St. Mary’s Church of the Assumption, Tullamore, Ireland is the third church to stand on the site since 1794. Upgrading the church’s electrical systems while retaining its character proved a challenge, but one that was successfully overcome, as Colin McDonnell reports.

Upgrading the electrical systems of a splendid heritage building, such as Tullamore Church, without significantly affecting its operation or damaging its aesthetics is not easy. St. Mary’s Church of the Assumption, Tullamore is a truly magnificent building that holds a special place in the hearts and minds of the local Catholic community, but by 2008, the electrical systems in the church were over 20 years old and needed an upgrade to current standards. An electrical test of the systems in the church highlighted serious defects in the escape lighting and fire alarm system coverage.

Planning the project

The parish council set the following rule: work should be in keeping with the style of the church and should minimise disruption to its day-to-day operation – this despite that fact that the budget and management resources were limited. The test report by Energy Systems Design Ltd (ESD) rated the work between one (should be considered) and five (urgent). This gave the parish council a basis for planning the project, working closely with the contractors.

A key problem was that the church building and the services layout did not lend themselves to the installation of new or upgraded electrical services. Much existing wiring had been cast into the structure in steel conduit or was hidden behind the wooden ceilings in the main areas of the nave and transepts. Also, there was no clear path to route new services from the main switchroom in the tower, across the transepts into the nave and the choir loft / day chapel areas.

To discover where cable routes had been installed, ESD personnel met with staff that had worked on the refurbishment of the building in the 1980s. Efforts were also made to track down the architect’s drawings from the rebuilding project. Some drawings for the original building were discovered in the offices of Tullamore Town Council and then it was found that a substantial tranche of architect’s and engineer’s drawings were still held by John Flanagan Developments, which had been the building contractor. This company kindly allowed a full set of copies to be made at the offices of Dermot O’Keeffe & Associates, consulting engineers. Unfortunately however, the routing of the power, lighting and fire alarm cabling still remained largely a mystery.

Since 2008, a new CCTV system has been fitted in the church, the escape lighting and fire alarm systems have been substantially upgraded and new control gear has been fitted to the interior lighting.

Pendant light fittings – Most of the main body of the church – the nave and the transepts – are lit by globe light fittings either suspended or on standards. The suspended luminaires are of the 150W high pressure sodium type which combine with the wooden finishes to fill the interior of the church with a warm golden light. However these lights were controlled through wire-wound ballasts and ignitors located in three banks. These old-fashioned components had a relatively high failure rate and emitted a lot of heat. There was evidence of heat damage (including charring) at all three locations. Indeed, in one case, a fire had started as a result of ignitor failure.

As is often the case, this seemingly straightforward problem proved one of the most difficult to resolve.

A sample equivalent luminaire with integral control gear was sourced, but this was heavier than the existing fitting and the ability of the existing mounting to support it was in doubt. There was no straightforward way to supplement the support mechanism without substantially affecting the wooden ceilings.

The next plan was to install modern electronic control gear (with integral protection against overheating) in the existing three control gear locations. This too proved problematic as the remote electronic control gear could only operate up to a distance of 25m and there was no way to determine the routes followed by the wiring to the fitting locations. In fact, on inspection, it was clear that even the wiring to fittings that were quite close to the control gear could follow quite a circuitous route to the fittings.

The solution finally adopted was one devised by Tom Martin Electrical and was elegant in its simplicity. A wooden box, similar in appearance to the existing ceiling finish, was installed at the top of each suspended light fitting and a new ballast / ignitor was installed at each point. The three banks of ballasts were stripped out and a new switchbank installed at the Sacristy.

Fire alarm system – The next system to be addressed was the fire alarm system. The original engineer’s drawings for the 1986 restoration of the building showed beam type fire detection in the nave and transepts. However, only a single beam detector had actually been installed – protecting the transepts from the southern (Harbour Street) to the northern (Benburb Street) entrances. The decision was taken to decommission this system, which only provided partial protection to the main body of the church and replace it with an aspirating system. The aspirating system relies on a network of air sampling tubes installed throughout the area to be protected. Air is drawn into these tubes and conveyed to a detector located at a central panel. This is a very sensitive type of fire detection system with many advantages for a Heritage Building with high ceilings.

The system chosen was supplied and commissioned by Lir Fire Alarm Systems of Tullamore. Over three weeks, Tom Martin Electrical installed the sampling pipe network throughout the church. All of the pipes and fittings were carefully painted to match the building finishes. The care taken resulted in a system installation that has had minimal impact on the building appearances and finishes.

Escape lighting system – When the church was originally restored in 1986, a battery unit was installed in the tower and connected to lamps installed along with the normal lighting fittings in standards along the centre aisles of both nave and transept. Over the years, this system had fallen into disuse. Initially it was thought that it could be re-commissioned, but – as a system – it fell far short of the coverage required by the latest Irish Standard (issued in 2008) and the decision was taken to install a complete new system.

Spotlight luminaires were installed in the main body of the church, with ceiling mounted fittings in lobbies, corridors and the Day Chapel. The twin-spot fittings are either a decorative type with a brass finish, or concealed with only the spotlight visible.

At time of going to press, installation of this extensive escape lighting system is nearing completion.

Good relationships bring success

Strong working relationships between the contractors and the parish council were key to the success of the project, bringing together the diverse technical abilities of all involved. Recognition of the key objectives of the project – the budget, the building’s heritage, and respect for the day-to-day operation of the church – has ensured that this beautiful building is available to future generations in the same pristine condition in which it was found.

The principals

Employer: Tullamore Parish Council www.tullamoreparish.ie

Contractor: Tom Martin Electrical T/A Proton Electrical Services Ltd.

Engineer: Energy Systems Design Ltd.