Contents (continued) 



Page 



REFERENCES 46 



BIBLIOGRAPHY 49 



APPENDIXES 



A - Plow Resistance Force and Power Analysis 54 



B - Excavation Analysis for Trenching 62 



C - Power Analysis of Auger Trenching 68 



D - Cable and Machine Drag 70 



LIST OF ILLUSTRATIONS 



Figure 1 . The bottom trawl 2 



Figure 2. Trencher modified for shallow-water coral 



trenching 10 



Figure 3. Raked plowshare with machined grooves 17 



Figure 4. Trenching modes 19 



Figure 5. Alveolator concept 29 



Figure A-1. Velocity dependency of soil shearing and 



viscous resistance 55 



Figure A-2. Cable plow/feed shoe size estimates 56 



Figure B-1. Trench configuration 62 



Figure B-2. Excavating wheel configuration 65 



Figure C-1. Auger configuration 68 



Figure D-1. Current profile 70 



Figure D-2. Umbilical length versus angle 72 



Figure D-3. Umbilical length versus tension '2 



LIST OF TABLES 



Table 1 . Specific Operational Requirements of Cable 



Burial System 9 



Table 2. Design Parameters 14 



Table 3. Power Conversion Efficiencies 15 



