ISO 20474-2:2017

Overview

ISO 20474-2:2017 is an international safety standard issued by ISO that specifies the safety requirements for dozers, including wheeled dozers and crawler dozers as defined in ISO 6165. This standard also addresses safety aspects related to rear-mounted winches on dozers. It is designed to be used alongside ISO 20474-1, which outlines general safety requirements common to multiple earth-moving machinery types. ISO 20474-2:2017 takes precedence over the general requirements when specific conditions for dozers apply.

This standard targets hazards, hazardous situations, and events that are relevant during the commissioning, operation, and maintenance of earth-moving dozers, focusing on reducing or eliminating risks through technical safety measures. It applies to machines manufactured after its publication date.

Key Topics

• Safety Requirements and Protective Measures
  The document sets out detailed safety measures tailored for dozers, including mandatory compliance with ISO 20474-1 general requirements unless overridden by dozer-specific provisions. It emphasizes operator seat safety, rear window features, and protection around rear-mounted winches.

• Operator Seat Standards
  For crawler dozers exceeding 50,000 kg operating mass, the operator’s seat must meet vibration criteria in ISO 7096:2008, class EM 6, improving operator comfort and safety.

• Rear Windows Safety Features
  Rear windows must have provisions for defrosting and be equipped with motorized wipers and washers, ensuring visibility under all weather conditions.

• Rear-mounted Winch Safety
  Specific requirements address the mechanical mounting strength of winches, control arrangements at the operator’s station, and protective screens to safeguard the operator from winch-related hazards. The screen must be made from steel wire mesh with minimum 6 mm wire diameter and openings no larger than 45 mm, fully covering the rear window or operator space.

• Information for Use
  The standard mandates safety labeling according to ISO 9244 and the use of specific symbols per ISO 6405-2 when winches are fitted. The operator’s manual must include instructions for safe winch and ripper operation. Additionally, the maximum pulling force of any winch must be clearly marked on the machine.

Applications

ISO 20474-2:2017 applies to manufacturers, designers, and users of earth-moving dozers operating in construction, mining, forestry, and land development sectors. Compliance ensures safer machine design and operation by reducing operator risks from hazards such as mechanical failures, control misuse, or visibility impairments.

• Ensures enhanced operator safety through ergonomic seating and visibility improvements.
• Provides guidelines for safe winch operation, a critical aspect when dozers perform towing or recovery tasks.
• Assists manufacturers in fulfilling international regulatory safety expectations, promoting global machine compatibility.
• Supports equipment owners and operators by offering standardized safety practices, reducing accidents and downtime.

Related Standards

ISO 20474-2:2017 works in conjunction with several key ISO standards to ensure comprehensive safety coverage for earth-moving machinery:

• ISO 20474-1:2017 – General safety requirements for earth-moving machines.
• ISO 6165 – Defines the basic types and terms for earth-moving machinery including dozers.
• ISO 7096:2008 – Specifies requirements for operator seat vibration testing, relevant for heavy crawler dozers.
• ISO 19472 – Provides design guidance and safety requirements for forestry winches, applicable to dozer-mounted winches.
• ISO 9244 – Outlines principles for machine safety labels.
• ISO 6405-2 – Defines symbols for operator controls and displays on earth-moving machinery.
• ISO 8084 – Details requirements for operator protective structures relevant to winch shielding.
• ISO 10968 – Covers the design and location of operator controls, including winch operation controls.

By aligning with these related standards, ISO 20474-2:2017 helps integrate dozers safely into larger fleets of earth-moving equipment while promoting best practices in machine safety.

Keywords: ISO 20474-2, dozer safety standard, earth-moving machinery safety, crawler dozers, wheeled dozers, rear-mounted winch safety, operator seat vibration, earth-moving machine safety labels, dozer hazard reduction, ISO earth-moving standards.