If there is one country more than another that ought to be possessed of ample and complete water communication, that country is surely Ireland. Surrounded on all sides by the sea, with a population greatly inured to the conditions of living upon or by the water, it should have at once the cheapest and the most comprehensive system of water transport in the world. This, however, is far from being the case. Neither in point of rivers, nor in point of canals, does Ireland compare favourably with Scotland, not to speak of the much more abundant resources of England. The actual waterways that are of real importance besides the Liffey, are the Earne and Shannon rivers, and the Grand Canal. About these we shall say as much as may be necessary to indicate their general characteristics.
It has been said that the unfortunate Earl of Strafford, from having seen the utility of inland navigation in the Low Countries, first suggested the improvement of river navigation in Ireland. In 1703 the first Act of Parliament was passed for rendering the Shannon navigable, and many improvements were projected. Nothing, however, was effected, although a useless expenditure of 140,000l. was made on the Shannon and Boyne in the year 1758. Various other large sums were afterwards granted, and frittered away in partial improvements of the Shannon, Boyne, Barrow, and Newry rivers, besides the Grand, Royal, Kildare, Naas, and Lough Earne navigations.
The Shannon.
The Shannon river forms the most important feature in the inland navigation of Ireland. For the first 144 miles of this waterway, from the head of Lough Allen to the sea below Limerick, the Shannon is like a series of rivers and lakes. Issuing from Lough Allen, it passes Leitrim, Carrick, Tarmonbury, &c., and then enters, at Lanesborough, a very irregularly-shaped and extensive sheet of water, called Lough Ree, about 17 miles in length. Leaving it, the river, now greatly augmented, passes Athlone, and then winds by Shannon Bridge and Banagher to Portumna, near which it expands into Lough Derg, another narrow lake, 23 miles long, with deep bays and inlets. From the southern extremity of this lake it flows on to Limerick. In this extent of navigation we have first Lough Allen, 10 miles; thence to Lough Ree, 43; Lough Ree itself, 17; thence to Lough Derg, 36; Lough Derg, 23; thence to Limerick, 15; making together 144 miles. The mean height of Lough Allen above the sea at Limerick is about 143½ feet, being on an average about a foot of declivity per mile. Instead of the natural fall, however, the water has been reduced by means of locks to a series of level pools. The estuary or firth of the Shannon extends south-west about 70 miles beyond Limerick to its mouth, which is finally about 8 miles wide between Loop Head and Kerry Head, at the Atlantic.
The direction of the Shannon from Lough Allen to Limerick, though generally south by south-west, is very circuitous, and broken by many streams, islands, and rocks. The soundings are as various, and both banks are liable to be overflowed by the river to a great extent; and the large expanse of the lakes would require a different sort of vessel from those which navigate the river. The works which have been constructed to overcome the natural difficulties of the navigation are either insufficient or in a state of decay; and it seems to be generally admitted that very little real good can be effected until the natural obstructions are removed, the number of lakes reduced, and the channel deepened and improved in various parts; though it is still doubted if the navigation would even then be suitable for anything but steam-vessels. The Shannon connects with the Royal Canal at Tarmonbury, and with the Grand Canal at Shannon harbour, near Banagher. At Shannon Bridge it receives on the west its principal tributary, the Suck; on the east, the Inny, the Upper and Lower Brosna, Mulkerna, Maig, Fergus, &c.
The Shannon river connects the tide water of the Atlantic in Limerick with Dublin by two canals, the Grand and the Royal. It passes by the towns of Limerick, Killaloe, Portumna, Banagher, Shannon Bridge, Athlone, Lanesboro’, Yarmon, Roosky, Drumsna, Carrick, Leitrim, and Drumshambo.
The expenditure on the river up to 1878 was 800,738l. The average cost of maintenance was 3300l., and the total receipts from tolls during the previous five years was 9510l., being an average yearly receipt of 1902l. This sum, deducted from the average expenditure of 3300l., left a net yearly loss of 1398l. At this average rate for the previous thirty years the money loss by the Shannon navigation amounts to 41,940l.
The depth of water for this navigation, over 7 feet to 10 feet, is maintained by eight wholly immovable weir-mounds. These weir-mounds cause inundations, damaging 24,000 acres of land. This damage during the last thirty years amounts to more than 100,000l. In the section between Limerick and Athlone, 68 miles, the average receipts of tolls for the five years ending 1878 was 1274l. Out of that sum an engineer and eighteen lock-keepers had to be paid 686l., together with repairs, which left from 300l. to 400l. a year profit.
In the section above Athlone, about 80 miles, the average receipt of tolls in the same five years was 197l., against the annual expenses of repairs and the salaries of an engineer and ten lock-keepers, amounting to 385l.
The interests of the Shannon drainage do not, in Mr. Lynam’s view,[58] require to diminish the minimum depth of water under 5½ feet on the lock sills. These interests require merely that the surface of the river and lakes shall be kept within a range of 5½ feet to 8½ feet on the sills of all locks from Athlone to Limerick. The bye-laws made by the Board of Works for the Shannon limit the draught of boats to 4 feet 10½ inches. The river and locks are maintained by the weir-mounds at levels that rarely are less than 7½ feet on the lock sills, and rise in floods to 9 feet.