Rehabilitation process ongoing on Kavkasioni (500kV)

In coordination with the National Dispatch Center, Power Transmission Line Kavkasioni (500kV) was put under repair from August 8 to 31, 2018. The volume of the repair work requires the switch off the transmission line. The operation will be performed on the territories of Georgia and Russian Federation.

The rehabilitation process conducted on Kavkasioni (500kV) on the territory of Russian Federation implies the replace of the damaged insulators and wires, the ascending inspection of the site, regulation of the stretchers of middle towers, restoration of the robbed towers, cleaning/cutting the territory from trees and bushes, repair work in the N13-N14 span of the line. The implementation of the mentioned activities is unsafe during the operation of the transmission line.

The power outage occurred on the Electricity Transmission Line Kavkasioni (500kV) on December 24, 2017. The place of the accident power failure was defined by the special tools and it was on the territory of Russian Federation, 104km away from Engurhesi, on the northern slope of the pass Nakhar. Due to the heavy snow and complicated relief area the territory was inspected by helicopter. The failure was found in the span between the towers N13 and N14. It was managed to visit the site on December 31 and define the volume of the damage. As a result of the inspection, it was found out that the wave of the avalanche disconnected the conductors of the phases B and C and other conductors were just damaged. The disconnected conductors were covered with snow and frozen ground and they could not be inspected. The restoration work could not be conducted due to the threat of avalanche. The decision was made about re-operation of the Kavkasioni under the temporal scheme and the disconnected conductors were cut in the span N13-N14.

It was managed to switch on the transmission line on January 3, 2018 and its capacity was decreased to 400 mw.  Steel-aluminum wire of АС 300/204 of 6km length was fully replaced between the towers N13-N14. The repair work is conducted on Kavkasioni, on the territory of Russian Federation, under the agreement concluded between the Karachay branch office of the UES JSC SAKRUSENERGO and the branch office “South” of the JSC FGC UNEG.

The following operations will be carried out within the rehabilitation process on the territory of Georgia: the replace of the damaged insulators and line accessories, the replace and the repair of the damaged conductors, cutting down activities between and around the towers, ascending inspection of the electricity transmission line, the restoration of the paths to towers, the repair of the basements, equipment of the towers with angles and bolts, etc. Besides the above operations to be performed on the section of Kavkasioni in Kodori Gorge, the angular tower N219 will be strengthened, as its basement is washed by the right stream of the river Klichi, river Achaphara that changed its bed after the natural disaster.

The finally, cutting down activities between and around the towers will be performed on 125 ha in 2018. The operation has already been over on 83 ha on the territory of Russian Federation.

As a result of the repair work performed on Kavkasioni (500kV) in 2018, the stability and the reliability of the transmission line will be significantly increased that will support the operation of the electricity transmission line without restrictions in Autumn and Winter.