Increase in axle load of freight wagons - PowerPoint PPT Presentation

1 / 18
About This Presentation
Title:

Increase in axle load of freight wagons

Description:

... fishplates, bolt-holes and fish-bolts , sleepers & ballast. ... defects viz. head checks & gauge corner cracking would occur resulting in more rail failures. – PowerPoint PPT presentation

Number of Views:213
Avg rating:3.0/5.0
Slides: 19
Provided by: 11428
Category:

less

Transcript and Presenter's Notes

Title: Increase in axle load of freight wagons


1
Increase in axle load of freight wagons

2
CC 8 2 LOADING
  • In order to enhance throughput to meet increasing
    traffic demands, Board has permitted running of
    BOXN BOXNHS wagons loaded up to CC82(axle
    load of 22.82t) at maximum permitted speed of 60
    kmph on identified iron/other ores routes w.e.f.
    May ,05 as a pilot project for a period of one
    year initially (currency of the project has
    been extended up to June,08).
  • Initially,16 routes were identified for such
    operation. Gradually, more routes were cleared
    totaling to 34 routes up to March ,07 on ER,
    SER, SCR, SWR, ECoR, SECR, SR WCR as per list
    in the annexure I.
  • However, a number of precautions and monitoring
    mechanisms have been prescribed for these trains.

3
CC 62 LOADING
  • To achieve further augmentation in throughput,
    Board has approved universalisation of running
    of CC62 t loaded BOXN,BOXNHS,BOBR,BOBRN,BCN,
    BCNA, BCNAHS BOST wagons for carrying
    coal,cement,rice,sugar etc. at maximum permitted
    speed of 60 kmph, except some sections where it
    will be restricted .
  • Restricted sections are given at Annexure II.
  • In case of emergencies such as accidents etc.
    running of CC62 loaded wagons in some
    restricted sections can be permitted. This shall
    be done at the level of PCE , who will advise
    suitable speed restrictions keeping in view the
    condition of fixed infrastructure.
  • The precautions and monitoring prescribed for
    these sections are essentially similar to those
    prescribed for CC82 axle load.

4
Precautions and Monitoring Mechanisms
  • Installation of electronic in-motion
    weigh-bridges at loading points to stop
    overloading.
  • Installation of adequate number of Wheel Impact
    Load Detectors (WILD) for recording of loading
    spectrum passing over track.
  • Ultrasonic testing of rails for detection of
    gauge corner cracks.
  • Quarterly review of the project by a
    multidisciplinary committee comprising of PHODs
    under GM of Zonal Railway.
  • Monitoring of defect generation rates in rails
    and welds based on USFD testing.
  • Monitoring systems to be installed at identified
    Bridges.
  • More frequent track recording to monitor track
    geometry.

5
Important technical parameters
  1. Track structure Minimum 52/60kg 72 UTS rails,
    sleeper density M7 and depth of ballast cushion
    250mm with a clear cushion of 100mm for running
    of these freight trains at maximum permissible
    speed of 60 Kmph . In case of 90R rails , maximum
    speed permitted shall not exceed 30 Kmph .
  2. Bridges Mostly of BGML standards are available
    on these sections.

6
Specific items for action ,monitoring recording
observations
  • TRACK
  • 90R rails should be replaced expeditiously as
    possible . While renewing rails, rails of 90
    UTS may be used from overall economics
    consideration as rail life will get shortened due
    to increased stresses .
  • Similarly, while replacing sleepers, sleeper
    density of 1660/km may be provided.
  • Ballasting will have to be given thrust.
  • Structural integrity of fastenings has to be
    ensured especially rubber pads.

7
Specific items for action ,monitoring recording
observations
  • v). As a good maintenance practice ,it may be
    desirable to destress LWRs twice every year ,
    once before winter and again before summer
    especially in Zone III Zone IV.
  • Behaviour of LWRs would have be watched
    critically and data collected.

