lifecycle of assets, and the need to ensure informational continuity among different subjects and tools. Managing large volumes of heterogeneous data requires coherent, reliable, and accessible informational models over time.

The adoption of open standards represents a concrete response to the main critical issues of railway digitalization, including:

• data fragmentation among technical disciplines, operational phases, and different software;
• dependence on proprietary formats, with risks of information loss and compatibility issues over time;
• loss of informational continuity, which can compromise the quality of models and the traceability of changes;
• difficulties in coordination among different actors, making it complex to ensure consistency and data updates.

IFC Railway addresses these critical issues by providing an open and structured model that allows:

• to centralize and organize information clearly and accessibly;
• to ensure the alignment of data with the actual state of the infrastructure;
• to preserve the quality and traceability of information over time;
• to promote collaboration among companies, designers, operators, and managers, improving the overall management of railway assets.

Standardization, digitalization, interoperability: the three pillars

The digitalization of railway infrastructures is based on three fundamental elements, essential to ensure efficiency and collaboration among all parties involved in the process, as well as to improve the quality of the final result:

• standardization: defines common rules for the representation of components, infrastructures, and relationships between systems. It allows all actors to interpret data in the same way, reducing errors and inconsistencies;
• digitalization: allows the creation of complete digital models that integrate geometric, technical, and functional data. These models become the informational foundation for all phases of the asset lifecycle, from design to operational management;
• interoperability: ensures that data can be used and exchanged between different software and across different organizations. Interoperability reduces duplication, improves coordination, and makes planning, construction, and maintenance activities more efficient.

These three pillars guarantee a consistent and reliable management of information and transform the digital model into an operational and shared tool, capable of supporting informed decisions and optimally managing railway infrastructures.

Loading the IFC railway file on a digital twin software

Avoiding data loss with open standards and long-term accessibility of files

Managing railway infrastructure requires accurate, complete, and time-available data. The use of proprietary formats can pose risks of information loss and compatibility issues with new versions of software.

Open standards solve these problems by offering:

• data preservation: all informational content remains readable and complete, regardless of the software used;
• long-term accessibility: information remains available even after many years, ensuring continuity for the asset’s lifecycle;
• compatibility and reuse: data can be shared, compared, and updated without risks of inconsistencies;
• support for integrated management: collaboration among designers, builders, operators, and managers is facilitated, reducing errors and duplications.

Thanks to this approach, information becomes reliable, traceable, and accessible at all stages of the infrastructure’s lifecycle, and railway digitization becomes sustainable and secure.

Encouraging global collaboration through shared digital strategies

The complexity of railway infrastructures requires the coordinated participation of multiple actors, often distributed across different countries and business realities. To achieve effective collaboration, it is necessary to define shared digital strategies based on open standards and uniform procedures for data management.

Such strategies allow for:

• ensuring consistency and integrity of information among all participants;
• facilitating data sharing and comparison among design, construction, and operational management teams;
• reducing errors, inconsistencies, and delays arising from the use of proprietary formats or different methodologies;
• promoting standardization of digital practices at an international level, facilitating regulatory harmonization.

The adoption of interoperable digital models, such as those based on IFC railway, provides a common reference for all stakeholders and creates the conditions for efficient, secure, and sustainable global collaboration.

What BIM software for the railway sector must guarantee: key requirements

BIM software dedicated to the railway sector must respond to very specific needs to ensure the complete management of infrastructure and data throughout the entire lifecycle of the assets.

Below are the main requirements that a BIM software must satisfy to operate effectively in the railway sector:

• infrastructure representation: accurately model and manage linear and non-linear works, networks extended over long distances, and complex systems involving multiple disciplines and complex organizational structures, with full integration of coordinates and linear references;
• land resource management: ensure consistency between the model’s geometry and the physical reality, regardless of the project’s scale;
• data control: manage data throughout the asset’s lifecycle, ensuring secure updates even in the case of significant changes or infrastructure restructuring;
• advanced modeling: support generative design and the automatic production of technical documentation through the creation of 3D models consistent with project information;
• multiple classifications: manage multiple classifications, such as PBS/ABS, to ensure procurement, material management, and coordination of activities among different operators;
• analysis and simulations: enable the assessment of buildability, costs, environmental impacts, operational flows, and movement dynamics, integrating multidimensional 5D and 6D analyses;
• data security and integrity: reduce risks of information loss and ensure complete traceability of changes;
• control and verification: provide tools that enhance the efficiency and quality of operational decisions throughout the infrastructure’s lifecycle;
• process efficiency: optimize productivity and competitiveness of railway companies;
• user accessibility: facilitate access to information and the adoption of software through intuitive interfaces and processes for all stakeholders.

