Grand Canal of Ireland

The Grand Canal is the southernmost of a pair of canals that connect Dublin, in the east of Ireland, with the River Shannon in the west, via Tullamore and a number of other villages and towns, the two canals nearly encircling Dublin's inner city. Its sister canal on the Northside of Dublin is the Royal Canal. The last working cargo barge passed through the Grand Canal in 1960.

The idea of connecting Dublin to the Shannon was proposed as early as 1715, and in 1757 the Irish Parliament granted Thomas Omer £20,000 to start construction of a canal. By 1759 he reported that 3 km (1.9 mi) in the Bog of Allen and 13 km (8.1 mi) of canal from the River Liffey near Sallins towards Dublin were complete. By 1763 he had completed 3 locks and 6 bridges towards Dublin and was concentrating on establishing a water supply from the Morell River near Sallins. At this point the Corporation of Dublin realised that the canal could be used to improve the water supply to the city, and put up the money to complete the canal into the city. But when the canal was filled, the banks gave way and the city didn't obtain its water. By 1768, £77,000 had been spent on the project and little more was forthcoming.

In 1772 the Grand Canal Company was established by a group of noblemen and merchants, including public subscription, to ensure the future of the canal and to tackle the biggest barrier to the canal, the Bog of Allen. This was a new venture for canals. The company invited John Smeaton and his assistant William Jessop to Ireland for two weeks to advise them. Smeaton made a recommendation to skirt round the bog but to build the canal at the full height, in contrast to Omer's efforts which attempted to drain parts of the bog and build at a lower level. This was to prove an expensive mistake, although he also advised reducing the generous locks that Omer had built (42m by 6 m / 137 ft by 20 ft) to 18m by 4m (60 ft by 14 ft), which would bring about considerable savings in the total cost of the canal. More details