Page 299 - International safety guide for oil tankers and terminals

TERMINAL SYSTEMS AND EQUIPMENT

Lighting levels should meet national or international engineering standards as a
minimum. Particular consideration should be given to lighting of the following areas:
---ใช้เพื่อการศึกษาเท่านั้น---
Berth or jetty-head working areas.
Access routes.
งานห้องสมุด ศูนย์ฝกพาณิชย์นาวี
Berth or jetty perimeters.

Boat landings.
Mooring dolphins and walkways.
Stairways to elevated gantries.
Emergency escape routes.
Lighting of water around berth to detect spillage and possibly unauthorised craft.

17.5 Ship/Shore Electrical Isolation

17.5.1 General
Due to possible differences in electrical potential between the ship and
the berth, there is a risk of electrical arcing at the manifold during
connection and disconnection of the shore hose or loading arm. To
protect against this risk, there should be a means of electrical isolation at
ึ
the ship/shore interface. This should be provided by the terminal.

It should be noted that the subject of ship-to-shore electric currents is
quite separate from static electricity, which is discussed in Chapter 3.

17.5.2 Ship-to-Shore Electric Currents

Large currents can flow in electrically conducting pipework and flexible
hose systems between the ship and shore. The sources of these currents
are:
Cathodic protection of the jetty or the hull of the ship provided by
either an impressed current system or by sacrificial anodes.

Stray currents arising from galvanic potential differences between ship
and shore or leakage effects from electrical power sources.

An all metal loading or discharge arm provides a very low resistance
connection between ship and shore and there is a very real danger of an
incendive arc when the ensuing large current is suddenly interrupted
during the connection or disconnection of the arm at the tanker manifold.

Similar arcs can occur with flexible hose strings containing metallic
connections between the flanges of each length of hose.

To prevent electrical flow between a ship and a berth during connection or
disconnection of the shore hose or loading arm, the terminal operator
should ensure that cargo hose strings and metal arms are fitted with an
insulating flange. An alternative solution with flexible hose strings is to
include, in each string, one length only of non-conducting hose without
internal bonding. The insertion of such a resistance completely blocks the
flow of stray current through the loading arm or the hose string. At the
same time, the whole system remains earthed, either to the ship or to the
shore. The above text is made with reference to conventional alongside

© ICS/OCIMF/IAPH 2006 265