Following to the great accidents the interest in preventing environmental pollution and the safety of people and means of maritime transport have increased. The idea of developing new, unconventional structures, imposed by the new requirements of Shipbuilding Rules related to safety and pollution is analyzed in the paper. The behavior of the unconventional double hull of a ship structure concept, named ARC, loaded to transversal impact is treated. In the paper the finite-element analysis is used because is important to provide the structural designer that no stress concentrations exist in a certain design. The results obtained for energy absorption and general ship hull behavior encouraged the authors to introduce in shipbuilding the unconventional double hull of the ship structure concept.