These requirements translate into five key performance areas, which represent the main objectives of BIM software in the railway sector:

• integration and interoperability: consistent data management across different disciplines and tools;
• sustainability of investments: optimization of time, resources, and costs throughout the asset’s lifecycle;
• integrity and security of information: reliability, traceability, and protection of data;
• end-user experience: simple and intuitive access to information for all stakeholders;
• business performance: support for operational efficiency and overall productivity.

To manage railway infrastructures effectively, you can rely on a digital twin software. With comprehensive and interoperable digital models, you can monitor the state of the networks in real-time, plan maintenance interventions, simulate operational scenarios, and optimize the entire asset lifecycle. BIM data transforms into strategic information, allowing you to make safer, more sustainable, and effective decisions in the daily management of infrastructures.

BIM software requirements

Technical innovations and real use cases: the practical application of the IFC 4.3 standard

The transition to the IFC 4.3 standard was not just a theoretical evolution, but the result of an intense dialogue between software vendors and international railway stakeholders (such as RFI, SNCF, and SBB), coordinated by the technical committee of buildingSMART International. This collaboration has allowed for the translation of concrete digitalization needs into technical specifications capable of managing the complexity of linear infrastructures.

The technological pillars of IFC 4.3

The evolution of IFC 4.3 is based on a profound redefinition of how data is structured, overcoming the limitations of formats originally designed for civil engineering:

• flexible spatial structure – unlike the “building” (where the hierarchy is fixed: site, building, floor, space), infrastructures require a spatial decomposition free from pre-existing constraints. This flexibility allows users to associate model entities with different spatial structures according to the specific use case (design, maintenance, or cost analysis);
• IfcAlignment as a semantic directive – it is the most important concept of the standard. The Alignment is not just a geometric line, but a semantic class that contains the mathematical definition of the trajectory along which all other objects are positioned. This version of the standard has completely revised the concept, making it not backward compatible with previous versions in order to ensure its technical effectiveness;
• linear positioning and stationing – while in construction, X, Y, Z coordinates are used, IFC 4.3 introduces linear positioning. This allows for the placement of an object (such as a sleeper or a signal) based on the reference “kilometric” (e.g., at km 3 of the track), reflecting the natural way of operating in the railway and road sector;
• parametric extrusions and regulatory control – software can generate complex geometries (such as tracks or the dynamic envelope of a train) starting from a parametric profile extruded along the track. This approach is essential for clash detection and code checking activities, such as verifying that the distance between a moving train and obstacles along the line adheres to safety regulations.

Use case analysis: the effectiveness of the standard in international “Storylines”

The reliability of IFC 4.3 has been tested through Storylines, which are applications on real assets coordinated by buildingSMART International with the participation of stakeholders and software vendors:

• maximum detail and large scale (RFI) – the Italian case of the Benevento-Cancello line (50 km) demonstrated that the standard can simultaneously manage the overall view of the infrastructure and extreme detail, down to the individual bolt of the sleeper, within a multidisciplinary model aimed at avoiding collisions between different components;
• parametric libraries and switches (SBB) – in Switzerland, the focus was on the creation of a BIM library for railway switches. Being finished and known objects, a very high geometric level was achieved, creating components ready to be inserted into real projects where they will then be valued with specific data;
• integration with Facility Management (Finland) – the Finnish Transport Agency tested models with lower geometric detail but very high information density. The main objective was the semantic linkage of data to existing external asset management systems, using concepts of “links and ports” for the digital wiring of networks;
• multidisciplinary coordination (Mind) – the French storyline “Mind” explored the federation of different models (railways, roads, bridges), focusing on the digitalization of telecommunication wirings and the semantic connections between objects from different disciplines.

Read the in-depth article: “openBIM standards”

FAQ – Frequently asked questions about IFC Railway

What is IFC Railway?

