The calculation of longitudinal strength is a significant activity in the design phase of the hull structure, and is especially important in large ships since the value of transverse forces and moments increases with the length of the ship. The calculation process is a complex process, and consists of several repetitive steps, ie it is iterative in nature and contains a large amount of mathematical operations, so the application of computers for the same is almost inevitable. Today, the calculation of longitudinal strength is done by numerical procedures, and as a software tool needed for programming the calculation, the program of wide use Rhinoceros, often used in shipbuilding, was chosen. As part of the Rhinoceros program, a package with the Python programming language is integrated. The input data required for the calculation are a model of the hull structure and a weight distribution diagram. The aim of the calculation is to check the forces and moments on individual cross-sections of the ship, and to analyze the forces and moments within the permitted limits prescribed by classification societies in terms of meeting the hull strength criteria. Three variants of solving the longitudinal strength calculation using the Python script in Rhino have been developed. The theoretical part, as well as the program code are explained for only one variant, which has a verified and generally accepted theoretical basis in shipbuilding. The first part of the thesis explains the theoretical part of the budget. The second part describes the steps of using a programming script, and the third describes the programming code in detail. Finally, the obtained results of all variants are compared, where the results of the project office of the shipyard are attached, which are also relevant, since the ship was built and in use.