A sealed and thermally insulating storage tank for a fluid that is anchored in a load-bearing structure built into a ship, the ship having a longitudinal direction, the tank having a loading/unloading tower suspended from a ceiling wall of the load-bearing structure, the loading/unloading tower including first, second and third vertical pylons defining a prism of triangular section, the loading/unloading tower carrying at least a first pump, the tank having a support foot that is fastened to the load-bearing structure, the tank having at least one sump, the first pump being arranged outside the triangular prism and being aligned with the support foot in a first transverse plane that is orthogonal to the longitudinal direction of the ship.