<rss version="2.0" xmlns:atom="https://www.w3.org/2005/Atom">
  <channel>
    <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" />
    <description></description>
    <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>
    </image>
    <item>
      <title>THE PROPORTIONING OF BRAKE BLOCKS</title>
      <link>https://trid.trb.org/View/6914</link>
      <description><![CDATA[Excerpts are presented from an article dealing with the temperature effects produced between two sliding bodies. The investigation had two main aspects:  first, the development of a satisfactory method of measuring the surface temperatures and, second, the application of this method to actual railway brake blocks in a full-scale series of tests.  In applying the apparatus to the measurement of surface temperatures of a railway tyre, the aim of the experiment was to correlate the results obtained with three variables:  speed, block pressure, and contact area.  It was found that in all the tests contact area was very small and moved along longitudinal strips parallel to the width of the block.  Working on the assumption that contact area should be a function of block material and block pressure, and should thus vary with the ratio of block length to block width, the authors began the most striking part of their research.  A block was progressively shortened to give three-quarters, one-half, and one-quarter the original area.  Blocks of type 1 and type 2 were used, as well as cast iron, at initial speeds of 60 and 30 m.p.h. and a brake block pressure of 1,240 lb.  The result was an astonishing decrease of temperature maxima for both the non-metallic blocks, although there was no such decrease in the cast-iron blocks.  Contact areas in the nonmetallic blocks now covered the full tyre width, instead of being confined to narrow longitudinal strips.  Measurements of wear show that the normal and half-blocks wear at exactly the same rate.  Since cracking of the tyre is known to arise from the true heat spots, it can be taken that by reducing brake block areas from the present standard size, in the case on non-metallic materials, the liability to the formation of cracks is minimized and the life of tyres can thus be greatly increased.]]></description>
      <pubDate>Sun, 04 Dec 1994 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/6914</guid>
    </item>
    <item>
      <title>WHAT CAUSES WHEEL TREAD DEFECTS? PART 1: SHELLING</title>
      <link>https://trid.trb.org/View/11688</link>
      <description><![CDATA[Studies were made of wheels that shelled in service after being subjected to the usual on-tread braking as well as a wheel equipped with disc-type brakes.  These studies have indicated that shelling is essentially a fatigue failure that is caused by rolling loads.  The formation of structurally weakened metal as the result of the heat of braking friction is believed to accelerate the formation of shelling cracks.  Macroscopic examinations of radial-tangential sections from shelled areas have indicated that shelling is caused by cracks that form at angles of 30 to 50 deg to the tread surface.  Because shelling cracks are oriented at 30 to 50 deg to the tread surface they are assumed to be caused by high shear stresses developed by rolling loads.]]></description>
      <pubDate>Fri, 08 Jul 1994 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/11688</guid>
    </item>
    <item>
      <title>THERMAL CHECKING OF WROUGHT-STEEL RAILWAY WHEEL MATERIAL</title>
      <link>https://trid.trb.org/View/7662</link>
      <description><![CDATA[Laboratory investigations were undertaken to study thermal checking in railway-car wheel steel.  Five compositions of steel were investigated.  Tests were designed to (a) give a measure of check sensitivity of wheel steels; (b) study microscopically the area in which the check initiates: (c) determine the critical hardness range of the material in which the check initiated; (d) determine the amount of contraction of martensite upon tempering fully hardened specimens of wheel steel; and (e) determine the sign and magnitude of the residual stresses resulting from the test procedure.  The thermal-check sensitivity was found to increase with increase in carbon content within the range of carbon content considered.  Hardness surveys showed that for a given class of steel the thermal checks initiated within a hardness range which was reasonably constant.  The data obtained from residual-stress determination were qualitative in nature.  Determination of the contraction of martensite upon tempering resulted in data that were in good agreement with previously reported works.  Microscopic examinations seemed to indicate that the checks were intergranular.  The microstructure varied from tempered martensite to nodular pearlite.]]></description>
      <pubDate>Fri, 08 Jul 1994 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/7662</guid>
