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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>
    <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>
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      <title>Transport Research International Documentation (TRID)</title>
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    <item>
      <title>A DEFORMED WAKE MODEL FOR MARINE PROPELLERS</title>
      <link>https://trid.trb.org/View/68520</link>
      <description><![CDATA[This Report, which is available in microfiche form, presents a systematic series of experiments in which the radius and pitch of propeller tip vortices are measured and analysed.  The measurements of ultimate wake pitch are compared with theoretical predictions based both on a simple activator disc model, and on a direct calculation of the self-induced velocities of the helical vortices.  The effect of wake deformation on the computed radial distribution of pitch and camber for a specific design example is given.]]></description>
      <pubDate>Mon, 12 Apr 2004 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/68520</guid>
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    <item>
      <title>COAST GUARD CUTTER DUTY CYCLE AND PROPELLER/DIESEL ENGINE EFFICIENCY STUDY</title>
      <link>https://trid.trb.org/View/164319</link>
      <description><![CDATA[This report covers an investigation into methods to reduce the fuel consumption of the large main propulsion diesel engines used on 378 high-endurance and 210B medium-endurance Coast Guard cutters.  This investigation involved, first, defining the duty cycles for the cutters and, second, analyzing the efficiency of the controllable pitch propellers and main diesel engines.  Based on this information, cycle composite cutter fuel consumption figures were calculated and changes in the operational procedures of these cutters were recommended where fuel savings appeared to be possible.  Methods of reducing fuel consumption which were analyzed where changes in the propeller pitch/engine speed combination needed to produce a given cutter speed, and possible single-engine operation at low cutter speeds. A study of the duty cycle of an icebreaker is also included in the program.]]></description>
      <pubDate>Fri, 12 Jun 1981 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/164319</guid>
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    <item>
      <title>BLADE SPINDLE TORQUE AND OFF-DESIGN BEHAVIOUR OF CONTROLLABLE PITCH PROPELLERS (CPP)</title>
      <link>https://trid.trb.org/View/163481</link>
      <description><![CDATA[Geometry and centrifugal loads on CPP are discussed including coordinates of blade surface in off design condition, effects of main parameters on section deformation, results of numerical analysis, and centrifugal forces and moments in arbitrary pitch position.  Experimental techniques and procedures for measuring blade spindle torque are dealt with. Calculation methods are described and comparison with measured results discussed.]]></description>
      <pubDate>Thu, 21 May 1981 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/163481</guid>
    </item>
    <item>
      <title>SLOW, CONTROLLED PITCH</title>
      <link>https://trid.trb.org/View/160823</link>
      <description><![CDATA[The Author, of the KMW Marine Laboratory, Kristinehamn, Sweden, after stressing the importance of improving propulsive efficiency in the face of rising fuel costs, describes how this can be achieved by combining a large- diameter CP Propeller with an unconventional hull form.  A single CP propeller driven by two or more Diesel engines enables a ship to operate at various speeds utilizing optimum propeller pitch.  This results in maximum propulsive efficiency, facilitates maintenance, and permits the use of shaft-driven generators running at constant speed.  The need to adopt an unconventional after-body hull form in order to reduce the effects of propeller/hull vibration etc. is emphasised and the use of semi-tunnel sterns in this field is described. To lend weight to the advantages of using a large-diameter CP propeller, the Author gives comparative data for the propulsive efficiency of two very similar self-unloading bulk carriers, Canadian Enterprise and Canadian Transport, both built by the Port Weller Dry Docks for Upper Lakes Shipping Ltd.  Both ships have single KaMeWa propellers driven by twin Diesels but the one fitted to Canadian Enterprise is of larger diameter and of controllable-pitch design and is located beneath a semi-tunnel stern.  Order from BSRA as No. 54,170.]]></description>
      <pubDate>Wed, 18 Feb 1981 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/160823</guid>
    </item>
    <item>
      <title>C.P. PROPELLERS-THE NEED FOR MODEL TESTING</title>
      <link>https://trid.trb.org/View/151861</link>
