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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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      <title>AMERICAN FREIGHT CAR TRUCKS</title>
      <link>https://trid.trb.org/View/24427</link>
      <description><![CDATA[A brief survey is presented of the fundamental performance requirements of trucks for railroad cars, and an outline is given of research in progress in this area by the AAR (Association of American Railroads) in cooperation with other interested organizations.  The functions of a truck can be summed up as follows: guidance of the car along the rail, isolation and protection of car and contents, support of car and contents...and, transmission of brake retarding forces.  One of the major problems being studied is divergent hunting in which the wheelset over-corrects for a displacement so that the amplitude of each cycle of oscillation is greater than the previous one.  Hunting is a complex phenomenon.  There appear to be at least 12 factors which influence the speed at which violent hunting will occur.]]></description>
      <pubDate>Mon, 13 Dec 1976 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/24427</guid>
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      <title>TESTS CONCERNING THE PROBLEMS INVOLVED WITH THE KINEMATIC GAUGE. TESTS AND FINAL REPORT</title>
      <link>https://trid.trb.org/View/15338</link>
      <description><![CDATA[In connection with the kinematic gauge (UIC question), ORE has conducted a study concerning the position of the bogies and wheelsets in the track.  The aim of the studies was to investigate the possibility of abandoning the position of the vehicles in the track, as prescribed in the Technical Unity, and to indicate new and more favourable positions relative to the permissible width of the vehicles.  Report No. 1 contains a theoretical study.  During this study, graphs were plotted for a curve with R = 150 m, indicating the longitudinal force as a function of the coefficient of adhesion between wheel and rail, in order that the most unfavourable position might be produced.  In the present report, graphs were plotted for other curvature radii. The great unknown factor in this problem is the minimum value to be taken into consideration for the coefficient of adhesion.  For this purpose, tests were conducted whose description and results are given in an Appendix. Apart from given exceptional cases, the tests have shown that the most unfavourable positions do not occur in reality.]]></description>
      <pubDate>Tue, 13 Jul 1976 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/15338</guid>
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    <item>
      <title>TRUCK DESIGN - A SYSTEMS APPROACH TO SOLVING PROBLEMS</title>
      <link>https://trid.trb.org/View/45161</link>
      <description><![CDATA[The responsibility for freight-car truck design is difficult to fix.  After examining the functions of various agencies involved in design, truck problems are examined.  Two areas for improved truck performance are modification of existing trucks to improve reliability and complete redesign to improve performance.]]></description>
      <pubDate>Sat, 05 Jun 1976 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/45161</guid>
    </item>
    <item>
      <title>EVALUATION OF RAILWAY CONTACT THEORY BY EXPERIMENTS</title>
      <link>https://trid.trb.org/View/37118</link>
      <description><![CDATA[The paper concerns an evaluation of a widely used mathematical model for the description of the wheel-rail forces in the equations of motion of a railway vehicle. By using the measured responses of a bogie on a normal track, actual values for the creep coefficients and the geometrical contact parameters will be determined. Interesting results have been obtained for the influence of the gravitational stiffness.]]></description>
      <pubDate>Wed, 21 Apr 1976 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/37118</guid>
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    <item>
      <title>MINIMAX OPTIMIZATION OF RAILWAY VEHICLE SUSPENSIONS</title>
      <link>https://trid.trb.org/View/20804</link>
      <description><![CDATA[The minimax response of a complex dynamic system, such as a railroad vehicle, can be obtained by choosing certain (optimum) values of the stiffness and damping elements in the system.  The railway vehicle is mathematically modeled as a linear, stable, strictly dissipative multi-degree of freedom dynamic system.  The system is excited at more than one point by synchronous harmonic forces.  A minimax principle reduces the problem to that of finite dimensional optimal design problem.  Non-linear mathematical programming techniques are used to minimize the non-linear objective function representing the maximum resonant response at a point of the system, and subjected to linear or non-linear constraints, over a certain frequency range.  The frequency range may be finite or infinite.  Dynamic response of the system before and after optimization is shown, and three-dimensional plots for the constrained and unconstrained objective function versus the two most important design parameters are illustrated.]]></description>
