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An 11 Kv. metering cubicle for the Point Substation was constructed and installed and new switchgear was built for Hororata Substation and Lake Coleridge power-house. A testing transformer of 6 Kv.A. short-time rating was built to deliver up to 2,000 amps, for relay and 0.C.8. testing. The tests and investigations recorded throughout the year were 299. (/) Survey. In May the survey of the Arthur's Pass - Otira section of the 66 Kv. West Coast transmissionline was started, and in spite of delays due to rough terrain and adverse weather conditions good progress was maintained. Three survey parties were engaged on this line, being located at Lake Coleridge, Arthur's Pass, and Hokitika. During the year the complete line route was selected. Preliminary inspections were made of a route for the Dunedin-Gore 110 Kv. line and also for extensions of the 66 Kv. lines to the north of Hokitika. The survey of the transmission-line from Lake Coleridge to Cass was also completed. Preliminary survey work in connection with the new substation sites at Arahura and Palmerston South was carried out. A special survey of lake contours and investigation of levels was carried out at lakes Tekapo, Ohau, and Pukaki and adjacent country. (g) West Coast Electrification. The proposal to supply power to the West Coast by a 66 Kv. transmission-line from Lake Coleridge was finalized early in the year, and survey work was commenced in May and practically completed during the year under review. Preparation of tower foundations for the Arthur's Pass section was made and a contract for the piling-work and erection of structures at the Waimakariri and Mingha river crossings was let. In July a site was selected for the Arahura main terminal substation, three miles from Hokitika. This site was surveyed and cleared in August, and a contract for the access-road excavation and metalling was let in February. In October an office was established in Hokitika to take local charge of the West Coast work. Additional survey staff was engaged and several bush-felling contracts for the transmission-line route were let. The first section of four miles of the main telephone-line from Arahura Substation to Otira was constructed. Investigation of sites for the Diesel Station and for Blackwater 66 Kv. Substation was made, and the site at Dobson was surveyed, a start on the excavation for machine foundations being made on 15th March. (2) Operation and Maintenance. (a) Power-stations. General. —During the year the Lake Coleridge and Waitaki power-stations operated in parallel satisfactorily, there being no troubles of any magnitude at either of these stations. The interchange of load between these stations has been very advantagageous for the carrying-out of maintenance-work and the control of lake level at Coleridge, this latter requirement being necessary during the new construction work at the Harper intake gates. Lake Coleridge Power-station. —The lake-level has been maintained throughout the year. The Harper River gates reached a stage of excessive wear, and flooding in May eroded No., 2 gate and blocked the channel with boulders and shingle, heavy maintenance-work being entailed. The new gates were started in January, as previously detailed. The Acheron diversion works have been maintained in good order. The grouting of No. 2 tunnel was completed in June and the pipes filled for service ; 235 tons of cement were used on this work. In February No. 3 generating-unit was overhauled and the turbine runner and shaft brought to Christchurch for fitting liner rings and refitting of thrust collar and filling of cavitated areas in the runner vanes. Adjustment and repairs to the Larner-Johnson valve control gear were carried out, and an overhaul of the K2 and K3 switch-gear and potential transformers was completed. Repair work on Nos. i and 5 main gates and Nos. 5 and 7 sluice gates was carried out. No. 7 pipe-line exterior was scraped and painted, and similar work on Nos. 4, 5, and 6 is proceeding. Waitaki Power-station. —The installation of a temporary 11 Kv./dOO V. bank of transformers and control switch-gear was completed in May. It was found that the river-flow was such that a light day load of 3,000 Kw. could be carried on the station conveniently without disorganizing the work on the dam. Repair work was carried out on the penstock-filling valves and the rod couplings strengthened to withstand the effects of vibration. Oil filtering of 0.C.8.'s was completed and insulators changed and cleaned down where necessary. The dismantling of overhead lines and substation equipment used for construction was carried out. The renovation of twelve cottages for staff was put in hand and the interior work finished in February. j In addition the usual maintenance-work on plant and village was done.' Lyttelton Diesel Station. —There was no occasion to call upon this plant during the year, but it was maintained in good order and test load runs were made in July. Towards the end of the financial year the dismantling of the building and plant was commenced preparatory to its transfer to Dobson for erection there as an auxiliary supply for the West Coast electrification scheme pending supply being available from Lake Coleridge.

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