Principles of naval engineering - Historic Naval Ships Association

CHAPTER 1THE DEVELOPMENT OF NAVAL SHIPSThe story of the development of naval shipsis the story of prime movers: oars, wind-filledsails, reciprocating steam engines, steam turbines,internal combustion engines, gas turbineengines. It is also the story of the conversionand utilization of energy: mechanical energy,thermal energy, chemical energy, electricalenergy, nuclear energy. Seen in broader context,the development of naval ships is merelyone fascinating aspect of man's long struggleto control and utilize energy and thereby releasehimself from the limiting slavery ofphysical labor.We have come a great distance in thesearch for the better utilization of energy,from the muscle power required to propel anancient Mediterranean galley to the vast reservesof power available in a shipboard nuclearreactor. No part of this search has been easy;progress has been slow, difficult, and oftenbeset with frustrations. And the search is farfrom over. Even within the next few years, newdevelopments may drastically change our presentconcepts of energy utilization.This chapter touches briefly on some of thehighlights in the development of naval ships.In any historical survey, it is inevitable that afew names will stand out and a few discoveriesor inventions will appear to be of crucial significance.We may note, however, that ourpresent complex and efficient fighting shipsare the result not only of brilliant work by arelatively small number of well known men butalso of the steady, continuing work of thousandsof lesser known or anonymous contributors whohave devised small but important improvementsin existing machinery and equipment. The primitiveman who invented the wheel is often citedas an unknown genius; we might do well toremember also the unknown genius who discoveredthat wheels work better when they turnin bearings. Similarly, the basic conceptsinvolved in the design of steam turbines, internalcombustion engines, and gas turbine engines maybe attributed to a few men; but the innumerablesmall improvements that have resulted in ourpresent efficient machines are very largelyanonymous.THE DEVELOPMENT OF STEAMMACHINERYOne of the earliest steam machines of recordis the aeolipile developed about 2000 years agoby the Greek mathematician Hero. This machine,which was actually considered more of atoy or novelty than a machine, consisted of ahollow sphere which carried four bent nozzles.The sphere was free to rotate on the tubes thatcarried steam from the boiler, below, to thesphere. As the steam flowed out through thenozzles, the sphere rotated rapidly in a directionopposite to the direction of steam flow. ThusHero's aeolipile may be considered as theworld's first reaction turbine.^Giovanni Battista della Porta's treatise onpneumatics (1601) describes and illustrates adevice which utilizes steam pressure to forcewater up from a separate vessel. In the sametreatise, the author suggests that the condensationof steam could be used to create a vacuum,and that the vacuum could be utilized to drawwater upward from a lower level— a remarkablysophisticated concept, for the time.Throughout the 17th century, many other deviceswere suggested (and some of them built)which attempted to utilize the motive power ofsteam. In many instances the scientific principleswere sound but the technology of the daydid not permit full development of the devices.Hero's aeolipile is illustrated in chapter 12 of thistext.