D-4

Arnold. —The river flow was maintained at or above continuous full-load requirements, except for a slight reduction in the station output for a period of twelve days in December. The repair and reconditioning of No. 2 machine was completed in April, work done including the fitting of new gates and main gate-ring connecting-links, replacement of the steel thrust-bearing-cooling water-pipes in copper, conversion of fittings to brass, and changing of the transformer cooling-water suction from the manhole cover to the scroll-case.

Machine-running Times

Monowai. —The normal operation of the station was interrupted by six faults due to fires on the transmission line and three faults due to surge on the lines. The rainfall for the year was 44-13 in. Floods occurred in December.

Machine-running Times

Dobson. —The Diesel station was called on to run as an auxiliary station, from April till August. The overhaul of No. 1 engine was commenced in February. No. 2 engine has been out of service since the failure of a compressor cylinder and piston in April, 1947, the overhaul of No. 3 engine was commenced in November and completed in February, and on completion of its overhaul, No. 4 engine was put into service in June, but was withdrawn at the end of July following the loosening of a pinion on the vertical drive to the camshaft. A head overhaul of this engine was completed in September and the repaired cam-shaft was fitted in November.

Machine-running Times

23

Time on Load. Time Idle. Time under Repair. Percentage Availability for Service. Generator No. Honrs. Percentage. Hours. Percentage. Not in Demand (Hours). In Demand (Hours). 1 2 8,184 8,049 93-2 91-6 359 77 41 0-9 241 658 97-3 92-5

Time on Load. Time Idle. Time under Uepair. Percentage' Availability for Service. Generator No. Hours. Percentage. Honrs. Percentage. Not in Demand (Hours). In Demand (Honrs). 1 2 3 5,385 5,600 5,194 61-3 63-8 59-1 3,348 3,136 3,534 381 35-7 40-2 51 48 56 99-4 99-5 99-4

Generator No. Time on Load. Time Idle. Time under Repair. Percentage Availability for Service. Hours. Percentage. Hours. Percentage. Not in Demand (Hours). In demand (Hours). 1 1,173 13-4 6,050 68-8 1,561 82-2 2 49 0-6 535 6-1 8,200 6-7 3 !! " 1,058 120 5,015 571 2,711 69 • 1 4 372 4-2 3,732 42-5 4,680 46-7