*.he relative magnitudes of the measured dynamic and 

 tare voltages. As a result, the uncertainty in the 

 load amplitude varied depending on the run condition. 



3. Tachometer- voltages were measured to 4 0.5 volt. As 

 a result, frequency resolution is 0.004 hertz and 

 circular frequency resolution is 0.024 radian per 

 second. 



4. With flow in the channel at 0.6 knot, speed is main- 

 tainable and uniform from surface to floor to within 



+ 10%. However, speed did not enter into the calcula- 

 tions which follow. 



In the data analysis, the above resolutions were included as error 



terms. For example, in Equation (18), the voltage V x was written as 



V ♦ 6 V where V is a measured voltaqe and f V is voltane resolution 

 xm xm 



(6 V = 0.05 millivolt). The final results are tabulated in Appendix A 

 in terms of values plus or minus cumulative error limits. 



EXPERIMENTAL RESULTS AND DISCUSSION 



The calibration matrix of Equation (18) was applied to the measured 

 steady voltages to obtain steady loads on the mooring models. These 

 results are summarized in Table 4. 



The tare correction Equations (19) and (20) and the calibration 

 matrix Equation (18) were applied to the measured cynamic voltages to 

 obtain dynamic load amplitudes on the mooring models. For comparison 

 with analytical predictions, Equations (23) and (24) were used to trans- 

 form the load amplitudes into horizontal and vertical response ratios. 

 The load amplitude results are tabulated in Appendix A. The load 

 response ratios art plotted versus reduced frequency u a/c in Figures 

 11 through 22. The results are shown in order of decreasing confi- 

 dence in the data, which is influenced by the following two factors: 



1. Similarity of the sample materials as model moorings 

 as noted in Table 2, and 



29 



