Patent · US Expired

Survey spar system for precision offshore seafloor surveys

US4335520A · kind A · utility

3Cited by
5References
11Claims
0Family size

Assignee

Inventor

Key dates

Filing dateSep 22, 1980
Grant dateJun 22, 1982
Priority date
Expiry dateSep 22, 2000

Classification

  • Technology area (CPC E)Fixed Constructions
  • CPC primaryE21B47/02
  • WIPO fieldCivil engineering
  • WIPO sectorOther fields

Abstract

A stiff, straight spar is allowed to pivot about an anchor on the seafloor. he location of the bottom with respect to the top is then determined by measuring the tilt of the spar and computing the offset of the bottom relative to the top. The straight member uses its internal buoyancy to remain erect and stable while the weight of the anchor keeps it in place on the seafloor. The top of the spar is tracked by shore stations while the tilt and heading of the spar is monitored by an instrumentation system. Simultaneous readings of the shore instruments and the spar's tilt and heading indicators allow direct determination of the anchor location relative to the shore. An air ballast control enables the apparatus to be easily maneuvered on the ocean bottom by divers or on the surface and an internal plumb bob system allows calibration of the overall system.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.