      <pubDate>Fri, 09 Jan 1976 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/20804</guid>
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      <title>DAMPING REQUIREMENTS TO CONTROL VERTICAL AND ROLL MOTION OF FREIGHT CARS</title>
      <link>https://trid.trb.org/View/24440</link>
      <description><![CDATA[Compression dampers located in the freight car spring group can effectively control the car body in the roll and vertical motion modes resulting from the more common track surface variations.  Computer drawn traces show the motion and forces between car body, truck components and track resulting from a multi-degree of freedom, three-dimensional, mathematical model of a 100 ton freight car traversing track with defined surface variations.  Comparisons of response resulting from hydraulically controlled springs and a conventional spring group suspension controlled only with coulomb friction shows generally that conventional suspension with only friction damping, results in a severe resonance for both vertical and roll modes with extreme weight shift and high reactions between freight car components and track - a resonance limited only by the system non-linearities.  Single acting hydraulic damping can be defined with sufficient energy absorption that can limit forces and motion at each given resonance, reducing weight shift and derailment jeopardy, as well as, equipment and track damage.]]></description>
      <pubDate>Fri, 09 Jan 1976 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/24440</guid>
    </item>
    <item>
      <title>RAILWAY TRUCK RESPONSE TO RANDOM RAIL IRREGULARITIES</title>
      <link>https://trid.trb.org/View/20805</link>
      <description><![CDATA[This paper discusses the random response of a seven degree of freedom passenger truck model to lateral rail irregularities.  Power spectral densities and root mean square levels of component displacements and contact forces are reported.  The truck model used in the study allows lateral and yaw degrees of freedom for each wheelset, and lateral, yaw and roll freedoms for the truck frame.  Linear creep relations are utilzed for the rail-wheel contact forces.  The lateral rail irregularities enter the analysis through the creep expressions.  The results described in the paper were obtained using frequency domain techniques to solve the equations of motion.  The reported results demonstrate that the guidance force needed when traveling over irregular rail at high speed utilizes a significant portion of the total available tangential force between wheel and rail.]]></description>
      <pubDate>Fri, 09 Jan 1976 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/20805</guid>
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    <item>
      <title>TRACK-TRAIN DYNAMIC ANALYSIS AND TEST PROGRAM, TRUCK STATIC TEST</title>
      <link>https://trid.trb.org/View/23940</link>
      <description><![CDATA[A series of tests were conducted to define the characteristics of an ASF 11 Ride Truck Assembly including joint slop, friction and stiffness. Loading to the truck assembly included vertical load to simulate the car/pool loading combined with lateral or moment loading that resulted in desired truck deflections for the various phases of testing. All seven test conditions were successfully completed with load and deflection data being collected. No attempt is made to reduce the applicable data other than to provide computer plots. (Author)]]></description>
      <pubDate>Thu, 26 Jun 1975 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/23940</guid>
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    <item>
      <title>THE HUNTING STABILITY AND CURVING ABILITY OF RAILWAY VEHICLES</title>
      <link>https://trid.trb.org/View/20029</link>
      <description><![CDATA[A novel railway suspension system using the principle of diagonal wheelset guidance in place of the parallel guidance commonly employed has been described in principle for two and three axle bogies (vehicles) and analyzed for curving ability and hunting stability of wheelset and body oscillations, and critical hunting speeds have been determined.  It has been shown that body instabilities can be controlled by the use of pseudo-slip damping and/or body suspension damping while wheelset stability can be maintained up to very high operating speeds without any real impairment of the steering ability of the standard rigid railway wheelset having conical or profiled wheel treads. For profiled wheels the ratio between lateral gravitational suspension stiffness and longitudinal suspension stiffness which ensures optimum steering on curved track has been derived.]]></description>
      <pubDate>Wed, 28 Aug 1974 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/20029</guid>
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