Table VII. Open Center Cutter Data 



Material Cut 



Number 



of 



Tests 



Cutting Time 

 Minutes 



Mean 



Range 



1/2" Steel Wire Rope 6x19 w/IWRC 



8 



0.1 



0.1-0.2 



Angle Iron 3/4x3/4x1/8 



2 



0.1 



0.1 



5/8" Diameter Steel Rebar 



2 



0.4 



0.1-0.7 



1" Diameter Marine Communication 

 Cable w/Armor Braid 



2 



0.1 



0.1 



The weight of the cutter (27 pounds in water)' made it difficult for 

 the divers to operate for more than half an hour. The divers felt that 

 if another handle was provided near the front of the cutter, it would 

 be easier to hold. Because of the tool's weight the divers preferred to 

 operate the cutter upside down (Figure 24) so that the material being 

 cut helped to support the cutter. 



The trigger of the open center cutter stuck repeatedly and the 

 trigger guard is too close to the trigger, especially for a large gloved 

 hand. However, these are minor problems which can be eliminated in a 

 subsequent cutter. 



This cutter was operated at 2-3 gpm and at a maximum pressure of 

 2000 psig during the test program. The pressure during cutting usually 

 increased to 2000 psig, opening the hydraulic unit pressure relief valve. 

 The cutter hydraulic circuitry performed reliably during the tests. 

 However, the cutter head was not satisfactory. After several cuts, the 

 female side of the cutting mechanism would often fill up with chips. 

 The chip problem was especially severe when cutting materials other 

 than wire rope. This cutter is being improved to eliminate the chip 

 accumulation problem by reversing the configuration of the cutting 

 mechanism. 



Underwater Winch 



A helicopter winch and a commercial hydraulic motor were modified 

 to simulate a "disposable" winch system (Figure 25) for moving salvage 

 material and equipment underwater. In a typical application inexpensive 

 winches would be attached underwater at the major material handling 

 areas. The winch lines would run through snatch blocks as required for 

 moving heavy loads and equipment into position. A hydraulic power 

 handle would enable one diver to operate any of the winches by mechan- 

 ically coupling the power handle to any winch. 



The helicopter winch housing contains a 40:1 worm and worm gear. 

 The gears operate in pressure-compensated Mil-H-6083c hydraulic fluid. 



28 



