Principles of naval engineering - Historic Naval Ships Association

PRINCIPLES OF NAVAL ENGINEERINGto becoming the major prime mover for navalships.With the advent of the steam turbine, theproblem of reconciling the speed of the primemover and the speed of the propeller becamecritical. The turbine operates most efficientlyat high speed, and the propeller operates mostefficiently at low speed. The obvious solutionwas to use reduction gears between the shaftof the prime mover and the shaft of the propeller;and, basically, this is the solution thatwas adopted and that is still in use on navalships today. However, other solutions are possible;and one—the use of turboelectric drivewastried out on a fairly large scale.During World War I, the collier Jupiter (laterconverted to the aircraft carrier Langley ) wasfitted with turboelectric drive. The high speedturbines drove generators which were electricallyconnected to low speed motors. The "bigfive" battleships— the Maryland, the Colorado ,the West Virginia , the California , and theTennessee— were all built with turboelectricdrive. Ultimately, however, starting with themodernization of the Navy in 1934, the turboelectricdrive gave way to the geared-turbinedrive; and today there are relatively few shipsof the Navy that have turboelectric drive.The period just before, during, and afterWorld War II saw increasing improvement andrefinement of the geared-turbine propulsionplant. One of the most notable developmentsof this period was the increase in operatingsteam pressures—from 400 psi to 600 psi andfinally, on some ships, to 1200 psi. Other improvementsincluded reduction in the size andweight of machinery and the use of a varietyof new alloys for high pressure and high temperatureservice.Although the development of naval surfaceships, unlike the development of submarines,has been largely dependent upon the developmentof steam machinery, we should not overlookthe importance of an alternate line ofwork—namely, the development of internal combustionengines. In the application of dieselengines to ship propulsion, Europe was considerablymore advanced than the United States;as late as 1932, in fact, the United States wasin the embarrassing position of having to buyGerman plans for diesel submarine engines. Aconcerted effort was made during the 1930's