IACS revised URs for cast copper alloy and steel propellers

The International Association of Classification Societies (IACS) has published the revised Unified Requirements for cast copper alloy and steel propellers.

Both documents (UR W24 Rev5 CLN and UR W27 Rev3 CLN) were published on 1 September and will enter into force on 1 January 2025.

Cast Copper Alloy Propellers

These comprehensive guidelines pertain to the procedures involved in manufacturing, inspecting, and repairing cast copper alloy propellers, blades, and bosses.

When considering the use of alternative alloys, it is necessary to provide details of their chemical composition, mechanical properties, and heat treatment for approval.

Additionally, these standards can also be employed for the repair of propellers that have been damaged during service, subject to prior agreement with the Classification Society.

The revisions introduced in Revision 5 must be consistently applied by IACS Societies for ships contracted for construction on or after January 1, 2025, or for applications for the certification of cast copper alloy propellers dated on or after January 1, 2025.

This also applies to applications for manufacturer approval dated on or after January 1, 2025.

Cast Steel Propellers

These standardized guidelines pertain to the production, examination, and restoration processes for cast steel propellers, as well as their blades and bosses.

If the use of alternative alloys is proposed, detailed information regarding their chemical composition, mechanical properties, and heat treatment must be submitted for approval.

These stipulations can also be employed for the repair of propellers that have sustained damage during service, provided there is prior agreement with the Classification Society.

The revisions introduced in Revision 3 are to be consistently implemented by IACS Societies in cases where ships are contracted for construction on or after January 1, 2025, or when applications for the certification of cast steel propellers are dated on or after January 1, 2025, or when applications for manufacturer approval certification are dated on or after January 1, 2025.

For more information, please see the documents below (available only to subscribers):