ISO 7255:1985

Overview

ISO 7255:1985 is an internationally recognized standard developed by the International Organization for Standardization (ISO) that provides clear and precise vocabulary related to active control units of ships. These units are auxiliary propellers designed to enhance a vessel’s maneuverability, directional stability, and positioning. This standard applies primarily to active control systems that produce thrust at various angles to improve vessel handling at low speeds or while at a standstill.

The primary goal of ISO 7255:1985 is to unify terminology across the shipbuilding and marine engineering industry so that all specialists interpret these terms identically-promoting clarity and reducing misunderstandings in technical communication and documentation.

Key Topics

• Active Control Units: Defined as devices with an autonomous prime mover creating thrust at an angle to the vessel’s centerline for effective maneuvering.
• Ship Lateral Thrusters: Active control units installed in channels or nozzles in the hull, producing thrust perpendicular to the centerline for sideways movement.
• Retractable Thrusters: Thrusters that can be lifted vertically inside the hull when not in use to reduce drag or protect the propeller.
• Propulsion-Steering Units: Units capable of both propelling and steering the vessel by changing thrust direction, including rudder-propellers.
• Rudder-Propellers: Steering and propulsion devices with the propeller mounted on a rotating column, allowing 360-degree directional thrust.
• Active Rudders: Installed in rudder blades, these units combine steering and thrust generation with adjustable thrust direction within rudder angle limits.
• Cycloidal Propellers: Advanced devices with vertical vanes producing thrust at variable directions by altering the vane angle.
• Rotatable Water Jets: Hydro-jet propulsion systems located inside the hull with adjustable direction of thrust from 0° to 360° by rotating the unit.

ISO 7255:1985 also specifies that each technical term has a single standardized form without synonyms to avoid ambiguity. Parentheses may be used in terms to allow shortened versions when context allows.

Applications

• Shipbuilders and Designers: Use ISO 7255:1985 terminology to uniformly specify active control unit features in ship plans, manuals, and blueprints.
• Marine Engineers: Rely on the standard for clear communication about components affecting vessel maneuvering and stability.
• Regulatory Bodies: Reference these terms for consistency in certification, inspection, and regulatory documentation.
• Manufacturers of Control Units: Ensure product datasheets, instruction manuals, and marketing materials use internationally accepted definitions.
• Training and Education: Serve as a foundational vocabulary guide in maritime engineering curricula and professional training resources.

By implementing the standardized vocabulary from ISO 7255:1985, maritime professionals can reduce errors, enhance collaboration, and improve safety related to ship maneuverability systems.

Related Standards

• ISO/TC 8 Shipbuilding and Marine Structures: The technical committee responsible for the development and maintenance of standards related to shipbuilding, which ensures ongoing revisions and updates of ISO 7255 and related documents.
• Standards on Hull Structures and Stability: Complement ISO 7255 by addressing vessel structural integrity and safety to support active control units.
• ISO Vocabulary Standards: Other ISO vocabulary standards for technical clarity across marine engineering and propulsion systems.
• International Maritime Organization (IMO) Guidelines: Often reference ISO standards for terminology consistency in international maritime regulations.

Keywords: ISO 7255:1985, active control units, shipbuilding vocabulary, ship maneuverability, auxiliary propellers, lateral thrusters, rudder-propellers, cycloidal propeller, water jet propulsion, maritime engineering standards, vessel positioning, directional stability, marine propulsion terminology, ISO shipbuilding standards.