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 Ranalagh Bridge. Twenty seven years later, in 1817, the canal reached the Shannon. The total cost of construction was £1,421,954. 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.