Technical Paper
Structural Degradation of Oil Tanker Operating in Indonesian Waterways
Tahun 2020
Corrosion is one of the significant factors for decreasing strength in floating marine
structures. In general, rules of classification society use the North Atlantic Ocean located in the
sub-tropical region as a reference area in the formulation of the structural strength. If the sub-
tropical area compare with tropical region such as Indonesia waterway, Indonesia waterway
has high salinity and humidity. This makes marine environment in Indonesia more corrosive.
One example of the effects of corrosion is the reduction in plate thickness. This leads to
decrease in ship strength. Using measured thickness data collected from 25-thickness
measurement reports from 24 Oil Tankers that sailing in Indonesian waterways, the diminution
of ship structural thickness has been analysed. The age of Oil Tankers, whose data was taken,
ranges from 5 to 23 years. Data analysis was carried out by using statistical approach based on
Weibull distribution. Using 95% cumulative probability, it was found that the thickness
diminution of Oil Tanker with design life of 20 years is 2,07 mm for deck plate, the side plate
is 2,06 mm, the bottom plate is 1,81 mm and the inner bottom plate is 1,53 mm