TSI LOC&PAS requirements: a practical guide

Who this is for: rolling-stock and RAMS engineers, homologation managers and assessors who need to navigate the TSI for locomotives and passenger rolling stock without reading 300 pages of regulation cold. This guide explains the scope, how the requirements are organised, where the main technical areas live, and how conformity is assessed. The TSI is public law — you can and should read the authoritative text on EUR-Lex — but knowing the map first saves hours.

What TSI LOC&PAS covers

TSI LOC&PAS is the Technical Specification for Interoperability relating to the rolling stock subsystem "locomotives and passenger rolling stock" of the EU rail system. It is set out in Commission Regulation (EU) No 1302/2014, and — this is the credibility-critical part — it has been amended several times. Its references were updated by Regulation (EU) 2019/776, and it was substantially amended by Commission Implementing Regulation (EU) 2023/1694 (the large 2023 package that revised multiple TSIs together). Always work from the current consolidated text, not the 2014 original, and confirm what is in force for your project's timeline.

The TSI applies to the rolling stock subsystem operated on the EU network. In its scope (the categories set out in the TSI's Chapter 2) it covers, broadly:

It explicitly does not cover metros, trams and light-rail vehicles, which fall outside the mainline interoperability regime. Note that the freight wagon subsystem is governed by a separate TSI (WAG), not by LOC&PAS — a common point of confusion (see the FAQ).

How the requirements are structured

Navigating the TSI is the reader's real pain, so understand the hierarchy before you dive in. It flows from law down to testable requirements:

  1. Essential requirements — the high-level objectives inherited from the interoperability directive: safety, reliability and availability, health, environmental protection, and technical compatibility (plus accessibility). These originate in the directive (originally Directive 2008/57/EC; now Directive (EU) 2016/797, which repealed and replaced it). You never verify against an essential requirement directly — it is too abstract.
  2. Basic parameters — the essential requirements are translated into concrete, verifiable basic parameters in the TSI's Chapter 4 (section 4.2). This is where the engineering requirements actually live, grouped by functional area.
  3. Cross-reference table — the TSI provides a table mapping each element of the rolling stock to the essential requirement(s) it satisfies, so you can trace any basic parameter back up to its legal justification.

The mental model: essential requirement → basic parameter → assessment. When someone asks "which TSI clause covers crashworthiness?", they mean "which basic parameter in section 4.2", and the answer is a 4.2.x reference.

Two more structural features are worth knowing before you start. First, many basic parameters do not spell out a test in full — they point to a harmonised EN standard (frequently an EN 5012x, EN 15227 for crashworthiness, EN 14363 for running behaviour, and so on) as the means of demonstrating conformity. So the TSI is a spine that repeatedly hands you off to a CENELEC standard for the detail; you cannot work the TSI in isolation. Second, ERA publishes an application guide for LOC&PAS that walks through the parameters clause by clause with the Agency's own interpretation. It is not legally binding, but it is the single most useful companion to the regulation and it is free — use it to disambiguate anything the regulation states tersely.

Key requirement areas (with where to look)

The basic parameters in section 4.2 are organised into functional groups. Below are the main areas and the section neighbourhood to consult in your licensed / official copy. Paraphrased for orientation only — read the actual clause for the binding requirement, and confirm numbering against the current consolidated text, as amendments can renumber.

Structure and mechanical parts (incl. crashworthiness)

Found around 4.2.2. Covers internal and end couplers, gangways, vehicle body strength, passive safety / crashworthiness (the collision scenarios the vehicle structure must withstand and the controlled deformation / survival-space objectives), lifting and jacking, and attachment of devices. Crashworthiness is one of the most-searched LOC&PAS topics and is a structural-strength-plus-collision-scenario requirement, not a single number.

Vehicle–track interaction and gauging

Found around 4.2.3. Covers gauging (the kinematic envelope the vehicle must respect), axle load and wheel load, running dynamics and running safety (including safety against derailment on twisted track), wheelset and wheel/axle geometry, and minimum negotiable curve radius. This is the group that determines whether a vehicle is physically compatible with a given network — a frequent source of open points and national rules.

