Objectives  The calculation of the ultimate residual capacity of a ship with a large crevasse is influenced by such factors as the location and size of the crevasse, floating state of the ship and nonlinear coupling.

  Methods  A ship hull with a large crevasse is chosen as the research objective, and the Smith method is used to calculate and analyze the longitudinal residual bearing capacity. Emphasis is placed on calculating the changes in the ship's inclined angle and floating state caused by damage to its longitudinal residual bearing capacity.

  Results  The results show that without considering the changes in the ship's floating state, calculation results which deduct the area of the crevasse only in the positive floating state of the ship will overestimate the longitudinal limit residual load capacity of a damaged ship.

  Conclusions  Using this research method, we can reasonably and simply evaluate the longitudinal residual load capacity of a hull under large breach damage, which can provide technical support for ship design and rapid decision-making after a ship sustains damage.