Bulk Best Practice for Supply Vessels by Peter Corbett

Bulk Best Practise for Offshore Vessels

Annex One UKOOA- Safe Management and Operation of Offshore Support Vessels Issue 4 November 2002 13. BULK TRANSFER OPERATIONS 13.1 General Requirements 13.1.1 The transfer of bulk cargo in port and particularly offshore, is a potentially hazardous operation and must be conducted in a safe and controlled manner. Offshore bulk cargo operations require a vessel to maintain position alongside an installation, sometimes for extended periods. The attachment of one or more hoses to the vessel restricts its availability to manoeuvre. Planning is therefore essential to minimise time alongside and to ensure a safe and efficient operation (see Appendices 9 and 10). 13.1.2 The following information should be requested by the receiver of the products: i) confirm type and quantity of product to be discharged and order of discharge; ii) estimated pumping rate for each product; iii) length of warning/estimate of time required to stop; iv) whether stop will be initiated from vessel or installation; v) emergency stop procedure established; vi) confirmation that the liquid bulk lines can be drained back to the vessel's tanks where necessary, by gravity only; vii) Material Safety Data Sheets (MSDS) for the product to be loaded must be made available to the Master prior to commencement of operations. 13.1.3 When the hose is connected and lines are set, the provider should be directed to start pumping at a slow rate. All system manifold connections should be checked for leaks at this time. For dry bulk transfers, purge air should be utilised prior to bulk transfer to clear lines and to prove connections. 13.1.4 If all is well, cargo is confirmed as entering the correct tanks, no leaks are observed and a good vent has been obtained (dry bulk), the provider should be advised to increase pumping, up to the full delivery rate. The venting of dry bulk tanks is governed by the Control of Pollution Act 1974 and the Environment Act 1995 Section 30F. 13.1.5 During bulk cargo operations the following points should be observed: i) the Master or person appointed for the task must ensure that he can see the bulk hose(s) at all times and he should not allow other operations to distract his attention away from the hose(s); ii) the vessel bridge and OIM or provider should confirm quantities discharged and received, at regular intervals, to ensure that there are no leaks within the respective systems; iii) the vessel deck crew, installation crane driver or provider must be readily available and close at hand throughout any transfer operation; iv) sufficient warning shall be given by each party prior to changing over tanks; v) installation, provider or vessel valves should not be closed against a cargo pump; vi) If at any stage in the operation the vessel Master, provider or OIM are in any doubt as to the integrity of the operation then that operation should be terminated; vii) The loading rate should be reduced to a manageable level to allow the receiver to top off tanks safely. 13.1.6 When pumping has finished, both the receiver and the provider should set their lines to allow the hose to be drained back to the vessel's tank. If the installation has a vacuum breaker fitted to the line, this should be used to aid draining. In suitable conditions the crane should also be used to lift the hose to aid draining. In the case of dry bulk, purge air should be used to clear the line. Compressed air must not be used to clear a wet bulk line, due to the possibility of damage to the vessel's tanks by overpressure. 13.1.7 When the hose is disconnected, the end should be fitted with a suitable cap or blank. 13.1.8 Product remaining in the line following transfer should be drained back into one of the vessel's tanks prior to disconnecting the hose. This does not apply to potable water. 13.1.9 Hoses used for potable water must not be used for transferring other bulk liquids, including drill water. Potable water lines should be flushed through prior to transferring water to avoid any residues within the lines contaminating the installation's supplies. 13.1.10 During periods of darkness, adequate illumination must be available over the hose and support vessel throughout the operation. To facilitate identification, hoses should be fitted with high visibility bands, high visibility tape or alternative means to mark the product. 13.1.11 Hoses are colour coded for manufacturers' identification and approval, frequently by use of spiral coloured bands within the hose structure.