      <description><![CDATA[Controllable-pitch propellers now hold a very large share of the propeller market, and propeller suppliers are giving them increased attention.  The Author discusses some of the mechanical and hydrodynamic aspects of the design of these propellers, with particular reference to the work of his company (SMM Engineering) and that done in the cavitation tunnel at Newcastle University.  Among the matters discussed are: (i) loads in the hub body due to thrust, centrifugal force, pitch-holding, and pitch-changing (the hub body is not, however, loaded by pitch-changing forces in some double-acting designs such as SMME's XX); (ii) model work associated with these loads; (iii) hub design to allow the hydrodynamicist the largest blade-palm, with its attendant advantages; (iv) blade area ratio; (v) boss diameter ratio; (vi) pitch-changing behaviour of ducted c.p. propellers during manoeuvring; (vii) spindle torque of ducted propellers (the work needed for one c.p. propeller is more than that needed for seven f.p.  propellers); (ix) the strain-gauge blade dynamometer.  Today's needs are for high efficiency (to minimise fuel consumption) and operational reliability, and for low first cost, which is largely a matter of having the smallest hub size.  Minimum blade-width not only increases efficiency but minimises spindle torque and hence reduces the hub size.  A further requirement is for large-diameter propellers running at low rpm.  Current and future needs relating to c.p. propeller design and construction are further discussed, and it is mentioned that blades designed for more exacting loadings will require careful maintenance and that it could become the practice to change the blades at survey periods and repair them ready for the next docking.  Future ships must have underwater hulls designed with more attention to improving the wake. Long slender blades of slow-running c.p. propellers will give the designer similar freedom in blade outline to that enjoyed by the designer of f.p. propellers.  Blade-tip vortices are among the other matters considered.  Feathering propellers (the small demand for these has recently tended to grow) are also discussed, together with some results of tests on them.  Finally, the Author briefly discusses priorities for future cavitation-tunnel work on c.p. propellers.  Although investigations relating to individual ship applications will always be important and may require short-term priority, in the long run it is the steady process of refinement and extension of standard information that will do most to help British c.p. propeller design. Order from BSRA as No. 53,402.]]></description>
      <pubDate>Wed, 08 Oct 1980 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/151861</guid>
    </item>
    <item>
      <title>COMPASS TUG DESIGN USING AZIMUTH CONTROLLABLE PITCH PROPELLERS AND INTEGRATED MANEUVERING SYSTEM</title>
      <link>https://trid.trb.org/View/155123</link>
      <description><![CDATA[The paper describes the engine room- and towing arrangement, the compass thruster which is capable of rotating through 360 degrees with nozzle and cp-propeller, the remote control system developed by "Helitron" and the "Poscon" integrated manoeuvring system.  The hydraulic pitch control system and piping diagram for the steering gear are illustrated.  Order from NSFI as No. 19477.]]></description>
      <pubDate>Wed, 08 Oct 1980 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/155123</guid>
    </item>
    <item>
      <title>A COMPUTER PROGRAM BASED ON INDUCTION FACTORS METHOD TO DESIGN MODERATELY LOADED PROPELLERS</title>
      <link>https://trid.trb.org/View/148987</link>
      <description><![CDATA[The first section of the paper illustrates the employed method to calculate lift coefficients, induced velocities and hydrodynamic pitch angles not only for wake adapted, but also for arbitrary radial loaded propellers.  Section two illustrates the approach for stress and cavitation computations needed to pass from hydrodynamic to geometrical propeller blade design.  The last section shows how three-dimensional surface effects are taken into account by introduction of correction factors calculated from the lifting surface theory.  Inquiries for obtaining this report should be made directly to the organization indicated in the reference above or to your national ship research institute. Order from NSFI as No. 19030.]]></description>
      <pubDate>Tue, 22 Apr 1980 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/148987</guid>
    </item>
    <item>
      <title>DETERMINATION OF OPTIMUM OPERATION CONDITIONS FOR DIESEL ENGINES DRIVING CONTROLLABLE PITCH PROPELLERS</title>
      <link>https://trid.trb.org/View/145790</link>
      <description><![CDATA[Soviet research and weather ships of the Passat series (length b.p. 86 m, 1000 dwt) are fitted and Sulzer medium-speed Diesel engines type 8TD48 (two engines per ship) driving a Liaaen S-80/90 controllable-pitch propeller. This article gives the results of trials in order to determine the optimum operating conditions for this combination of engines and propeller as installed in these ships.  The results are given as graphs of fuel consumption against engine r.p.m., for various ship speeds and values of propeller pitch.  A comparison is made between conditions with a clean hull, a hull with light fouling, and a hull with heavy fouling.  A general graph is derived and recommended for use by the ships' command.  It is stated that fuel economies of the order of 5--8% have been achieved in these ships following the recommendation.  Order from BSRA as No. 51,435.]]></description>
      <pubDate>Wed, 07 Nov 1979 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/145790</guid>
    </item>
    <item>
      <title>ZEROING A CPP</title>
      <link>https://trid.trb.org/View/60029</link>
      <description><![CDATA[The Coast Guard has been operating cutters using controllable pitch propellers since the mid-sixties.  Over these years many engineers and operators have been frustrated and, in some cases, annoyed because the cutter creeps forward or aft, with all built-in indicators indicating zero pitch.  This has occurred even after precise alignment of the system during drydocking, or by using the services of divers to check match marks on the blades/hub. This ariticle will attempt to explain what is happening and suggest a procedure to be used that will make everyone (well, almost) happy.]]></description>
