Page 141 - International safety guide for oil tankers and terminals

SHIPBOARD SYSTEMS

simultaneously and that a suitable loading rate is determined for the
particular loading operation.
---ใช้เพื่อการศึกษาเท่านั้น---
Offshore floating hoses that meet OCIMF guidelines (see Bibliography)
and having a nominal diameter of less than 400 mm are suitable for
washing from slop tanks. In such instances, the limiting factors of theย์นาวี
continuous operation at a flow velocity of 21 m/s. Offshore floating hoses
having a diameter greater than 400 mm are suitable for continuous
operations at a flow velocity of 15 m/s. However, the maximum loading
rate may be controlled by the size of the ship’s loading line inboard of
where the hose is connected.

7.3.3.3 Rate of Rise of Liquid in the Cargo Tank
งานห้องสมุด ศูนย์ฝกพาณิช
Small tanks, such as slop tanks, may have larger filling or suction valves
than their size would normally require, to accommodate certain
operations for which they may be used, such as recirculatory crude oil

venting flow rate and the liquid line flow rate may not be suitable for
assessing maximum loading rates. It is then also necessary to consider
the rate of rise of the liquid in the tank if over-filling is to be avoided.

To exercise control over the rate of liquid rise in any cargo tank, it may be
appropriate to set the loading rate to limit the rate of rise of liquid in a
cargo tank to a maximum of 150 mm/minute.
ึ
7.3.3.4 Loading Rates for Ballast Tanks
Loading rates for ballast tanks should be determined in the same manner
as for cargo tanks, taking into account the size of vent outlets using a
vent velocity of 36 metres/second. Liquid filling rates can be calculated
using a pipeline flow rate of 12 metres/second, and a similar rate of rise
of liquid of 150 mm/minute should also be considered, where practical.

7.3.4 Monitoring of Void and Ballast Spaces
Void and ballast spaces located within the cargo tank block should be routinely
monitored to check that no leakage has occurred from adjacent tanks.
Monitoring should include regular atmosphere checks for hydrocarbon content
and regular sounding/ullaging of the empty spaces (see also Section 11.8).

7.4 Power and Propulsion Systems

While a tanker is berthed at a terminal, its boilers, main engines, steering machinery
and other equipment essential for manoeuvring should normally be kept in a condition
that will permit the ship to be moved away from the berth in the event of an emergency.
See Section 22.7.1.1 for advice about planned immobilisation.

A terminal may allow some degree of immobilisation of the propulsion plant whilst the
ship is alongside. The tanker must, however, obtain permission from the Terminal
Representative or local authority before taking any action affecting the readiness of the
ship to move under its own power.

Any unplanned condition that results in the loss of operational capability, particularly to
any safety system, should be immediately communicated to the terminal.

© ICS/OCIMF/IAPH 2006 107