DISCUSSION OF RESULTS 

 Entanglement 



Only three entanglements were observed during seventeen tests; two 

 of these entanglements occurred during the anchor-mating tests and the 

 other one during a deep-water test. 



As the guide frame emerged from the water near the end of deep-water 

 test D1 , it was observed that the guide frame had rotated 360 degrees 

 from its initial orientation. The rotation recording (Figure 9) indicated 

 that the entanglement was formed near the seafloor and had been pulled all 

 the way to the surface. However, the entanglement did not cause any 

 damage to the guideline system and did not delay the hoisting operation. 

 Technically, the system was entangled; but, practically, the entanglement 

 was not serious. 



Both anchor-mating test runs, one in 600-foot depth and one in 

 4,500-foot depth (Tests Ml and KD-1) ended with serious entanglements. 

 l\T-ien the add-on block was retrieved with the anchor block, the lift line 

 and the guideline were twisted about five times. Since in both cases 

 the add-on block reached the anchor block on the seafloor, the entangle- 

 ment must have occurred during retrieval of the assembly with both lift 

 line and guidelines. 



Guide-Frame Motion 



The rotation of the guide frame is considered an index of the 

 stability of the guide-frame/payload system. If the rotational displace- 

 ment of the guide frame is large, the system is considered unstable and 

 is liable to become entangled with the guideline. The rotation was 

 measured by a compass inside the Geodyne current meter mounted on the 

 guide frame. 



During processing of the recording film, the data from the double 

 guideline tests in shallow water (Tests 1 through 4) were lost; the 

 remaining shallow-water data are presented in Table 2. Of the varied 

 parameters of Table 2, only three have a strong effect on guide frame 

 rotation- -the guide frame span (the distance between lift line and 

 guideline supports); the submerged weight of the test load; and the 

 guideline span (the horizontal distance between anchor point and the 

 surface support point). The effects of the guide frame span and the 

 submerged weight of the test load are shown in Figure 10. The initial 

 orientation of the guide frame at the surface was 330 degrees from 

 North in the clockwise direction. The prevailing current direction is 

 about 280 degrees from North (coming from East). Almost all rotations 

 of the guide frame with heavy test loads were clockwise, with respect 

 to the initial guide frame orientation, whereas the guide frame with a 

 light load rotated only in the counterclockwise direction. The rotational 

 displacement is found to be inversely proportional to the guide frame 

 span, suggesting there is a constant, relative, current-induced, linear 

 displacement between the lift line and the guideline. 



