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 M13 Rev1 CLN
UR M13 Re-categorised as “Recommendation” No.28 Rev.1 CLN
UR M14 Deleted
Mass production of internal combustion engines: definition of mass production - Deleted Feb 2015
UR M15 Deleted
Re-categorized as “Recommendation” No. 29
UR M16 Rev1 CLN
UR M16 Devices for emergency operation of propulsion steam turbines - Rev.1 Jan 2005
UR M17 Deleted
Deleted 1 July 1998
UR M18 Deleted
Parts of internal combustion engines for which material tests are required - Deleted Feb 2015
UR M19 Deleted
Parts of internal combustion engines for which nondestructive tests are required - Deleted Feb 2015
UR M20 Deleted
Periodical survey of machinery - Deleted Nov 2001
UR M21 Deleted
Mass production of internal combustion engines: type test conditions - Deleted Feb 2015
UR M23 Deleted
Mass production of engines: mass produced exhaust driven turboblowers - Deleted Feb 2015
UR M24 Rev1 CLN
UR M24 Requirements concerning use of crude oil or slops as fuel for tanker boilers - Rev.1 1976
UR M25 Rev3 CLN
UR M26 Corr1 CLN
UR M26 Safety devices of steam turbines - Corr.1 Feb 2005
UR M27 New
UR M27 Bilge level alarms for unattended machinery spaces - 1976
UR M28 New
UR M28 Ambient reference conditions - 1978
UR M29 Rev3 CLN
UR M29 Alarm systems for vessels with periodically unattended machinery spaces - Rev.3 1997
UR M30 Rev1 CLN
UR M30 Safety systems for vessels with periodically unattended machinery spaces - Rev.1 1997
UR M31 New
UR M31 Continuity of electrical power supply for vessels with periodically unattended machinery spaces - 1978
UR M32 Deleted
Definition of diesel engine type - Deleted Feb 2015
UR M33 Deleted
Scantlings of intermediate shafts - Deleted Feb 2005