Structure failure detector with signal transmission through the structure itself

• US 4,502,041 A
• Filed: 05/03/1982
• Issued: 02/26/1985
• Est. Priority Date: 05/03/1982
• Status: Expired due to Fees

• Current Assignee: Regents of the University of California (University of California)
• Original Assignee: Regents of the University of California (University of California)
• Inventors: Penzien, Joseph
• Primary Examiner(s): Crosland, Donnie L.
• Application Number:
  US06/373,967
• Time in Patent Office: 1,030 Days
• Field of Search: 340/532, 340/601, 340/602, 340/592, 340/591, 340/603, 340/604, 340/605, 340/611, 340/612, 340/614, 340/621, 340/566, 340/683, 340/665, 340/679, 116/109, 181/0.5, 181/105, 181/108, 181/106, 181/110, 181/111, 181/112, 181/113, 181/118, 181/119, 181/120, 73/40, 73/40.5 R, 73/40.5 A, 73/41.2, 73/46, 73/49.1, 310/311, 310/314, 310/318, 310/320, 310/321, 310/337
• US Class Current: 340/532
• CPC Class Codes: E02B 17/0034 Maintenance, repair or inspection of offshore constructions
• CPC Class Codes: G01M 3/02 by using fluid or vacuum

Abstract

An offshore drilling tower has at least one upright hollow member extending from below the water to support an above-water platform. A detector in or on the hollow member, usually below the water, responds to a water leak into the hollow member. The detector includes a signal generator responsive to pressure or chemical effect of the water. The detector is effective when actuated by water intrusion into the hollow member and into contact with the detector to send a signal of a unique or distinct frequency through the member itself to a signal receiver, preferably on the platform. The receiver is tuned to the distinct frequency and is effective upon receipt of such signal to afford an indication that the detector has been actuated by a water leak at a particular location. Variously tuned signal generators can be located within and without the tower on different ones of the hollow members, so that each, when energized, actuates a comparably tuned receiver on the platform, thus affording unique indications of various leak locations.

Claims

1. A structural failure detector especially for an offshore tower wherein a platform having well-servicing machinery transmitting vibrations at frequencies associated with said servicing machinery is supported on a hollow frame extending beneath the water comprising a signal generator adapted to generate a signal having a frequency distinct from said frequencies associated with said servicing machinery and to transmit said signal at said distinct frequency through said hollow frame to said platform, means connected to said hollow frame and effective to activate said signal generator to generate a signal at said distinct frequency in response to leakage of water into said hollow frame, and means on said platform for receiving from and through said hollow frame said signal having said distinct frequency and for indicating receipt of said signal having said distinct frequency.

2. Mechanism as in claim 1 having several individual ones of said signal generators, each of said signal generators having a frequency distinct from the frequency of others of said signal generators and distinct from said frequencies associated with said servicing machinery, and means at said platform for responding to said several distinct frequencies only.

3. A structural failure detector for use with a drilling platform supported on a hollow leg extending beneath the water and having servicing machinery on said platform adapted to transmit vibrations at first predetermined frequencies through the material of said hollow leg comprising means on said leg activated by water in said hollow leg for generating vibrations at second predetermined frequencies different from said first predetermined frequencies and transmitting said vibrations at said second predetermined frequencies through the material of said hollow leg to said platform, and means on said platform for selectively receiving and indicating the receipt of said vibrations at only said second predetermined frequencies.