History of BoomHall

Boom Hall Historic Landscapes

Boom Hall stands within the townland of Ballynashallog, near the northwestern bank of the River Foyle, on land granted to The Honourable, The Irish Society during the Ulster Plantation, formerly belonging to the Abbey of St.Colmcille.  The house takes its name from its close proximity to the boom constructed across the Foyle by the Jacobite army during the Siege of Derry in 1689. 

Boom Hall and Lighthouse in the late 19th Century

Much of the Boom Hall landscape is relatively flat, only sloping gently towards the Foyle, however, the strip of land about 35 metres wide, immediately adjacent to the water’s edge forms a much steeper bank. 

A series of diverse phases of activity have been superimposed upon the Boom Hall landscape.  In the first half of the 1980s the demesne was bisected by the construction of the Foyle Bridge and Madam’s Bank Road.  During the Second World War the house was requisitioned by the Admiralty and occupied by the Women’s Royal Naval Service (WRNS) who erected several American Quonsett huts around at least two sides of Boom Hall, the concrete bases of which remain.

The present Boom Hall (a large, two-storey villa built in the Classical style and now a neglected ruin) was built by the Alexander family in the 1770s.  At the same time it appears that much of the demesne was remodelled as a landscape park in the naturalistic style then in vogue. 

Historical evidence suggests that the Alexander family, who acquired the lease on Boom Hall at some point after the Williamite Wars, had lived in an earlier house on the estate, also called Boom Hall - the precise location of this earlier Boom Hall is not known, although a family history prepared in 1863, but not published until 1946, by the Rev. Robert Alexander (1795-1872), who had lived at Boom Hall as a child, indicates that it was located to the north of the present Boom Hall, possibly somewhere in the vicinity of the walled garden. 

The survival of a curvilinear Ha-Ha wall, presumably dating to the 18th Century, to the southwest, south and southeast of this position is consistent with this suggestion. 

                                                                                     Example of a Ha-Ha Wall

This earlier Boom Hall would also have been associated with a garden landscape, but one probably laid out in the more formal style typical of the period before 1740.  A number of garden features, datable to both periods of parkland design, can still be identified either on the ground or from aerial photographic evidence.

The 17th Century Military Landscape

The most archaeologically interesting phase of activity within the Boom Hall landscape is, however, the military activity associated with the two sieges of Derry in the 17th Century.  Unfortunately, no visible remains of this landscape are readily identifiable on the ground, probably as a result of landscaping associated with the 18th Century parks and destruction associated with both the occupation of the site by the WReNS and the construction of the Foyle Bridge. 

Within the immediate vicinity of Boom Hall the military features include Charles Fort built by Royalist forces in 1649 during the first siege of Derry.  Charles Fort was attacked twice, without success, by ‘parliamentary’ ships before the siege was lifted.  Charles Fort was reoccupied during the second siege of Derry in 1688-89 by Jacobite forces intent on maintaining a blockade of the city.  In order to prevent ships delivering supplies to the city, the Jacobite army built a boom across the Foyle.  The boom’s western end was located somewhere within what would subsequently become the Boom Hall demesne.  In addition to the reoccupied Charles Fort, the western end of the boom was also protected by the creation of a bastion (sometimes known as the New Fort) and several adjacent entrenchments.

Jacobite Forces on the Move Along the Foyle

These military features are best represented in a siege map titled ‘A New Map Of The City of Londonderry with its Confines; As it was besieged by the Irish Army in the year 1689 . Exactly Survey’d by Capt. Francis Nevill’.

Captain Francis Nevill had been present in the city at the very beginning of the siege, but was taken prisoner by the Jacobites. 

The map shows (from left to right) along the riverfront: Charles Fort, a series of entrenchments placed at various angles, an L-shaped entrenchment (labelled 17), a stream crossed by a bridge (presumably built by the Jacobite army in order to facilitate movement between their headquarters at Brook Hall and Charles Fort), a series of three entrenchments aligned in parallel with the river, a bastion on the water’s edge and a long, zig-zagging entrenchment.  The western end of the boom can be seen immediately to the south of the bridge. 

Behind the entrenchments depicted on Nevill’s map, and presumably located on the relatively flat ground above the sloping bank, are a series of military camps.


Detail from ‘A New Map Of The City of Londonderry with its Confines; As it was besieged by the Irish Army in the year 1689 . Exactly Survey’d by Capt. Francis Nevill’

The Siege Boom


 The Siege Boom was an important part of the Jacobean plan to starve the be-sieged inhabitants of the Walled City. The floating boom (made up of wooden spars, iron cramps and thick ropes) was constructed across the Foyle (at its narrowest point) in order to halt any attempted relief of the city by way of the river.  The actual site of the boom is north of the ruined Boom Hall and was anchored to a large rocky outcrop at the mouth of a stream which ran into the Foyle. The other end of the boom was anchored by rocks across the Foyle at Gransha.  Each end of the boom was guarded by cannons in forts known as Grange Fort and Charles Fort on the Boom Hall side. 


