1. The relationship between plunger and piston areas should be fully explored. Model 

 experiments are recommended to determine the best values for plunger and piston sizes that will 

 produce more than 7 foot-pounds on a consistent basis, without increasing drill body motion. 

 Model results should be confirmed through testing of modified impact mechanism component 

 parts. 



2. The lengthened plunger cutout should be experimentally evaluated as a means to 

 eliminate double impacting in combination with any future design seeking higher impact energies. 



3. The seawater drive motor for bit indexing and related elements should be added to the 

 DADS model to determine what parameters can be altered to compensate for the observed 

 negative effects on hardware performance. The effects of adding the seawater motor in parallel 

 and in series to the linear impact mechanism should be compared for selection of the best drill 

 performance. 



4. Finally, the Dynamic Analysis and Design System (DADS) software and the modeling 

 techniques developed under this tasking should be applied to the design of complex seawater 

 hydraulic system components. Use of this capability will enhance component performance and 

 result in significant cost savings over traditional build and test methods of hardware development. 



REFERENCES 



1. J. Kunsemiller and S. Black. "Case study of an environmentally safe diver tool system", 

 presented at the Underwater Intervention Conference, San Diego, CA, Feb 1994. 



2. Naval Civil Engineering Laboratory. Technical Note N- 1826: Development of a seawater 

 hydraulic rock drill, by J. Kunsemiller. Port Hueneme, CA, Mar 1991. 



3. William C. Maurer. Advanced drilling techniques, Chapter 2. Tulsa, OK, Petroleum 

 Publishing Co., 1980. 



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