This post first appeared in the September 2013 Asdem Newsletter. To see this Newsletter please go to www.asdem.co.uk and look for the ‘Newsletters’ tab
Stripping cargo tanks is carried out to ensure that as much cargo as possible is discharged. Normally the vessel will use stripping pumps and lines for this purpose as they will reach the last drop of cargo that the bulk discharge pumps cannot reach. Stripping is an integral part of the discharge and if carried out properly should cause little delay to the vessel. Normally, the discharge plan will see the ship’s tanks discharged in a certain order. As soon as the first tanks become empty stripping can commence. Stripping can be carried out whilst the vessel is bulk discharging the remainder of the tanks and as the next tanks become empty, stripping of those tanks will tanks will begin. It is only at the end of bulk discharge that there will be a period of time when the vessel is only carrying out stripping. The bulk discharge is finished but the last two or three tanks to be discharged now need to be stripped. Clearly as there is no bulk discharge, it is impossible for the vessel to meet the back pressure required under the charter party of, say, 100psi.
3 thoughts on “Stripping Cargo Tanks and Demurrage”
Hi Phil! Thanks for excellent blog, its quite a learning.
Laytime clause normally agreed as "Vessel is capable of discharging full cargo in 24 hours or maintaining an average of 100 PSI throughout the discharge and EXCLUDING STRIPPING ……..", and laytime clock stop ticking on disconnection of hoses. You are right that even with an old lady with Skillful officers and crew, 3 hours of stripping is quite enough to make sure that tanks are dry.
"Pumping Log" is most important document in laytime calculations and should be read carefully for any remarks. Master and attending surveyors should insert appropriate remarks in pumping log.
The worst experience I had with stripping failure was "Liquid Cargo Remaining Onboard", vessel was finally allowed to sail from discharge port after quantity survey by independent surveyor and owners paid for liquid cargo remaining onboard due to stripping failure. Excess time (more than 3 hours) for stripping was deducted from demurrage.
Babur
the procedure of stripping is understood, But I don´t think the vessel has to stop all operations to perform and internal stripping, ?
Hi Cesar
thanks for your comment. It is only at the end of the bulk discharge will the vessel be stripping tanks when no other discharge is taken place as stripping should normally be carried out during bulk discharge apart from the last two or three tanks. If the vessel is carrying more than one grade then there may be more one of these periods of stripping particularly where the grades are discharge consecutively rather than concurrently.
best regards
Phil