Page 127 - 6634

Shell’s most recent Truss SPAR broke the deepwater record and will be

operational in 2010. Truss SPARs are characterized by the tubular members that

provide a connection between the hard tank and the keel. The truss system also

support to the heave plates which reduce improve stability by reducing heave.

The Cell SPAR was also designed by Kerr-McGee in the Red Hawk project.

Red Hawk was installed in the Gulf of Mexico and made operational in 2004. Cell

SPARs have several design features including. The Hard Tank is made up of 6
cylindrical tubes that surround a seventh central tube.

Each of these tubes is 20 ft in diameter and contain variable-ballast tanks
and redundant, independent cells. The middle hull section is an extension of three

of the seven cylindrical tubes, and serves as a rigid connection between the hard
tank and the keel tank. The lower section, or keel, contains the permanent ballast.

a b

a – construction; b – building

Figure 6.34 – Cell SPAR

Red Hawk SPAR is a first and only Cell SPAR. The separate tubesare

connected by heave plates. Heave plates give the structure addedstability by

reducing the force transferred from ocean waves and current.

128