Page 108 - International safety guide for oil tankers and terminals

INTERNATIONAL SAFETY GUIDE FOR OIL TANKERS AND TERMINALS

edge of such tools, and can then cause incendive sparks on impact with
ferrous or other hard metals. The use of non-ferrous tools is therefore not
---ใช้เพื่อการศึกษาเท่านั้น---
recommended.

งานห้องสมุด ศูนย์ฝกพาณิชย์นาวี
4.6 Equipment Made of Aluminium

Aluminium equipment should not be dragged or rubbed across steel since it may leave
a smear which, if subsequently struck by a hammer or falling object, can cause an
incendive spark. It is therefore recommended that the undersides of aluminium
gangways and other heavy portable aluminium structures are protected with a hard
plastic or wooden strip to prevent smears being transferred to steel surfaces.

The use of other aluminium equipment in cargo tanks and on cargo decks should be
subjected to a risk assessment and, where necessary, carefully controlled.

4.7 Cathodic Protection Anodes in Cargo Tanks

If magnesium anodes strike rusty steel, they are very likely to produce an incendive
spark. Such anodes must not therefore be fitted in tanks where flammable gases can
be present.
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Aluminium anodes give rise to incendive sparking on violent impact and therefore
should only be installed at approved locations within cargo tanks, and should never be
moved to another location without proper supervision. Moreover, as aluminium anodes
could easily be mistaken for zinc anodes and installed in potentially dangerous
locations, it is advisable to restrict their use to permanent ballast tanks.

Zinc anodes do not generate an incendive spark on impact with rusty steel and
therefore are not subject to the above restrictions.

The location, securing and type of anode installed in cargo tanks will be subject to
approval by the appropriate authorities. Their recommendations should be observed
and inspections made as frequently as possible to check the security of the anodes and
mountings. Anodes have become more susceptible to physical damage with the advent
of high capacity tank washing machines.

4.8 Communications Equipment

4.8.1 General

Unless certified as intrinsically safe or of other approved design, all
communications equipment on board ships, such as telephones, talk-back
systems, signalling lamps, search lights, loud hailers, closed circuit television
cameras and electrical controls for ships’ whistles, should neither be used nor
connected or disconnected when the areas in which they are positioned come
within the boundary of a shore hazardous zone.

4.8.2 Ship’s Radio Equipment
The use of a tanker’s radio equipment during cargo or ballast handling
operations is potentially dangerous.

74 © ICS/OCIMF/IAPH 2006