IFC Railway is the extension of the IFC standard dedicated to openBIM modeling of railway infrastructures. It is part of IFC 4.3, the version of the standard developed by buildingSMART for linear infrastructures, allowing for interoperable data exchange throughout the entire lifecycle of railway assets.

What is the relationship between IFC Railway and IFC 4.3?

IFC Railway represents the railway domain of the IFC 4.3 schema, the extension of the IFC standard dedicated to roads, railways, bridges, and tunnels. IFC 4.3 introduces entities such as IfcAlignment and mechanisms of linear referencing, essential for modeling infrastructures developed along extended alignments.

What is the purpose of IFC Railway in the railway sector?

IFC Railway allows for the modeling, exchanging, and managing of BIM data related to complex railway networks through an open and non-proprietary format. It supports collaboration between different disciplines and ensures information continuity from design to construction, through to operational management and maintenance.

How does IFC Railway support interoperability?

The standard enables the exchange of data between different software, avoiding technological constraints and dependencies on specific platforms. It promotes integration between civil works, structures, signaling, power supply, and technological systems, ensuring uniform access to information and reducing errors and duplications.

Why is IFC Railway important for the lifecycle of railway assets?

IFC Railway ensures a coherent and readable flow of data from any software throughout all phases of the lifecycle: development, design, construction, and operational management. This approach preserves the quality, traceability, and reliability of information over time.

What benefits does the adoption of IFC Railway offer?

The adoption of the openBIM standard brings advantages to railway companies, institutions, and end-users. It improves productivity and competitiveness, promotes data-driven decision-making, reduces risks associated with proprietary formats, and contributes to the creation of more efficient, safe, and sustainable infrastructures.

What is the role of the digital twin in an IFC Railway environment?

The digital twin integrates geometric, technical, and functional data of the railway infrastructure, maintaining alignment between the digital model and the real structure. It allows for monitoring performance, planning maintenance, simulating operational scenarios, and supporting strategic decisions throughout the lifecycle of the asset.

What requirements must BIM software meet to manage railway infrastructures?

Railway BIM software must support the modeling of extended linear works, integration of coordinates and linear references, data control throughout the lifecycle, multidimensional analysis, and secure information management, ensuring interoperability and complete traceability.

What are the characteristics of the spatial structure in IFC 4.3?

Unlike traditional civil engineering (‘building’) where the hierarchical decomposition is fixed, linear infrastructures require a spatial structure free from pre-established constraints. This flexibility allows users to associate entities with different spatial structures depending on the specific use case, such as design or maintenance.

What is IfcAlignment and why does it represent a fundamental concept?

Alignment is the most important concept for linear infrastructures, as it defines the direction along which all other objects are positioned and geometries are generated. It is a semantic class that contains the mathematical definition of the trajectory, completely revised in this version of the standard and not backward compatible with previous ones.

How does linear positioning work in IFC railway 4.3?

While in construction the X, Y, and Z coordinates are used, IFC 4.3 introduces linear positioning based on the reference ‘kilometer’ in relation to the alignment. This allows for the placement of elements such as a sleeper or a signal along the track, reflecting the traditional working method of the sector.

What are parametric extrusions used for in the new standard?

Parametric extrusions allow software to generate complex geometries, such as tracks, starting from a parametric profile extruded along the track. This approach is essential for conducting clash detection and regulatory safety checks (‘code checking’), such as verifying the dynamic envelope of the train.

What were the use cases presented?

• The company SBB focused on creating a BIM library dedicated to railway switches. Being finite components, a very high geometric detail level was achieved to obtain ready-to-use objects for actual projects, where specific data will later be integrated.
• The French storyline ‘Mind’ explored the federation of models belonging to different infrastructure disciplines such as railways, roads, and bridges. The study focused on the digitization of telecommunications cabling and the semantic connections between objects of multidisciplinary coordination.
• Finland tested models with lower geometric detail but a very high information density, aimed at connecting to existing external facility management systems. The semantic concept of ‘links and ports’ was utilized for the digital cabling of networks.
• The Italian stakeholder RFI tested the standard by digitizing approximately 50 km of the real Benevento-Cancello railway, demonstrating that IFC railway 4.3 can simultaneously handle large dimensions and maximum detail, down to the individual bolt of the sleeper, within a multidisciplinary model aimed at avoiding collisions.