PREDICTING SHIP SQUAT IN NIGERIAN WATERWAYS (CASE STUDY: NIGER DELTA)

In view of the desire to prevent vessel grounding at port and channel entry thus, maintaining ship's continued trading, this research work presents how Maximum squats and the remaining under-keel clearances can be predictedfor two vessel categories (Container and General Cargo) along two prominent channels (BONNY ACCESS and the BONNY TO ONNE JUNCTION) in Nigeria using empirical models developed for maximum squat in the open water and confined channels conditions. The results obtained show that maximum squat increase with increasing vessel speed as the ratio of water depth to vessel draft (H/T) reduces for any particular channel or vessel. However, an opposite trend was observed with the remaining under-keel-clearances as they zero up and even cross to negatives, indicating vessel grounding; both of which agree with the results of previous researchers. Further analysis revealed that for optimal vessel safety the cruising speed within these channels should be between 0.5 knots to 5knots for the open water conditions,(H/T between1.10 -1.40),investigated. Hence, if pilots should cruise at the speed limit for the critical H/T ratio where the remaining under-keel clearance is not lower than the channel designed minimum, safety is guaranteed along either channel even with changing depths.