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    <title>Transport Research International Documentation (TRID)</title>
    <link>https://trid.trb.org/</link>
    <atom:link href="https://trid.trb.org/Record/RSS?s=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" rel="self" type="application/rss+xml" />
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    <language>en-us</language>
    <copyright>Copyright © 2026. National Academy of Sciences. All rights reserved.</copyright>
    <docs>http://blogs.law.harvard.edu/tech/rss</docs>
    <managingEditor>tris-trb@nas.edu (Bill McLeod)</managingEditor>
    <webMaster>tris-trb@nas.edu (Bill McLeod)</webMaster>
    <image>
      <title>Transport Research International Documentation (TRID)</title>
      <url>https://trid.trb.org/Images/PageHeader-wTitle.jpg</url>
      <link>https://trid.trb.org/</link>
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    <item>
      <title>PROBLEMS ON APPLICATIONS OF ELECTROMAGNETIC GEARS</title>
      <link>https://trid.trb.org/View/146361</link>
      <description><![CDATA[The primary reason why electromagnetic gears could be considered to be used on board is that it was found that an electromagnetic gear can be manufactured at almost the same cost as that of a mechanical gear of the same capacity.  The paper looks into the possibility of using combinations of diesel engines (e.g. slow-speed and medium-speed) and combination of diesel engine and gas turbine in connection with electromagnetic gears.  Order from NSFI as No. 17927.]]></description>
      <pubDate>Wed, 19 Dec 1979 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/146361</guid>
    </item>
    <item>
      <title>SOME GAS-TURBINE PROPULSION GEAR CONFIGURATIONS</title>
      <link>https://trid.trb.org/View/87435</link>
      <description><![CDATA[The ship-propulsion gas-turbine calls for gearing with a configuration that resembles that of a medium-speed Diesel engine rather than that of a steam turbine.  The various configurations that have been applied or proposed are here listed for pure gas-turbine plants with c.p.  propellers, for those with fixed-pitch propellers, and for combined gas-turbine/Diesel plants (all with c.p. propellers); they include the gearing in the Finnjet, the Euroliner-class ships, and several warships.  Each of the 22 gearing configurations listed is shown diagrammatically, and described and discussed.  The Author mentions that the design of these transmissions has not yet settled down, but there are indications that typical configurations will emerge and form new standards as in the case of Diesel installations.  Order from BSRA as No. 49,651.]]></description>
      <pubDate>Tue, 31 Jul 1979 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/87435</guid>
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      <title>NAVAL GEAR DESIGN--THE INTERPRETATION OF SHIP PROPULSION REQUIREMENTS</title>
      <link>https://trid.trb.org/View/86659</link>
      <description><![CDATA[The Author examines three examples of current naval construction utilizing a General Electric (USA) LM 2500 gas turbine, developing 25,000 hp, with Diesel engines for cruising power.  The smallest vessels, about 260 tons, have been ordered by the Indonesian Navy.  A three-module gearbox is used, weighting 12.5 tons, and cruising power is provided by two MTU 12V331 Diesel engines.  To achieve a power/weight ratio of 2,000 hp/ton the design of rotating and stationary parts has been carefully refined; for example, the primary gearbox has a hollow pinion and idler gears, in which the shafts are welded directly to the gear rim, and fabricated wheels with internal coned plates to resist relatively large transverse and axial forces applied through the bearings. The second example, for the Royal Danish Navy KV class corvettes, is a similar concept, with a single turbine driving dual propellers, but approached from a completely different standpoint.  These vessels have a displacement of 1,500 tons and cruising power provided by a single MTU 20V956 Diesel engine of 4,800 bhp.  Disconnection of the engine is provided by an oil-operated Ortlinghaus friction clutch, a compact unit capable of accepting the gas turbine overrunning condition on its own.  The weight of this gearbox is 44 tons, giving a hp/ton ratio of 570.  The third example is the installation for the Italian navy A/S "Maestrale"--class frigates, twin-screw vessels of 2,800 tons displacement and with a gas-turbine power of 50,000 hp. Speed is expected to be some 32 knots.  Because the LM 2500 is not made for handed rotation, the gearboxes for port and starboard sets differ.  The latter gearbox contains an additional set of "reverse gears" situated between the turbine and the first reduction pinion.  The total weight of the combined gearboxes is 72 tons, equivalent to 700 hp/ton. Cruising power is provided by two GMT B230.20 DVM engines, rated 5,500 bhp for continuous operation, and driving through Wichita pneumatic friction clutches.  Order from BSRA as No. 49,964.]]></description>
