Accession Number : AD0600305

Title :   STRUCTURES IN DEEP OCEAN: ENGINEERING MANUAL FOR UNDERWATER CONSTRUCTION. CHAPTER 3. RECONNAISSANCE AND POSITIONING.

Descriptive Note : Technical rept.

Corporate Author : NAVAL CIVIL ENGINEERING LAB PORT HUENEME CALIF

Personal Author(s) : Lee,T. T.

Report Date : 15 MAR 1964

Pagination or Media Count : 236

Abstract : The chief factors involved in reconnaissance and positioning for a deep-ocean construction site are described in this report. In determining surface position from landfall, the two chief methods are the optical (sextant-angle fix) and the electromagnetic methods. Electromagnetic methods involve radar and other techniques such as the Tellurometer, Raydist, and Geodimeter. In determining position from a point out of sight of land, celestial navigation is the general measurement. Electromagnetic techniques, such as Shoran and Loran, are effective for long-range accuracy (distances between 50 and 1400 miles). LORAC is considered to be one of the most accurate long-range (500 miles or greater) positioning systems. Maintaining a position relative to an underwater construction site represents a major problem to the constructor. Factors involved include that o a suitable mooring system. Conventional anchor cable systems are commonly used for depths less than 6,000 feet. For greater depths, the U. S. Navy Bureau of Yards and Docks has devised a special deep-sea mooring system.

Descriptors :   (*SITE SELECTION, UNDERWATER), (*UNDERWATER, CONSTRUCTION), (*INSTRUCTION MANUALS, ENGINEERING), POSITION FINDING, NAVIGATION, CIVIL ENGINEERING, OCEANS, MILITARY STRATEGY, OCEAN BOTTOM SAMPLING, OCEANOGRAPHIC SHIPS

Distribution Statement : APPROVED FOR PUBLIC RELEASE