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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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      <link>https://trid.trb.org/</link>
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      <title>Trackside sensors in unattended train mainline systems - A case study of alarm logs from Sweden</title>
      <link>https://trid.trb.org/View/2348302</link>
      <description><![CDATA[Implementing unattended train operation on the mainline could make the railway more competitive by reducing operating costs since there will be no staff onboard the train. This will, however, lead to new challenges. One of those challenges is how to deal with manually controlling trackside sensor alarms. In this paper, the authors study all trackside sensor alarms (hotbox/hotwheel and wheel damage) in Sweden for one year (2019) to study their frequency and context. The results show that freight trains have 10 times higher frequency for alarms per train kilometer than passenger trains. There are statistically significant seasonal and climate zone differences. The highest frequency of trackside alarms occurs in wintertime in the colder climate zone. The results can be used in the development of unattended train operation support systems on the mainline.]]></description>
      <pubDate>Tue, 14 May 2024 11:44:20 GMT</pubDate>
      <guid>https://trid.trb.org/View/2348302</guid>
    </item>
    <item>
      <title>An investigation into wayside hot-box detector efficacy and optimization</title>
      <link>https://trid.trb.org/View/1717722</link>
      <description><![CDATA[Wayside hot-box detectors (HBDs) are devices used to assess the health of railcar components including bearings, axles, and brakes by monitoring their temperatures. HBDs use infrared (IR) sensors to record the temperatures of railroad bearings. Bearings that trigger an alarm or exhibit warm trending are removed and sent for inspection. In many cases, no discernable defects were found in the flagged bearings. Motivated by this finding, an investigation was conducted which included performing a controlled field test as well as exhaustive laboratory testing utilizing an HBD simulator. Data acquired from field and laboratory testing was used to evaluate the accuracy and efficacy of wayside HBDs. The results suggest that the scanning location on the bearing cup significantly affects the temperature measurement. Different calibrations for the field- and laboratory-acquired data were also explored. An optimized calibration technique along with proper IR sensor alignment can markedly improve the accuracy of HBD measurements.]]></description>
      <pubDate>Wed, 15 Jul 2020 09:17:56 GMT</pubDate>
      <guid>https://trid.trb.org/View/1717722</guid>
    </item>
    <item>
      <title>Radiative Heat Transfer Analysis of Railroad Bearings Using a Single Bearing Test Rig for Wayside Thermal Detector Optimization</title>
      <link>https://trid.trb.org/View/1576423</link>
      <description><![CDATA[Wayside hot-box detectors (HBDs) are devices that are currently used to evaluate the health of railcar components including bearings, axles, and brakes by monitoring their temperatures. While HBDs have been instrumental in reducing some train derailments in the past few decades, the number of non-verified bearing removals has increased significantly. In general, HBDs tend to underestimate bearing temperatures in both field service and in laboratory testing, which is not surprising considering the simple calibration method that is used to calibrate these devices. Because of this, different calibrations were compared and analyzed including two-point, three-point, and multi-point calibrations. Analysis of the results also suggests that the scanning location significantly affects the temperature measurement. The work summarized here describes how an optimized calibration technique along with proper infrared (IR) sensor alignment can markedly improve the accuracy and precision of wayside HBD temperature measurements in field service.]]></description>
      <pubDate>Tue, 15 Jan 2019 10:41:59 GMT</pubDate>
      <guid>https://trid.trb.org/View/1576423</guid>
    </item>
    <item>
      <title>PREEMPTIVE STRIKES : SUPPLIERS ANSWER RAILROADS' CALL FOR MONITORING, WARNING DEVICES THAT ARE DESIGNED TO IMPROVE EFFICIENCY, SAFETY</title>
      <link>https://trid.trb.org/View/723318</link>
      <description><![CDATA[This article presents a survey of different monitoring and safety devices for trains and crossings. They include end-of-train devices, cab-signaling systems, rail-flaw detectors, monitors of grade crossings and systems to monitor the operation of the monitoring systems themselves. Wireless remote monitoring of all the mechanical functions of a train; rail sensors to measure the quality of the train's ride; and controllers and event recorders at grade crossings are among the tools manufacturers have developed.]]></description>
      <pubDate>Fri, 30 Aug 2002 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/723318</guid>
    </item>
    <item>
      <title>NEW APPROACHES TO SHIPPERS' PROBLEMS. IN: PERSPECTIVES IN TRANSPORTATION</title>
      <link>https://trid.trb.org/View/712299</link>
