25/002 - Provision of Onshore and or Nearshore Inspection Services

Description

The Contracting Entity is seeking applications from suitably experienced inspection companies to carry out offshore, nearshore and onshore inspection surveys of two submarine gas transmission pipelines each approximately 200km long, Scotland to Ireland from shore to shore, and one spur and one umbilical approximately 11km long to the Isle of Man. The network cathodic protection is provided by means of sacrificial aluminium alloy half shell bracelet anodes. The network entire lengths are either trenched, or rockdumped in lieu of trenching. The seabed is varied and includes sandwaves towards the Scottish end. The maximum water depth is approximately 140 metres. The inspection scope requires vessels equipped for visual inspection, acoustic examination, cathodic protection monitoring and the assessment of the disposition of the pipeline relative to the seabed. There is also a requirement for a capability for conducting intervention tasks involving the removal of seabed debris and/or freespan rectification and maintenance capability for a subsea tee in approximately 30 metres water depth. There is a further requirement for a capability to mobilise an offshore diving spread to conduct subsea intervention tasks using divers. There will also be a requirement to mobilise at short notice for unplanned debris surveys of the pipelines as required.