The increase in diving depth necessitated by improved anti-submarine detection required that the pressure hull should be circular throughout its length, having specially-shaped domed ends, and be constructed of special quality steel.
Ukwanda kobunzulu bokuntywila obubangelwe kukuphu-cuka kokujongwe kwenkwili kufuna ukuba uxirizelelo lwesiqu malubo sisezinese kubude buphela, lube nekumila ekukodwa ekungqukuva ekupheleni, sibenokwakhiwa ngestili esisodwa esibulunga baneleyo.