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 and Anchoring C : Containers D : Mobile Offshore Drilling Units
E : Electrical and Electronic Installations F : Fire Protection G : Gas Tankers
I : Polar Class K : Propellers L : Subdivision, Stability and 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

CC : IBC Code / BCH Code COLREG : COLREG FTP : FTP Code
GC : IGC Code / GC Code GF : IGF Code HSC : HSC Code
LL : Load Line MODU : MODU Code MPC : MARPOL
PASSUB : Passenger Submersible Craft SC : SOLAS TM : Tonnage Measurement

IACS Unified Requirement

Resolution Revision Adoption Date Title Implementation Date
UR M61 Rev.3 Feb. 2024 Starting Arrangements of Internal Combustion Engines 1 Jul. 2025
UR M84 New Feb. 2024 Capacity and availability of compressed air for essential services 1 Jul. 2025
UR M47 Del. Feb. 2024 Bridge control of propulsion machinery for attended machinery spaces ---
UR M43 Rev.1 Feb. 2024 Bridge control of propulsion machinery 1 Jan. 2025
UR M3 Rev.7 Feb. 2024 Speed governor and overspeed protective device 1 Jan. 2025
UR M78 Rev.2 Jan. 2024 Reciprocating Internal Combustion Engines Fuelled by Natural Gas 1 Jan. 2025
UR G3 Rev.8 Oct. 2023 Liquefied gas cargo and process piping 1 January 2025
UR H1 New Jan. 2024 Control of Ammonia releases in Ammonia fuelled vessels Jan. 2025
UR L2 Rev.3 Nov. 2023 Intact stability – matter of class 1 Jan. 2025
UR F42 Del. Nov. 2023 Fire testing of flexible pipes ---
UR E26 Rev.1 Nov. 2023 Cyber resilience of ships 1 July 2024
UR W35 Rev.1 Oct. 2023 Requirements for NDT Service Suppliers 1 Jan. 2025
UR G1 Rev.3 Corr.3 Sep. 2023 Vessels with cargo containment system for liquefied gas ---
UR F15 Rev.7 Sep. 2023 Reinforced thickness of ballast and cargo oil piping 1 January 2025
UR W27 Rev.3 Sep. 2023 Cast Steel Propellers 1 Jan. 2025
UR W24 Rev.5 Sep. 2023 Cast Copper Alloy Propellers 1 Jan. 2025
UR E27 Rev.1 Sep. 2023 Cyber resilience of on-board systems and equipment 1 July 2024
UR M24 Rev.2 Aug. 2023 Requirements concerning use of crude oil or slops as fuel for tanker boilers 1 January 2025
UR M61 Rev.2 Aug. 2023 Starting Arrangements of Internal Combustion Engines 1 January 2025
UR E10 Rev.9 Aug. 2023 Test Specification for Type Approval 1 July 2024
UR M46 Rev.3 Aug. 2023 Ambient conditions – Inclinations and Ship Accelerations and Motions 1 January 2025
UR Z10.3 Rev.21 Aug. 2023 Hull Surveys of Chemical Tankers 1 July 2024
UR M81 Rev. 1 July 2023 Safety measures against chemical treatment fluids used for exhaust gas cleaning systems and the residues which have hazardous properties 1 July 2024
UR E22 Rev.3 June 2023 Computer-based systems 1 July 2024
UR S10 Rev.7 Corr.1 Jun. 2023 Rudders, sole pieces and rudder horns ---
UR S3 Rev.2 Jun. 2023 Strength of end bulkheads of superstructures and deckhouses 1 Jul. 2024
UR A1 Rev.8 Jun. 2023 Anchoring Equipment 1 Jul. 2024
UR M53 Rev.5 May 2023 Calculations for I.C. Engine Crankshafts 1 Jul. 2024
UR M73 Rev.2 May 2023 Turbochargers 1 Jul. 2024
UR Z11 Rev.6 May 2023 Mandatory Ship Type and Enhanced Survey Programme (ESP) Notations 1 Jul. 2024
UR Z17 Rev.18 Corr.1 May 2023 Procedural Requirements for Service Suppliers ---
UR Z23 Rev.7 Corr.2 May 2023 Hull Survey for New Construction ---
