The year 1707 is an important milestone in the story of Dublin. In that year, parliament passed ‘An Act for Cleansing the Port, Harbour, and River of Dublin and for Erecting a Ballast Office in the said city’. The Ballast Office was the first municipal authority to take control of the port — it had been a prerogative of the crown until this moment — and it quickly made its presence felt.
The key functions of the Ballast Office were the imposition of port charges and the maintenance of the navigation channel, the latter a perennial problem. It also continued the progressive embanking of the river that had begun in earnest in the last quarter of the previous century. The construction of the quays on the north bank of the river, collectively to be known as the North Wall, was completed in less than twenty years. Charles Brooking’s map of 1728 clearly shows a continuous embanking wall running from around the site of the modern Custom House to a point opposite Ringsend, roughly where the O2 arena stands today. The East Wall was an extension of the North Wall following the line of the present East Wall Road around to Ballybough.
The North and East Walls required constant renewal and maintenance and were greatly improved in the nineteenth century when civil engineering skills were much advanced. But the construction of the originals in such an impressively short time was evidence of the energy which the early Ballast Office brought to the discharge of its duties. The leading traders and merchants of the city — they included such names as Humphrey Jervis, John Rogerson,William Fownes and John Eccles, all immortalised in street names — had an obvious material interest in improving the port.
They did not stop there. As early as 1715, they turned their attention to the south shore and began the construction of what was eventually to become the Great South Wall. Work started on this heroic project as early as 1716. The Ballast Office showed great consistency of purpose over a long period of time in the face of formidable practical difficulties. A wall of timbered piles was first laid down, pushing out towards what is now the Poolbeg lighthouse. By 1731, the basic structure was complete from the Pigeon House to the Poolbeg. A lightship marked the eastern end of the piles. It was a rickety and unsatisfactory structure in practice. The disturbance of wind and tides was often too much for the timber wall. Individual piles were displaced and the constant maintenance requirements were onerous. Moreover, the uncertain mooring of the lightship presented a near insoluble problem.
This in turn raised the question of a permanent lighthouse as the only effective substitute. The Ballast Office first proposed it in 1736. The idea got nowhere; it was raised again in 1744 with similar results. It was not until 1759 that the piles themselves were acknowledged to be an inadequate solution and the decision was taken to build a stone wall. The design incorporated a provision for a lighthouse foundation at the eastern end.
The abutment for the lighthouse foundation was built first and then construction of the wall proceeded from east to west, or back towards the city. It took over thirty years to carry the wall all the way up to the site of the present O’Connell Bridge but the lighthouse was finished and functioning as early as 1767.
The Great South Wall is not simply one of the finest engineering and construction achievements in the city’s history. It is a testimony to the tenacity of purpose and consistency of vision of the city authorities through the entire length of the eighteenth century. A project that was a gleam in the eye in 1716 was not completed until the 1790s, by which time the Ballast Office, the original sponsoring body, had been replaced by a new Ballast Board (1786) and no one alive at the start had survived to see it finished.
The whole raison d’être of the Irish capital has always been seaborne trade. That was why the Vikings founded it in the ninth century. Yet the port had consistently presented problems: strongly tidal, leaving a shallow draught for shipping at low water; chronically prone to silting because of the effect of the tides on the two large sandbanks in the bay known as the North and South Bulls, thus churning the sands and dumping them in the shipping channel; and the consequent inability to establish secure landing places near to the city centre.
All these problems were eliminated or ameliorated by the building of the North, East and Great South Walls — and by the later addition of the North Bull Wall, jutting into the harbour from the Clontarf shore and creating a pinch point opposite the Poolbeg lighthouse at the end of the Great South Wall which produced a natural scouring and dredging effect on the ebb tide. In sum, these various walls and embankments made possible the modern development of the port of Dublin.
Of all these admirable engineering works, the Great South Wall was the finest, in that it faced the greatest and most formidable series of obstacles over a long period of time. It is in its way as fine a memorial to the city’s golden age as any Georgian square or municipal building.