      <pubDate>Wed, 13 Jun 1979 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/86659</guid>
    </item>
    <item>
      <title>SMALL WATERPLANE AREA TWIN HULL (SWATH) COMBATANT SHIP PARAMETRIC STUDY</title>
      <link>https://trid.trb.org/View/82664</link>
      <description><![CDATA[This study defines the anticipated size and speed of SWATH escort ships. The study baseline assumes conventional state-of-the-art materials, subsystems, design philosophy, and operational practices. Double reduction gear and planetary gear transmission systems were included with prime movers in the hulls. Conventional geared electric, right angle drive, and cryogenic systems with turbines in the box or cross-structure were also studied. Installed powers of 45,000 SHP (2 LM 2500s), 70,000 SHP (2 FT9s), 90,000 (2 LM 5000s or 4 LM 2500s), 140,000 SHP (4 FT 9s) and 180,000 SHP (4 LM 5000s) were studied. In addition, the sensitivity of the results to assumptions made in the study was examined. The study results show that current technology SWATH escort ships will displace 5,000 to 8,000 tons. Sustained speeds of these ships will be about 25 knots. Speeds of 30 knots or better are possible by combining a right angle drive or cryogenic transmission system with increased installed horsepower speeds are possible by using all aluminum structure, reducing crew size, or changing mission elements such as range and endurance speed. Such changes will require strong endorsement by the operational community. (Author)]]></description>
      <pubDate>Fri, 11 May 1979 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/82664</guid>
    </item>
    <item>
      <title>STEAM TURBINE PROPULSION INSTALLATIONS</title>
      <link>https://trid.trb.org/View/74376</link>
      <description><![CDATA[The Author presents a brief historical review of the development of the steam turbine as a marine propulsion unit.  He then considers various methods for improving the efficiency of the turbine, e.g.  higher steam temperature and pressure, reheating of partially expanded steam, preheating of feedwater, etc.  The combined system of turbine and gearing is then discussed from the aspects of sizing, reliability, maintenance and repair.  Vibration spectra from a number of turbo-generator coupled gearboxes are shown to illustrate the effect of repairs and of encasing.  The Author concludes with a discussion of techno-economic questions related to future developments in steam turbine machinery, particularly that of fluid-bed combustion.  Order from: BSRA as No. 48,368.]]></description>
      <pubDate>Sat, 19 Aug 1978 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/74376</guid>
    </item>
    <item>
      <title>SOME FACTORS IN MARINE GEARING FOR CLASSIFICATION PURPOSES</title>
      <link>https://trid.trb.org/View/47126</link>
      <description><![CDATA[The paper gives a brief history of the evolution of the Rules of Lloyd's Register of Shipping up to the adoption of the basic I.S.O. formulas for design, and analyzes the main defects in both steam turbine and oil engine gearing over the past seventeen years.  With this background, the values applicable to the factors for surface loading and tooth bending strength are discussed.  Finally, the manufacturing tolerances and installation practices, particularly with regard to external effects, necessary to obtain the conditions at the mesh appropriate to the permissible loadings, have been outlined.  I.S.O. notation has been used in the paper and, where the coefficients in Lloyd's Register's published Rules differ, the correlation has been indicated.]]></description>
      <pubDate>Tue, 26 Oct 1976 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/47126</guid>
    </item>
    <item>
      <title>GEARING FOR MODERN MARINE PROPULSION SYSTEMS</title>
      <link>https://trid.trb.org/View/40352</link>
      <description><![CDATA[The purpose of gearing in marine propulsions is to enable both engine and propeller to function to their best advantage.  The application of gearing to steam turbines gas turbines, diesel engines, electric drives and combined power units is considered, along with modern ideas regarding materials, tooth form, gear arrangement, gearcase structure and ancillary equipment.  Traditional limitations on the use of nitrided steels are analyzed, and the value of the popular Hertzian shear stress criterion is challenged.  The future place of epicyclic gears is discussed with particular reference to diesel drives.  The effect of friction forces in tooth-coupling drives is dealt with.]]></description>
