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Insulated Catenary
Insulated Catenary are generally used under Overline structures to avoid any breakage of catenary strands subsequent to any earth fault.
The various instructions earlier issued on the subject matter is being reproduced below in chronological manner for kind appraisal and superseding/cancellations of earlier instructions to avoid confusion among various levels.
TI/MI/0036 was issued on 08.09.1999 for PROVISION OF INSULATED CADMIUM COPPER CATENARY WIRE under OVERLINE structures along with RDSO specification number TI/SPC/OHE/INSCAT/0000 dated June 2009 (Copy Attached).
Subsequent to the failure of Srirangam- Tiruchchirapalli Town section on dated 17.08.2012 in which found that 9 outer layer was damaged during erection at the time of electrification in the section on 22.03.2009 itself and remaining 10 strands (3 outer 7 inner ) has cut subsequent to that with the elapses of time. SMI TI/MI/0047 was issued on 28.09.2012 after this failure (Copy Attached).
Recent case of failure of Contact and Catenary wires of Surat-Udhna section of Western Railway dated 24.05.2017 RB letter no 2003/RE/161/1/Vol IIi/Pt. dated 19.06.2017 for using contact piece in place of catenary wire at vulnerable location and contact wire along with catenary wire at other locations has issued alongwith not using 9T composite insulator in vertical position with same letter no dated 19.06.17 has also issued (Copy Attached).
Another one study report submitted by RDSO in the regard of provision of Insulating Paint on overline structure vide letter number TI/OHE/EC-AC/11 dated 24.11.2011 after studing the provision of insulating paint on the bottom of ROB at Patripul in Kalyan at CR (Copy Attached).
In the same line the ECR/HQ letter No ECR/ELE/100/2 dated 21.12.16 and RDSO letter No. TI/OHE/POLICY/INS CAT/16/01 DATED 02.12.2016 also needs to be withdrawn (Copy Attached).
Development of Shielded insualted catenary and effects of CORONA on the failure of insulation of insulated catenary vide RDSO letter No. TI/PSI/PROTCT/FAILURE/12/02 DATED 21.02.2017 and recommendation of RDSO for using contact wire in place of insulated catenary wire by letter no TI/PSI/PROTCT/Failure/12 dated 18.03.2016 susequent to NR and WR failures has attached along with RB notesheet of the decision of same with Noting of ED/EEM, AML and MTR.
Auxiliary Transformers
Various Guidelines have issued by RDSO and RB reagrding AUXILIARY TRANSFORMER as a reliable source of back up power supply for SIGNALLING EQUIPMENTS as well as PASSENGER TICKETING AND RESERVATION SYSTEM and TRAIN OPERATIONS. However there is itself also mentioned that BACK UP of other power sources like LOCAL SUPPLY, DG SETS, SOLAR POWER, IPS and UPS should be kept for taking BACK UP for sufficient durations during any FAILURE or POWER BLOCKS. Also failure of these power supplies for a short period should be not reasoned for reasons in interruption of train operations due to availability of other power sources as well as UPS and IPS.
Also these sources should not be used for other services other than those specified.
Panto Entaglement
For smooth operation of locomotive, the movement of pantograph should be unobstructed on the contact wire. Entanglement of pantograph with OHE normally takes place due to mechanical problems either in the OHE or with the pantograph. Entanglement can also take place during an accident or rough weather such as storm etc. Pantograph entanglement causes damages to the pantograph and overhead equipment resulting in dislocation of electric traction traffic.
Once the pantograph entanglement happens it becomes rather very difficult to establish the defect of the loco pantograph or the OHE. It is a great effort to be made to find out either OHE failed first or the pantograph. For this purpose all the evidences are to be preserved. The officer or supervisor of the electrical department arriving first at site of break down, particularly those involving entanglement of pantograph with the OHE, should make a very careful note of all relevant details pertaining to breakdown and also prepare a sketch indicating the particulars. He will also arrange for preservation of such evidence as may be useful for investigating the cause of breakdown/ entanglement. Items to be checked on the pantograph and OHE are indicated in proformas I & II. Maintenance staff, after ensuring that OHE is dead, and earthed in association with OHE staff will climb on the roof the locomotive. They will remove the HPT links of the damaged pantograph and earth it and will secure the pantograph with wire rope from the base frame of the pantograph in such a manner that it does not come in contact with OHE during the run.
Para 20824 of ACTM VOL II Part I deals with the necessary action needs to be taken after any case of Panto Entanglement.
When a pantograph gets entangled with the OHE, it is often very difficult to establish whether the damage originated from a faulty pantograph or a defect on the OHE. The first Officer or Supervisor of the Electrical Department arriving at site of a breakdown particularly those involving entanglement of pantographs with the OHE, should make a very careful note of all relevant details pertaining to the breakdown and also prepare a sketch indicating the particulars. He will also arranges for preservation of such evidence as may be useful subsequently for investigating the cause of the breakdown. Items to be checked on the pantograph and OHE are indicated in the Annexure 8.01 and 8.02.
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