The work was entrusted to Edmund Dummer, naval engineer and surveyor to the Navy Board. His new dry dock (the "Great Stone Dock" as it was called) was built to a pioneering new design, using brick and stone rather than wood and with an increased number of 'altars' or steps (the stepped sides allowed shorter timbers to be used for shoring and made it much easier for shipwrights to reach the underside of vessels needing repair). Extensively rebuilt in 1769, the Great Stone Dock is now known as No.5 dock.