ISO 20474-4:2017

Overview

ISO 20474-4:2017 - Earth-moving machinery - Safety - Part 4: Requirements for backhoe loaders specifies safety requirements that are specific to wheeled and crawler backhoe loaders (as defined in ISO 6165). It is a type-C standard intended to be used together with ISO 20474‑1:2017 (general requirements); where the two differ, the specific provisions of ISO 20474‑4 take precedence. The standard addresses significant hazards, hazardous situations and events during commissioning, operation and maintenance, and it defines technical measures to eliminate or reduce those risks. ISO 20474‑4:2017 is not applicable to machines manufactured before its publication date.

Key topics and technical requirements

The standard focuses on safety-critical areas for backhoe loaders and includes:

• Operator’s station
  • Minimum cab space envelope (e.g., cab height above the SIP with retractable rear window ≥ 920 mm).
  • Operator controls and alternative operator positions requirements, including braking/steering controls at alternative positions.
  • Operator seat vibration requirements in accordance with ISO 7096:2000, input spectral class EM5 (and EM8 for compact backhoe loaders).
• Warning devices
  • Audible and visual warnings for outriggers and travel engagement; sound level requirement of ≥ 93 dB(A) measured at 7 m from the backhoe swing centre to the rear.
  • Operator must be able to activate warnings from the backhoe operation position.
• Stability and rated operating capacity
  • Determination of rated capacities for loader and backhoe portions, including bucket, fork and log‑handling applications.
  • Loader bucket capacities per ISO 14397‑1 and volumetric ratings per ISO 7546.
  • Fork application stability factors (example: rated load as percentage of tipping load - 60% rough terrain, 80% firm and level ground; crawler backhoe loaders limited to 35% of tipping load for some assessments).
  • Log handling stability factors (wheeled: 75% rough, 85% firm; crawler: 50% rough, 60% firm).
• Testing and annexes
  • Annex A: normative test method for backhoe lift capacity at the backhoe portion.
  • Annex B: informative illustrations to support interpretation.

Practical applications - who uses this standard

ISO 20474‑4:2017 is primarily used by:

• Backhoe loader manufacturers and design engineers for machine design and safety integration.
• Safety and compliance teams for risk assessments, conformity checks and CE marking activities.
• Test laboratories and certification bodies to verify rated capacities, stability and warning device performance.
• Fleet owners, procurement and maintenance managers to specify safe equipment and maintenance procedures.
• Regulatory authorities and inspectors as a reference for national/regional safety expectations (note: local regulations may impose additional requirements).

Related standards

• ISO 20474‑1:2017 (General requirements for earth‑moving machinery)
• ISO 6165 (Machine types and definitions)
• ISO 14397‑1 / ISO 14397‑2 (Rated operating capacity and test methods)
• ISO 7546, ISO 7096, ISO 2330 and others cited as normative references

Keywords: ISO 20474-4:2017, backhoe loaders safety, earth-moving machinery, operator’s station, stability, rated operating capacity, warning devices, ISO standards.