A preliminary guideline test was conducted in 1969 in 800 feet of 

 water with a single guideline [6]. Line tensions in both guideline and 

 lift line were measured, but payload motion was not measured; and current 

 measurements were incomplete. Nevertheless, it was encouraging to find 

 that no entanglement was observed during this test. 



The guideline system may be the answer to many seafloor construction 

 problems. The system can be used to guide the vertical lifting and 

 lowering of heavy, bulky materials or structural components; the structure, 

 for example, could be an underwater cable car for surface-to- seafloor 

 transportation. Most important, however, is the potential application 

 of the guideline system for remote assembly of prefabricated structural 

 modules on the seafloor. Such construction techniques would not only 

 allow the construction of integrated, large structures with limited 

 equipment but also would allow covertness during implant. 



The immediate application of the guideline system is deep-water 

 salvage and rescue operations and the addition of weights to gravity 

 anchors. 



SEA TESTS 



The sea tests were performed in two stages. The first series of 

 tests, conducted in 600 feet of water, was designed to obtain informa- 

 tion on the effects of various parameters on the static and dynamic 

 response of the guideline system. The second series of tests was con- 

 ducted in 4,500 feet of water to verify the results from the shallow- 

 water tests for entanglement -free operation of guideline systems. 

 Table 1 presents a summary of all sea tests. 



Hardware 



Guidelines. The guidelines used in the shallow-water tests were 

 3/4-inch-diameter ; 2-in-1 braided nylon ropes; and 1 /2-inch-diameter , 

 6x19 wire ropes. In the deep-water tests, only 3/8-inch-diameter , 

 torque-balanced steel wire rope with a polyethylene jacket was used. 

 The lower ends of the guidelines were connected to the guide posts by 

 roller-bearing swivels (Figure 3) to avoid torque accumulation in the 

 guidelines. 



Guide Posts and Anchor Blocks. Each guide post was a 3-1 /2-inch- 

 diameter pipe section with one end embedded in a concrete anchor block. 

 The top end of the post was tapered and was topped by a lift ring. A 

 notched guide cylinder fabricated of 4-inch pipe was welded on the 

 3-1 /2-inch-diameter pipe for the bottom mating of the anchor block and 

 the add-on block. The single anchor block measured 4x4x2 feet; the 

 double anchor block measured 4x10x2 feet. A male conical catch was 

 embedded in the middle of the double block, and the guide posts were 

 embedded 3 feet on either side of the catch (Figure 4). The catch, when 



