In times past, Dublin Bay had a long-running problem with silting, notably at the mouth of the River Liffey. After years of primitive dredging, an attempt to maintain a clear channel more effectively was begun when, in 1715, the first piles were driven of what was to become the Great South Wall, completed in 1730. This barrier was breached by storm action some years later, and in 1761, a stone pier was commenced, working from the Poolbeg Lighthouse (1768), back to shore, the construction of massive granite blocks being completed in 1795. It was during this period that the building of a North Bull Wall was also proposed, and when it was seen that the South Wall did not solve the silting problem, the authorities responsible for Dublin Port commissioned studies on the matter. Captain William Bligh, of Bounty fame, surveyed Dublin Bay for the Ballast Board in 1801, highlighting the potential of the North Bull sandbank. Its purpose was to clear a sandbar by Venturi action.
