Q. & Ans - What precautions are to be taken during deep screening by BCM, followed by tamping machine & DTS?

Question  - What precautions are to be taken during deep screening by BCM, followed by tamping machine & DTS?

Answer - Precaution to be taken during deep screening of track by BCM followed by TTM and DTS machines are as under -

1. All precautions laid down in LWR manual (specially those in para no. 6.3.2) shall be strictly followed.

Note - Para no. 6.3.2 of LWR manual  i.e. Deep screening/mechanised cleaning of ballast is as -

i) Provisions laid down in para 238 of IRPWM will also apply mutatis- mutandis to LWR/CWR with further provisions as mentioned hereafter in this para. Wherever mechanised cleaning of ballast is resorted, the detailed procedure laid down in para 238 (2) (e) of IRPWM for manual deep screening shall stand replaced by the sequence of operations of Ballast Cleaning Machine (BCM). 

ii) Ballast Cleaning Machine (BCM), tamping machine and Dynamic Track Stabilizer (DTS) shall, as far as possible, be deployed in one consist. 

iii) Temperature records of the sections where deep screening is to be undertaken, shall be studied for the previous and the current year. The maximum and minimum rail temperature attainable during the period of deep screening and during the period of consolidation shall be estimated. Any of the following three methods may be adopted for carrying out the work of deep screening/ mechanised cleaning:- 

a) If range of rail temperature falls within td +10OC to td -20OC, deep screening may be done without cutting or temporary destressing. 

b) If range of rail temperature falls outside (a) above, temporary destressing shall be carried out 10OC below the maximum rail temperature likely to be attained during the period of work. CWR shall be cut into LWRs of about 1 km length with two temporary buffer rails of 6.5 metre long clamped as per arrangements 

c) Wherever rail renewals are being carried out, LWR/CWR may be converted into three rail panels and deep screening done. 

iv) Constant monitoring of rail temperature shall be done during the progress of work. Should the temperature rise more than 10OC above td /temporary destressing temperature, adequate precautions shall be taken including another round of temporary destressing. 

Note : Deep screening shall be undertaken within 15 days of temporary destressing failing which temporary destressing may become due again, if the rail temperature varies appreciably. 

v) During the period of deep screening, if there is any possibility of minimum temperature falling 30OC below td /temporary destressing temperature, cold weather patrol as per para 9.1.2 (ii) should be introduced to detect/ guard against rail fractures. 

vi) Sequence of operation: - 

a) Deep screening of LWR may be done from one end of LWR to other end. 

b) After deep screening and consolidation as per para 1.18, destressing of LWR shall be undertaken as per para 5.7.

2. Hard Sal wood blocks of size 600 x 300 x 300 mm ( six numbers ) duly end bounded shall be arranged for supporting ends of three adjoining sleepers where cutter bar is left in the track and remains untamped.

3. Sleepers of cutter bar area shall be manually packed and ballast under cutter bar location sleepers shall be removed only half an hour before the expected traffic block. Adequate care shall be taken to ensure that wooden blocks are not dislodged before arrival of BCM at site.

4. Fish plated joint shall not be located in cutter bar location.

5. Ramp shall not be located in locations like level crossing, girder bridge, transition portion of curve etc. It shall be kept minimum two rail length away.

6, In case of fracture or cut in CWR / LWR, a speed restriction of 20 Kmph shall be imposed till it is repaired as per para 7.2.3 of LWR Manual.

7. In case of malfunctioning of TTM and or DTS, deep screening shall be stopped and track which has not been tamped and stabilized shall be attended manually by ballast ramming and correction of track geometry to ensure safety of running trains. Speed restriction shall be imposed and relaxed in term of IRPWM para 238 ( 2 ) ( g ) ( i ) or ( ii ) which ever is the case.

8. In case of non availability of traffic block on subsequent days of deep screening by BCM speed restriction shall be imposed and relaxed in term of IRPWM para 238 ( 2 ) ( g ) ( i ) or ( ii ) which ever is the case.

9. When BRM is not deployed, adequate track men shall be deputed to recoup ballast, particularly in shoulder and maintain ballast profile after machine working.

10. Lifting of track shall be resorted after ensuring adequate availability of ballast for maintaining ballast profile for planned lifting.

11. Adequate arrangements for supply and training out of ballast prior to deep screening should be made. Special care shall be taken by deploying watchman on stretches overdue for rail renewal.

Also See 

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