UR S26 Rev.5 May 2023 Strength and Securing of Small Hatches on the Exposed Fore Deck 1 Jul. 2024
UR G2 Rev.3 May 2023 Liquefied gas cargo tanks and process pressure vessels 1 Jul. 2024
UR M72 Rev.3 Apr. 2023 Certification of Engine Components 1 Jul. 2024
UR M56 Rev.4 Corr.2 Mar. 2023 Marine gears – load capacity of involute parallel axis spur and helical gears ---
UR Z10.5 Rev.20 Feb. 2023 Hull Surveys of Double Skin Bulk Carriers 1 Jul. 2024
UR Z10.4 Rev.18 Feb. 2023 Hull Surveys of Double Hull Oil Tankers 1 Jul. 2024
UR Z10.2 Rev.37 Feb. 2023 Hull Surveys of Bulk Carriers 1 Jul. 2024
UR Z10.1 Rev.25 Feb. 2023 Hull Surveys of Oil Tankers 1 Jul. 2024
UR M82 New Mar. 2023 Type Testing Procedure of Explosion Relief Devices for Combustion Air Inlet and Exhaust Gas Manifolds of I.C. Engines Using Gas as Fuel Jul. 2024
UR W31 Rev.3 Mar. 2023 YP47 Steels and Brittle Crack Arrest Steels 1 Jul. 2024
UR Z17 Rev.18 Feb. 2023 Procedural Requirements for Service Suppliers Jul. 2023
UR S10 Rev.7 Feb. 2023 Rudders, sole pieces and rudder horns 1 Jul. 2024
UR M77 Rev.4 Feb. 2023 Storage and use of SCR reductants Jan. 2024
UR I3 Rev.2 Jan. 2023 Machinery Requirements for Polar Class Ships Jul. 2024
UR M31 Del. Jan. 2023 Continuity of electrical power supply for vessels with periodically unattended machinery spaces ---
UR M63 Rev.1 Jan. 2023 Alarms and safeguards for emergency internal combustion (I.C.) engines Jan. 2024
UR S35 New Feb. 2023 Buckling Strength Assessment of Ship Structural Elements 1 Jul. 2024
UR S21A Del. Jan. 2023 Evaluation of Scantlings of Hatch Covers and Hatch Coamings and Closing Arrangements of Cargo Holds of Ships 1 Jul. 2024
UR S21 Rev.6 Jan. 2023 Evaluation of Scantlings of Hatch Covers and Hatch Coamings and Closing Arrangements of Cargo Holds of Ships 1 Jul. 2024
UR G5 New Dec. 2022 Fail-close action of Emergency Shut Down (ESD) valve Jan. 2024
UR S14 Rev.7 Dec. 2022 Testing Procedures of Watertight Compartments 1 Jan. 2024
UR D11 Rev.4 Corr.1 Dec. 2022 Safety features ---
UR M45 Del. Nov. 2022 Ventilation of Machinery Spaces ---
UR Z23 Rev.7 Corr.1 Oct. 2022 Hull Survey for New Construction ---
UR Z1 Rev.9 Jul. 2022 Annual and intermediate classification survey coverage of IMO Resolution A.1156(32) ---
UR Z17 Rev.17 Jul. 2022 Procedural Requirements for Service Suppliers 1 Jul. 2023
UR P4 Rev.7 Jun. 2022 Production and Application of Plastic Piping Systems on Ships 1 Jul. 2023
UR M73 Rev.1 Mar. 2022 Turbochargers 1 Jan. 2023
UR Z16 Rev.4 Corr.1 May 2022 Periodical surveys of cargo installations on ships carrying liquefied gases in bulk ---
UR Z7 Rev.29 May 2022 Hull Classification Surveys 1 Jul. 2023
UR E13 Rev. 3 Corr.1 May 2022 Test requirements for Rotating Machines ---
UR Z10.4 Rev.17 May 2022 Hull Surveys of Double Hull Oil Tankers 1 Jan. 2023
UR Z10.3 Rev.20 May 2022 Hull Surveys of Chemical Tanker 1 Jan. 2023
UR Z29 New Mar. 2022 Remote Classification Surveys 1 Jan. 2023
UR W8 Rev.3 Mar. 2022 Hull and machinery steel castings 1 Jul. 2023
UR M69 Del. Mar. 2022 Qualitative Failure Analysis for Propulsion and Steering on Passenger Ships ---
UR M27 Del. Mar. 2022 Bilge level alarms for unattended machinery spaces ---
UR E25 Rev. 2 Mar. 2022 Failure detection and response of all types of steering control systems Jul. 2023
