D-4

Hororata. —The concrete pad for the 0.C.8. controlling the new fourth line CH/D has been poured and cable ducts have been extended. Milton. —An 110/11 kV. 4,500 kVA. transformer bank and associated equipment was completed. This substation supplies five auto reclose feeders to the Otago Electricpower Board. The equipment is housed in a ferro-concrete building built by the Department after tenders had been called unsuccessfully. The substation went into service on 31st March, 1947, and is unattended. Ohai. —Rebuilding of this substation to supply a growing mining load in the Ohai coalfields and to meet the electrification of sawmills in the Tuatapere district is well in hand. A concrete switch-house has been erected by the Department and the installation of four auto reclose feeders is in hand. The present transformer bank of 750 kVA. is being replaced by a 2,250 kVA. bank. Edendale. —A concrete switch-room has been erected by the Department preparatory to construction of an 110 kV. substation. 3. Transmission-lines A new fourth line linking Addington and Hororata has been erected from Addington to the Waireka River. About 7 miles of further erection will complete this important work. Extensions and alterations were carried out near Coleridge Power Station to the two lines linking Coleridge with Otira to enable power to be supplied through the new steelwork. Plans for the Gore-Invercargill 110 kV. line were completed and some poles and conductors were delivered. Enough material has not yet been received to warrant commencement of construction. A reconnaissance has been carried out on the Gore-Coal Creek 110 kV. and a route has been selected. A route has also been located for the Invercargill-Bluff and Invercargill-Riverton 66 kV. lines. A commencement has been made on a 4J mile 33 kV. line on concrete poles to connect a 500 kW. steam auxiliary at Kaitangata Coal-mines into the Otago Electric-power Board system at Stirling. NELSON-MARLBOROUGH SECTION A. SYSTEM OPERATION AND LOAD DESPATCH 1. Load The maximum load on the system was 8,240 kW. on Wednesday, the 17th July, an increase of 14-75 per cent, compared with last year's peak of 7,180 kW., and there was a 20 per cent, increase from 34,288,308 to 41,143,020 in the number of units generated. The greatest weekly generation was 886,194 units for the week ended 28th July, 1946, this being 12| per cent, higher than last year's figure of 787,700 units for the week ended 22nd July, 1945. The system annual load factor was 57 per cent., and 5-4 per cent, of the units generated were unproductive. Units generated (compared with 1945-46) are as follows :

Due to the extremely dry period from December to March, all auxiliary and standby stations were operated, as far as possible, at their maximum and resulted in these stations generating 11-2 per cent, of the total, compared with 2-8 per cent, last year.

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Station. Year ended 31st March, 1947. Year ended 31st March, 1946. Percentage Increase. Cobb Power-station Auxiliary and standby stations 36,530,900 4,612,120 33,464,800 823,508 9-1 460-1 Total units .. 41,143,020 34,288,308 20