The CPT, once sitting on the ocean floor, uses the weight of the
unit, as well as suction anchors, to force a cone-shaped probe
into the seabed to depths of up to 150 feet. By pressurizing the
inside of the probe and modifying the load cell design inside
the cone, the CPT is insensitive to external hydrostatic
pressure, which can reach 5,000psi at a working depth of up to
13,000 feet. The design is the achievement of Ronald Boggess, a
marine services operations manager for Gregg. It essentially
takes the pressure factor out of the equation at these depths
and allows for much more accurate readings of density, shear
strength, and tip resistance in soil whose consistency has been
described as oatmeal. The innovations in both the cone and the
Seabed CPT provide tremendous advantages for the user.
Productivity increases by providing two to three times the
footage in a period with less impact on the exploration site.
One of the many hurdles Boggess had to overcome was finding a
way to maintain the correct amount o