UR M42 Rev. 6 Mar. 2022 Steering Gear Jul. 2023
UR M44 Rev.10 Corr. 1 Feb. 2022 Documents for the approval of diesel engines ---
UR SC123 Rev.3 Corr.1 Feb. 2022 Machinery Installations - Service Tank Arrangements ---
UR L4 Rev.3 Corr.2 Feb. 2022 Closure of Chain Lockers ---
UR W7 Rev.4 Feb. 2022 Hull and machinery steel forgings 1 Jul. 2023
UR F15 Rev.6 Corr.1 Feb. 2022 Reinforced thickness of ballast and cargo oil piping ---
UR M61 Rev.1 Feb. 2022 Starting Arrangements of Internal Combustion Engines Jan. 2023
UR E10 Rev.8 Corr.1 Jan. 2022 Test Specification for Type Approval ---

 

IACS Unified Interpretation

Resolution Revision Adoption Date Title Implementation Date
UI SC266 Del. Feb. 2024 Revised guidelines for cargo securing manual and code of safe practice for cargo stowage and securing– scope of application ---
UR M83 New Oct. 2023 Testing of the control system of controllable pitch propellers intended for main propulsion 1 Jan. 2025
UI GF19 New Dec. 2023 Fuel Supply to Consumers – single common flanges 1 Jul. 2024
UI SC249 Rev.2 Jan. 2024 Implementation of SOLAS II-1, Regulation 3-5 and MSC.1/Circ.1379 1 Jan. 2025
UI MPC29 Rev.2 Dec. 2023 Annex VI of MARPOL 73/78 1 Jul. 2024
UI MPC12 Rev.3 Corr.2 Dec. 2023 Annex VI of MARPOL 73/78 ---
UI SC264 New Corr.1 Dec. 2023 Non-combustible material as ‘steel or equivalent’ for ventilation ducts (SOLAS II-2/Reg. 9.7.1.1) ---
UI SC298 New Corr.1 Nov. 2023 Interpretations of various Performance Standards related to GMDSS radio installations ---
UI SC265 Del. Nov. 2023 Code of safe practice for cargo stowage and securing – Annex 14 ---
UI SC212 Rev.1 Nov. 2023 Shipboard fittings and supporting hull structures associated with towing and mooring on conventional vessels (SOLAS regulation II-1/3-8) 1 Jan. 2024
UI SC120 Rev.2 Corr.2 Oct. 2023 Access to forecastle spaces on tankers ---
UI GC39 New Sep. 2023 Interpretation of 2014 IGC Code (MSC.370(93), as amended) Paragraphs 11.3.1 11.4.1, 11.4.3 and 18.10.3.2 w.r.t additional bunkering manifold equipment fitted on L.N.G. Bunkering Ships 1 Jul. 2024
UI SC300 New Aug. 2023 Containment of fire: details of fire insulation of duct penetrations 1 Jul. 2024
UI SC123 Rev.5 Jul. 2023 Machinery Installations - Service Tank Arrangements 1 July 2024
UI GC13 Rev.3 Aug. 2023 Verifications before and after the first loaded voyage 1 January 2024
UI SC299 New Jul. 2023 Watertight testing after fire testing of penetrations in watertight divisions in passenger ships 1 Jul. 2024
UI GF13 Rev.1 May 2023 Fire protection of spaces containing equipment for the fuel preparation 1 Jan. 2024
UI MPC125 Rev.1 May 2023 Technical Code on Control of Emission of Nitrogen Oxides from Marine Diesel Engines (NOx Technical Code 2008, Chapter 4, Paragraph 4.4.6.1) 1 Jan. 2024
UI SC70 Rev.4 Corr.1 Apr. 2023 Cargo tank vent systems and selection of electrical equipment ---
UI SC121 Rev.2 Corr.1 Apr. 2023 Fire Pump Isolation Requirements ---
UI SC30 Rev.3 Mar. 2023 Fire-extinguishing arrangements in machinery spaces ---
UI SC138 New Corr.1 Feb. 2023 Safe Access to Tanker Bows ---
UI SC245 Rev.1 Jan. 2023 Suction and discharge piping of emergency fire pumps, which are run through the machinery space July 2023
