IACS History File + TB
Part A
UI SC 70 “Cargo tank vent systems and selection of
electrical equipment”
Part A. Revision History
Version no.
Approval date
Rev.3 (Oct 2010)
Rev.2 (Nov 2005)
Rev.1 (May 2001)
New (1985)
28 October 2010
17 November 2005
22 May 2001
-
•
Implementation date
when applicable
1 January 2012
1 July 2001
-
Rev.3 (Oct 2010)
.1 Origin of Change:
;
Suggestion by an IACS member
.2 Main Reason for Change:
To align the cargo tank vent location arrangements between SOLAS and the IEC
standard. Also the original document contained unified interpretations for two SOLAS
rules, when moving from Rev 1 to Rev 2 the second SOLAS reference was accidentally
omitted as well as the quoted text for the SOLAS Rule which was inadvertently
deleted.
.3 List of non-IACS Member classification societies contributing through the
TC Forum and/or participating in IACS Working Group:
None
.4 History of Decisions Made:
The Form A was agreed in the Machinery Panel and approved by the GPG. It was
agreed to carry out the task by correspondence.
.5 Other Resolutions Changes:
IACS UR F44
.6 Dates:
Original Proposal: 16 January 2007 Made by the Machinery Panel
Panel Approval: 23 August 2010
GPG Approval: 28 October 2010 (Ref: 7518_IGe)
•
Rev.1 (May 2001)
WP/EL submitted a revised text of SC 70 for approval in its Report to GPG 50.
No TB document available.
Page 1 of 2
Part B
Part B. Technical Background
List of Technical Background (TB) documents for UI SC 70:
Annex 1.
TB for Rev.3 (Oct 2010)
See separate TB document in Annex 1.
◄▼►
Note: There are no separate Technical Background (TB) documents for New (1985),
Rev.1 (May 2001) and Rev.2 (Nov 2005).
Page 2 of 2
Part B, Annex 1
Technical Background for UI SC70 Rev.3, Oct 2010
1. Scope and objectives
To align the cargo tank vent location arrangements between SOLAS and the IEC
standard. Also the original document contained unified interpretations for two SOLAS
rules. When moving from Rev 1 to Rev 2 the second SOLAS reference was accidentally
omitted as well as the quoted text for the SOLAS Rule was inadvertently deleted.
The objective of this revision is to reinstate the proposed change from Rev1 to Rev2
where the SOLAS reference changed. It is also proposed that the text immediately
following the second SOLAS reference was deleted by error as the subsequent
interpretation relates to this text.
2. Engineering background for technical basis and rationale
The changes to UI SC70 are to align the cargo tank vent location arrangements
between SOLAS and the IEC standard. However, an anomaly arises with the
specification of the Zone 2 distance. The SOLAS requirement is that the vent distance
should be a total of at least 5m from the nearest air intakes. However, the IEC
document specifies a Zone 1 of 3m and a Zone 2 of 1.5m which totals 4.5m. In this
instance the IACS machinery panel have deferred to the SOLAS requirement and have
specified the Zone 2 distance to be 2m. This special case has been identified within the
UI.
3. Source/derivation of the proposed IACS Resolution
IACS UI SC70 (Rev.2 Nov 2005)
SOLAS
IEC 60092-502
4. Summary of Changes intended for the revised Resolution:
IACS has agreed to accept the IEC standard 60092-502 with regard to the installation
of electrical equipment in tankers. The standard introduces a zoning concept for
hazardous areas and has new requirements to the electrical installations in line with
generic principles laid down in the IEC 60079-series of standards for electrical
installations in hazardous areas. The zonal concept gives permission to the use of
electrical motors and other electrical equipment in Cargo Pump Room and similar
hazardous spaces. This is agreed to be in line with the IACS opinion. It is also agreed
that the electrical installation should be limited as far as practical as stated.
It should be made clear that this increased distance for Zone 2 is only related to the
location of cargo tank vents, for all other cases the IEC distance of 1.5m remains.
The title of the UI SC70 was also changed to clearly reflect its contents.
Also:
i) Add second SOLAS reference to Reg. II-2/4.5.3.4.1.
ii) Remove the strikethrough on the text following the second SOLAS reference.
“Text:
Not less than 10m measured horizontally from the nearest air intakes and openings to
enclosed spaces containing a source of ignition and from deck machinery and
equipment which may constitute an ignition hazard.”
5. Points of discussions or possible discussions
None
6. Attachments if any
None