On June 2 nd 1772, The Grand Canal Company was formed to build the Canal as a private venture receiving full control from the commissioners for Inland Navigation. It was decided to build initially to the Barrow River rather to the Shannon, it being felt that such a route would prove profitable immediately.

In 1786, the line to Monasterevin was opened and a link was made with the Barrow River Navigation. In 1791, the Canal was extended to change from Grand Canal to the River Navigation Athy and it was there that the navigation was henceforth made.

Boats left James' Street Harbour and Portobello each morning and afternoon for Athy and Tullamore, Shannon Harbour and Ballinasloe. These boats were, of course, horse drawn. From 1834 these were "Fly Boats" which had four horses.

Passenger boats only travelled by day and stopped at the company hotels for the night. Passenger traffic increased until the advent of the railway. This being faster had an adverse effect and passenger traffic finally ceased in 1853.

The 28 th Lock (Barrow Line) leads directly into the River Barrow. There is a narrow bridge across the river just above the Junction. This is known as the Horse Bridge, since it was used at one time to allow the horses to cross the river and tow the boats down the left bank.

Towards its lower end is the first lock on the Barrow - Ardreigh lock. Just outside the upper end of the Ardreigh Canal, the Barrow is spanned by a concrete bridge carrying the railway branch, which now merely serves the Asbestos Cement Factory. One of the Piers of the Bridge was placed in the navigation channel when the bridge was built in 1918. It does not make navigation in an already tricky spot any easier.