UI SC121 Rev.2 Jan. 2023 Fire Pump Isolation Requirements July 2023
UI LL16 Rev.2 Jan. 2023 Sheer ---
UI SC120 Rev.2 Corr.1 Jan. 2023 Access to forecastle spaces on tankers ---
UI SC127 Rev.2 Corr.1 Jan. 2023 Paints, varnishes and other finishes ---
UI MPC14 Rev.3 Dec. 2022 Annex VI of MARPOL 73/78 Jan. 2023
UI SC298 New Dec. 2022 Interpretations of various Performance Standards related to GMDSS radio installations Jan. 2024
UI FTP4 Rev.2 Nov. 2022 Fire resistant windows on tankers Jul. 2023
UI LL61 Del. Nov. 2022 Method of correction for the effect of free surface of liquids in tanks Nov. 2022
UI SC60 Del. Nov. 2022 Fixed deck foam systems Nov. 2022
UI SC32 Del. Nov. 2022 Fixed high expansion foam fire-extinguishing System Nov. 2022
UI SC250 New Corr.2 Nov. 2022 Fire-Extinguishing Arrangements in Cargo Spaces (IMSBC Code, as amended) ---
UI FTP2 Del. Oct. 2022 Pipe and duct penetrations Oct. 2022
UI HSC8 New Corr.1 Sep. 2022 Protection of load bearing structures ---
UI FTP5 New Corr.1 Sep. 2022 Testing and approval of “A” class divisions – fastening of insulation material and details of joints ---
UI SC198 New Corr.1 Sep. 2022 Sections in local application fire extinguishing systems ---
UI SC155 Del. Aug. 2022 Lightweight check in lieu of inclining test Jan. 2023
UI SC254 Del. Aug. 2022 Fall Preventer Devices (MSC.1/Circ.1392 and Circ.1327) Aug. 2022
UI SC217 New Corr.2 Aug. 2022 Nozzles installation for fixed water based local application fire-fighting systems for use in category A machinery spaces (MSC/Circ913) ---
UI CC6 Rev.1 Aug. 2022 Lining approved for use with acids – IBC Code item 15.11.2 Jan. 2023
UI SC297 New Aug. 2022 Amendment to stability/loading information in conjunction with the alterations of lightweight Jan. 2023
UI LL11 Rev.4 Jul. 2022 Scuppers, inlets and discharges ---
UI SC219 Rev.1 Jul. 2022 Fire Testing of Equivalent Water-Based Fire Extinguishing Systems Jul. 2023
UI SC218 Rev.1 Jul. 2022 Fire Testing of Equivalent Water-Based Fire Extinguishing Systems Jul. 2023
UI LL80 Rev.1 June 2022 Unprotected openings Jul. 2023
UI SC280 Rev.1 June 2022 Angle of down-flooding (ϕf) / Angle at which an opening incapable of being closed weathertight (θv) Jul. 2023
UI LL81 New May 2022 Deduction for superstructure and trunks Jan. 2023
UI SC161 Rev.3 May 2022 Timber deck cargo in the context of damage stability requirements Jan. 2023
UI SC204 New Corr.1 May 2022 Storage of fire-extinguishing media forward the cargo holds ---
UI SC201 Rev.1 Corr.1 May 2022 Location of paint lockers within cargo block ---
UI SC200 New Corr.1 May 2022 Container storage arrangement for equivalent fixed gas fire extinguishing systems (FSS Code, Ch. 5, 2.4) ---
UI SC296 New May 2022 Noise level limit in workshops onboard ships Jan. 2023
UI SC261 Rev.1 Apr. 2022 Interpretation of Performance Standards for voyage data recorders (VDRs) Jul. 2022
UI GC38 New Mar. 2022 Deck areas above F.O. tanks installed at the after end of the aftermost hold space 1 Jul. 2022
UI GC32 Rev.1 Feb. 2022 Outer Duct in Gas Fuel Piping Systems Jan. 2023
UI LL59 Rev.1 Corr.1 Feb. 2022 Cargo manifold gutter bars - freeing arrangements and intact stability ---
UI MPC20 Rev.1 Corr.2 Feb. 2022 Annex VI of MARPOL 73/78 Regulation 13.2.1.1 and 13.2.2 ---