526 



ISAACS 



[chap. 24 



Bethanized steel wire and a stranded Bethanized steel wire. The solid wire size 

 has varied from 0.082-in. diameter to 0.120-in. diameter. The stranded wire 

 size has varied from 0.123-in. to 0.200-in. diameter. 



Experimental stations using a special (1x7, long lay) stranded wire with a 

 tensile strength of 260,000 lb/in 2 have been installed. Experience indicates that 

 such stations have a life expectancy at least equal to, if not greater than, 

 stations using a solid wire. A few well-spaced butt welds can be used in fabri- 

 cating the individual strands, for the loss in strength is reduced by the number 

 of strands. 



There are several advantages in using stranded wire. The stranded wire will 

 take a smaller radius bend than the solid wire, it is simpler to unspool because 

 of a reduced tendency to "cut in" to the underlying layers, it is possible to 

 make the stranded wire in extremely long continuous lengths without special 

 processing, and it has good tension/drag and strength/weight ratios. 



Special machined wire clamps are used to hold the mooring wire without (or 

 with minimum) loss of breaking strength. These clamps can be secured to the 

 standing part of the wire while it is under tension. 



6. The Anchors 



In anchors a material having a high density is usually desirable both for its 

 lowering characteristics and for its compactness. Various kinds of anchors have 

 been used. Some have been solid steel cubes with pad eyes welded on to the 

 top and bottom and some have been ordinary railroad-car wheels. As moorings 

 increase in size and complexity, a more sophisticated design of anchor will be 

 required if the size of the mooring wire is to be kept at a minimum. For our 

 installations, gravity anchors have been designed so that the net vertical 

 reaction against the bottom (i.e. weight of anchor in water and weight of wire 

 in water minus the buoyancy of floats) is at least equal to 1.4 times the sum of 

 the expected horizontal forces. This has led to satisfactory performance on a 

 relatively flat bottom. For a sloping bottom the net reaction must be increased 

 as follows : 



(W-F v )=FJ(0.7-\on<H) 



With these assumptions a simple gravity anchor becomes impractical on 



