As a result of a considerable number of experiments it 
can be assumed that the drag coefficient, Cy > of a circular 
cable is about 1.2 over the range of interest. The validity 
of this assumption is subject to question depending upon the 
roughness of the surface, vibration, free-stream turbulence, 
and the Reynolds Number. The Reynolds Number is defined by 
Re = be » where v is the kinematic viscosity of the fluid. 
Figure 3 shows the variation of Cp with R, for a smooth 
cylinder normal to the stream, and it can be seen that Cp 
falls considerably below 1.2 at the so-called transition 
point. The value of Rg at which transition occurs, as well 
as the values o£ Cp, are highly dependent on the cable rough- 
ness, the free-stream turbulence level, and the vibration of 
the cable. Nevertheless, it is believed that a value of 1.2 
is a good compromise for use in these calculations. With 
this value for Cp we can therefore write 
R= 1.2 PSE aye (9) 
We must now consider the manner in which the hydrodynamic 
loading on the bare cable depends on the angle g. It has been 
13 
