The English island "Isle of Wight" faces a summer without water shortage

The water supply on the English island Isle of Wight, situated in the English Channel and separated from the mainland by the narrow strait The Solent, is mainly based on two underwater pipelines originating from the English coast around Lepe and ending at Isle of Wight near Gunard.

Unfortunately, one of the pipelines was torn by a ship’s anchor during the winter of 2003. This forced the second pipeline to handle the water supply single-handedly, while a solution was considered. The hot summer of 2003 made it impossible for the remaining pipeline to handle the necessary water demand due to the large number of tourists visiting the island. It was imperative that the problems were taken care of prior to the start of the tourist season 2004.

NKT-Flexible produced a new pipeline section to repair the defect. Subsequently, JD-Contractor A/S, experts in this field of work, was contracted to plan and execute the practical part of the repair process. Ten years ago, the two existing water pipes were laid out by the company’s cable transport and laying vessel Henry P. Lading, along with most of its current crew, thereby giving us a pre-hand knowledge of the conditions in the area.

Over the following months, engineers from JD-Contractor A/S travelled between England and Denmark to plan the following task, and prepare the "White Book" containing procedures and plans for all phases of the job, according to the customer demands. The preparation was performed in co-operation with the consulting engineering company JP Kenny (UK), who are consultants for Southern Water that own the water supply.

The extreme currents of The Solent brought about great uncertainty regarding the conditions of the pipelines on the sea bed and whether it would be possible to repair the pipes, or if the metal-cover of the pipes was corroded.

Initially, it was decided to send the dive support vessel C/S Cable One to inspect the pipe in order to localise damaged areas and collect samples for evaluation of the condition of the pipe. C/S Cable One is equipped with the RTK-DGPS positioning system of JD-Contractor A/S to ensure a precise positioning of ship and anchors between the many existing cables - and also to ensure that the divers entered the water at the correct positions.

C/S Cable One quickly surveyed the extent of the damage and located the section of the pipe to be replaced. The damaged section was detached by use of the company’s diamond wire saw system. A sample of the pipe showed that it was repairable.

The replacement section was produced by NKT-Flexible and loaded onto the turntable of C/B Henry P. Lading early in 2004 before heading for The Solent.

When C/B Henry P. Lading arrived the work was immediately initiated. The end of the pipe was prepared and equipped with straps to lift it aboard and mounted with a repair flange which was subsequently connected to the flange on the spare pipe. The 600 metre long repair section was laid out to the second repair spot. Here the other end of the pipe was lifted up and equipped with a flange. After purging the pipe with a cleaning pig from both ends, the pipes were joined together and pressure tested. The repaired pipeline was then lowered onto the sea bed where it was packed in concrete sacks to avoid corrosion at the sites of repair.

The defect pipe sections were then taken to Denmark to be disposed of and C/B Henry P. Lading could safely return home in the knowledge of a job well done. The pipe is now repaired and put back in its original trace, and there are no obstacles to the water flow to the Isle of Wight which can now face the summer seasons to come without fear of water shortage.