COSTLY engineering works may be required to preserve Carnlough’s historic harbour for posterity.
It has been discovered that the picturesque harbour wall may not have been built on firm foundations and Larne Borough Council has engaged consultants to advise on how best to protect and restore the heritage site.
Funded by the Marchioness of Londonderry and built around 1850, the harbour served as a port for the export of locally quarried limestone until the 1950s and is now predominantly a berth for yachts and pleasure boats. The limestone walls make it a popular stop-over for tourists travelling the Antrim Coast Road.
Recently, the council commissioned a geotechnical survey around the crescent area at the harbour, where repairs are needed to the steps, and found voids which were of sufficient concern to halt the excavations.
Councillors were told at a recent development committee meeting that the geology of the site indicates the harbour wall may be resting on either sand or Mercia mudstone, formed of post-glacial raised beach deposits. It was also discovered during the excavations that the wall structure is “highly porous”.
The next step is to sink a borehole to bedrock level to establish the geology, which will enable the consultants to advise if the crescent area should be removed; whether a sheet piling will resolve the problem; or whether a more costly concrete wall is required.
In the meantime, the council is considering how to manage the area in the interest of public safety. The local authority has stressed that it will do all in its power to ensure that the All-Ireland Rowing Club Championships in August are not disrupted.
The consultants have met with host club officials and advised that racing can proceed by installing a stainless steel platform over the crescent area and inserting metal steps further north on the harbour wall to access temporary floating pontoons from which competitors will board their boats.