KBR and alliance partners achieve one million hour safety record on Sydney desalination project
The barge Nebula which laid the Botany Bay pipeline
Sydney Water has acknowledged its commitment to safety with a ceremony commending the Water Delivery Alliance on achieving a significant safety record on the recently-completed Sydney desalination plant. The alliance comprises global engineering, construction and services firm KBR (Kellogg Brown & Root) and its partners Bovis Lend Lease, McConnell Dowell, Worley Parsons, Environmental Resources Management and Sydney Water.
Sydney Water (SW) Managing Director, Kerry Schott, said the alliance partners worked one million hours without a single recordable safety incident. She described this as “an outstanding result that has never been reached on any Sydney Water project before.”
KBR’s Director of Water, Asia Pacific, Ted Cusack, described the result as a pleasing reflection of KBR’s own commitment to safety. He added, “‘I couldn’t think of a better way to celebrate KBR’s 50th birthday in Australia.” The Water Delivery Alliance recently completed design and construction of the 18-kilometre pipeline that delivers drinking water from the new desalination plant in Kurnell to the Sydney suburb of Erskineville. The desalination plant itself was designed and built by the Blue Water Joint Venture, comprising John Holland and Veolia Water. The entire project received the Government Partnership Excellence Award at Infrastructure Partnerships Australia’s National Infrastructure Awards.
The Water Delivery Alliance achieved a first on the drinking water pipeline across Botany Bay as part of Sydney’s $1.8 billion desalination project. A major part of the pipeline was laid under Botany Bay and the crossing was completed using a purposebuilt 130 metre-long and six storey-high lay-barge to lay a seven kilometre long twin pipeline of 1,400-mm diameter steel pipes. It was the first time ever that twin pipes of this size and length had been laid beneath a waterway.
The pipeline, from the desalination plant at Kurnell to the City Water Tunnel at Erskineville, is one of the largest pieces of infrastructure in the Sydney Water supply system. The pipeline is transporting up to 250 million litres of drinking water a day (with capacity for 500 million litres a day in the future) to a network supplying 1.5 million residents south of Sydney Harbour. As well as the Botany Bay crossing, the pipeline included 10 kilometres of landbased trenched and tunnelled pipelines of 1,800-mm diameter beneath mediumdensity residential, commercial, industrial and open-space areas.
Sydney Water awarded the design, build and commissioning contract for the pipeline to the Water Delivery Alliance as part of the $650 million Water Delivery The barge Nebula which laid the Botany Bay pipeline Infrastructure Project. The pipeline also incorporated:
- One of the country’s biggest drinking water pumping stations
- Flow and pressure controls
- Corrosion protection including monitoring systems, air relief, isolation, scour and other valves.
- Environmental management, OH&S management, community and stakeholder consultation and liaison, quality management, and incident and risk management.
Construction of the pipeline began in early 2008 and finished 10 days before the date to switch on the plant on January 28, 2010. The twin pipes (about 1,200 individual lengths of 12-metre pipe weighing 30 tonnes each) were laid down across Botany Bay, and connected to a mincrotunnelled 800-metre section of 1.8-metre diameter pipe. This section of the pipeline was microtunnelled under the bay to avoid impacting on sensitive seagrasses off Silver Beach at Kurnell. One of three tunnel-boring machines (TBMs) employed on the project operated 24 hours a day on the TBM drive. It took a month to complete and involved the installation of 271 jacking pipes. The best distance achieved in a 12-hour shift was 36 metres.
KBR’s Craig Nichelsen, Design and Completion Manager for the Water Delivery Alliance, said that in the main, environmentally friendly trenchless technology was adopted for the onshore pipeline. “Only around three kilometres was installed by conventional open-cut method, with sheetpile and trench-box shoring. The remaining seven kilometres was achieved using the TBMs to cause minimal disruption to residents and other stakeholders. Of the 18-kilometre route, only 1.3 kilometres was laid in residential areas’.
Notwithstanding the world first for the underwater twin-pipe laying operation, some of the tunnels for this project were the longest ever undertaken by pipe jack method in the Southern Hemisphere. As well as membership of the Water Delivery Alliance, KBR undertook independent verification for the Bluewater Joint Venture (John Holland and Veolia Water), which constructed the desalination plant. On time and around $60 million under budget, Sydney’s desalination plant is providing water to meet up to 15% of Sydney’s water needs.
