Excess load on ships and its effects on stability performance in Nigerian waterways

Abstract

This research has been carried out to examine the impact of excess shipload on ship performance and stability. The objectives are to analyse the trend of sinking ships in Nigeria occasioned to ship excess load. Secondly, to examine the relationship between load size and ship stability and identify the various factors responsible for ship instability. Data were gathered from operators in the maritime industry using structured questionnaires and interviews as data collection instruments. Four significant stakeholders that can provide information based on their involvement across three strata of management, operation and general cadre were sampled. Pearson Moment Correlation technique has been used to examine the relationship between load size and ship stability, and Analysis of Variance-one was used to identify the various factors responsible for ship instability. The Pearson Moment Correlation technique analysis shows a significant relationship between load size and stability. The analysis of variance revealed that "hogging and sagging" is the most crucial factor among the factors identified for ship instability. It has the highest value of F-ratio of 17.837 with a significance at p<0.05. The research concluded that resultant accidents from the instability of vessels are caused majorly by hogging and sagging of vessels, and notably, the occurrence is much in riverine areas in Nigeria. Loading the vessel has a relationship with the vessel's stability, as depicted from the analysis in this research. Recommendations on how to enhance stability through boat construction, shipbuilding, loading and passenger's use of life jackets, among others were made.