As shown in Table 4, there were two types of mooring line breakage during the tsunami. The first breakage type was that the lines were broken immediately after the ship movements, and the second one was that the lines were broken after reaching the limit of the winch brake. Thus the line tension property has been newly modeled by not only the relation between elongation and tension but also by additional parameters such as the winch brake force (Oil Companies International Marine Forum (OCIMF), 2008) and total length of mooring line