1. In discharge of its responsibility under Rule 4 (j) of NLDC Rules, 2005, NLDC has submitted to CEA and CTU the report on “Operational Feedback on Transmission Constraints” for the quarter April to June, 2015 (1 quarter of 2015). A copy of the report has been endorsed to the Commission vide NLDC's letter dated 21.7.2015
2. In para 1.6 of the report, NLDC has given a list of 21 no. of 400 kV and above lines and 4 No of 220 kV lines where some towers have collapsed during the first quarter of 2015 leading to line outage. Out of the 25 lines, PGCIL is the owner of 17 lines and the remaining lines belong to UPPCL, RRVPNL, WBSETCL. NLDC has further stated in the report that the number of tower collapse is more during the first quarter of 2015 compared to the corresponding quarter in the year 2014-15. The relevant para of the report is extracted as under:—
“Comparing the first quarter of 2014 (viz. April, May, June) and the first quarter of 2015, there is an increase in the 765 kV tower collapse/damages. The comparison table is give below. It is important that these failures are investigated thoroughly and the root cause identified and the remedial vulnerable. In the eventually that the investigations indicate that all these outages are in the nature of force majeure (which again appears improbable considering the geographically widespread nature of these incidents), it calls for a re-look at the transmission planning criteria. In case the reasons for failure are otherwise, it calls for a re-look of the operation and maintenance practices and the need to secure and protect critical infrastructure such as transmission lines.
Voltage LevelNo. Of tower collapse in the first quarter in 2014-15No. Of tower collapse in the first quarter in 2015-16765 kV39400 kV912Total1221
3. The Commission is concerned about the rising incidents of tower collapse. The Commission accordingly directs the CEA and CTU to investigate into the incidents of tower collapse during the 1 quarter of 2015 and submit reports containing the reasons for tower collapse. CTU is also directed to explain the reasons where the revival time of the towers has exceeded 30 days.
4. POSOCO (NLDC) is directed to submit a report containing the details of impact of tower collapses during the 1 quarter of 2015 and the consequent line tripping on the system operation and grid security, the action taken by concerned RLDCs in this regard and the response of the constituent entities to the directions of RLDCs.
5. The reports as per the directions above shall be submitted by CEA, CTU and POSOCO (NLDC) by 30.11.2015
6. It is also noticed from the list of transmission lines at Annexure, five lines are owned by UPPTCL, RRVPNL and WBSETCL. In case of three transmission lines of UPPTCL, the revival time ranges from 44 days to 345 days. In case of two transmission lines of RRVPNL, the revival time is 76 days and 97 days. Though the transmission system of UPPTCL, RRVPNL and WBSETCL fall under the jurisdiction of the respective State Commissions, their outage on account of tower collapse affect the safe and secure operation of the national grid. We request the concerned State Commission to look into the reasons for tower collapse and the unusually long time take to revive the towers.
7. The matter shall be listed for further directions on 3.12.2015
Annexure
DETAILS of LINE OUTAGE DUE TO TOWER COLLAPSE AND REVIVAL DURING 1 QUARTER of 2015S. No.LineVoltagenRegionOwnerOutage DateOutage TimeRevival dateRevival TimeReasonTd* (days)1Mainpuri-Paricha-I400NRUPPTCL31.05.14173511.05.151127Towers Collapsed3452Mainpuri-Paricha-II400NRUPPTCL31.05.14173509.05.151141Towers Collapsed3423Akal-Barmer-I400NRRRVPNL15.02.1572322.05.150855Towers Collapsed974Anta RSPhagi-I765NRRRVPNL14.03.15181330.05.151055Towers Collapsed765Raipur-KSK-I & II400WRPGCIL25.04.15173106.05.152034 & 2039Towers Collapsed126Tamnar-Raipur-I400WRPGCIL25.04.15173223.05.151152Towers Collapsed287Tamnar-Raipur-II400WRPGCIL25.04.15173203.05.152355Towers Collapsed68Unnao-Lucknow400NRUPPTCL28.04.15063212.06.151103Towers Collapsed449VTPSSatna-I & II400WRPGCIL13.05.15133526.05.152233&22 59Towers Collapsed1310Fatehpur-Gaya765NR/ERPGCIL14.05.15142502.06.152112Towers Collapsed1811Fatehpur-Gaya765NR/ERPGCIL12.06.15142526.06.152102Tower Damaged1412Satna-Bina-I765WRPGCIL16.05.15141426.05.150236Towers Collapsed1013Agra-Meerut765NRPGCIL19.05.15180303.06.151813Towers Collapsed1514Satna-Bina-II765WRPGCIL19.05.15200831.05.151336Towers Collapsed4115FarakkAGurgapur-II400ERPGCIL24.05.15181012.06.1514437 Towers Collapsed1916Sagardighi -Durgapur-II 400ERWBSET CL24.05.15184212.06.1519242 Towers Collapsed1917Sagardighi-Durgapur-I400ERWBSET CL24.05.15184212.06.1519362 Towers Collapsed1918Bina-Gwalior III765WRPGCIL02.06.15171820.06.151923Tower Damaged1819Bhilai-Koradi400WRPGCIL06.06.150849’08.06.151930Tower Damaged220Dharamjai garh-New Ranchi-II765WR/ERPGCIL16.06.150719’21.06.151946Tower Damaged521Agra-Jhatikara765NRPGCIL23.06.15162227.06.152056Tower Damaged4