Success Story

A Lighter Heart for a Heavy Lifter

$50 million savings in lifetime repair cost

Saltwater corrosion is the silent enemy of every seagoing vessel. Average ocean salinity is 3.5%, producing metal-eating corrosion rates as high as 2.5 in. or 60 mm per year. Salt exposure is unavoidable: it flows through ballast pipes, splashes external surfaces, and fills the air.

Pioneering Spirit was designed to thrive in ruthless ocean environments. This one-of-a-kind vessel performs single-lift installation and removal of large offshore oil and gas platforms, along with installation of oil and gas pipelines. A series of horizontal lifting beams can install platform topsides weighing 48,000 tons (43,545 tonnes) all in one piece and remove 25,000-ton (22,680-tonne) rig jackets in a single lift.

An aerial image of the Pioneering Spirit ship at sea

Measuring 1,253 ft (382 m) long and 407 ft (124 m) wide, Pioneering Spirit is almost the size of a floating Empire State Building. At its deepest draft it reaches a world-record displacement of 1 million tons of seawater, making it the heaviest floating object on Earth.

With measurements like these, pulling into a dry dock for repairs isn’t a practical option. The challenge was to build Pioneering Spirit with lighter materials that stopped salt corrosion before it could start.

A graphic demonstrating the length of the fiberglass-enforced ship Pioneering Spirit (1,253 ft) against the Empire State building (1,454 ft)

Allseas commissioned NOV's Fiber Glass Systems to build a maintenance-free ballast system to protect their $2.9 billion (€2.6 billion) investment. After intensive review of design specifications, the Bondstrand 2000M pipe series was selected for its corrosion resistance, toughness, and temperature performance. With a projected lifespan of five decades or more, the ballast system will last for the life of the vessel and beyond.

Using detailed pre-design analysis, Fiber Glass Systems produced almost 5 miles of custom fiberglass pipe of various diameters, along with 11,000 fittings. "Just-in-Time" technology delivered materials to the building site right before installation. This approach prevented exposure damage while the pipe spools were in the shipyard, freeing up precious yard space and eliminating warehouse costs.

A chart showing the fiberglass structure of the Pioneering Spirit ship

Almost 5 miles of fiberglass pipe (green) were used to construct the ballast system for Pioneering Spirit. (Allseas)

A steel pipe ballast system would have experienced seawater corrosion almost immediately, requiring costly repairs. Pipe replacement has an estimated labor cost of $500 (€443) per foot, not including materials and downtime. Selecting the Bondstrand 2000M pipe potentially saved $50 million (€44 million) in labor cost alone to replace corroded ballast pipe.

A graphic demonstrating the weight and pumping energy differences between fiberglass and carbon steel

Fiberglass is also a kinder choice for the environment. It eliminates the waste and disposal of replacing steel pipe, saving up to 80% of the energy required to produce new steel pipe. The smoother inner surfaces require less pumping energy, providing up to 90% of energy savings during a 20-year life cycle.

The corrosion-free ballast system forms the strong, pumping heart of the Pioneering Spirit. With a life expectancy of more than 50 years, this heart will definitely go on.

Authors

Stephen Ching
Director of Global Market Business Development
NOV Employee Stephen Ching

Stephen Ching has over 25 years of experience in the business of delivering glass-reinforced epoxy piping to the marine and offshore industries. The Pioneering Spirit is one among many of such projects, and others include all large new-build FPSOs.