IACS Unified Requirement and Unified Interpretation

This page provides the text of newly established IACS Unified Requirements (UR) and Unified Interpretations (UI) as well as their most recent revisions and corrigenda. Recent revisions and changes have been underlined for easy reference.
Texts of the IACS Unified Requirements and Unified Interpretations are made available on this page for the period of one year following the date of adoption. Texts of all current UR/UI can be found on the IACS website (http://www.iacs.org.uk).

IACS Unified Requirements

IACS Unified Requirements are the minimum class requirements shared among all IACS Member Societies. Unless an application date is specified, Unified Requirements are to be incorporated in the Rules and practices of each IACS Member Society within one year of their adoption by IACS.

IACS Unified Interpretations

IACS Unified Interpretations were created with a view to the uniform implementation of IMO conventions among all IACS Member Societies and provide interpretations of IMO Conventions which are vaguely worded or have been left to the satisfaction of each Administration.

The outlines of technical resolutions adopted by IACS are available at the links shown below.

Implementation Dates

The Implementation dates of the Unified Requirements (UR) and Unified Interpretations (UI) are shown in the "Implementation Date" column of the tables. However, as each UR / UI has its own implementation scheme, e.g. contract basis, keel laying basis, etc. please confirm the implementation dates included in the texts.

Unified Requirements and Unified Interpretations will be incorporated into the ClassNK Rules / Guidance and apply to ships classed with ClassNK.

UR Abbreviations

A : Mooring, Anchoring and Towing C : Containers D : Mobile Offshore Drilling Units
E : Electrical Installations F : Fire Protection G : Gas Tankers
I : Polar Class K : Propellers L : Load Line
M : Machinery Installations N : Navigation P : Pipes and Pressure Vessels
S : Strength of Ships W : Materials and Welding Z : Survey and Certification

UI Abbreviations

GC : IGC Code / GC Code HSC : HSC Code LL : Load Line
MPC : MARPOL PASSUB : Passenger Submersible Craft
SC : SOLAS TM : Tonnage Measurement

IACS Unified Requirement

Resolution Revision Adoption Date Title Implementation Date
UR P2 --- Jan. 2021 P2.7.4 (Rev.10): Mechanical joints  P2.11 (Rev.5): Type Approval of Mechanical joints  P2.13 (Rev.1): Installation Jul. 2022
UR M81 New Jan 2021 Safety measures against chemical treatment fluids used for exhaust gas cleaning systems and the residues which have hazardous properties Jul. 2022
UR M75 Rev.1 Jan 2021 Ventilation of emergency generator rooms Jan. 2022
UR E12 Rev.2 Dec. 2020 Electrical Equipment allowed in paint stores and in the enclosed spaces leading to paint stores Jan. 2022
UR M77 Rev.2 Dec. 2020 Storage and use of SCR reductants Jan. 2022
UR E15 Rev.4 Dec. 2020 Electrical Services Required to be Operable Under Fire Conditions and Fire Resistant Cables Jan. 2022
UR E13 Rev.3 Dec. 2020 Test requirements for Rotating Machines Jan. 2022
UR Z7 Rev.28 Corr.1 Dec. 2020 Hull Classification Surveys ---
UR S11 Rev.10 Dec. 2020 Longitudinal Strength Standard 1 Jan. 2022
UR F7 Rev.3 Corr.1 Nov. 2020 Portable instruments for measuring oxygen and flammable vapour concentrations ---
UR Z28 New Oct. 2020 Surveys of Watertight Cable Transits 1 Jul. 2021
UR Z23 Rev.7 Oct. 2020 Hull Survey for New Construction 1 Jul. 2021
UR Z17 Rev.15 Oct. 2020 Procedural Requirements for Service Suppliers 1 Jul. 2021
UR W27 Corr.1 Sep. 2020 Cast Steel Propellers ---
UR A2 Rev.5 Sep. 2020 Shipboard fittings and supporting hull structures associated with towing and mooring on conventional ships 1 Jan. 2022
UR A1 Rev.7 Sep. 2020 Anchoring Equipment 1 Jan. 2022
UR W32 Rev.1 Sep. 2020 Qualification scheme for welders of hull structural steels 1 Jan. 2022
UR Z1 Rev.8 Jul. 2020 Annual and intermediate classification survey coverage of IMO Resolution A.1140(31) ---
UR W27 Rev.2 Jul. 2020 Cast Steel Propellers 1 Jul. 2021
UR W24 Rev.4 Jul. 2020 Cast Copper Alloy Propellers 1 Jul. 2021
UR L5 Rev.4 Jun. 2020 Computer Software for Onboard Stability Calculations 1 Jul. 2021
UR F7 Rev.3 Jun. 2020 Portable instruments for measuring oxygen and flammable vapour concentrations 1 Jul. 2021
UR W33 Rev.1 May 2020 Non-destructive testing of ship hull steel welds 1 Jul. 2021
UR Z18 Rev. 9 Apr. 2020 Survey of Machinery Jul. 2021
UR S33 Rev.3 Feb. 2020 Requirements for Use of Extremely Thick Steel Plates in Container Ships 1 Jul. 2021
UR M79 Rev. 1 Feb. 2020 Towing winch emergency release Systems Jul. 2021


