to have a fixed pivot, the line was attached to the 

 pivot pin on top of the tie-down block shown in Figure 4. 

 Where some mooring line was to lie on the bottom, it was 

 attached to the bottom of the tie-d^wn block. 



2. Anchor Position - For the fixed pivot cases, the tie- 

 down block was positioned on the channel floor in align- 

 ment with two cross references, Where some mooring line 

 was to lie on the bottom, a reference mark on the line 

 was aligned with reference lines on the channel floor 



In this case several feet of line separated the anchor 

 and the point of mooring line tangency with the bottom. 



3. The upper end of the mooting line was attached to the two 

 component load dynamometer. 



4. The current flow was established at either or 0.6 knots. 



5. The steady-state configuration was established by moving 

 the upper end of the mooring line on the carriage down- 

 stream until the desired configuration was obtained. 

 Reference marks on the channel wall were used to determine 

 the mooring line terminal points to within ± 1/8-inch. 



6. Steady-state forces were recorded. 



After the equilibrium configuration had been set and recorded, 

 vertical harmonic oscillation of the upper end was established at the 

 desired frequencies, and dynamic input motion and loads were recorded. 

 Throughout most of the experiments, the amplitude of vertical motion 

 remained fixed at 0.5 inch. Movies were taken through the surface to 

 observe any out-of-plane motions (normal to the current) in the mooring 

 line. Movies also were taken through the side windows in tne channel 

 to observe both standing and traveling. waves in the mooring line. Both 

 types of observations yielded qualitative results. These procedures 

 were repeated for different preset locations and material samples. 



