In the second phase of ASIS 's 7-year research project for improved tanker safety against collision and grounding supported by Ministry of Transport, a series of numerical simulations of side damage due to collision was carried out adopting ASIS's methodology based on the customized explicit FEM simulation system in order to demonstrate its potential power in the field of practical application Assuming the simplified rigid bow of a 150K DWT colliding ship, the energy absorption capacity of the various side double hull design options for a VLCC, such as increased number of side stringers, double side structure with top side tank in conjunction with hopper tank, and unidirectional girder stiffening system, was studied The contribution of each structural component, -side shell, inner hull, transverse web, side stringer, etc. -was also investigated in detail. Based on the results of both the numerical study and the 1/2-scale collision experiments, a new conceptual design of a VLCC side structure was developed Further study on crushable bow structure against collision and enhanced design of bottom structure against grounding is now in progress.