    </item>
    <item>
      <title>STUDY OF THE DEFECTS THAT ORIGINATE AND DEVELOP IN THE TREADS OF RAILROAD WHEELS DURING SERVICE</title>
      <link>https://trid.trb.org/View/7580</link>
      <description><![CDATA[Mechanism theories for the formation of defects that originate and develop in the treads of railroad wheels during service are presented.  These defects were classified after a study of wheels that developed these defects during service and of wheels that were subjected to simulated service tests on a wheel-testing dynamometer.  At least two general types of defects were found to occur during service-defects caused by stresses developed by braking and defects caused by stresses imposed by rolling loads.]]></description>
      <pubDate>Fri, 08 Jul 1994 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/7580</guid>
    </item>
    <item>
      <title>SELECTED BY THE S.N.C.F.: MONOBLOCK WHEELS OF NON-ALLOY STEEL, SURFACE TREATED</title>
      <link>https://trid.trb.org/View/5068</link>
      <description><![CDATA[Discusses the types of stresses to which wheels are subject.  Also, the damage caused by stress and the ways in which they may be controlled.  Thermic flows, exfoliations, fissures of wheel rims are wheel problems which are treated in detail, and a practical solution to these problems is discussed.]]></description>
      <pubDate>Fri, 08 Jul 1994 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/5068</guid>
    </item>
    <item>
      <title>WHEEL, AXLE, AND RAIL STRESS PROBLEMS RELATED TO HIGHER CAPACITY CARS--WHEEL PROBLEMS</title>
      <link>https://trid.trb.org/View/7581</link>
      <description><![CDATA[Factors to consider in selecting a wheel for high capacity cars--aside from dimensional compatibility with the rail and truck, are wheel class, wheel diameter, and rim thickness.  Rim thickness determines replacement period and is primarily a function of car utilization.  Wheel diameter determines stress in the contact area of the wheel tread and rail.  Wheel class determines relative resistance of wheels to wear and service damage, principally shelling and thermal cracking.  Safety and economy of the operation depends largely on freedom from excessive shelling, thermal cracking, and rapid wear, all commensurate with the cost of new wheels, reconditioning, and maintenance.]]></description>
      <pubDate>Fri, 08 Jul 1994 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/7581</guid>
    </item>
    <item>
      <title>DISC BRAKES IN THE U.S.A.</title>
      <link>https://trid.trb.org/View/6719</link>
      <description><![CDATA[In 1948 the Union Pacific Railroad decided to use disc brakes in new stock.  When the first disc-braked cars were put in service, they  were mixed with cars equipped with clasp brakes.  Trains composed exclusively of cars with disc brakes were assembled.  The results have been a reduction in noise and in jolting when trains are being stopped.  Thermal cracking of wheel tires has been virtually eliminated.  Certain interesting cost figures have been got out comparing the use of clasp and disc brakes on one of the trains over a 12-month period.  The cast-iron tread shoes of the clasp brakes required renewal after every round trip of 4,598 miles, 73 changes of shoes thus being made during the year; the disc brake shoes ran an average of 90,000 miles each, and so required an average of 3.73 changes only.  Over a full year, the renewals of short clasp brakes cost a total of $48,865.60 and of the long type $65,045.26, whereas the corresponding expenditure for Budd disc brake renewals was $7,221.48.]]></description>
      <pubDate>Fri, 08 Jul 1994 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/6719</guid>
    </item>
    <item>
      <title>WHAT CAUSES WHEEL TREAD DEFECTS? PART 2: THERMAL CRACKING</title>
      <link>https://trid.trb.org/View/11697</link>
      <description><![CDATA[United States Steel undertook an investigation of wheel-tread defects.  Shelling was shown to be the result of repeated stress application to the rolling wheel, which apparently caused the tread metal to fail in shear.  Cracks propagate from below to the tread surface.  When two of these cracks of opposed orientation meet beneath the tread, metal between them is loosened and finally expelled.  This is the typical shelling type of failure.  While shelling apparently is not caused by braking, there are wheel defects which can be caused by stresses that develop in the wheel rim as a result of thermal gradients generated by friction between the tread and brake shoe during braking. Shelling and thermal cracking of railroad wheels shorten wheel life, and checking brought on by severe braking may occasionally result in a complete wheel failure.]]></description>
      <pubDate>Fri, 08 Jul 1994 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/11697</guid>
