Please note: this Class News was previously sent with the wrong subject line.

A clarification has been adopted confirming that the weight of fixed fire-fighting mediums (CO2, dry chemical powder, foam concentrate, fresh water, etc.) should be included as part of the lightweight and lightship condition.

It should be noted that only fresh water carried in dedicated fire-fighting water tanks should be included. Where the fresh water that is to be used for fire-fighting (either directly or to mix with foam concentrate) is carried in a shared-use tank, it should not be included in the lightweight or lightship condition.

The weight of the fire-fighting mediums in the delivery system at operating levels and the effect of any free surfaces of fluids should be taken into account in the derivation of the ship’s lightweight.

Please be advised that the International Association of Classification Societies has adopted the following Unified Interpretations (UIs):

• UI SC 273 Inclusion of mediums of the fire-fighting systems in lightweight (SOLAS II-1/2.21, SOLAS II-2/3.28) and lightship condition (2008 IS Code, paragraph 2.23)
• UI MPC 128 Inclusion of mediums of the fire-fighting systems in lightweight (MARPOL Annex I/Regulation 1.24)
• UI MODU 2 Inclusion of mediums of the fire-fighting systems in lightweight (2009 MODU Code, Chapter 1, paragraph 1.3.30)

There are also the following related IMO Circulars:

• MSC.1/Circ.1539 Unified Interpretations of SOLAS Chapter II-1, Regulation 2.21, Definition of the term “Lightweight”
• MSC.1/Circ.1540 Unified Interpretations of the 2009 MODU Code, Chapter 1, paragraph 1.3.30, Definition of the term “Lightweight”
• MSC.1/Circ.1541 Unified Interpretations of the 1994 HSC Code, Chapter 1, paragraph 1.4.27, Definition of the term “Lightweight”
• MSC.1/Circ.1542 Unified Interpretations of the 2000 HSC Code, Chapter 1, paragraph 1.4.34, Definition of the term “Lightweight”