D—4

Arnold.—During one week low river flow caused a slight reduction in output. Because of increasing leakage from the tunnel, the station was closed down from. 6th February to 18th March, 1950, for extensive repairs to the concrete lining of thetunnel to be carried out by the Ministry of Works. Divers were employed to seal leaksin the headgate structure, overhaul underwater equipment, and remove waterlogged timber from the vicinity of the headgates. During this period the generating-units wereoverhauled, and the control wiring almost completely renewed.

Machine-running Times

Monowai. —The rainfall for the year was 46-33 in., compared with 57-38 in. lastyear. Floods occurred in April and February, when water ran to waste. An inter-turn fault developed in No. 2 generator on Friday, 17th February,. 1950. A complete set of new windings was installed, the work being completed by 27th March, 1950.

Machine-running Times

Dobson. —Pending the receipt of.new crankshafts one engine only was serviceable,, and its running was kept to a minimum.

Machine-running Times

25

Generator No. Time on Load. Time Idle. Time Under Repair. Percentage Availability for Service. Hours. Percentage. Hours. [ 1 Percentage. Not in Demand (Hours). In Demand (Hours). 1 2 i 7,760 7,758 j 88-6 88-6 43 48 *o lO 957 954 89-1 89-1

Time on Load. Time Idle. Time Under Repair. Percentage Availability for Service. Generator No. Hours. Percentage. Hours. Percentage. Not in Demand (Hours). In Demand (Hours). 1 2 3 7,176 6,329 6,965 81-9 72-3 79-5 1,484 1,408 1,672 16-9 161 1 19-1 1 99 1,022 122 1 1 1 98-8 88-4 98-6

Generator No, Time on LoadTime Idle. Time under Repair. Percentage Availability for Service. Hours. Percentage. Hours. Percentage. Not in Demand (Hours). | In Demand (Hours). 1 1 8,760 I 0-0 2 8,760 0-0 3 !! !! 56 0-6 8,704 99-4 i .. 100-0 4 ! j 8,760 0-0