Braking

Found around 4.2.4. Covers braking functional and safety requirements, braking performance (emergency and service braking), wheel-slide protection, dynamic and parking brakes, and thermal capacity. Braking spans both the "safety" essential requirement and "technical compatibility", because braking performance has to match the signalling and line assumptions.

Passenger-related and environmental conditions

Passenger items sit around 4.2.5 — exterior and interior doors, toilets/sanitary systems, passenger information and alarm, air quality and clearances. Environmental conditions sit around 4.2.6 — the range of ambient conditions the vehicle must tolerate, plus aerodynamic effects: slipstream on people, pressure pulse in open air and in tunnels, and crosswind stability. Accessibility for persons with reduced mobility is governed primarily by the separate PRM TSI, which interfaces here.

Other functional groups in section 4.2 include external lights and horns, traction and electrical equipment, the driver's cab and man–machine interface, fire safety and evacuation, servicing, and documentation. If a topic isn't in the group you expect, check the adjacent 4.2.x block.

Conformity assessment for LOC&PAS

Once you know what is required, you need to demonstrate conformity. Two levels matter:

The assessment uses the standard EU conformity-assessment modules (type examination, production-phase quality assurance, unit verification, full quality management, etc.), executed by a Notified Body (NoBo). Where national rules apply — for open points and specific cases — a Designated Body (DeBo) assesses those. For who does what and how the modules combine, see NoBo vs DeBo vs AsBo.

In practice the assessment produces two outputs that people routinely conflate: the type and the vehicle. Most rolling stock is authorised as a type first (a design that has been verified against the TSI and national rules), after which individual vehicles conforming to that authorised type can be placed on the market with a lighter check. Getting the type right is therefore where the assessment effort concentrates — a defect in the type propagates to every vehicle built to it. The dossier the NoBo, DeBo and applicant build up feeds the authorisation application submitted to the authorising entity (the European Union Agency for Railways for multi-state use, or a National Safety Authority for a single state). Note the deliberate division of labour: the assessment bodies verify conformity and manage the technical evidence; the authorising entity checks the process was correct and grants the authorisation — it does not re-run the technical assessment.

LOC&PAS and the other TSIs / EN 5012x

LOC&PAS does not stand alone. Key interfaces:

Open points and national rules

No TSI is complete. Two mechanisms handle the gaps, and both are unavoidable in real projects:

The practical consequence: a vehicle for cross-border use is verified against the TSI plus each state's national rules for the open points and specific cases relevant to its routes. For how national rules sit relative to the TSIs, see NoBo vs DeBo vs AsBo.

Frequently asked questions

Which revision of TSI LOC&PAS is current?
The base regulation is Commission Regulation (EU) No 1302/2014, but it has been amended — most significantly by Commission Implementing Regulation (EU) 2023/1694 (published in the Official Journal in September 2023), which revised multiple TSIs together, following earlier amendments including 2019/776. Work from the current consolidated version on EUR-Lex for your project's applicable date, not the 2014 text.
Does TSI LOC&PAS cover freight wagons?
No. Freight wagons are covered by the separate WAG TSI. LOC&PAS covers locomotives and passenger rolling stock (and traction units and certain on-track machines). A locomotive that hauls freight is in LOC&PAS; the wagons it hauls are in WAG.
How do open points work?
An open point is a subject the TSI has not (yet) harmonised. For that subject, the national rules of the state(s) of use apply, notified by the Member State and assessed by a Designated Body. Once the TSI is amended to close the open point, the national rule falls away for future authorisations. Open points are listed in a TSI appendix.
What is the difference between an interoperability constituent and the subsystem?
An interoperability constituent is a defined component (a coupler, a wheel, a pantograph) certified in its own right with an EC declaration of conformity. The subsystem is the whole vehicle, verified by the EC verification procedure. ICs are building blocks; the subsystem is the assembled, authorised vehicle. Assessing the ICs does not on its own authorise the vehicle — a set of conformant constituents can still fail subsystem-level requirements when integrated, which is precisely why the two levels of assessment exist.

Sources

ERA Standards is an independent product and is not affiliated with the European Union Agency for Railways. This guide is general information, not certification advice.