| 摘要 |
A mobile marine drilling assembly has a horizontally disposed pontoon which floats on or is submerged below the surface of a marine environment. A first vertically disposed column is secured to the pontoon and extends upwardly therefrom. A work platform has an opening through which the column extends, and the platform overlies the pontoon and is vertically movable relative thereto along the column. A jack system is operably connected with the work platform and with the column for jacking the work platform along the column between a first position wherein the pontoon floats on the surface of the marine environment and a second position wherein the pontoon is disposed a substantial distance below the surface of the marine environment. An anchor is secured to the floor of the marine environment. A plurality of resilient tendons extend between and are secured to the pontoon and the anchor, and the tendons are under tension when the pontoon is in the second position so that wave and current induced horizontal movement of the pontoon and thereby of the column and the work platform is permitted, and vertical movement is resisted.
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