Overview
ISO 11169:1993 specifies vocabulary, performance test methods and pass/fail criteria for brake systems on self‑propelled, rubber‑tyred special forestry machines (as defined in ISO 6814) - for example skidders, forwarders and feller‑buncher combinations. The standard covers service, secondary and parking brake systems, defines key terms (stopping distance, mean deceleration, machine mass, cold brakes, burnish, etc.) and sets uniform test procedures to assess braking performance and holding capability.
Key topics and requirements
- Scope and definitions: Clear vocabulary for brake components (controls, brakes, retarders, common components) and machine mass (including operator and approved equipment/payload).
- Required systems: Machines must have a service brake, a secondary brake and a parking brake. No brake may be connected to the wheel/tyre through a disconnect device (e.g., clutch).
- Control ergonomics and forces: Brake controls must be operable from the operator’s seat; maximum control forces for tests are specified (e.g., finger grasp 20 N, hand grasp up to 400 N, fore/aft/sideways 300 N, foot pedal 600 N, ankle control 350 N).
- Holding performance: Service and parking brakes must hold the machine (forward and reverse) on a 40% gradient using the machine mass defined by the manufacturer; parking brake must be operable from the driver’s seat.
- Stopping performance and tests:
- Stopping tests are conducted from 32 km/h ± 3 km/h (or the machine’s maximum surface speed if lower).
- Cold‑brake tests (two runs, one each direction) and heat‑fade tests (four consecutive maximum deceleration stops, with a fifth stop limited to ≤125% of the specified stopping distance) are defined.
- Test course and instrument accuracy requirements are specified to ensure repeatable measurements.
- Stored‑energy systems and warnings: Stored‑energy (air/hydraulic) service brakes require a visible/audible warning if energy falls below specified levels; friction‑type parking brakes that don’t disengage with transmission engagement must have a continuous warning when applied.
- Use of common components: Common components between systems are permitted, but a single component failure (except tyre) must not prevent compliance with secondary brake requirements.
Applications and who uses it
ISO 11169 is used to:
- Validate braking performance during design and production of forestry wheeled special machines (manufacturers and OEMs).
- Define test protocols for test laboratories, certification bodies and regulatory agencies assessing machine safety.
- Guide maintenance teams and fleet managers on acceptable brake conditions and performance expectations.
- Support safety auditors and equipment specifiers in procurement and compliance decisions.
Keywords: ISO 11169, brake systems, forestry machinery, wheeled special machines, stopping distance, parking brake, service brake, secondary brake, performance test methods.
Related standards
- ISO 6814 - definition and classification of self‑propelled rubber‑tyred special forestry machines (referenced by ISO 11169).
- Other ISO/TC 23 documents addressing tractor and forestry machinery safety and terminology.
Open preview (PDF)Machinery for forestry — Wheeled special machines — Vocabulary, performance test methods and criteria for brake systems
