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

CC : IBC Code / BCH Code COLREG : COLREG FTP : FTP Code
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 G1 Corr.1 May 2018 Cargo containment of gas tankers ---
UR S10 Rev.5 May 2018 Rudders, sole pieces and rudder horns 1 Jul. 2019
UR W17 Rev.5 Mar. 2018 Approval of consumables for welding normal and higher strength hull structural steels 1 Jul. 2019
UR W23 Rev.2 Apr. 2018 Approval of Welding Consumables for High Strength Steels for Welded Structures 1 Jul. 2019
UR S21A Corr.1 Feb. 2018 Evaluation of Scantlings of Hatch Covers and Hatch Coamings and Closing Arrangements of Cargo Holds of Ships ---
UR Z10.5 Rev.18 Jan. 2018 Hull Surveys of Double Skin Bulk Carriers 1 Jan. 2019
UR Z10.4 Rev.15 Jan. 2018 Hull Surveys of Double Hull Oil Tankers 1 Jan. 2019
UR Z10.3 Rev.18 Jan. 2018 Hull Surveys of Chemical Tanker 1 Jan. 2019
UR Z10.2 Rev.35 Jan. 2018 Hull Surveys of Bulk Carriers 1 Jan. 2019
UR Z10.1 Rev.23 Jan. 2018 Hull Surveys of Oil Tankers 1 Jan. 2019
UR Z17 Rev.13 Jan. 2018 Procedural Requirements for Service Suppliers 1 Jan. 2019
UR Z7.2 Rev.7 Jan. 2018 Hull Surveys for Liquefied Gas Carriers 1 Jan. 2019
UR Z7.1 Rev.14 Jan. 2018 Hull Surveys for General Dry Cargo Ships 1 Jan. 2019
UR Z7 Rev.26 Jan. 2018 Hull Classification Surveys 1 Jan. 2019
UR Z3 Rev.7 Jan. 2018 Periodical Survey of the Outside of the Ship’s Bottom and Related Items 1 Jan. 2019
UR Z10.5 Rev.17 Sep. 2017 Hull Surveys of Double Skin Bulk Carriers 1 Jan. 2019
UR Z10.2 Rev.34 Sep. 2017 Hull Surveys of Bulk Carriers 1 Jan. 2019
UR Z25 Rev.1 Sep. 2017 Periodic Survey of Fuel Installations on Ships other than Liquefied Gas Carriers utilizing gas or other low flash point fuels 1 Jan. 2019
UR Z7.1 Rev.13 Aug. 2017 Hull Surveys for General Dry Cargo Ships 1 Jan. 2019
UR Z18 Rev.7 Jun. 2017 Survey of Machinery 1 Jul. 2018
UR M25 Rev.4 Jun. 2017 Astern power for main propulsion 1 Jul. 2018
UR L5 Rev.3 Jun. 2017 Computer Software for Onboard Stability Calculations 1 Jul. 2018
UR M53 Rev.3 Jun. 2017 Calculations for I.C. Engine Crankshafts 1 Jul. 2018
UR A3 New Jun. 2017 Anchor Windlass Design and Testing 1 Jul. 2018
UR W11 Rev.9 May 2017 Normal and higher strength hull structural steels 1 Jul. 2018
UR S4 Rev.4 Apr. 2017 Criteria for the Use of High Tensile Steel with Minimum Yield Stress of 315 N/mm2, 355 N/mm2 and 390 N/mm2 ---
UR A2 Corr.2 Mar. 2017 Shipboard fittings and supporting hull structures associated with towing and mooring on conventional ships 1 Jul. 2018
UR A1 Corr.2 Mar. 2017 Anchoring Equipment 1 Jul. 2018
UR Z25 New Jan. 2017 Periodic Survey of Fuel Installations on Ships other than Liquefied Gas Carriers utilizing gas or other low flash point fuels 1 Jan. 2018

 

IACS Unified Interpretation

Resolution Revision Adoption Date Title Implementation Date
UI GC22 New Apr. 2018 Water spray system 1 Jul. 2019
UI GF1 New Jan. 2017 Test for gas fuel tank’s high level alarm 1 Jan. 2018
UI GC18 Corr. 1 Mar. 2017 Test for cargo tank’s high level alarm (on ships built on or after 1 July 2016) 1 Jan. 2018
UI COLREG5 New May 2018 Interpretation to COLREG 1972 Annex I Sections 9(a)(i) and 10(a)(i) 1 Jul. 2019
UI SC94 Corr.1 Jan. 2018 Mechanical, hydraulic and electrical independency of steering gear control systems ---
UI GF12 New Dec. 2017 Ventilation inlet for double wall piping or duct 1 Jan. 2018
UI GF11 New Dec. 2017 Ventilation of double piping and gas valve unit spaces in gas safe engine-rooms 1 Jan. 2018
UI GF10 New Dec. 2017 Ventilation of machinery spaces 1 Jan. 2018
UI GF9 New Dec. 2017 Special consideration within the risk assessment of closed or semi-enclosed bunkering stations 1 Jan. 2018
UI GF8 New Dec. 2017 Control and maintenance of pressure and temperature of liquefied gas fuel tanks after the activation of the safety system 1 Jan. 2018
UI GF7 New Dec. 2017 External surface area of the tank for determining sizing of pressure relief valve 1 Jan. 2018
UI GF6 New Dec. 2017 Protection against cryogenic leakage and control of hazardous zones in fuel preparation rooms on open deck 1 Jan. 2018
UI GF5 New Dec. 2017 Appropriate location of premixed engines using fuel gas mixed with air before the turbocharger 1 Jan. 2018
UI GF4 New Dec. 2017 Fuel preparation room 1 Jan. 2018
UI GF3 New Dec. 2017 Tank connection space for tanks on open deck and tank connection space equipment 1 Jan. 2018
UI SC144 Rev.3 Oct. 2017 Maintenance, Thorough Examination, Operational Testing, Overhaul and Repair of Lifeboats, Rescue Boats and Fast Rescue Boats, Launching Appliances and Release Gear 1 Jan. 2020
UI SC221 Withdrawn Sep. 2017 Separation of Galley Exhaust Ducts from Spaces (Reg II-2/9) ---
UI SC283 New Aug. 2017 Fire detection and alarms for boilers in unattended machinery spaces (SOLAS Reg. II/47-1) 1 Jul. 2018
UI GF2 New Sep. 2017 Ship Steel Protection against Liquefied Gas Fuel (Part A-1, paragraph 6.3.10) 1 Jan. 2019
UI GC15 Rev.1 Aug. 2017 Closing Devices for Air Intakes 1 Jan. 2018
UI GC19 New Aug. 2017 External surface area of the tank for determining sizing of pressure relief valve (paragraph 8.4.1.2 and figure 8.1) 1 Jan. 2018
UI SC220 Corr.2 Mar. 2017 Special requirements for ro-ro passenger ships ---
UI SC281 Withdrawn Jun. 2017 Single fall and hook system used for launching a lifeboat or rescue boat - Interpretation of the LSA Code as amended by MSC.320(89) and MSC.81(70) as amended by MSC.321(89) ---
UI SC191 Corr.3 --- IACS Unified Interpretations (UI) SC 191 for the application of amended SOLAS regulation II-1/3-6 (resolution MSC.151(78)) and revised Technical provisions for means of access for inspections (resolution MSC.158(78)) ---
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