Overview
EN ISO 13929:2017 - Small craft - Steering gear - Geared link systems specifies minimum construction, installation and testing requirements for geared‑link steering systems used on small craft with hull length up to 24 m. The standard covers geared gearbox-and-draglink arrangements that translate steering‑wheel rotation into rudder motion. It excludes remote‑control cable steering for outboards and systems covered by ISO 8848 and ISO 9775, as well as emergency steering arrangements where those are specifically required.
Key topics and technical requirements
- Scope and definitions: Defines a geared link system, draglink, rack and rudder operating levers, and maximum output force concept.
- Construction requirements
- Materials: Selection to minimise corrosion and galvanic action.
- Fasteners: Critical threaded fasteners must have positive locking or integral locking means.
- Draglink design: Must permit adjustment (specified length adjustment capability) and angular misalignment; secure locking after adjustment is required.
- Rudder/rack geometry: Lever ratios and attachments must provide reliable full‑rudder travel and withstand specified loads.
- Rudderstops: Fitted to prevent exceeding manufacturer’s maximum rudder angle and sized to resist specified load factors.
- Installation requirements
- Secure fastening to reinforced structure where necessary.
- Visibility or tactile verification of locking devices for critical fasteners.
- Correct connection of remotely mounted gearboxes (universal joints and solid linkages).
- Testing
- Axial force test: A push‑pull axial load of 670 N over a 100 mm span applied for cycles (document specifies 10 cycles of at least 5 s).
- Tangential torque test: Apply 150% of rated maximum output torque for cycles (document specifies 10 cycles of at least 5 s) with rudder shaft fixed.
- System must show no fracture or permanent distortion after tests.
- Marking and documentation
- Systems must be marked with standard number, manufacturer and model/type.
- Owner’s manual: Operation description and safety/maintenance precautions.
- Installer’s manual: Model references, largest wheel diameter, rating, installation and test procedures, maintenance, exploded parts diagrams, maximum permissible output torque and corresponding rudder forces.
Applications and users
- Useful for manufacturers and designers of small craft steering systems, shipyards, marine equipment installers, and conformity assessors.
- Applies to boat builders and installers seeking compliance with EU safety rules; the standard supports conformity with EU Directive 2013/53/EU (Annex 1.A.5.4.1 for steering systems) when cited nationally.
- Valuable for marine surveyors, classification societies and maintenance personnel who test, inspect or repair geared link steering gear.
Related standards
- ISO 8848 - Remote steering systems (excluded from EN ISO 13929 scope)
- ISO 9775 - Remote steering for single outboard motors (excluded)
Keywords: EN ISO 13929:2017, small craft, steering gear, geared link systems, steering systems testing, installation requirements, owner’s manual, installer’s manual, EU Directive 2013/53/EU.