British Naval ships were laid up at Inch Island, but feared sailing down the Foyle due to the boom and Jacobean cannon emplacements along the river, particularly at Culmore Fort.

A Prospect of Culmore (Kilmore) Fort, 1700 from the King George III Topographical Collection.

Further insight into the arrangement of the Jacobite siegeworks and independent confirmation of the accuracy of Nevill’s map, is provided by the account of the French engineer, Mons. Pointis, who was responsible for the construction of the boom.  Writing to Louis the King of France on the 14th June 1689 from ‘The Camp before Londonderry’ Pointis reports that:

At last in spite of the dearth of all things in which we are here I have completed the boom which I have had the honour of telling you, my Lord, in my last letter of the 6th of this month that I was about to take in hand. It consists of beams a foot square in thickness which I have had removed from houses and joined to another by mortises of a foot and a half; each beam end being attached to the side of that to which it is joined by two iron cramps passed through the one into the other leaving a little play and freedom to these pieces. I have placed crosswise upon and underneath the mortises one end of a cable (doubled for want of iron chains) well fixed through each beam, and I have run the whole length of the boom a 5 or 6 in. rope which is the thickest I have been able to obtain and which is joined to the said beams by iron cramps in which it runs like a rod in curtain-rings and it has been noticed in stretching out the boom that this rope on the side of the beams which is most in the water was able that way to make the cutting of it difficult.

I know well that with the narrow course ships have in a river it is not possible that these different mutually supporting parts making one structure can be broken asunder. To prevent their being cut I got forts built on each bank of the river right at the ends of the boom. It will be necessary to equip these with guns that will strike between wind and water the vessels which cannot be farther distant than pistol shot.

The banks of the river being raised with a very steep slope I have had entrenchments dug in the form of an amphitheatre one above the other where our troops which will be stationed there in such numbers as are needed will be safe even from artillery, not only because of the parapet but from the depth in the earth. The whole fore which will be discharged from almost the same point (each entrenchment firing easily over the heads of those who will be in the other, by reason of the steepness of the slope) can enfilade the boom and with that I have difficulty in believing that they will attempt to cut it with hatchet blows, the workers, as I have said, not being farther than pistol shot from our entrenchments, and you know well, my Lord, with what difficulty you work on what is in water for it is always giving way.              

Mons. Pointis continues his letter explaining how the position of the boom and the arrangement of ‘forts’ and ‘entrenchments’ was expected to function:

I shall not be quite happy until the English are foolish enough presently to attempt this enterprise [i.e. of trying to break the boom] when I shall have the pleasure of worsting them. Because as they must come with the wind entirely behind or at least nearly so, once they are at the boom, return being impossible, they must perish under the fire; for they cannot be strong enough to land.

(trans. J.Wallis; quoted in Milligan 1946, 17).



However, on the evening of 28th July 1689, three merchant ships, the Phoenix, the Mountjoy and the Jerusalem, escorted by HMS Dartmouth and HMS Swallow's longboat, made their way to Culmore Point. The Mountjoy and the Swallow's longboat sailed towards the boom with the Phoenix.  The Mountjoy struck the boom, rebounded and ran aground.  Her captain, Michael Browning, was killed by Jacobite fire. However, the sailors in the longboat cut through the cables and chains of the boom.



The ships, under a barrage of fire, were able to make their way through the boom bringing provisions to the starving city, ending the Siege which had lasted three and a half months.

Extract from "The Apprentice Boys of Derry"

At about 7o'clock on the calm Sunday summer evening of July 28th, 1689, the Dartmouth, followed by the Mountjoy, Phoenix and the longboat, made course for Culmore, a move that hadn't gone unnoticed on the walls. Walker, who had just given his congregation a particularly rousing address, wrote, that "about an hour after the sermon, being in the midst of our extremity, we saw some ships in the Lough make towards us, and we soon discovered they were the ships Major-General Kirke had sent us, according to his promise that when we could hold out no longer he would be sure to relieve us."

The Dartmouth came under fire from Culmore, but didn't fire until the other ships were getting close. When the Dartmouth fired the other ships sailed past in the cover of the Dartmouth's cannonade. The other ships were heavily fired upon as they moved towards the boom. The Mountjoy, being the larger ship, sailed into the boom "and broke the iron part thereof", while the crew of the longboat "cut the wooden part of the boom" with their axes. However the Mountjoy had rebounded from the collision and her stern was stuck in the mud on the west bank.

In an attempt to halt the Irish advance, the Mountjoy fired three guns loaded with partridge shot. Their attempt succeeded, killing several of the Irish and causing the rest to flee. The recoil of those three shots had sent the Mountjoy off the mud, into deeper water, where she re-floated. Lead by the Phoenix she passed through the broken remains of the boom and continued on their way to the city.

By 10 o'clock the ships were at last tied up at the quayside.

While the people of the city were celebrating, the man who had saved them lay dead on the deck. The Mountjoy's Captain Browning had been shot in the head as he stood cheering his men on, and died on the spot.