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    <title>Transport Research International Documentation (TRID)</title>
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    <copyright>Copyright © 2026. National Academy of Sciences. All rights reserved.</copyright>
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    <managingEditor>tris-trb@nas.edu (Bill McLeod)</managingEditor>
    <webMaster>tris-trb@nas.edu (Bill McLeod)</webMaster>
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      <title>A NEW PROPULSION SYSTEM FOR SHIPS</title>
      <link>https://trid.trb.org/View/71680</link>
      <description><![CDATA[A new propulsion system is described eliminating the reduction gear aboard ships.  The propulsion system consists of a hydraulic transmission located outside the ships hull driving the propeller.  The transmission is of the axial flow type having both an axial flow pump and axial flow turbine.  It is an open system using seawater as a transmission fluid.  The propulsive thrust is divided between the propeller and the fluid discharge from the transmission turbine.  By properly selecting pump and turbine configurations, the transmission ratio can be varied within wide limits.  Variable vanes inside the transmission permit the change of the transmission ratio.  A reversing mechanism can be incorporated in the transmission eliminating the need for the provision of conventional thrust reversing systems.  The propulsion system lends itself to a variety of arrangements to meet ship design requirements.]]></description>
      <pubDate>Wed, 03 May 1978 00:00:00 GMT</pubDate>
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      <title>HYDROKINETIC PROPULSION DRIVES; A FEASIBILITY STUDY</title>
      <link>https://trid.trb.org/View/11125</link>
      <description><![CDATA[This study examines the feasibility of a hydrokinetic (turbohydraulic) closed-loop marine propulsion transmission system in general, and particularly in a large hydrofoil vessel.  As it is a synthesis of existing knowledge and hardware, this thesis primarily serves to collect the information needed for the conceptual design of such a transmission, and to present a procedure by which an engineer can quickly determine whether a hydrokinetic transmission is likely to meet his requirements.  The sample design calculation was based on a 750 ton hydrofoil craft, and the resulting system was compared with other propulsion transmission options, including mechanical superconducting electric drive, and varous water jet systems.  As the craft chosen was optimized for a water jet system and was far from the optimal application of a hydrokinetic transmission, the latter appeared to be only barely competitive with the water jets, and inferior to the other alternatives.  The author concluded that the potential application of the hydrokinetic system would be limited, although such a system was found to be technically feasible with existing hardware, and open to considerable improvement with a relatively small developmental effort.]]></description>
      <pubDate>Wed, 14 Nov 1973 00:00:00 GMT</pubDate>
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      <title>TURBINES AND GEARING FOR VLCC</title>
      <link>https://trid.trb.org/View/11150</link>
      <description><![CDATA[Very large tankers with their heavy investments and dangerous cargoes, require engines fulfilling certain essential requirements, such as increased torque and thrust in the propeller shaft compared to earlier units; best possible manoeuvering and stopping ability, very high reliability and adequate emergency systems; adaption to new machine room dimensions, increased hull movements, stiffer propeller shafts and so on.  The paper deals mainly, with engines for 300,000 tdw tankers, and larger.  Most important is the question of whether steam turbine drives can be used for large single screw applications.  Important components are reviewed briefly and a new gearing for high torques is presented.  The claim is made that the designs of turbines and gearing now available will match demands in size as well as in quality and know-how.  Power in the range of 35 to 45 MW at 80 rev/min single screw, and even more, is ready for production at request.  Also discussed are twin screw arrangements and the overlapping propeller engine.  As regards turbine machinery it is primarily the gears, the propeller thrust block and the shafting that have to be increased for single screw use.  Relatively speaking, turbines are still rather small and attention must be paid to marine conditions such as varying speed, rapid manoeuvering and reversing direction of rotation.]]></description>
      <pubDate>Wed, 14 Nov 1973 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/11150</guid>
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      <title>CENTRIFUGAL AND AXIAL FLOW MARINE PUMPS</title>
      <link>https://trid.trb.org/View/601</link>
      <description><![CDATA[This is a translation of selected chapters from the book Centrifugal and Axial Flow Marine Pumps.  The contents are as follows:  pump characteristics; regulation and combined pump operations; unusual pump operating conditions; condensate pumps; booster pumps; feed pumps; circulating pumps; turbine drives.]]></description>
      <pubDate>Tue, 23 Mar 1971 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/601</guid>
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