Unified Requirements


Unified Requirements are adopted resolutions on matters directly connected to or covered by specific Rule requirements and practices of classification societies and the general philosophy on which the rules and practices of classification societies are established.

Subject to ratification by the governing body of each Member Society, Unified Requirements shall be incorporated in the Rules and practices of the Member Societies, within one year of approval by the IACS General Policy Group. 

The existence of a UR does not oblige a Member Society to issue respective Rules if it chooses not to have Rules for the type of ship or marine structure concerned.

Unified Requirements are minimum requirements. Each Member remains free to set more stringent requirements.

The technical backgrounds (development histories) of Unified Requirements since 1999 can be found by following this link.

A list of the IACS working groups responsible for each Unified Requirement may be found here.

UR S25 Deleted

Deleted May 2010

UR S26 Rev4 CLN

UR S26 Strength and Securing of Small Hatches on the Exposed Fore Deck Rev.4 May 2010

UR S27 Rev6 CLN

UR S27 Strength Requirements for Fore Deck Fittings and Equipment - Rev.6 Jun 2013

UR S28 Rev3 CLN

UR S28 Requirements for the Fitting of a Forecastle for Bulk Carriers, Ore Carriers and Combination Carriers - Rev.3 May 2010

UR S30 Rev1 CLN

UR S30 Cargo Hatch Cover Securing Arrangements for Bulk Carriers not Built in Accordance with UR S21 (Rev.3) - Rev.1 Aug 2003

UR S31 Rev4 CLN

UR S31 Renewal Criteria for Side Shell Frames and Brackets in Single Side Skin Bulk Carriers and Single Side Skin OBO Carriers not Built in Accordance with UR S12 Rev.1 or Subsequent Revisions - Rev.4 Apr 2007

UR S32 Deleted

Deleted May 2010

UR S33 Rev1 CLN

UR S33 Requirements for Use of Extremely Thick Steel Plates in Container Ships - Rev.1 Sept 2015

UR S34 New

UR S34 Functional Requirements on Load Cases for Strength Assessment of Container Ships by Finite Element Analysis - May 2015


Materials and Welding

UR W1 Rev3 CLN

UR W1 Materials and welding for gas tankers - Rev.3 Aug 2016

UR W2 Rev2 CLN

UR W2 Test specimens and mechanical testing procedures for materials - Rev.2 July 2003

UR W3 Deleted


UR W4 Deleted


UR W5 Deleted


UR W6 Deleted


UR W7 Rev3 CLN

UR W7 Hull and machinery steel forgings - Rev.3 May 2004

UR W8 Rev2 CLN

UR W8 Hull and machinery steel castings - Rev.2 May 2004

UR W9 Rev2 CLN

UR W9 Grey iron castings - Rev.2 May 2004

UR W10 Rev2 CLN

UR W10 Spheroidal or nodular graphite iron castings - Rev.2 May 2004

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