| 摘要 |
1473781 Offshore structures G E DOWNS 22 Jan 1976 [23 Jan 1975] 3083/75 Heading E1H A semi-submersible platform structure is made by disposing or constructing a deck 10 on a jetty 11 so that it overhangs the sides of the jetty, leg sections 13a then being floated on barges 14 beneath the overhanging deck ends and the barge ballasting adjusted to engage sections 13a with deck 10, the sections then being welded to the deck and the barges further de-ballasted to raise the deck. Supports 15 are then placed between the deck and jetty, the barges ballasted and removed. Further leg sections are added in the same way, followed by horizontal flotation hulls (17), Fig. 8 (not shown) and inclined bracing legs (16). Equipment and accommodation are installed in and on the deck while on the jetty. The completed structure is then floated off the jetty on the barges, which are secured together by bridge pieces (19), and secured to the deck by cables (22), Fig. 9 (not shown) extending from winches (23) on the deck. At the installation site, the barges are sunk to anchor the structure and the cables and ballast adjusted to provide the required height above the sea bed, Fig. 11 (not shown). |
