PRINCIPLES OF NAVAL ENGINEERING 



error signaL This signal produces a rapid re- 

 sponse from the system when the engineering 

 plant is in the maneuvering mode. Under normal 

 mode of plant operation the speed feedback signal 

 is not utilized. 



The signals for astern throttle movement are 

 handled in the same manner but all of the polari- 

 ties are reversed. 



In the near future we may see a substantial 

 increase in the automation of naval propulsion 

 machinery and auxiliary machinery. At the pres- 

 ent time, it is entirely possible to design a 

 completely automated ship. Although complete 

 automation is an unlikely goal for the naval ship, 

 three is little doubt that automation will increase 

 to some extent within the next few years. 



FUEL CONVERSION PROGRAM 



As of this writing, the Department of Defense 

 has authorized the Navy to shift to an all dis- 

 tillate marine diesel type fuel which will replace 

 the Navy Special Fuel Oil (NSFO) now in use. 

 The shift will take place on a gradual basis over 

 a three year period. This conversion will ease 

 the principal adverse factors associated with the 

 use of Navy Special Fuel Oil such as: 



1. Fouling of firesides of boilers by permis- 

 sible impurities in Navy Special Fuel Oil, prin- 

 cipally sulphur, ash, and carbon residue. 



2. Decrease in ship readiness associated 

 principally with cleaning of firesides. 



3. High corrosion rate of above-deck equip- 

 ment associated with exposure to products of 

 combustion of Navy Special Fuel Oil. 



4. Substantially below average retention rate 

 of Navy enlisted personnel who perform boiler 

 cleaning operations. 



Testing planned completion date 1975, is 

 presently taking place with diesel engines and 

 gas turbine propulsion plants; the results of these 

 tests are to be evaluated for the "Single- Fuel" 

 Navy concept, which will permit the Navy to 

 operate either steam diesel, or gas turbine 

 driven propulsion plants with one and the same 

 type fuel. 



GENERAL TRENDS 



In conclusion, it may be of interest to note 

 some general trends in naval engineering and to 

 hazard a few predictions concerning possible 

 future developments. 



First, we may expect continuing refinement 

 and improvement of the machinery and equipment 

 now in use. The steam turbine, the diesel engine, 

 the gas turbine, thenuclear propulsion plant— all 

 are capable of further development and perhaps 

 increased efficiency. We may reasonably lookfor 

 new designs in boilers, turbines, reducing gears, 

 bearings, propellers, condensers and other heat 

 exchangers, and a wide variety of auxiliary ma- 

 chinery. Some improvements may be aimed at 

 reducing mechanical losses, others at increasing 

 the utilization of power developed by the prime 

 mover, others at reducing noise levels, and still 

 others at minimizing maintenance requirements. 



We may look forward to the introduction of 

 new engineering materials-metals and alloys, 

 plastics, ceramics, lubricants, and others. We 

 may watch for — though not necessarily count on— 

 a materials breakthrough that would raise the 

 upper temperature limits of our present ma- 

 chinery. If it is not possible to devise new ma- 

 terials to withstand ultra-high temperatures, we 

 may perhaps lookfor new designs that will enable 

 us to utilize higher temperatures with some of 

 our present materials. We may also expect new 

 and improved techniques for welding or other- 

 wise joining metals, new methods of metal form- 

 ing and shaping, new methods of treating metals 

 to obtain desired properties, and new procedures 

 for the nondestructive testing of engineering ma- 

 terials. 



In the more distant future, perhaps, we might 

 look for some entirely new concepts of ship pro- 

 pulsion. In particular, we might expect to see 

 ship and machinery designs tending toward the 

 ultimate goal of integrating the prime mover, the 

 propulsive device, the steering device, and the 

 hull form into one coordinated unit. Designers of 

 ships and propulsion machinery have long looked 

 with envy at the fully integrated propulsion sys- 

 tems of many fish, and a good deal of work has 

 been done in analyzing fish propulsion with a view 

 to picking up some usable ideas. One approach 

 that has been suggested is to effect undulation of 

 a flexible hull by pumping water in a sinusoidal 

 path through a series of compartments. Still 

 another approach utilizes a series of undulating 

 plates. Although no type of simulated fish pro- 

 pulsion is even close to being operational at pres- 

 ent, these approaches should not be dismissed 

 as frivolous or trivial. A great deal has already 

 been learned through biological and simulation 

 studies of fish propulsion. 



Altogether, we may expect the future to bring 

 at least a few surprises, a few practical results 



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