      <pubDate>Tue, 30 Sep 1975 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/40352</guid>
    </item>
    <item>
      <title>OPERATING EXPERIENCE WITH HIGH POWER MARINE GEARS</title>
      <link>https://trid.trb.org/View/15819</link>
      <description><![CDATA[The rapid increase in ship size, power, and propeller torque in the past decade has led to the introduction of the dual torque path (locked train) gear into merchant marine service.  The performance of these units has been excellent, with relatively few "teething" problems.  The continued growth in ship size and power emphasizes the need to consider the machinery and hull structure as a system rather than as discrete elements.  Future trends may dictate more novel propulsion machinery arrangements.]]></description>
      <pubDate>Tue, 07 May 1974 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/15819</guid>
    </item>
    <item>
      <title>TORSIONAL CHARACTERISTICS OF GEARED TURBINE SYSTEMS</title>
      <link>https://trid.trb.org/View/13300</link>
      <description><![CDATA[Paper presents a study of the torsional vibration characteristics of various types of marine turbine propulsion units found in practice.  Through the use of a digital computer program based on the Holzer-Newton methods, a comparison is made of torsional citical speeds of tuned and untuned systems.  It is shown that tuned systems bear the distinct advantage of having antiresonant modes of vibration while untuned systems may have a large range of critical speed values.  When dealing with partially or completely untuned systems there will always be at least one resonant mode in the operating range.  It is necessary for the designer to make a more complete forced vibration analysis only at those resonant frequencies to ensure that the system is free from the damaging effects of propeller-excited torsional vibrations.]]></description>
      <pubDate>Wed, 14 Nov 1973 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/13300</guid>
    </item>
    <item>
      <title>EVOLUTION OF A NEW RANGE OF MARINE TURBINE GEARBOXES</title>
      <link>https://trid.trb.org/View/11148</link>
      <description><![CDATA[This paper follows in sequence previous papers by the author in which he forecast a "new breed of gearcase in which the load-carrying frame is reduced to a single fabrication", outlined the principles of such a gearcase and gave details of the background of research and development.  At the time of IMAS 73 this new gearcase, in its form applicable to cross-compound turbines, will be in service in four different classes of ships, in three different dual tandem frame sizes and one single tandem frame.  After covering service experience with prior gearcases, the paper describes th initial conception of the new design, its evolution and the arrival at a position where a standard range of boxes can now be provided in conjunction with a standard range of turbines to cover all the power and speed requirements likely in the foreseeable future.  Manufacturing experience, consequential design modification and performance on trials at sea are also discussed.  The author looks into the future, noting the effect of surface-hardened first reduction gear trains in extending the power and speed range of the gearbox without sacrificing its basic principles, and discusses the special requirements of the gas turbine drive and the provision of reversing means within the confines of a compact layout.  In conclusion some comments are made on turbine and main shafting alignment problems insofar as they affect the new gearcase.]]></description>
      <pubDate>Wed, 14 Nov 1973 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/11148</guid>
    </item>
    <item>
      <title>SHIPBUILDING. NUMBER 10, 1970. SELECTED TRANSLATIONS</title>
      <link>https://trid.trb.org/View/8982</link>
      <description><![CDATA[Status and trends in the development of passenger ship construction; Determination of the resultant of the pulsating pressures created by a screw propeller; Foreign shipbuilding; Investigation of the operation of the 6DR30/50 diesel engine on residual fuel oil; A calculation for tangential blade air directors; 'Quality mark' to the TS-2 main geared turbine set; Dynamics of a geared turbine set with shaft generator; Mechanization and automation of production processes in hull fabrication shops; Side launching of ships from self-tilting balanced building ways; Hydrofoil fireboat.]]></description>
