Development of Software for Anchor Trajectory to Be Applied for Drag Anchor Analysis on Subsea Gas Pipeline Case Study: Madura Strait

Abstract

High risk of danger occurred when subsea pipeline gas is laid on the sailing area. Several risks possibility that may appear includes drop anchor, drag anchor and ship sinking. The study case in this paper will try to analyze the passing gas pipeline passing through the ship anchoring area towards the danger of drag anchor and the anchor trajectories. The segment that is embedded in the soil and the installation line characteristics will affect the positioning of drag anchors in seabed. In addition, the positioning of drag anchors in seabed is not solely affected not only by the anchor and soil properties itself. Three segments are used in this analysis. The catenary line is the segment of the installation line in the seawater, the horizontal line is the segment on the seafloor surface, and the embedded line is the segment embedded in soils, which presents a reverse curvature compared with the catenary line. Analytical method for positioning drag anchors on the seafloor surface as shown on the previous research that the interactional system between the drag anchor and installation line is firstly introduced for the analysis of anchor positioning. Reasonable and understandable theoretical approach to examine the anchor behaviors in soils has been acquired by combining the interactional system between the drag anchor and the installation line as an analytical method for positioning drag anchors. VBA Software in Microsoft Excel is used in this study. The movement of anchor trajectory was developed to obtain development of software for anchor trajectory to be applied for drag anchor analysis on subsea gas pipeline passing through the area of anchoring on the case study in Madura Strait to stimulate the anchor position on the conditions at the point of a safety distance.