Vessels utilized at Diego Garcia for the reported installation were 

 two YC barges and an LCM-8 workboat. The barges provided working plat- 

 forms with ample deck space for equipment and anchor hardware. The use 

 of two separate barges provided flexibility to allow an anchor to be 

 installed while a previously installed anchor was being proof-loaded 

 elsewhere. The workboat provided positioning thrust for either or both 

 barges as well as transportation for personnel and additional hardware. 



On the ''crane barge'' was mounted a 30-ton crawler crane fitted 

 with a single- line hook and a four-part hook capable of independent 

 operation. This greatly facilitated tilting of the launch vehicle for 

 preparation. The crane also was essential in lifting the heavy anchor 

 components during assembly operations and was used to retrieve pistons 

 after they had been extracted from the seafloor by the winch barge. 



On the ''winch barge'' were mounted three winches - two smaller 

 ones with 3/4-inch (19 mm) wire and one larger, double drum winch with 

 1-inch (25 mm) wire and 5/8- inch (16 mm) wire on its two drums. At the 

 opposite end of the winch barge was mounted a 30-inch (760 mm) -diameter 

 roller sheave provided by CEL for proof-loading the anchors without 

 damaging the anchor load line. The main anchor load line was sufficiently 

 long [110 feet] (34 m) that diver assistance was not required, although 

 swimmer assistance was employed frequently to facilitate making connec- 

 tions. This line was retrieved by hauling in on a preattached tag line. 



A beach gear purchase section - a nine-part block and tackle designed 

 for applying large loads to anchor lines during salvage operations — was 

 threaded with the 5/8-inch (16 mm) wire from one of the center winch 

 drums to provide the large required proof- loads. A 10,000-pound (45 kN) 

 dynamometer was attached to a stationary block and rigged to deflect the 

 5/8-inch (16 mm) line through an angle having a sine of about 0.25 to 

 provide load data; this, combined with the nine-to-one mechanical advan- 

 tage of the beach gear, gave an attenuation factor for the load reading 

 of about 36. The effects of friction were judged to reduce this factor 

 to 31.5 ±1.5. Hence, the desired 100,000-pound (450 kN) proof -load was 

 well within the range of the dynamometer. The ±5% range of precision 

 of this system was considered satisfactory. 



A welder was required onboard the barge to secure connections to 

 the anchor projectile after system assembly. Also, onsite modifications 

 to make anchor components mate properly (tie rods to projectiles) required 

 the shipboard use of a cutting torch on each projectile. In addition, a 

 well- stocked toolbox was required for system assembly and adjustment and 

 preparation of the S/A device before each shot. 



Briefly, the anchor installation operation began with preparation 

 of the system by fitting the launch vehicle with a piston, a projectile, 

 and lines while it lay on its side. After the launch vehicle was set 

 upright, a cartridge was loaded, the breech block and the S/A device 

 secured, and the firing cable and a safety line for disarming taped in 

 place. The system was deployed by crane to the seafloor at a spot 

 premarked by a small buoy while control was maintained of a tag line 

 attached to the end of the main anchor load line to effect proper 



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