      <description><![CDATA[This paper discusses new approaches that can be used to make the use of railroads more efficient for shipping.  With the world changing so fast, plans that may be on the drawing board are often obsolete before the plan ever has a chance to make it to implementation.  Railroads must maintain a steady pace of progressive thinking in order to keep up with time demands and the new demands of shippers.  By designing and utilizing new types of rail equipment, railroads have larger cars capable of greater cubic capacity, greater tonnage-loading, and can carry lightly-packed commodities greater distances without damage. The refrigerator system in rail cars has been improved in order to provide and maintain accurate control of frozen or chilled products.  These improvement efforts have allowed the railroads to make rates that are attracting shifting traffic back to the rails.]]></description>
      <pubDate>Fri, 08 Mar 2002 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/712299</guid>
    </item>
    <item>
      <title>HOT BOX WARNING DEVICE FOR CONTINUOUS MONITORING TO DETECT OVERHEATED JOURNAL BEARINGS</title>
      <link>https://trid.trb.org/View/7169</link>
      <description><![CDATA[The devices discussed include: smoke and odor alarms, pyrotechnic devices, chemical detectors, infrared bolometer detectors, and mechanical and fusable plug devices.]]></description>
      <pubDate>Fri, 08 Jul 1994 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/7169</guid>
    </item>
    <item>
      <title>INVESTIGATION OF FREIGHT CAR JOURNAL BEARING AND JOURNAL BOX SURFACE TEMPERATURES IN CONNECTION WITH HOT BOX DETECTORS</title>
      <link>https://trid.trb.org/View/7557</link>
      <description><![CDATA[Laboratory and field tests are described for the Servo Hot Box Detective Unit, which is a track side installation.  Some of the conclusions follow.  Box surface temperature decreases approximately 0.6 degrees F for each 1.0 degrees F decrease in ambient temperature while the bearing temperature remains constant.  The bearing temperatures increase more rapidly than the related box surface temperatures.  The box surface temperatures do not always indicate that certain conditions are causing rapid increases in bearing temperatures.  Operating conditions, such as restricted speeds, stops, etc., prior to trains passing over hot box detectors decrease the possibility of true hot box conditions being detected.  It was recommended that the Servos be adjusted for changes in seasonal ambient temperature.  Also it is suggested that the relocation of the sensor be studied.]]></description>
      <pubDate>Fri, 08 Jul 1994 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/7557</guid>
    </item>
    <item>
      <title>FIRST PROGRESS REPORT OF THE COMMITTEE ON HOT BOX ALARMS</title>
      <link>https://trid.trb.org/View/7488</link>
      <description><![CDATA[The object of the tests was to determine whether a device exists or might be developed which can effectively warn the train crews of the danger of a hot box.  As a result of tests it was determined that the sensitive element of the device must be located in the bearing or the journal itself. The alarm should be sounded at a bearing temperature of approximately 350 degrees F for plain bearings.  No one type of sensitive element or means of transmission was found superior to the others.]]></description>
      <pubDate>Fri, 08 Jul 1994 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/7488</guid>
    </item>
    <item>
      <title>DETECTORS FOR ACCIDENT PREVENTION</title>
      <link>https://trid.trb.org/View/11226</link>
      <description><![CDATA[For dragging equipment detection, a series of brittle, cast-iron loops are mounted between and outside the rails, just below standard clearnace for rolling stock.  Hanging parts break one or more of the detector loops and these being connected in a detector circuit de-energise a relay and operate warning devices.  A device that automatically detects broken wheel flanges as well as wheels that are loose on the axle, while wagons are in motion, is described. The hot box detector has proved that the principles employed have been most successful in detecting hot axleboxes.  The equipment was designed by a firm who are manufacturers of infra-red control systems.]]></description>
      <pubDate>Fri, 08 Jul 1994 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/11226</guid>
    </item>
    <item>
      <title>HOT-BOX DETECTORS IN THE U.S.A.</title>
      <link>https://trid.trb.org/View/11418</link>
      <description><![CDATA[The problem is now being solved by the installation of hot-box detectors situated at strategic points beside the track and susceptible to any overheated box on a train passing at speed; they report the occurrence automatically to a controller or other operating officer.  There is one detector on each side of the line and if there is an overheated box on one side or the other it is picked up by the detector on that side.  The heat signal imposed on the telephone lines is instantaneously transmitted from the detector to the control office.  Two separate Harmon F.M. carrier channels are provided, one reporting from each detector.  The respective frequencies are 40 kcs. and 55 kcs.  Any abnormal temperature is indicated to the controller on a graph, and he arranges for the train to be stopped by a special signal five miles after it has passed the detectors and for a maintenance call-light to be switched on.  The train crew answering the call is informed of the position on the train of the heated journal, and decides whether the vehicle involved must be cut off.]]></description>
      <pubDate>Fri, 08 Jul 1994 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/11418</guid>
    </item>
    <item>
      <title>HOT BOX RESEARCH</title>
      <link>https://trid.trb.org/View/7644</link>
