Overview
ISO 20474-3:2017 - Earth-moving machinery - Safety - Part 3: Requirements for loaders - is a type‑C ISO safety standard that specifies machine‑family specific safety requirements for loaders (see ISO 6165). Designed to be used in conjunction with ISO 20474-1 (general requirements), the Part 3 requirements take precedence where they differ. The standard addresses significant hazards during commissioning, operation and maintenance for machines built on or after its publication (not applicable to machines manufactured before 2017).
Key topics and technical requirements
- Scope and applicability: Applies to self‑propelled wheeled and tracked loaders (including compact, skid‑steer and swing loaders) and derivative applications.
- Operator protection and controls
- Compact loaders with front access must have lifting/movement/attachment controls automatically secured or deactivated when the operator leaves/enters the compartment.
- Side guarding to prevent operator access to trapping zones between lift arms and fixed parts while seated.
- Front protection for the operator’s lower limbs if lift arms/attachments pass within 1.5 m forward of the SIP (seat index point); minimum front protective structure height 200 mm.
- Rear windows (except compact loaders) require a motorised wiper and washer.
- Stability and rated operating capacity
- Rated operating capacity shall be determined per ISO 14397-1 (with specific modifications for some applications).
- Bucket volumetric rating per ISO 7546; bucket capacity and material density must be considered.
- Fork applications: specified stability factors (e.g., wheel loaders on rough terrain 60% of tipping load, firm level ground 80%); skid‑steer wheel loaders limited to 50% and tracked skid‑steer loaders to 35%.
- Log handling: defined stability percentages for wheel and crawler loaders (e.g., wheel loader rough terrain 75%, firm 85%).
- Single heavy objects: load‑centre distance tables provided (examples: up to 100 kN → D = 600 mm).
- Information for use: Manufacturers must publish rated operating capacities and operating conditions for each application type.
Practical applications
- Ensures safe design and operation of loaders used in construction, quarrying, forestry and material‑handling.
- Guides machine designers, OEMs and attachment manufacturers on guarding, control interlocks and stability testing.
- Provides specifications for labeling, operator manuals, and capacity charts used by fleet managers and site safety personnel.
Who should use this standard
- Loader manufacturers and designers
- Attachment and coupling suppliers
- Safety engineers, compliance officers and test laboratories
- Certification bodies and technical regulators
- Fleet managers and maintenance teams seeking conformity to international safety practice
Related standards
Keywords: ISO 20474-3, loaders, earth‑moving machinery safety, rated operating capacity, stability, guarding, operator controls, fork application, bucket application.