    </item>
    <item>
      <title>RAILROAD ACCIDENT REPORT - DERAILMENT OF NEW YORK CITY TRANSIT AUTHORITY SUBWAY TRAIN, NEW YORK, NEW YORK, DECEMBER 12, 1978</title>
      <link>https://trid.trb.org/View/143876</link>
      <description><![CDATA[About 4:38 p.m., on December 12, 1978, the sixth and seventh cars of a New York City Transit Authority subway train designated "CC" 4:06 p.m. derailed within moments after departing 59th Street station. Twenty-two persons were injured, and property damage was estimated to be $667,500. While the Safety Board was investigating this accident, three other trains derailed from what appeared to be similar causes. Therefore, the investigation was expanded to include all four accidents. The National Transportation Safety Board determines that the probable cause of each of the four accidents was a cracked wheel which had resulted from extensive overheating. Contributing to the cause of the overheating of the wheels was the partial application of a handbrake. Because of a lack of adequate inspection procedures, the New York City Transit Authority employees failed to detect the partially applied handbrake and the thermally damaged wheels before they cracked.]]></description>
      <pubDate>Thu, 11 Feb 1982 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/143876</guid>
    </item>
    <item>
      <title>STEEL WHEEL PLATE CRACKING</title>
      <link>https://trid.trb.org/View/28697</link>
      <description><![CDATA[This document describes the results of an investigation into the cause of premature cracking on 28-inch reversed dish transit car wheels. Methods used in determining the operating thermal and track load stresses in the critical areas of a wheel are presented. The observations made on the cracked specimens all indicate that the cracks which formed were due to fatigue. The problem was resolved by specifying a new wheel plate thickness and also by machining and shot peening the plate surface.]]></description>
      <pubDate>Thu, 10 Sep 1981 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/28697</guid>
    </item>
    <item>
      <title>FATIGUE ANALYSIS OF RAILROAD FREIGHT CAR WHEELS UNDER THERMAL LOADING CONDITIONS</title>
      <link>https://trid.trb.org/View/164475</link>
      <description><![CDATA[When a wheel is subjected to repeated thermal loading from drag braking conditions, cracks can develop and propagate due to fatigue.  Wheels of 36, 33 and 28 inch diameter were studied using the finite element method.  The wheels were subjected to drag braking thermal inputs of 30, 40 and 50 hp, each applied for 30 minutes.  The fatigue life was calculated for an assumed load history using Miner's linear cumulative damage rule.  The temperature distribution in the wheel was obtained by means of the DOT computer program. The CREEP-PLAST program was then used to calculate the stress and strain distributions.  The stress and strain values increased as the braking horsepower increased.  For the same thermal loading conditions, the calculated fatigue life was lower for the smaller wheels than for the larger wheels.]]></description>
      <pubDate>Fri, 12 Jun 1981 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/164475</guid>
    </item>
    <item>
      <title>GENERAL PROBLEMS CONNECTED WITH WHEELS AND THEIR ASSEMBLY: SOLID CAST - STEEL WHEELS, WHEELS OF DIFFERENT DIAMETER AND SHAPE. ROLLED STEEL WHEELS. SECOND CONTRIBUTION TO THE STUDY OF SMALL WHEELS. (VOLUMES 1 AND 2: TEST, AND APPENDICES 1-6)</title>
      <link>https://trid.trb.org/View/15174</link>
      <description><![CDATA[In this report, an account is given of the running tests, the wheel testing machine, the hauling tests on the flat track and the test-runs on long, steep falling-gradients, already carried out.  These tests complete those already outlined in Report B 98/RP 2, the conclusions of which are confirmed.  It is indicated that a very significant improvement in the performance of wheels of 660 mm, 840 mm and 920 mm diameter is obtained in using, instead of wheels of BV 1 and BV 2 steel, solid rolled wheels of unalloyed steel with treated running tread, having carbon and manganese contents of less than 0.52% and 0.80% respectively, with an ultimate tensile strength, measured at a distance of 15 mm below the running tread, of more than 82 hbar and an elongation of more than 14%.  Furthermore, an improved performance is obtained for the DB 730/680 mm diameter wheels in using solid wheels of BV 1 steel with tempered running tread, with a hardness corresponding to a tensile strength of 88.2 hbar. Moreover, the tests have revealed very disturbing deformations of the solid wheels under the effect of the heat generated during tread braking with brake blocks, these deformations sometimes reaching such values that there is a danger of certain international prescriptions failing to be complied with.  The solution to the problem might be sought in the choice of the most suitable design and shape of the solid cast-steel wheel. The programme of work has been prepared with this in mind.]]></description>
