Entries in rehabilitation (4)
The problem was that some 5 years ago pipeline survey works highlighted that ground movement has caused deterioration and cracking in sewers the vicinity of the cathedral, with the situation being carefully monitored by DALROD since. A more recent survey indicated that the sewers were now in need of relining, which is normally a straightforward procedure for the DALROD team. However, in this instance, one particular 225 mm (9 in) diameter sewer system, which was approximately 2.8 to 3.0 metres deep, had particularly difficult access problems. The access was tricky for various reasons including that the pipeline runs below a terrace of pre-war-built houses with no rodable access points from most of the lateral connections as well as poor access to most of the gardens of each individual property which made it difficult to reopen the lateral connections subsequent to the main line lining work. In addition to the access difficulties, most of the properties comprised 3-storey buildings that had live systems which could not be shut down adding to the general operational difficulties. All of this meant that Dal Rod had to reline the sewers whilst the system was live and over-pump where flows required it to make sure that no flooding occurred in the basements of any of the 3-storey buildings during the works. This was clearly a case for a trenchless lining or 'no-dig' solution. Having examined the options it was decided that Brawoliner was best suited to the work, a system which the DALROD team had previously utilised on similar jobs.
AES Kilroot Power Station (KPS), near Carrickfergus, some 12 miles northeast of Belfast, is an oil and coal burning power station that produces around one third of Northern Ireland’s electricity. Being such an important power generator for the area, however, the current facility must be kept at its best efficiency and operational performance at all times. As part of the ongoing maintenance work to ensure this performance is achieved, a CCTV survey of the existing 420 mm diameter, steel, sea water pipelines which have been in use for over 30 years was undertaken. The survey showed signs of severe encrustation and corrosion, with, in places, up to 30% of the pipe cross section being obstructed. Corrosion had also removed a length of approximately 7.0 m in the invert of one pipe and there were also numerous small holes throughout the length of the pipes which allowed the ingress of water in the form of jets and seepage.