      <pubDate>Wed, 23 Nov 1977 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/60029</guid>
    </item>
    <item>
      <title>LIFTING SURFACE CORRECTIONS FOR 4-BLADED OPTIMUM C.P. PROPELLERS</title>
      <link>https://trid.trb.org/View/51110</link>
      <description><![CDATA[Correction factors for ideal angle of attack due to loading and thickness, and for camber due to loading are presented for 4-bladed 0.3R hub propellers, with NACA-66 thickness distribution.  The calculation of the the factors is based on propeller lifting-surface theory.  The propellers are optimum free running propellers with chordwise loadings identical to NACA a = 0.8 meanline.  The tables presented in the report are direct and unfaired computer output.]]></description>
      <pubDate>Tue, 20 Sep 1977 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/51110</guid>
    </item>
    <item>
      <title>OPERATING CHARACTERISTICS OF CONTROLLABLE PITCH PROPELLERS WITH NEGATIVE ADVANCE RATIOS</title>
      <link>https://trid.trb.org/View/53182</link>
      <description><![CDATA[The use of controllable pitch propellers is gradually increasing, for ships of all types, owing to the advantages they offer in some of their operating aspects.  The main advantages of these propellers are the following: 1.  The possible absorption of the total available engine power, at the nominal rpm, in any loading condition.  2.  Easy ship handling enhanced by the manual propeller pitch control.  In studying the most adequate propeller pitch position, when going astern, it is necessary to have information on the operating characteristics of these propellers with negative advance ratio.  In order to add to the scarce data now existing about this subject, the results of tests carried with negative advance ratio, for three C.P.P., are presented in this paper.]]></description>
      <pubDate>Sat, 02 Jul 1977 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/53182</guid>
    </item>
    <item>
      <title>EXPERIMENTAL INVESTIGATION OF THE EFFECT OF PROPELLER BLADE PITCH ON PROPELLER-PRODUCED UNSTEADY BEARING FORCES AND MOMENTS</title>
      <link>https://trid.trb.org/View/48960</link>
      <description><![CDATA[Experimental results are presented to show the effect of pitch-diameter ratio on propeller-produced unsteady loads. Eight three-bladed propellers with changes of equal increments of pitch resulting in pitch-diameter ratios from 0.58 to 1.75 were tested in three-cycle and four-cycle wake screens. The data indicated that, in general, for the same thrust loading coefficient C sub Th, the unsteady thrust and bending moments tend to decrease with increasing pitch whereas the torque increases and the side forces change negligibly. However, it is impracticable to reduce unsteady thrust by altering pitch.]]></description>
      <pubDate>Tue, 31 May 1977 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/48960</guid>
    </item>
    <item>
      <title>THE EFFECT OF PROPELLER WAKE DEFORMATION ON PROPELLER DESIGN</title>
      <link>https://trid.trb.org/View/52072</link>
      <description><![CDATA[A great deal of effort has been devoted in recent years to study of the deformation of the wake from propeller blades. Relationships between loading, vortex rollup, contraction, and pitch variation have been studied.  This paper discusses analytical and experimental developments, and emphasizes the effects on design and performance of high speed high thrust subcavitating propellers.]]></description>
      <pubDate>Wed, 11 May 1977 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/52072</guid>
    </item>
    <item>
      <title>CAVITATION PERFORMANCE OF PROPELLERS WITH AND WITHOUT CUPPING</title>
      <link>https://trid.trb.org/View/63572</link>
      <description><![CDATA[Four commercial propellers were characterized over a range of cavitation numbers and advance coefficients. Three of the propellers were then cupped to different degrees on the trailing edge and characterized over the same range of cavitation numbers and advance coefficients. The results show an increase in K sub T, K sub Q, and effective pitch corresponding to increasing degrees of cupping. An empirical relationship is derived between the amount of cupping and the resulting increase in effective pitch. It is concluded that cupping is an effective means of correcting an underpitched propeller, at the expense of efficiency and danger of increased cavitation. (Author)]]></description>
      <pubDate>Wed, 16 Feb 1977 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/63572</guid>
    </item>
    <item>
      <title>OPTIMUM PROPELLERS WITH CAVITY-DRAG AND FRICTIONAL-DRAG EFFECTS</title>
      <link>https://trid.trb.org/View/66343</link>
      <description><![CDATA[In a variational problem for the optimum pitch distribution of a propeller, the Euler differential equation with Munk's displacement theory is utilized.  Effects of frictional-drag and cavity-drag are considered through simple approximate relations of drag-lift ratio and the circulation.  Simple relations between the optimum pitch distributions and the drag-lift ratio are obtained both for free-running and wake- adapted propellers.]]></description>
      <pubDate>Wed, 16 Feb 1977 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/66343</guid>
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