Table 2. Summary of Test Results 



Date 



Sea State 



Payload 



Mode 



Data 

 Sets 



Dynamic Line Tension 

 (Percent of Static) 



Ship-Motion Averages 



Average 



Maximum 



Minimum 



Deck Acceleration (g) 



Period (sec) 



28 Sep 1972 

 28 Sep 1972 

 2 Oct 1972 

 19 Nov 1973 

 21 Nov 1973 



2 

 2 

 2 

 3 

 3 



light" 

 light 

 heavy 

 light 

 heavy 



hard 

 soft 



hard 

 soft 



hard 

 soft 



hard 

 soft 



hard 

 soft 



2 



4 





 11 



6 

 12 



4 

 11 



5 

 5 



29.6 

 13.1 



10.9 



20.0 

 13.7 



31.3 

 13.2 



22.4 

 12.8 



45.5 

 15.4 



22.2 



27.4 

 23.1 



48.5 

 18.6 



33.6 

 16.0 



13.6 

 10.7 



8.9 



11.1 

 9.7 



16.2 

 10.5 



13.0 

 9.5 



0.0071 



o.ou'' 



0.0095'' 



o.oogs'^ 



0.1 3*^ 

 0.14 



0.16 

 0.12 



4.96 

 5.08^ 



5.47'' 



5.9 

 5.8 



5.0'^ 



4.5 



5.1 

 4.9 



12,100 pounds in water. 

 Based on six data sets. 

 Based on five data sets. 

 40,000 pounds in water. 



design operation limits by an unavoidable combina- 

 tion of unexpected circumstances. An understanding 

 of what can be expected when this happens is 

 necessary to ensure the survivability of such a 

 system. 



In answer to the question of what changes need 

 to be made in the existing hardware to make it per- 

 form satisfactorily, the first step is to conduct a 

 comprehensive nonlinear analysis. 



This analysis, combined with measurements of 

 gas temperatures and pressures on the existing 

 hardware, can then be used to provide specific quanti- 

 tative requirements for the following items. 



1. Modification of the spring system to provide 

 an adequate cushion at each end of the boom stroke 

 to ensure survivability. 



2. Increase in the amount of the boomstroke to 

 allow for the less-than-perfect accuracy in the 

 automatic boom-centering system. 



3. Improvement in the automatic boom- 

 centering system. 



4. Reduction of the internal sticktion of the 

 system. 



CONCLUSIONS AND RECOMMENDATIONS 



Based on the totality of the development and 

 the testing effort with the existing MCLS hardware, 

 the following conclusions and recommendations are 

 presented: 



1. A passive, fluid-spring lift system of the boom- 

 bobber type can be designed and built to provide 

 significant motion-compensating capabilities for 

 single-cable lifts in sea conditions at least through sea 

 state 3. 



25 



