Water Tower, aka Magherally Guage Tank, Kilmacrew Road, Banbridge, Co Down, BT 32

Known as the Magherally Gauge Tank, this is a disused brick and reinforced-concrete water tower and associated underground reservoir, erected in 1951 by the Portadown & Banbridge Regional Waterworks Joint Board. It stands along the route of the East Trunk Main, the pipeline carrying water from Fofanny Reservoir in the Mournes to Portadown. Although utilitarian in character, its elevated form reflects its function in regulating water pressure along the pipeline and to local users. It is likely a scarce surviving example of mid-20th century water tank technology in Northern Ireland. Planning consent for its demolition was granted on 26 April 2012 (planning application reference Q/2010/0468, described as "Replacement of disused water tower with dwelling").

ARCHITECTURAL DESCRIPTION

The tower is a rectangular, two-stage structure aligned north to south, with its principal façade facing west. It is built of brick with cement rendering, augmented by reinforced concrete. The upper stage, which contains the reservoir, is smooth rendered, while the lower stage is harled (roughcast). The two stages are separated by a plain string course running around the building. A slightly projecting flat concrete roof covers the reservoir within the upper stage. The roof is surrounded by a two-bar tubular metal railing, and two metal ventilators are mounted on it. Access to the tank is only possible through a roof hatch, reached by a vertical galvanised steel ladder fixed to the south side of the building; the lower end of this ladder has been removed, presumably for public safety reasons given that the site is now abandoned.

The west elevation is the most architecturally considered face of the building. At ground level there is a two-leaf tongue-and-groove timber entrance door, flanked on each side by metal casement windows of two-by-three panes, set in timber frames. Each of these openings sits within a recessed panel and all have flat concrete heads; the windows also have concrete cills. Above the doorway is a cement-rendered panel to which metal letters — possibly bronze — are affixed, reading: "Portadown & Banbridge / Regional Waterworks / Joint Board / [date now missing]." A narrow stucco cornice runs across the top of this panel. Below the left-hand window is a covered pipe.

The north elevation is blank. The east elevation is similarly plain, save for a single metal casement window set within the middle of three recessed panels. A vertical cast-iron pipe runs up the right-hand side of this elevation; there appears to have been a timber cladding around it, probably as frost protection. This pipe was likely either the water intake from the adjoining underground reservoir or an overflow pipe. The south elevation has no openings other than the roof access ladder affixed to it.

Immediately to the east of the tower, within the same plot, is a grass-covered underground water reservoir, also now disused. It has two galvanised steel inspection covers and a cast-iron pipe outlet fitted with a manual butterfly valve.

SETTING

The tower stands on the south side of a minor road near the top of a hill, within a triangular plot enclosed by a post-and-wire fence. Directly opposite, on the north side of the road, is a modern tarmac-covered service reservoir. The site is overlooked to the immediate south-east by Magherally Old Church. A larger service tank, still in use, stands on the opposite side of the road.

Construction materials: concrete roof; brick walls with cement render and harling; timber and metal casement windows; no rainwater goods recorded.

TECHNICAL FUNCTION

The precise technical function of the tank is not fully understood. Board minutes from 1949 refer to a "break-pressure tank" at Magherally, while later minutes refer to a "water gauge tank." The physical evidence — an elevated, rendered brick structure bearing the Board's name on its façade — is consistent with it being the gauge tank referenced in the July 1951 minutes, which suggest it was likely standing by that point but not yet rendered.

A break-pressure tank works by reducing the pressure of water within the main, thereby minimising the risk of pipe bursts under excessive loading. Water flowing downhill from Fofannybane towards Portadown would have built up considerable pressure. The break-pressure tank resets that pressure to atmospheric pressure at Magherally, so that the residual pressure at Portadown reflects only the difference in elevation between Magherally and Portadown, minus friction losses along the pipe — rather than the full pressure accumulated from the higher starting point. In operation, the incoming main discharged into the top of the tank, with flow regulated by a stopcock. The tank filled until the stopcock cut off the supply; as water continued to flow out along the main and the level dropped, the stopcock reopened to admit more water, creating a continuous regulated flow through the tank.

However, given that the covered underground reservoir over which the elevated tower sits could itself have served as a pressure-break device, it is equally possible that the elevated tank functioned primarily as a storage reservoir to supply local demand, with its height providing sufficient pressure for the surrounding area.

HISTORICAL BACKGROUND

The Portadown & Banbridge Regional Waterworks Joint Board was constituted in 1946 and enlarged in 1948 to include representation from the Borough of Portadown, the Urban Districts of Banbridge, Dromore and Newry, and the Rural Districts of Banbridge, Downpatrick, Newry (No. 1) and Tandragee. The Board's first major undertaking was the East Trunk Main, a new water main from Fofanny Reservoir in the Mournes, near Rathfriland, to Portadown. This augmented an earlier main laid in the early 1900s by the Portadown & Banbridge Joint Water Board. The East Trunk Main was constructed by direct labour between 1949 and 1951, under the supervision of the Board's consulting engineers Messrs Ferguson & McIlveen.

Board minutes record that on 30 March 1949, during construction, the Committee visited the site of a break-pressure tank at Magherally. Pipelaying in that locality is also recorded in May 1949. The minutes of 5 October 1950 note a discussion regarding the transfer of land for a water gauge tank at Magherally. By 7 June 1951, a quotation for the brickwork at the Magherally gauge tank had been received from Messrs Weir & Co of Portadown. The minutes of 10 July 1951 record the following decision: "It was suggested that as this was an elevated tank with visible brick work, an inscription should be incorporated in the brick work and it was decided that the full name of the Board and the year should appear." The last pipe on the East Trunk Main was laid on 25 July 1951, though minor works continued. The minutes of 8 November 1951 record approval for contract plasterers — rather than in-house staff — to plaster the gauge tanks. Water first flowed from Fofanny to Portadown along the new main on 3 February 1952; there was no official opening ceremony, the reason given being to avoid unnecessary expense to the public purse.

The minutes of 7 February 1952 noted that a main from Magherally to Banbridge should be laid as soon as possible, along with a new reservoir at Banbridge. On 18 May 1956 foundation stones were laid for a new reservoir at Spelga and a water treatment works at Fofannybane; both were officially opened on 30 June 1960, with their supply directed along the East Trunk Main and a further main to Newry.

The original East Trunk Main was replaced in 1997–98, and both the elevated tower and the underground reservoir were declared surplus to requirements in 2001. The property was sold by public auction to a private buyer in 2008.