Most floating platforms are set upright by an external force — a crane, a controlled tow, a mechanical jacking system. Perdido's hull did it differently: it arrived in the Gulf of Mexico lying on its side, and stood itself up by flooding its own compartments in a deliberate sequence, with no crane involved in the rotation at all.

Built by Technip at Pori, Finland, the hull was carried horizontal aboard Dockwise's heavy-transport vessel Mighty Servant 1 across roughly 8,200 miles to Kiewit Offshore Services' yard in Ingleside, Texas, before sailing on to its final site at Alaminos Canyon Block 857 — around 200 miles south of Freeport, in water deep enough that the platform still ranks among the deepest spar-type structures ever installed.

~7,820 ft
Water depth
118 ft
Hull diameter
9,773 short tons
Topsides, single lift
9
Polyester mooring lines
Stage 1
Fabrication and transport
The hull was built at Technip's Pori, Finland yard between November 2006 and May 2008, then shipped horizontal, deck-loaded, aboard Dockwise's semi-submersible transport vessel Mighty Servant 1 to Kiewit's outfitting yard in Ingleside, Texas — arriving mid-June 2008.
Stage 2
Soft-tank flooding
Once towed to site, tugs opened plugs on a soft tank at the base of the hull, letting seawater enter under control. This induced a deliberate, protective roll — designed to safeguard equipment already installed inside the hull — bringing the spar to roughly a 15-degree incline within about an hour.
Stage 3
Hard-tank ballasting to vertical
Heerema's crane vessel DCV Balder then pumped ballast water into the hull's hard tank at roughly 1,500 cubic metres per hour — around 20,000 cubic metres in total — sequentially draining higher tanks into lower ones to preserve stability as the spar rotated the rest of the way to full vertical. No mechanical lift or external rotating force was applied; the hull turned under its own shifting centre of gravity as it flooded.
Stage 4
Mooring and storm-safe condition
Nine polyester mooring lines secured the spar in place, three of which had been pre-installed at their anchor locations before the hull even arrived on site — a sequencing choice aimed specifically at getting the platform to a storm-safe condition as quickly as possible once upended.
Stage 5
Topsides installation
The topsides — a single-piece module of 9,773 short tons (about 8,866 tonnes), the heaviest single lift in the U.S. Gulf of Mexico at the time — was installed separately in March 2009 by Heerema's semi-submersible crane vessel SSCV Thialf, sailing from Ingleside on 8 March and completing the lift five days later.
Timing note

The hull was upended and moored in August 2008, directly ahead of Hurricane Ike making landfall on the Texas coast that September. The storm flooded Shell's Galveston supply base and heliport, forcing a shift of helicopter operations to Corpus Christi — a reminder that even a carefully sequenced ballast-controlled installation still has to survive the hurricane season it was scheduled inside of.

Perdido's hull never touched a crane to stand up. It stood itself up, one flooded compartment at a time.

First production began in March 2010. Perdido was described at commissioning as the world's deepest floating oil and gas production platform — a record for floating production overall that Shell's own Stones development, a disconnectable FPSO in roughly 9,500 ft of water, later surpassed in 2016. What hasn't changed is the installation method: a self-upending spar hull, floated to site and stood vertical by nothing more than sequenced, controlled flooding, remains one of the more distinctive heavy-lift stories in deepwater installation.

For further reading, see Heavy Lift Engineering for Offshore & Marine Construction, which places spar and jacket installation methods in a wider sector context.