      <pubDate>Wed, 06 Oct 1976 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/15174</guid>
    </item>
    <item>
      <title>HOT SPOT HEATING BY COMPOSITION SHOES</title>
      <link>https://trid.trb.org/View/31443</link>
      <description><![CDATA[It is generally understood that uneven heating of the tread of a wheel during braking is possible.  A method has been devised to measure the intensity and frequency of hot spots on the wheel tread surface.  After a description of the measurement apparatus and technique, results of a study of hot spots during constant speed brake applications with single composition shoes are presented.  Possible lowering of the hot spot level by increasing the conformability of the brake shoe is studied by cutting one slot across each pad of a brake shoe.  This method of hot spot study may be useful for future analysis and improvement of brake shoes.]]></description>
      <pubDate>Fri, 02 Jul 1976 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/31443</guid>
    </item>
    <item>
      <title>MAINTENANCE OF THE WHEELSETS OF TRAILER STOCK. CATALOGUE OF DEFECTS ON THE WHEELS OF RAILWAY TRAILER STOCK</title>
      <link>https://trid.trb.org/View/4183</link>
      <description><![CDATA[This report forms a contribution towards the standardization of the terms used for designating the most frequent defects encountered on the wheels of trailer stock wheelsets.  The defects have been grouped according to their location i.e. running tread and surface of the flange, wheel rim with tyre (solid wheel) or tyre and rim (tyre wheel), wheel disc, hub.  For each type of defect, its designation, characteristics and apperance accompanied whenever possible by one or more characteristic photographs, have been indicated.  In addition, information has been given concerning the means for detecting the defect, recommendations (of a general nature) concerning the procedure to be adopted following its detection, and its probable origin.]]></description>
      <pubDate>Wed, 16 Jun 1976 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/4183</guid>
    </item>
    <item>
      <title>GENERAL PROBLEMS CONNECTED WITH WHEELS AND THEIR ASSEMBLY: SOLID CAST-STEEL WHEELS, WHEELS OF DIFFERENT DIAMETER AND SHAPE--THIRD CONTRIBUTION TO THE STUDY OF SOLID CAST-STEEL WHEELS</title>
      <link>https://trid.trb.org/View/7683</link>
      <description><![CDATA[In this report an account is given of the running tests, the braking tests on the wheel testing machine and the test runs on steep falling gradients.  The running tests employed wheels of 730 mm diameter with treated wheel-rim of non-alloyed steel with a carbon content of either 0.61% or lower than 0.5% with an ultimate tensile strength of 115 to 130 hbar and 84 to 101 hbar respectively.  Other tests were made with solid wheels of 920 mm diameter made of Wt steel (carbon and manganese content lower than or equal to 0.52% and 0.80% respectively.  These tests consisted of falling-gradient runs on the St. Gothard line and of runs on flat sections under loaded wagons.  Some wheels were also submitted to tests on the test rigs at MINDEN, VITRE-sur-SEINE and DERBY, in order to determine their behavior under the effect of heat generated by braking (liability to thermal cracks and deformations of the wheel-rim).  Finally, one wheel of 730 mm diameter and wheels of 920 mm diameter of Wt steel were submitted to investigations in the laboratory and the latter wheels were in addition, studied with a view to the stresses developed. The braking tests carried on the rig with 730 mm diameter ABEX wheels have given unfavorable results.  The running tests in commercial service have also given unfavorable results (spalling of running-tread).  Concerning the GRIFFIN wheels of the same diameter, the running tests have also supplied disappointing results, there wheels displaying spalling or even perhaps flaking.  The ABEX and GRIFFIN wheels of 970 mm diameter with treated wheel-rim and somewhat high carbon content showed a good behavior in SWEDEN during tests under high load (25 t/axle) but very mild braking conditions, the climatic conditions however being very severe.  The 920 mm ABEX wheels, ordered in Wt steel have shown a good behavior during the running tests and during the braking-tests on the MINDEN, VITRY and DERBY rigs (resistance to thermal cracks).  However, during the falling-gradient runs on the St. Gothard line, they had given rise to deformations reducing the play of the axle.]]></description>
      <pubDate>Thu, 22 Jan 1976 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/7683</guid>
    </item>
  </channel>
</rss>