Royal Canal

Plaque near the 12th lock naming the bridge as '1790 Ranelagh Bridge'

In 1755, Thomas Williams and John Cooley made a survey to find a suitable route for a man-made waterway across north Leinster from Dublin to the Shannon. They originally planned to use a series of rivers and lakes, including the Boyne, Blackwater, Deel, Yellow, Camlin and Inny and Lough Derravaragh. A disgruntled director of the Grand Canal Company sought support to build a canal from Dublin to Cloondara, on the Shannon in West County Longford.

Work on this massive project commenced in May 1790 at Cross Guns Bridge, Phibsborough in a westerly direction towards Ashtown. This is commemorated in the plaque beneath the keystone of Ranelagh Bridge. Twenty-seven years later, in 1817, the canal reached the Shannon.[1] The total cost of construction was £1,421,954.[2] Building was unexpectedly expensive, and the project was riven with problems; in 1794 the Royal Canal Company was declared bankrupt. The Duke of Leinster, a board member, insisted that the new waterway take in his local town of Maynooth. The builders had to deviate from the planned route and necessitated the construction of a 'deep sinking' between Blanchardstown and Clonsilla. The diversion also called for the building of the Ryewater Aqueduct, at Leixlip.[3]

The original 1796 fare from Dublin to Kilcock was 1/1, much cheaper than the stagecoach.

By the 1830s the canal carried 80,000 tons of freight and 40,000 passengers a year.

Quaternion plaque on Brougham (Broom) Bridge, Dublin

Ferns' Lock

In 1843, while walking with his wife along the Royal Canal, Sir William Rowan Hamilton realised the formula for quaternions and carved his initial thoughts into a stone on the Broom Bridge over the canal. The annual Hamilton Walk commemorates this event. In 1845 the canal was bought by the Midland Great Western Railway Company. They considered draining the canal and building a new railway along its bed but decided instead to build the railway beside the canal. The two run side by side from Dublin to Mullingar.

In May 1847, during the Great Famine, tenants of Major Denis Mahon, left his Strokestown Park estate in County Roscommon. The tenants, who would become known locally as the "Missing 1,490", had been offered a choice of emigration with assisted passage, starvation on their blighted potato farms or a place in the local workhouse. Weakened by starvation, the 1,490 walked for days along the towpaths of the Royal Canal to Dublin, where they were put on boats to Liverpool, and from there travelled to Grosse Île, Quebec on four "coffin ships" – cargo vessels that were also, ironically, loaded with grain from Ireland, and were unsuitable for passengers. It is estimated that half of the emigrants died before reaching Grosse Île. This was the largest single exodus of tenants during the Famine. Mahon was assassinated in November 1847, after news reached Roscommon about the fate of his former tenants. An annual walk on the canal banks commemorates these events.

Competition from the railways gradually eroded the canal's business and by the 1880s annual tonnage was down to about 30,000 and the passenger traffic had all but disappeared.

It had a brief resurgence during World War II, when horses and barges returned to the canal. CIÉ took over the canal in 1944. As rail and road traffic increased, the canal fell into disuse. In 1974, volunteers from the Inland Waterways Association of Ireland formed the Royal Canal Amenity Group to save the canal. By 1990 they had 74 kilometres of canal, from the 12th lock in Blanchardstown to Mullingar, open again for navigation. In 2000, the canal was taken over by Waterways Ireland, a cross-border body charged with administering Ireland's inland navigations. On 1 October 2010, the whole length of the canal was formally reopened.

Famine Way memorial, 12th Lock

The Royal Canal was originally planned to terminate in Dublin at Broadstone, to serve the then fashionable area of residence, as well as King's Inns and the nearby markets, but it was extended so that now, at the Dublin end, the canal reaches the Liffey through a wide sequence of dock and locks at Spencer Dock, with a final sea lock to manage access to the river and sea.

The Dublin – Mullingar railway line was built alongside the canal for much of its length. The meandering route of the canal resulted in many speed-limiting curves on the railway. The canal was bought by the Midland Great Western Railway to provide a route to the West of Ireland, the original plan being to close the canal and build the railway along its bed.

The canal travels across one of the major junctions on the M50 where it meets the N3, in a specially constructed aqueduct.

The Royal Canal was immortalised in verse by Brendan Behan in The Auld Triangle. A monument featuring Behan sitting on a bench was erected on the canal bank at Binn's Bridge in Drumcondra in 2004.

And the auld triangle went jingle jangle,

All along the banks of the Royal Canal.