Page 305 - International safety guide for oil tankers and terminals

Chapter 18
การศึกษาเท่านั้น---
CARGO TRANSFER

งานห้องสมุด ศูนย์ฝกพาณิชย์นาวี
EQUIPMENT

This Chapter describes hard arms and flexible hoses used to make the ship/shore
connection. The type of equipment is described, together with recommendations
regarding its operation, maintenance, inspection and testing. If not properly
engineered and maintained, this equipment will provide a weak link that may
jeopardise the cargo system’s integrity.

18.1 Metal Cargo Arms

18.1.1 Operating Envelope
All metal cargo arms have a designed operating envelope, which takes
into account the following:
for which the berth has been designed. ึ
Tidal range at the berth.
Maximum and minimum freeboards of the largest and smallest tankers

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Minimum and maximum manifold setbacks from the deck edge.
Limits for changes in horizontal position due to drift off and ranging.
Maximum and minimum spacing when operating with other arms in a
bank.

The limits of this operating envelope should be thoroughly understood by
berth operators. Metal arm installations should have a visual indication of
the operating envelope and/or be provided with alarms to indicate
excessive range and drift.

The person in charge of operations on a berth should ensure that the
tanker’s manifolds are kept within the operating envelope during all stages
of loading and discharging operations. To achieve this, the tanker may be
required to ballast or deballast.

18.1.2 Forces on Manifolds

Most metal cargo arms are counterbalanced so that no weight, other than
that of the liquid content of the arm, is placed on the manifold. Because
the weight of oil in the arms can be considerable (particularly for larger
diameter arms), it may be advisable for this weight to be relieved by a
support or jack provided by the terminal.

Some arms have integral jacks that are also used to avoid overstressing
of the tanker’s manifold by the weight of the arm or other external forces
such as the wind.

© OCIMF/ ICS/ IAPH 2006 271