The side protection system incorporated five compartments divided by torpedo bulkheads and a large anti-torpedo bulge that ran the length of the "armored raft". The outer two compartments, the innermost compartment and the bulge would remain empty, while the third and fourth compartments would be filled with liquid. The system was reduced in depth at either end by the forward and rear gun turrets. In these areas, the fifth compartment was deleted; instead, there was an outer empty compartment and two liquid-filled spaces, backed by another empty compartment. To compensate for the reduced underwater protection system, these sections received additional armor plating, up to in thickness. The complete system was deep and designed to withstand warheads of up to of TNT. Underwater protection was rounded out by a triple bottom that was deep. The bottom layer was thick and was kept filled with fluid, while the upper thick layer was kept empty. The triple bottom was also heavily subdivided to prevent catastrophic flooding should the upper layer be penetrated.