‘St Malachy’s Wall’ is the only visible remnant of the medieval monastic foundation of Bangor Abbey. The monastery was of international importance and renown some 800 years ago. As its oldest upstanding structure, St Malachy’s Wall is a very important historical asset for Bangor, North Down borough and Northern Ireland as a whole.
The structure is scheduled for protection under the Historic Monuments and Archaeological Objects (Northern Ireland) Order 1995. NIEA: Historic Monuments Unit has been working with North Down Borough Council and Bangor Abbey Select Vestry since 2002 to assess and agree the best approach to protect and manage the monument.
The first part of the conservation process was to clear the thick matte of ivy and other vegetation from the masonry. The Council undertook this in line with NIEA guidelines and has been treating any re-established vegetation on an ongoing basis since. This enabled the first comprehensive assessment and recording of the structure for quite some time. The wall has had an eventful life, as evidenced by the many alterations and additions that can be seen in the masonry fabric. It also contains some very interesting features. Evidence of three lancet windows exist on the north side of the original building. Lancet windows are tall and narrow with a pointed arch at the top and their presence helps us to date the wall to around the 13th century.
Initial assessment of the wall also revealed that its eastern portion showed a marked lean outwards, but it was initially unclear how serious this might be.
As this was an unusual and specific project, Mann Williams Ltd, specialist conservation engineers based in Bath, was engaged by NIEA. It was eventually agreed that the most appropriate course of action was to try to rectify the lean to an acceptable degree, along with consolidation of the masonry.
The wall heads were recorded and carefully removed. The leaning portion of the wall was jacked to a more vertical position with a jacking system constructed against the leaning face. The section of wall to be jacked was separated from adjoining masonry by raking out two deliberate breaks (these were made where later masonry joined onto the medieval fabric). A trench was created on the other side of the wall to allow the structure to settle back into a more vertical position.
Following jacking, a series of vertical ‘cintec anchors’ were drilled down through the wall and into the ground. A cintec anchor is a steel bar enclosed in a mesh fabric sleeve into which a specially developed grout is injected under low pressure. A series of horizontal anchors were also set throughout the wall to give it more homogeneity.
The deliberately created breaks were then rectified. After analysis of a sample of original mortar from the wall, the localised consolidation of masonry fabric was undertaken using Natural Hydraulic Lime (3.5), as well as localised grouting work. The wall heads were reset in their original position. Three blocked ‘putlog holes’ (holes from the original scaffolding used by medieval masons) were reopened to enhance appreciation of the site.
This conservation scheme has been the result of four years concentrated deliberation, discussion and collaboration between NIEA, North Down Council, the Select Vestry of Bangor Abbey, and Department of Finance and Personnel engineers. In line with best conservation practice, we have worked on the principles of minimum intervention; maximum retention of historic fabric; clarity of new work; and reversibility.
NIEA’s aim was not to make Malachy’s wall ‘look like new’. Rather, it was to ensure that what had been left by earlier generations was looked after, understood and passed on to our successors, in the most secure condition possible. The wall could have dismantled, stone by stone, and rebuilt - but then we would have just built a new wall, using historic masonry. This way, the original build will stay intact. When the conservation job is completed, people will be able see, touch and feel stonework that medieval masons cut and put in place, and that the monks and lay people of Bangor used over the centuries.