5.5 Cargo transfer and cargo sampling
Clasification Society 2024 - Version 9.40
Statutory Documents - IMO Publications and Documents - Specifications and Manuals - Inert Gas Systems - 5 Application to Cargo Tank Operation - 5.5 Cargo transfer and cargo sampling

5.5 Cargo transfer and cargo sampling

  5.5.1 Ullaging devices of the closed type should be used to avoid the opening of ullage ports.

  5.5.2 However, it may be necessary to infrequently relieve the inert gas pressure in the cargo tanks on certain occasions to permit manual tank gauge or cargo sampling before or after cargo is transferred. If this is done, no cargo or ballasting operation is to be undertaken and a minimum number of small tank openings are to be uncovered for as short a time as necessary to enable these measurements to be completed. Manual gauging or cargo sampling may be performed during the following four periods:

  • .1 At the loading port, prior to cargo loading.

  • .2 At the loading port, after cargo loading.

  • .3 At the discharge port, prior to cargo discharge.

  • .4 At the discharge port, after cargo discharge.

  5.5.3 The tanks should then be re-pressurized immediately after the measurements or cargo samples have been taken.

  5.5.4 If the tank is opened prior to cargo transfer, cargo transfer should not be commenced until all the conditions have been checked and are in order. Similarly, if the tank is opened after cargo transfer, normal ship operations should not be commenced until all the conditions have been checked and are in order.

  5.5.5 During cargo transfer the oxygen content and pressure of the inert gas in the inert gas main should be continuously recorded (see regulation 62.16.1.1 and .2).


Copyright 2022 Clasifications Register Group Limited, International Maritime Organization, International Labour Organization or Maritime and Coastguard Agency. All rights reserved. Clasifications Register Group Limited, its affiliates and subsidiaries and their respective officers, employees or agents are, individually and collectively, referred to in this clause as 'Clasifications Register'. Clasifications Register assumes no responsibility and shall not be liable to any person for any loss, damage or expense caused by reliance on the information or advice in this document or howsoever provided, unless that person has signed a contract with the relevant Clasifications Register entity for the provision of this information or advice and in that case any responsibility or liability is exclusively on the terms and conditions set out in that contract.