Fortifications in the Shannon Estuary

Following a petition from the Limerick merchants on the lack of defences to protect shipping in the Shannon Estuary in 1781, a battery of eight 24-pounders had been constructed by 1783 at Tarbert Island, but it appears that this was a temporary work, abandoned or dismantled over the following ten years. War with France early in 1793 renewed the need for defence of the estuary here, where a large number of vessels were able to anchor south-east of the island, sheltered from westerly and north-westerly winds. Two batteries were under construction between 1794 and 1795; in August 1794, ten large pieces of ordnance were landed at Tarbert. The Ennis Chronicle reported the following month that eight wagons carrying gunpowder and sixteen carts loaded with grapeshot and roundshot arrived at Limerick from Dublin on their way to the Tarbert fortifications (two forts were under construction, supervised by Colonel James Ferrier of the Royal Irish Engineers), most of the guns being mounted on the batteries by this time. In June 1795 it was reported that the works were nearly completed, with sixteen 24-pounders and six 6-pounders to be mounted on gun platforms formed of stone slabs from Shanagolden.^[1] This suggests perhaps two batteries each with eight 24-pounders commanding the river and some 6-pounders for landward defence.

Documents of the Board of Ordnance of 1804 note that a lease was entered into by the Irish Board of Ordnance in May 1797 for land at Knockayne or Massey Hill, on which a dwelling-house, storehouse, guardroom and magazine were built, supervised by Ferrier. By 1804 these were unoccupied, as the works had been dismantled —possibly during the Peace of Amiens, from March 1802 to May 1803. Massey’s Hill is on the mainland just to the south of the western point of Tarbert Island, so that it seems possible that one of the batteries was sited near here.

The Shannon Estuary was one of the three invasion areas included in the French government’s instructions to Vice-Admiral Villaret de Joyeuse in October 1796 during the preparations for the expedition to Ireland. The suggested landing places in order of preference were Galway Bay, Bantry Bay, and the mouth of the Shannon. Included in the orders issued to the ships’ captains of the French fleet that arrived at Bantry Bay in December 1796 was a rendezvous at the mouth of the Shannon in case of separation and failure to meet off Mizen Head. Wolfe Tone was in favour of the ships that remained in Bantry Bay attempting a landing in the Shannon Estuary. By this time small detachments of the government forces had been marched towards Bantry and were assembling between Bantry and Cork at such towns as Bandon and Mallow. The detachment of the Londonderry Militia stationed at Tarbert marched to Mallow, joining other companies of the Londonderry and the Louth and Westmeath Militia, which had all been marched from Limerick during the first days after the French fleet’s arrival in Bantry Bay.^[2] Consequently, a French landing near Tarbert or elsewhere on the estuary of the Shannon would have met with little opposition, the Limerick garrison being some two days’ march away.

In August 1806, Arthur Wellesley visited Tarbert on his tour of the defences of the south and west coasts.^[3] His journal notes the forts on Tarbert, and he advocated having four or six 24-pounder or 32-pounder long guns ‘fitted on the non recoil principle’ here—perhaps a reference to guns mounted on traversing platforms. He went aboard the gunboat Trial and with the flood tide travelled up river, noting that some guns should be placed on Foynes Island. Aughinish Point some two miles east of Foynes Island was another place ‘where guns might be placed with advantage and appear absolutely necessary as this is the anchorage the furthest up the Shannon which a vessel of heavy draught of water would think of’.

General Charles Dumouriez, commander-in-chief of the French army in 1792, later deserted to the Austrians and in 1808 prepared a military memoir on the defence of Ireland for the British government.^[4] In this report he examined places convenient for an enemy to land and suggested the construction of batteries at estuaries, bays and harbours. At the mouth of the Shannon, where it is some two miles wide, he proposed a battery at each side, and a battery was subsequently constructed on the north side at Kilcredaun Point here. He also suggested a battery on Carrig Island, which is also the site of a later battery, a fort on Scattery Island, which today has a battery constructed a few years after his memoir, and a fort on ‘Killanin’ promontory, which appears to be Kilkerin Point, where another of the Shannon batteries was to be erected. He advocated a battery on Foynes Island, and the use of gunboats, bomb-vessels and fireships in the shallow waters of the estuary. Dumouriez does not mention Tarbert as the site for a battery or fort, presumably because of the existing defence works there in 1808 (see map, below).

Before Wellington’s inspection of 1806 and the memoir by Dumouriez, plans were under way for defences on the lower Shannon as part of the general scheme of defence for Ireland. In June 1804 the lord lieutenant, the Earl of Hardwicke, reported to London that works were in progress between Loop Head and Tarbert.^[5] Permanent works of any importance would presumably have been inspected by Wellington in 1806 or noted by Dumouriez in his memoir of January 1808: it seems likely that temporary batteries may have preceded the permanent works, all of which, except perhaps the battery that survived until recently on Tarbert Island, must have been erected after 1808.

Shannon Estuary 1793-1815

The Shannon Estuary batteries are all of a similar layout, with the exception of that at Tarbert, which resembled an obtuse-angled bastion in plan. The battery in each case is semicircular or D-shaped in plan, surrounded by a dry moat with six guns (except for the four-gun battery at Doonaha) arranged around the curved part of the perimeter, firing over the broad parapet. The rear of the battery was protected by a rectangular blockhouse or ‘bombproof barrack’ built in the moat at the centre of the landward side. On the roof of this structure were two guns for landward defence, either carronades or howitzers. Similar batteries are to be found at Keelogue on the Shannon above Portumna and at Rathmullan on Lough Swilly. The blockhouse or barrack was also described in contemporary accounts as a ‘defensible guardhouse’ capable of accommodating all or most of the garrison of a battery or redoubt, loop-holed for musketry, the roof to be arched over if possible with a terrace or platform on top.