IACS Unified Interpretation

Resolution Revision Adoption Date Title Implementation Date
UI SC156 Rev.2 Jan. 2021 Doors in watertight bulkhead of cargo ships and passenger ships 1 Jul. 2021
UI SC63 Del. Jan. 2021 Pre-discharge alarm of fixed gas fire extinguishing system (FSS Code, Ch. ---
UI SC62 Rev.2 Dec. 2020 Inert gas systems Jan. 2022
UI FTP1 Del. Dec. 2020 Adhesives used in A or B class divisions ---
UI SC125 Rev.3 Dec. 2020 B and C Class Divisions ---
UI SC34 Del. Dec. 2020 Automatic sprinkler, fire detection and fire alarm system ---
UI LL10 Rev.2 Nov. 2020 Air pipes (Regulation 20) ---
UI SC137 Rev.1 Nov. 2020 Definition of High-Speed Craft ---
UI SC86 Del. Nov. 2020 Weather Decks ---
UI SC17 Rev.3 Nov. 2020 Definitions – Control Stations ---
UI SC117 Del. Sep. 2020 Fire detection system with remotely and individually identifiable detectors ---
UI MPC20 Corr. 1 Jul. 2020 Annex VI of MARPOL 73/78 Regulation and 13.2.2 ---
UI MPC101 Corr.1 Sep. 2020 Supplement to the International Air Pollution Prevention (IAPP) Certificate – Section 2.3 ---
UI GC31 New Jun. 2020 Discharge test of dry chemical powder fire-extinguishing systems 1 Jan. 2021
UI MPC115 Corr. 1 May 2020 2017 Guidelines Addressing Additional Aspects of the NOx Technical Code 2008 with regard to Particular Requirements related to Marine Diesel Engines Fitted With Selective Catalytic Reduction (SCR) Systems ---
UI SC182 Del. Apr. 2020 Bulk carriers not complying with SOLAS XII/9 as of 1 January 2004 ---
UI GC22 Rev.1 Apr. 2020 Water spray system 1 Jan. 2021
UI GC30 New Apr. 2020 Emergency fire pump Jan. 2021
UI SC292 New Feb. 2020 Ships intended to operate in low air temperature in Polar waters - Survival craft and rescue boat communications capabilities 1 Jul. 2021
UI SC293 New Feb. 2020 Lifebuoy Arrangements for Means of Embarkation/Disembarkation Jul. 2020
UI SC294 New Feb. 2020 Fire integrity of the division between engine room and urea or sodium hydroxide solution tank installation spaces Jul. 2020
UI SC291 New Jan. 2020 Safe Type requirements for twoway portable radiotelephone apparatus for fire-fighter's communication 1 Jul. 2020
UI SC207 Corr.2 Jan. 2020 SOLAS XII/5 in terms of Structural Strength of Bulk Carriers in case of Accidental Hold Flooding ---
UI MPC32 Rev. 1 Jan. 2020 Technical Code on Control of Emission of Nitrogen Oxides from Marine Diesel Engines Jul. 2020
UI SC242 Rev. 2 Jan. 2020 Arrangements for steering capability and function on ships fitted with propulsion and steering systems other than traditional arrangements for a ship’s directional control 1 Jul. 2020