One of the crownholes that appeared.

Kingscourt-Carrick road 'safe' after mine collapse

The Kingscourt to Carrickmacross road has been deemed safe to use after a major subsidence incident in 2018.

That's the conclusion of a report, which follows on from one released by mining company Gyproc and another commissioned by the Department of the Environment in February, which deals with outstanding issues or questions raised.

Gyproc commissioned consultants SRK to investigate the incident, with that report published in 2019. The Department of the Environment subsequently commissioned Wardell Armstrong to carry out a separate, independent review.

An underground, disused mine collapsed in the Drumgossett and Knocknacran areas of Magheracloone in September 2018, leading to concern over the stability of the area.

The R179 road linking Carrickmacross and Kingscourt was closed as a precaution, as well as a local road in the area. Both subsequently reopened.

The local community centre and GAA grounds were condemned and later demolished after large cracks and holes opened at the site.

Investigations found that Gyproc had used the former mine to store water run-off from its site to reduce the impact on the nearby River Brusk.

However, it found this had the effect of eroding support pillars in the mine, which then collapsed, leading to a crownhole opening on the surface.

Wardell Armstrong published interim reports in June 2020 and February 2021 but said a number of questions needed addressing, leading to this addendum report.

It says Gyproc and SRK have “addressed all issues in a full and acceptable manner”.

It said the investigation and study work related to one area “did not give a full picture of the complicated geological structure that affects the area”. It says this led to a need to obtain further information to back up the claim from Gyproc and SRK that the R179 road was safe to use.

In another area Wardell Armstrong said high pressure pockets of air caused by flooding of the mine made laser scanning difficult.

It says this was carried out in May 2021 once water levels reduced. Wardell Armstrong conclude a review of the results "does not show any cause for concern” and the pillars appear to be in a stable condition.

It says following the report from Gyproc and SRK and the subsequent information provided, it agrees with the conclusions that the R179 road is safe to use. However, it says it would be “prudent” for the monitoring system, which was put in place by Gyproc in 2018 to allow for an early warning of any subsidence, to remain in place.