What is Ship Constant?
The ships constant is the difference between a vessels design lightship and it’s actual displacement when empty. The ships constant is determined by a draft survey. The ships constant will vary over the life of the vessel.
Unintentional Reasons for Variations
– Sedimentation in ballast or fuel oil tanks
– Corrosion
– Fouling of hull
– Coating build-up (paintwork, tank coatings, etc.)
– Garbage collection, particularly in cargo holds
– Wear and tear of mechanical devices
Other Reasons for Variations
– Modifications to ship spaces
– Accumulation of stores (i.e., in paint locker, engineering stores, spares)
– Refit, overhauls, addition/removal of equipment.
Continue reading “Negative Constant in Draft Survey”