      <pubDate>Tue, 18 Sep 1973 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/8982</guid>
    </item>
    <item>
      <title>GEAR TEST FOR MARINE REDUCTION GEAR</title>
      <link>https://trid.trb.org/View/12086</link>
      <description><![CDATA[Together with the recent increase of power in marine turbines, a decrease in scale of reduction gears as well as gear case has become important.  Because the reduction gears are extremely big, tempered steel is employed.  Accordingly the service life of the gears is determined almost entirely by the origin of the pitting.  The object of the test was to investigate the endurance limit of the gears at various speeds and under various conditions of the tooth bearings. However, gear endurance is greatly affected by gear temperature, dynamic load, variation of torque, etc., so these influencing parameters were examined simultantously. The experiments were conducted by employing a large gear testing machine of power circulation type.]]></description>
      <pubDate>Fri, 06 Apr 1973 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/12086</guid>
    </item>
    <item>
      <title>MARINE TURBINE GEARING</title>
      <link>https://trid.trb.org/View/4087</link>
      <description><![CDATA[The first AP propulsion units employing epicyclic gears as primary reduction and parallel shaft gears as secondary reduction went into service in 1965.  Later triple reduction gearing for propeller speeds down to 80 rpm were introducted and the first unit of this kind was commissioned in 1967. Service experience from more than 100 units now installed in medium and large size tankers as well as high power container ships has been accumulated during a period which has seen rapid growth of ship sizes and propulsive power. This development has forced the engine and ship builder into closer cooperation during design, installation and commissioning stages.  Much valuable experience has been gained which is also reflected in present and future design of gearing components and foundations and installation procedures.  Some aspects of design and layout of gear will be given for future ships like 500,000 ton tankers and large high speed container ships.]]></description>
      <pubDate>Fri, 28 Apr 1972 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/4087</guid>
    </item>
    <item>
      <title>SELECTION OF THE KINEMATIC CHAIN FOR THE REDUCTION GEAR FOR LARGE SHIPS</title>
      <link>https://trid.trb.org/View/578</link>
      <description><![CDATA[The modern steam turbine plant in a large cargo ship can be characterized as highly economical, primarily the result of using steam with superhigh parameters and a thermodynamic cycle with intermediate steam superheating.  A tendency to reduce propeller rpm has also developed.  These features, in combination with the direct increase in power transmitted by the turbines, have made it necessary for the leading turbine building firms to review traditional marine reduction gear designs and to undertake a wide-ranging search for new kinematic chains that will ensure dependable transmission of power from the turbines to the propeller.  This paper reviews the effect these features have on the selection of a rational reduction gear chain that will, to a considerable degree, determine such very important parameters of the main geared turbine set as a whole as operational dependability, cost, weight and size, desirable arrangement, and the like.]]></description>
      <pubDate>Fri, 25 Feb 1972 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/578</guid>
    </item>
    <item>
      <title>WESTINGHOUSE HIGH-POWERED TURBINE PROPULSION PLANTS</title>
      <link>https://trid.trb.org/View/1423</link>
      <description><![CDATA[The range of marine steam turbine propulsion plants manufactured by Westinghouse Electric Corp in California is described. Details are given for the machinery in this family on order for APL and Farrell Lines. The turbines are of cross-compound type and the complete unit has an overall height of 19 ft 5 in. Steam supply is at 850-psig and 950 F and the steam exhausts at 28.5 in. of vacuum. Operating under these conditions, the turbine will require 183,000 lb/hr of steam and will deliver 134,000 lb to the condenser, the remainder being extraction steam. Major design features are explained for the high pressure turbine, the low pressure turbine, and astern turbine, and reduction gear.]]></description>
      <pubDate>Thu, 13 May 1971 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/1423</guid>
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