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Time Corridor

By on May 16, 2013

Time Corridor is the time period specified during the 24 hour interval for a specific activity of running trains of similar  maximum and average speed . The activities are

  • Running of fast coaching trains
  • Passenger trains
  • Freight trains
  • Maintenance corridor

There are certain observations made watching train operation  to derive this concept of time corridor

  • Train bunching takes place during  breakdowns. After restoration, all the coaching trains are cleared one after another and it does not take much time to clear the bunched trains.
  • Maintenance corridors were identified and specified in the working timetable. This concept was introduced sometime during the year 2000. The time interval of coaching corridor is getting compressed and now it is very difficult to find more than an hour time.
  • It takes around 9-10  and 5-6 minutes for a freight and a coaching train to stop,  start and regain speed respectively. It should not be compared with road vehicle such as  the Maruti 800 which picks up speed of 100 kmph in 21 seconds.
  • Efforts made to run freight trains on a timetable had not been successful. This has been a personality oriented drive system requiring strict administrative control. There is so much  optimism, that  any mobility damage caused by this drive is ignored.
  • Freight train is permitted to run even for a one block section seeing  time slot of just 15 minutes.
  • Time Spacing between two coaching trains varies from 10 minutes to 30 minutes. If a following train is over 30 minutes, it will either waste sectional capacity of 20 minutes or results ladder formation in a freight train run.

Drawing ladder

 Indian Railways shall calculate lost capacity due to varying time difference between two trains.

Acceleration for different type of stock on level section

1.3m/sec2  or 5 Kmph/Sec and above – Four wheeler road vehicle

0.25-1.2 m/sec2    or 1 to 4 Kmph/Sec (1.95 Avg and 2.7 from 0-40 Kmph 3 phase emu)  – Suburban,

0.15- 0.25 m/sec2   or  0.5 to 1.0 Kmph/Sec    -Main Line – Taking 4-5 minutes to attain the speed of 100 Kmph, with  minimum  loss of 2-3 minute if not stopped.

0.05 – 0.12 m/sec2  or 0.2 to 0.4 Kmph/Sec – Freight – Taking 6-7 minutes to attain the speed of 60 Kmph with minimum loss of about 3-4 minute if not stopped.

The most important sustainable conclusion  visible is  that freight train shall have a minimum run of at least 100 km without stop. This can only be possible if there is a freight corridor where trains can run for 2-3 hrs without control for precedence or doubt arising in the mind of controller due toany uncertainty that exists with the reliability of freight train. This has been wished by the Railways but without designing defined  time corridor for coaching trains with the assumption ‘ it is not possible’. Why? Is it difficult to  integrate  the trains coming from different directions in coaching corridor. Constraints identified are

  • Path
  • Platform occupation
  • Pit line occupancy
  • Precedence of one coaching train over another
  • Suitability of time at start and destination

Freight corridor is possible only when Coaching corridor is designed and all coaching trains are pushed into coaching corridors. Coaching corridors are possible when it is not conceived in isolation of Divisional or zonal territory but in totality over Indian Railways.

Designing Coaching Time Corridor

  1. It is simple to design coaching time corridor. Identify 4 nos of 2-3 hour block on 24 hours time frame which runs at an average speed of 55-65 Kmph or the speed Indian Railway decides.
  2. One of the coaching corridorsis nominated for trains to run at an average speed of 90-95Kmph calledRajdhani/Duranto  corridor.
    1. Rajdhani is defined as train which arrives and originates from Delhi at around 0900 and  1700 Hrs. Respectively at an average speed of 90 Kmph and timings of the destination is worked out.
    2. Duranto is defined as train which runs non-stop with technical halt from crew changing and is planned between two major cities having end to end demands.
    3. Shatabdi trains are day time intercity trains running at an average speed of 80-90 kmph starting from major city at 0600-0700 hrs and returning back by 2200 hrs covering the passenger demand for a distance of about 500 km.
    4. Every group of  train shall be defined in these lines.
  3. The average speed of a national corridor need not be uniform; it can be made to vary say higher during night time and lower during day time because stoppage demands are mainly during day time.
  4. Coaching Time Corridors are designed at national level and not at zonal or divisional level.
  5. Shatabdi Trains are accommodated at the beginning or the end of the coaching corridor running at a speed of 65-70kmph
  6. Intra-coaching corridor speed differential shall be avoided
  7. Coaching corridors are plotted on the RHS at designed average speed and Tables of Indian Railway Time Table at a glance on the RHS. Three or four corridors are identified and all trains pushed to nearest corridor.
  8. Indian Railways run around 11000 trains a day and it could conveniently be done through some programming and a capacity enhancer time table can be designed.
  9.  In case reader has knowledge of writing programs, love for Indian Railways, time, interest may take a lead to take up this assignment and present it to Indian Railway management. I am sure that will interest every one. There may be a genuine question, why Indian Railways is not doing it?  The answer is generally “idea is good but difficult to implement”. I am certain that this is possible and continuous effort may click results one day.
  10. Enthusiasts may contact me for any guidance.

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There is 1 Comment

  1. Jaydeep Banerjee says:

    Respected Mahesh Kumar Jain Sir,

    I have hone through your note on “Time Corridor”. You have written a important thing and illustrated it very well.

    I will go through your other topics also.

    Jaydeep BanerjeeI, TI, Operating department in S.E.Railway.