8
Specific items for action,monitoring recording
observations (Contd.)
  • vi) Due to increase in lateral forces on curves,
    increased deterioration in lateral alignment
    would occur.
  • Hence, curves may have to be inspected
    more frequently .

9
Specific items for action ,monitoring recording
observations (Contd.)
  • vii)Due to increased bogie rotational resistance,
    rail-wear on curves will increase. Rail profile
    would be required to be monitored to understand
    rail-wear pattern. On curves, increased angular
    wear may be dangerous and need to be watched.
  • The observations of rail wear will be
    useful in decisions for rail replacement.

10
Specific items for action ,monitoring recording
observations (Contd.)
  • viii) Due to increased load ,rolling contact
    fatigue (RCF) defects viz. head checks gauge
    corner cracking would occur resulting in more
    rail failures.
  • USFD examination of rails at more frequent
    interval would be required to be done.

    As a preventive measure, rail grinding will be
    helpful to eliminate such defects.

11
Specific items for actions,monitoring recording
observations (Contd.)
  • ix) Rail/wheel impact forces due to defects
    in the rail/wheel surface, viz. dip at rail
    joint, cup formation in AT welds, flat tyres, out
    of round wheels will increase damage to
    rail-heads, fishplates, bolt-holes and fish-bolts
    , sleepers ballast. These will cause increased
    deterioration in track geometry.
    Since the track is going
    be overstressed, Wheel Impact Load Detectors
    should be installed at suitable locations to
    prevent further overstressing.

12
Specific items for action ,monitoring recording
observations (Contd.)
  • x) Rail corrugations may develop due to
    high dynamic forces.
  • These would have to be monitored and if
    necessary, rail grinding may be done to eliminate
    the same.

13
Specific items for action,monitoring recording
observations (Contd.)
  • xi) Points crossings maintenance
    activities will get increased viz. packing,
    correction to alignment/level, replacement/
    reconditioning of switches crossings .
  • Due to increased bogie rotational
    resistance, the increased lateral forces may
    increase the tendency of derailment on a weak
    turn-in/turn-out curve, by gauge spreading.
  • Thus, PC will require close monitoring.

14
Specific items for action,monitoring recording
observations (Contd.)
  • xii) Transitions, viz. bridge approaches,
    level crossings, culverts, tunnels etc., where
    the track stiffness changes abruptly, will
    require special monitoring due to abrupt change
    in vertical dynamics of heavy wheels.

15
Specific items for action,monitoring recording
observations (Contd.)
  • FORMATION
  • Weak stretches of formation would have to be
    rehabilitated by providing blanket layer as given
    in RDSO Guideline GEG-6.
    Till such time it is done, frequent
    monitoring of the track geometry at such
    locations should be done.

16
Specific items for monitoring recording
observations (Contd.)
  • BRIDGES Each bridge would have to be evaluated
    as an individual identity reg. safety vis-a-vis
    its physical condition.
  • Speed restriction may have to be imposed
    from safety consideration,if required.
  • Rehabilitation/strengthening should be
    carried out as per the increased trailing loading
    density of 8.51 t/m .
  • Sample vulnerable bridges should be got
    instruemented through specialised agencies .
  • NDT tests may be carried periodically.

17
Specific items for monitoring recording
observations (Contd.)
  • Extra maintenance effort would be
    required due to increase in inspection,monitoring,
    maintenace of track,formation and bridges.
    Therefore, a proper record should be kept costs
    worked out so that proper evaluation can be done
    at the end of the pilot project.

18
Conclusion
  • RDSO should be associated in the studies and
    monitoring exercises.
  • Railways should put in place the monitoring
    mechanism by the Monitoring Committee comprising
    of PCE/CE,CME,COM under GM .
  • Instructions for installation and functioning of
    weigh bridges for detecting overloading of wagons
    have to be meticulously observed
Write a Comment
User Comments (0)
About PowerShow.com