Overview
ISO 129-4:2013 - Technical product documentation (TPD) - Indication of dimensions and tolerances - Part 4: Dimensioning of shipbuilding drawings specifies standardized dimensioning practices for metal hulls on shipbuilding drawings. It is part of the ISO 129 series for technical product documentation and is intended to ensure clear, consistent, and unambiguous presentation of dimensions and tolerances used in ship design, fabrication and inspection.
Key topics and requirements
- Scope and references
- Applies to dimensioning of metal hull structures on shipbuilding drawings.
- Normative references include ISO 128-25 (lines on shipbuilding drawings) and ISO 129-1 (general principles of dimensioning).
- General principles
- Location dimensions of hull structure are referenced from standard ship reference lines: BL (base line), CL (centre line), AP/FP (after/forward perpendicular), WL (water line).
- Dimensions for the same member or identical members are shown only once, on the view that displays them most clearly.
- Basic dimensioning rules
- Longitudinal dimensions: referenced to frames, stations or midship.
- Vertical dimensions: referenced to BL, WL or deck lines.
- Transverse dimensions: referenced to CL or broadside.
- Dimension lines and extension lines
- Dimension lines: continuous narrow lines; preferred termination with closed 30° arrowheads; alternatives per ISO 129‑1 permitted.
- Extension lines: originate from moulded lines, frame lines, stations or axes; normally perpendicular to the dimension line but may be oblique and parallel where appropriate.
- Presentation rules
- Dimension text written above the dimension line; avoid crossing lines.
- Equal spacing of repetitive members can be indicated with compact notation.
- Curved offsets presented using offset tables (example: funnel offsets).
- Inclinations are defined by rectangular coordinates, not angular measures.
- Openings, manholes and holes
- Rules for dimensioning rectangular openings, coaming height (notation “h”), corner radii (“R”), and locating openings by centrelines.
- Manholes/lightening holes and drain/clearance/air hole dimension formats are specified.
- Plates, profiles and brackets
- Table of standard symbols and dimension order (e.g., plate: thickness × width × length; pipe: outer diameter × thickness; L‑section: width × width × thickness).
Applications and users
ISO 129-4:2013 is used by:
- Naval architects, marine engineers and ship designers
- Shipyard draughtsmen and CAD specialists producing shipbuilding drawings
- Fabrication and production teams for plate and profile cutting
- Classification societies and surveyors for plan approval and inspection
- Suppliers and subcontractors who require unambiguous manufacturing dimensions
Practical benefits include improved drawing clarity, reduced fabrication errors, standardized communication across shipbuilding supply chains, and easier compliance review.
Related standards
- ISO 129-1 - Indication of dimensions and tolerances - General principles
- ISO 128-25 - Technical drawings - Lines on shipbuilding drawings
- Other parts of ISO 129 for mechanical and architectural dimensioning
Keywords: ISO 129-4:2013, shipbuilding drawings, dimensioning, technical product documentation, metal hulls, dimension lines, extension lines, offset tables, plate dimensions, profiles.