Barge is one type of ship that is widely used to transport various cargoes. One type of barge is a deck crane barge, barges with shear leg cranes or full rotating cranes. In the construction design, it is necessary to calculate the strength to avoid construction failure. One of the methods used to construction calculations is the finite element method. The finite element method is one of the most widely used numerical methods for engineering calculations. In this study, the strength of the deck crane barge was calculated using the finite element method. SHELL181 and BEAM189 elements were used in this study to simplified the modelling. The results of modeling with the finite element method produce that the maximum stress occurs at the connection between the bulkhead girder and the transverse frame (bracket), at Node 625. The construction strength of the deck crane barge model with a crane capacity of 250 tons (model 1) below the permissible stress, the value is 151.01 MPa. And the stress of the deck crane barge with a crane capacity of 350 tons (model 2) is 190.92 MPa, the stress exceeds the permessible stress.

Beside of environmental conditions, ship characteristics also greatly affect in ship behavior when operating at sea, called seakeeping ability. The shape of the hull, appendages, damping, and the weight distribution of ship are some of the factors that determine how the ship motion response occurred. This paper examines how much the pitch motion is influenced in high-speed craft due to the changing of the gyration radius. By using the strip theory method, and by taking the irregular head sea condition and a wave height of 4 meters, then the ship speed and the wave period are varied to determine the pitch motion amplitude at 3 values ​​of gyration radius: 0.2, 0.25 and 0.3 of the ship's length. The results of the study show that at higher ship speeds, the gyration radii greatly influence the pitch amplitude. As for changes in the wave period, the influence is significant at value of 5 second. From these two results, it is clear that the ship's gyration radii must be determined precisely to be able to predict an accurate pitch motion response on a high-speed craft.