By the year 1770 the establishment had so expanded that, including the gun wharf, it stretched a mile (1.6 km) in length, and included an area of in excess of 95 acres (384,000 m²), possessing four slip ways and four large docks.
Between 1862 and 1885, the yard underwent another large building programme as the Admiralty adjusted to the new technology of steam-powered ships with metal hulls.