Reminder & Precaution during Deballasting.especially on Bulk Carriers. 1.Always ensure that Shearing Forces and Bending Moments are well within limit at all stages of deballasting and loading operations. 2.Capacity of ballast pumps and loading rate to be taken into account, some loading ports in Australia and Kalimantan loading rate is 4,500 - 6,000 metric tonnes per hour.thats means deballasting should be completed within 12 - 15 hrs.For Panamax Ships total ballast are bet 22,000 - 24,000 metric tonnes..Usually the terminal and charterer gives allowance for 4 - 6 hours extra for complete deballasting, if not, off hire or down time will be calculated. 3.All ballast tanks should be 100% full prior initial draft survey , so as to get correct draft calculation and get exact constant. 4.Ballast exchange to be made and completed prior 24hrs arr port limit,and forms ready.Australia Quarantine,China, Canada and Russia are very strict about this, if not compliance loading will be cancelled and off hired. 5.Att all stages of de ballasting ensure that the ship air draft is well within limit to the height of the loader or cranes. 6.Propeller and suction pipe of Emergency Fire pump to be always well submerge at all stages, for safety reason and to avoid fines by the Port State Control. 7.Ensure enough trim is maintained to have good suction. 8 Full use of drop valves if fitted, as to minimise deballasting time and strains on the ballast pumps, but before it being operated ensure that ballast water does not spill over the loading crane motor or bunker barge by the side. 9.Test the ballast pump suction before arrival loading port. 10.Sometime pumps are ok, but there still not enough suction or unable to pump out completely, beside wrong valves, there are possibility that many ship officers does not realised.After long ballast voyage, due to dynamic stresses, the dresser coupling of the ballast pipes gives way, and leaks , so suction could not be maintained.Its always happen if the ballast pipes pass thru the top sides tanks.
Posted on: Tue, 16 Dec 2014 13:51:45 +0000