文档介绍：MOBILE OFFSHORE DRILLING UNITS HULL GAUGING AND WASTAGE ALLOWANCES Classification Surveys for MODU/MOU Attachment M– Revision 0 Page 1 of 17 SWZ-002-02-P08 GENERAL INFORMATION – GAUGING & WASTAGE Gauging requirements are shown in Tables 2a, 3a and 4a. When gauging a drilling unit, wastage found is to be limited to the wastage allowances shown in Tables 2b, 3b and 4b. These allowances are only acceptable when local wastage is evident. “ Local Wastage ” is defined as average wastage of structure within two stiffener spacing and between frames/girders, . “ Panel ” structure. However, where wastage is throughout a single structural bay, circumference, panel, etc., (hereinafter, called a“ Global Wastage ”), wastage allowances shown in Tables 2b, 3b and 4b are not sufficient and considered eptable. Typically, global wastage would be where wastage is found throughout one of the following areas: A single bay ofa leg structure ona SEDU; A single girth of cylindrical leg shell plating ona SEDU; Entire length of either bottom, deck or shell plating ofa preload tank ona SEDU; A leg-well structure (shell or internals) ona SEDU; Circumference ofa diagonal / horizontal bracing ona CSDU; Circumference ofa column ona CSDU; Bracing / column / hull intersection ona CSDU; Entire drill-floor substructure members on any MODU; Entire helicopter-deck structure on any MODU; A single belt gauged on any MODU. Above listing is just a sample of global wastage, but should give an idea as to what it means. Even if the wastage was less than “ substantial corrosion ”, this may be considered as excessive wastage and require renewal. Where the Owner decides not to renew excessive global wastage and requests to continue operations for extended period of time, the attending Surveyor is to mend global strength analysis to be carried by the Owner, submitted to ABS engineering and accepted by ABS before the extension is accepted. Global wastage percentage of Special Application Structu