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ISO/TS 25740-1:2011 — Global Essential Safety Requirements for Escalators and Moving Walks
Safety requirements for escalators and moving walks — Part 1: Global essential safety requirements (GESR)
Introduction: The Need for Global Escalator Safety Standards
Escalators and moving walks are among the most widely used passenger conveyance systems in the world — found in shopping centres, airports, transit stations, and office buildings. Despite their apparent simplicity, these machines involve complex electromechanical systems with significant kinetic energy, numerous pinch points, and the potential for serious injury if not properly designed and maintained.
ISO/TS 25740-1:2011 addresses a critical challenge: the existence of discrepancies among regional and national safety standards for escalators and moving walks. While standards like EN 115 (European) and ASME A17.1 (North American) have served their respective regions well, they differ in detailed requirements, creating trade barriers and potentially inconsistent safety levels globally.
The standard was developed following the methodology established in ISO 14798 (Risk assessment and risk reduction for lifts, escalators and moving walks), ensuring a consistent, risk-based foundation for all safety requirements.
Understanding GESRs: Global Essential Safety Requirements
What Makes GESRs Different
Unlike traditional prescriptive standards that specify exact dimensions, materials, or mechanisms, GESRs define safety objectives — what is to be achieved, not how to achieve it. This approach offers several advantages:
- Innovation-friendly: Manufacturers can develop novel solutions as long as they meet the safety objective
- Technology-neutral: Requirements remain relevant as technology evolves
- Globally applicable: One set of objectives can replace multiple regional prescriptive standards
- Future-proof: New risks identified through field experience can be addressed without rewriting the entire standard
Structure of the GESRs
The GESRs are organized by the persons at risk and their location relative to the escalator or moving walk:
| Category | Who is at Risk | Example GESRs |
|---|---|---|
| Common GESRs (6.2) | All persons at any location | Strength and size, fall prevention, electric shock protection, EMC, earthquake effects, noise and vibration |
| Non-users (6.3) | Persons near but not on the equipment | Contact with moving parts, failure mode safety, environmental influence |
| Persons on landings (6.4) | Those entering or exiting | Fall from landings, access/egress, alignment of LCU and landing |
| Users on LCU (6.5) | Passengers on the steps/palks | Entrapment prevention, uncontrolled movement prevention, speed change safety, stopping means |
| Authorized persons (6.6) | Maintenance and inspection personnel | Working space, lockable access, sole control of movement, ergonomic principles |
Critical safety consideration: The standard distinguishes between “users” (passengers), “non-users” (people near the equipment, especially children), and “authorized persons” (maintenance staff). Each group faces different hazards and requires different protective measures. For example, children playing near an escalator (non-users) need different protection from passengers riding it (users).
Key Safety Requirements in Detail
Common GESRs — Protecting Everyone
Strength and size (6.2.1): The escalator or moving walk structure, including the load-carrying unit (LCU), supporting structures, and building attachments, must withstand all foreseeable loads — dead loads, live loads (passenger loading), and environmental loads (wind, snow where applicable). This includes dynamic effects from starting and stopping.
Falling prevention (6.2.2): The LCU area must be enclosed to prevent falls from the side or between moving steps/palks. Balustrades, skirting panels, and comb plates must be designed to prevent a person from slipping through or being drawn into gaps.
Electric shock protection (6.2.9): All electrical equipment must comply with relevant IEC standards for protection against direct and indirect contact. Bonding and earthing must be provided for all metallic parts that could become live under fault conditions.
User-Specific GESRs — Passenger Safety
Entrapment prevention (6.5.3, 6.5.4): One of the most critical safety areas in escalator design is preventing entrapment — between steps, between steps and skirting, at the comb plate, and between the moving handrail and fixed structure. The standard requires that clearances be maintained and that any entrapment risk triggers an immediate stop.
Uncontrolled movement (6.5.5): Braking systems must be capable of stopping the loaded escalator under all conditions, including power failure. The stopping distance must be within specified limits — too short causes passenger falling, too long creates collision risk.
Engineering insight: The braking system design for escalators involves a delicate trade-off. A typical 30-metre vertical rise escalator travelling at 0.5 m/s carries substantial kinetic energy. The braking distance is typically specified as a range (e.g., 0.3–1.0 m for a given speed range) — short enough to prevent collision at the bottom but long enough to avoid jerking passengers off their feet.
Verification and Compliance
Multiple Verification Routes
ISO/TS 25740-1 does not prescribe a single compliance path. Instead, it recognizes several methods for verifying that GESRs are met:
- Design review: Examination of design documentation against the safety objectives
- Type testing: Physical testing of components or subsystems
- Calculation: Engineering analysis (finite element analysis, kinematic simulation)
- Inspection: Visual and dimensional inspection of installed equipment
- Functional testing: Operational tests under normal and fault conditions
The standard specifically addresses different audiences — standards developers (who use GESRs to create detailed regional standards), designers and manufacturers (who design to meet objectives), conformity assessment bodies (who certify compliance), and inspection/testing bodies (who verify field installations).
The standard explicitly requires that escalators and moving walks be designed so that a single failure does not lead to a hazardous situation. This “single-failure tolerance” principle is fundamental to safety engineering and drives redundancy requirements for brakes, speed governors, and safety circuits.
Frequently Asked Questions
Q: How does ISO/TS 25740-1 relate to regional standards like EN 115 or ASME A17.1?
A: ISO/TS 25740-1 provides the high-level safety objectives (GESRs). Regional standards are expected to derive detailed, prescriptive requirements from these objectives. A future part (ISO/TS 25740-2) will provide Global Essential Safety Parameters (GESPs) to further harmonize implementation.
A: ISO/TS 25740-1 provides the high-level safety objectives (GESRs). Regional standards are expected to derive detailed, prescriptive requirements from these objectives. A future part (ISO/TS 25740-2) will provide Global Essential Safety Parameters (GESPs) to further harmonize implementation.
Q: Does the standard cover escalators already in service, or only new installations?
A: The primary focus is on new installations. However, the GESR framework can be used to assess existing installations and identify safety upgrade priorities during modernization projects.
A: The primary focus is on new installations. However, the GESR framework can be used to assess existing installations and identify safety upgrade priorities during modernization projects.
Q: What about escalator cleaning and maintenance — is that covered?
A: Yes. GESRs for authorized persons (Clause 6.6) specifically address maintenance and service personnel safety, including working space, lockable access, protection from moving parts, and ergonomic principles for maintenance tasks.
A: Yes. GESRs for authorized persons (Clause 6.6) specifically address maintenance and service personnel safety, including working space, lockable access, protection from moving parts, and ergonomic principles for maintenance tasks.
Q: Are there specific requirements for escalators in earthquake-prone areas?
A: Yes. GESR 6.2.13 addresses the effects of earthquake loading. The standard requires that escalators and moving walks in seismic zones be designed to maintain structural integrity and prevent hazards during and after seismic events, referencing applicable seismic design codes.
A: Yes. GESR 6.2.13 addresses the effects of earthquake loading. The standard requires that escalators and moving walks in seismic zones be designed to maintain structural integrity and prevent hazards during and after seismic events, referencing applicable seismic design codes.
