Abstract
Introduction of the semi-elastic barrier into fuel tanks rise environmental protection level in case of ship collision or grounding. Last law regulations requires change of localisation of fuel tanks in ship structure in a such way to increasing distance between fuel and surounding water. Application of semielastic barrier into fuel tank make possible to localise fuel tanks in double bottomspace. Calculation of hipothetical outflow of fuel from damaged fuel tan in case of application of senielastic barier is presented.