      <description><![CDATA[In order to determine the causes of hot boxes and to direct further research on the journal box assembly and truck details for improvement of plain journal bearing operation, a task force was authorized to make a field survey of hot boxes.  Many of the undesirable conditions found in this study were of the type that design and material changes could avoid.  It was determined that with a good journal lubricator, over a thousand miles could be run before all the free oil was wicked from the box.  It was also found that generally 5,000 to 10,000 miles could be run without adding free oil before the bearing was in distress.  These data suggest that changes in journal box, bearing, lubricator and other components should be made to eliminate the need for any servicing of these items at intermediate terminals.  With the use of a reliable hot box detector to locate journal boxes operating above normal temperature, it appears that trains could be moved through terminals with minimum delay and the hot box set-outs between terminals greatly reduced.]]></description>
      <pubDate>Fri, 08 Jul 1994 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/7644</guid>
    </item>
    <item>
      <title>HOT BOX RESEARCH--FIELD SURVEY ON CAUSES OF HOT BOXES</title>
      <link>https://trid.trb.org/View/7667</link>
      <description><![CDATA[In order to determine the causes of hot boxes and to direct further research on the journal box assembly and truck details for improvement of plain journal bearing operation, a task force was authorized to make a field survey of hot boxes.  This survey was made on 131 repair tracks, in 15 shops, and in 61 transportation yards of 51 representative railroads.  The geographical distribution of the railroads was selected to represent all of the regional territories of the United States, and to embrace operations under all of the climatic conditions encountered.  Data were collected through the following methods:  1. By examination of 295 cars which had developed 341 hot boxes.  2. By examination of 17,256 journal boxes in transportation yards after switching, both hump and flat, and before servicing.  3. By examination of 2,422 journal boxes at terminals after inspection and servicing by the regular yard forces.  4. By examination of 3,628 journal boxes at intermediate points where no journal box attention is given.  5. By observations of general maintenance practices on repair tracks.  6. By measurement of 1,588 journal temperatures on 10 trains.  7. By examination of 32 journal boxes which had indication of above normal temperature as recorded by fixed trackside hot box detectors.  8. By examination of 158 journal finishes through the use of a profilometer.  In this study, primary attention was given to the journal bearing and its immediately related mechanical parts.  However, the scope was extended sufficiently to include determination of the condition of such items as springs, center plates, side bearings, truck sides, and bolsters.]]></description>
      <pubDate>Fri, 08 Jul 1994 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/7667</guid>
    </item>
    <item>
      <title>NEW DEVELOPMENTS IN AIR BRAKES</title>
      <link>https://trid.trb.org/View/6907</link>
      <description><![CDATA[The article surveys a number of recent improvements in brake equipment and associated pneumatic controls.  The D22 special control valve design differs from the "universal" control valve in that the air is governed by a relay valve.  A device called the Decelostat momentarily reduces braking force on slippery wheels permitting them to return to train speed.  Hot-box detectors utilizing the Wheatstone bridge principle provide warning when overheating is imminent.  A new type of driver's brake valve (No. 24) incorporates five sections to suit various requirements for freight and passenger service.  A new variable-load brake has been designed for light-weight wagons.  A brake-cylinder release valve device isolates reservoirs and vents the brake cylinder when the "bleed" valve is pulled, thus permitting the shunter to pass from one vehicle to the next without waiting.]]></description>
      <pubDate>Fri, 08 Jul 1994 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/6907</guid>
    </item>
    <item>
      <title>RAPID TRANSIT--NEW USE FOR HOT BOX DETECTORS</title>
      <link>https://trid.trb.org/View/79725</link>
      <description><![CDATA[Modification of a standard railroad hot box detector for detection of hot inboard  journals on rapid transit cars is described.  Installations have been made at scanner sites 1500 ft in advance of the line's two terminals.  A dragging equipment detector is also part of the inspection facility. Car maintenance costs have been cut and utilization increased.  The hot box detector is now being studied as a method of monitoring traction motor conditions.]]></description>
      <pubDate>Sat, 14 Nov 1981 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/79725</guid>
    </item>
    <item>
      <title>ADVANCES IN AUTOMATIC BEARING IDENTIFICATION FOR HOT BOX DETECTOR SYSTEMS</title>
      <link>https://trid.trb.org/View/174811</link>
      <description><![CDATA[Means of identifying freight cars and then whether they have plain or roller journal bearings have been incorporated in the Servosens Bearing Discriminator, an accessory for the Servo hot-box detector system.  Since different alarm levels are necessary because roller bearings run hotter than plain bearings, bearing temperature signals are properly analyzed with system noise and waveform distortion virtually eliminated and passenger cars and locomotives positively identified.]]></description>
      <pubDate>Wed, 16 Sep 1981 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/174811</guid>
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