Chelsea Harbour, London

JSM’s Faults and Services team were called out to the prestigious area of London’s Chelsea Harbour by a major UK DNO to work on an extremely problematic joint fault.

This project saw the installation of two Ericsson transition joints on an ASR circuit between a 66kV 300ml² oil-filled cable and a 66kV XLPE cable on Townmead Road and Burnaby St. These installed joints were a part of a bigger scheme of underground multi-utilities diversionary works which would accommodate a new residential building proposed in the area.

The initial oil-filled cable used within the circuit was replaced with XLPE cables due to the technology of oil-filled cables becoming obsolete and posing a threat to the environment. Many oil-filled cable networks were installed in the 1930-40s and are reaching the end of their shelf life. They are beginning to degrade and break down. XLPE stands for Cross-Linked Polyethylene and where the old style of cable used oil to insulate the copper core XLPE uses chemically bonded polyethylene molecules which has a high resistance to deformation at high temperatures.

The residents, local businesses and local authorities were very pleased with JSM while operating in Chelsea Harbour. To satisfy the various stakeholders JSM committed to working round the clock including late nights and weekends.

In recent years, the landscape of Chelsea Harbour has changed with new residential spaces, commercial spaces, footpaths and carriageways being constructed, thus underground utility services has possibly been diverted and relocated numerous times.  During this project, JSM discovered some existing utilities services were omitted from utility records. Nevertheless, JSM overcame this challenge and proceeded with the project at hand.

33kV jointing works are very common for JSM however what makes this job relatively special for JSM was the higher voltage of 66kV and the complexity of the joint involved.