BEFORE ARDNACRUSHA power-station was built, writes Brian J. Goggin, there was another waterway route from Killaloe to Limerick, with some very interesting features

The old route had five sections: three of canal and two of river. The old canal at Killaloe originally had three locks, two of which were submerged when Ardnacrusha was built. Below that, boats used the river for the next section, which brought them past the village of O'Briensbridge, where again strong currents were a problem. Then, about 2km further downstream, they turned right into the Plassey–Errina Canal, although it was also possible to go a little further downstream to a quay at the upper end of the village of Castleconnell.

The Plassey–Errina Canal had six locks, two of them doubles. The uppermost lock, at Errina, was originally a triple-chambered lock, unique in Ireland, but it was later converted to a double. This canal rejoined the Shannon at Plassey, where the University of Limerick is now.

At this point, horses were originally ferried across the river; a bridge was built later. The navigation used the river briefly until it met the short Park Canal on its left: this cut off a loop of river leading through the rapids and weirs of Corbally. The boats went through one lock to reach the Limerick canal harbour; another lock, just above where Abbey Bridge is now, allowed boats to go downriver to the Limerick docks and the estuary.

Charles Wye Williams, who ran the Irish Inland Steam Navigation Company, was aware of Scottish trials that showed that long and narrow horse-drawn boats could reach higher speeds with less effort. He therefore constructed the iron Nonsuch, 80' x 6'6". He told the Institution of Civil Engineers in 1840 that "The boat thus constructed has been found to answer perfectly... it is capable of carrying 60 passengers, travelling at a speed of nine miles per hour, with the same power that was required to draw a 60ft boat with a less load, and there is much less action on the canal bank in consequence of the increased length... this boat has been working without intermission for three years between Limerick and Killaloe, traversing twice daily a distance of 15 miles, on a navigation of considerable intricacy, and passing 11 locks, without any incident having hitherto occurred."

The only problem was that the boat was too long for the locks. However, Williams had constructed it with hinged ends: "... having the stem and stern ends (each ten foot long) attached by strong hinges to the body, and susceptible of being rapidly raised to a vertical position by means of winches; thus reducing the length to 60ft when required to pass through a lock." Each of the lifting sections could be kept down, when underway, by the weight of one man.Charles Wye Williams, who ran the Irish Inland Steam Navigation Company, was aware of Scottish trials that showed that long and narrow horse-drawn boats could reach higher speeds with less effort. He therefore constructed the iron Nonsuch, 80' x 6'6". He told the Institution of Civil Engineers in 1840 that "The boat thus constructed has been found to answer perfectly... it is capable of carrying 60 passengers, travelling at a speed of nine miles per hour, with the same power that was required to draw a 60ft boat with a less load, and there is much less action on the canal bank in consequence of the increased length... this boat has been working without intermission for three years between Limerick and Killaloe, traversing twice daily a distance of 15 miles, on a navigation of considerable intricacy, and passing 11 locks, without any incident having hitherto occurred."

The only problem was that the boat was too long for the locks. However, Williams had constructed it with hinged ends: "... having the stem and stern ends (each ten foot long) attached by strong hinges to the body, and susceptible of being rapidly raised to a vertical position by means of winches; thus reducing the length to 60ft when required to pass through a lock." Each of the lifting sections could be kept down, when underway, by the weight of one man.

Guinness and sand
In the 1880s, Guinness began sending their porter to Limerick by canal, undercutting the local breweries. Limerick Guinness drinkers maintained that the four- or five-day voyage from Dublin, on the calm waters of the canal, allowed the porter to mature, so that the pint served in Limerick was the best in Ireland, with (according to Séamus Ó Cinnéide) "a delicious nutty flavour".

This trade continued after other traffic on the Grand Canal ceased on 1 January 1960. Guinness needed time to build a depot near Limerick's railway station, so CIE kept 14 canal-boats and two tugs in commission until mid-1960 to serve the drinkers of Limerick. The last cargo was carried by 51M.

By that time, the old navigation was no longer in use. The building of the Ardnacrusha power station, and the weir at Plassey Villa, had flooded an area below Killaloe and blocked access to the stretch of river that included O'Briensbridge, Castleconnell and the entrance to the Plassey–Errina Canal. After that, boats travelled through the headrace canal, the lock at Ardnacrusha, the tailrace canal and the Abbey River. But they continued to use the old harbour at the bottom of the Park Canal so, just before where Abbey Bridge is now, they had to make a sharp left turn and travel up through the tidal lock into the harbour. They used horns to warn the lock-keepers to have the gates open for them; a boom across the river stopped boats from being swept sideways under Baal's Bridge.

In Limerick itself, you can visit the Park Canal and the old harbour, which is close to the Abbey Bridge on the route from Dublin into the city centre. Some of the old buildings are still visible. The harbour and the canal have been dredged recently and new lock gates have been fitted: note the patented mechanism on the upper gates, which is designed to resist high tidal water on the wrong (downstream) side of the gates. It is possible to walk from here all the way to the University of Limerick, passing the second lock and the Guinness footbridge at the Park Canal's junction with the Shannon.

From within the University, you can walk down the riverbank to the old Plassey Mill, which had its own lock for the barges that carried workers and goods to Limerick. There are traditional fishing cots nearby, as well as a reproduction sand-cot. The old horse-bridge still spans the Shannon, and across it you can see the Annaghbeg Lock, the bottom lock of the Plassey-Errina Canal.

It seems unlikely that the whole of the lower Shannon navigation will ever be restored, but the Park Canal is being restored for walkers, cyclists and boaters, and the old harbour would make a better mooring-place than the Custom House jetties. And upstream, navigation could be restored to O'Briensbridge and Castleconnell, providing Killaloe-based boaters with a new destination, simply by providing a lock at Parteen Villa Weir.

Published in Afloat February//March 2008

(Acccessed on 24th November 2015 http://afloat.ie/item/15441-limerick%E2%80%99s-hidden-history)