The Use of Untrimmed End Volumetric Heeling Moments in the Grain Stability Calculation for Specially Suitable Bulk Carriers

Abstract

Reasons for the use of untrimmed end volumetric heeling moments in the National Cargo Bureau's (NCB) "Grain Stability Calculation" form are described In detail. Severe loading delays are caused by merchant marine officers' lack of knowledge regarding the necessity of trimming the hold end spaces on conventional bulk-carrying vessels. The paper offers a remedy for this situation by explaining the laws dealing with the carriage of bulk grain on this type of vessel and by outlining methods of trimming hold end spaces where required. The alternative of using "untrimmed ends" moments is discussed, along with the associated savings in both time and money. Actual calculations of the "Stability Summary" section of the NCB form present three different loading arrangements utilizing untrimmed end moments. The paper concludes that every bulk carrier engaged for at least a few voyages in the grain trade should have a table of "untrimmed end volumetric heeling moments" on board since they do provide a loading alternative that can considerably lower or eliminate trimming costs and reduce a vessel's turnaround time.