Overview
ISO 3797:2023 - Ships and marine technology - Vertical steel ladders - specifies the types, structure, dimensions and technical requirements for vertical steel ladders fitted on board ships. It applies to the design and manufacture of ladders used in marine environments and updates the previous 1976 edition by extending types, dimensions and adding fall-protection, material and surface-treatment requirements.
Key topics and technical requirements
- Types: Two ladder types are defined
- Structure & dimensions: Standardized layout (stringers, rungs, supports) with step pitch equal and recommended at 300 mm (range 250–350 mm). Tabled dimensions cover standard widths, rung sizes and stringer profiles.
- Material: Steel to ISO 630-2, minimum grade S235.
- Surface treatment: Protective coatings as appropriate; ladders for ballast tanks must meet PSPC requirements. Edges rounded to R2 mm and hot-dip galvanizing recommended after cleaning per ISO 1461 (coating thickness per ISO 1461).
- Support & fixation: Welding or movable (bolt) connection supports permitted. Each support shall be adequate to sustain 1 000 N with a safety factor of 1:5. Adjacent supports should be no further than 2 500 mm apart to limit vibration.
- Appearance & tolerances: No burrs, dents or cracks; width tolerance ±2 mm (ISO 2768-1). Mass tolerance not to exceed 4% of theoretical weight.
- Safety protection: Fall protection such as ladder hoops (basket or single type) is required/recommended; examples are provided.
Practical applications and users
ISO 3797:2023 is directly relevant to:
- Shipbuilders, shipyards and marine equipment manufacturers specifying and fabricating vertical steel ladders for accommodation, access ways, machinery spaces and tank spaces.
- Naval architects and ship designers incorporating compliant access ladders into vessel plans.
- Procurement and classification personnel who need standardized designation and documentation.
- Safety officers and maintenance teams responsible for inspection, repair and retrofitting of ladders and fall-protection elements.
Benefits include consistent safety, interchangeability of components, corrosion protection guidance and clear designation rules for delivery documentation.
Related standards
Example designation: Vertical steel ladder ISO 3797:2023 A22-M-3 600 × 400 (type, rung, connection, length × width).