Achill Island ESB Works

Project Description

This project involved the removal of approximately 70 metres of concrete surrounding the submarine cable between High water mark and low water mark on Clare island beach. The concrete was removed from the submarine cable on the beach section using a hydraulic breaker, involving the switching out of the cable to facilitate this. The broken concrete segments were removed from beach and disposed of to a licensed waste facility.

Client – Areas: Mayo County Council

Project Timeline – August 2021 -September 2021

Role – Main Contractor including PCSC

The scope of the project included:

Approximately 70 m of 0.4×0.4 m trench in rock using hydraulic rock breaker and excavator was excavated between low and high-water marks along shallow depression adjoining a protective rock outcrop ledge.
Dive survey of rock outcrops beyond low water out to approximately 50m position was undertaken and best route around these rock outcrops was mapped out using small buoys attached to weights.
Floats were attached to the cable over the slack area and beyond for a distance of approximately 50m to enable the cable slack to be deployed to follow the outcrop avoiding route mapped out previously.
Care was taken to avoid kinking the cable while manoeuvring the cable around rock outcrops using a combination of RIB boats and divers. Floats were removed once cable was laid in final route minimizing the amount of cable lying on rock outcrops.
Cable beyond low water mark was fitted with articulating cast iron cable protectors for a distance of approximately 150 metres. This involved partially lifting the cable free from the seabed to allow enough room for divers to position and bolt together the heavy half covers around the cable.
For a distance of approximately 10m in the vicinity of the low water mark area, once the cast iron cable protectors were installed, the cable was pinned to the flat rock surface beneath using U-shaped marine grade stainless steel pins. These pins were applied at 1-meter intervals to prevent cable movement on the flat rock area.
Between the 150m and the 300m mark out from low water mark, the cable was buried to a depth of 0.5m depth using divers.

Achill Island ESB Works

Project Description

The scope of the project included:

Quick Links

Our Culture

Contact Us