D—4

All equipment has been given schedule maintenance and has operated satisfactorily. A replacement for one 0.C.8. damaged by fire in 1944 was installed.

Machine-running Times

Dobson.—The Diesel station was called on for considerable running on account of system loading requirements. This running, approximately two shifts per day, commenced intermittently in May, and the Diesels were running almost continuously from early in June until the end of August. Similar running was again required at the end of February, continuing to the end of the year. The station also ran continuously to supply West Coast load in conjunction with Arnold when the Coleridge-Otira line was out from 27th to 29th November and on six other occasions for system maintenance purposes. Further major failures were experienced on No. 4 engine, on which No. 9 pistonskirt broke in June. New walking-rod parts and piston-skirt were made in New Zealand. On reassembly and after a short pgriod of running in February a'further seizure occurred, this being attributed to a small sand acclusion in the piston-skirt casting. As a result of these failures, No. 4 unit was not available for most of the year. A good deal of trouble was experienced with broken liner sealing-ring bolts, and smaller rubber sealing-rings are being used when fitting replacements. The Diesels are rendering considerable assistance to the system, but their percentage availability is deteriorating rapidly because replacement parts are unprocurable.

Machine-running Times

2. Substations (a) HOW. Hororata. —The construction of a new line will increase the capacity of the existing three lines connecting Hororata with Addington, and the terminal point at Hororata is being installed. TemuJca. —On load tap-changing equipment was placed in service on 2nd July. Cable ducts which were leaking badly have been plastered.

24

Generator No. Time oil Load. Time Idle. Time under Repair. Percentage Availability for Service. Hours. Percentage. Hours. Percentage. Not in Demand (Hours). In Demand (Hours). 1 4,867 55-7 3,832 43-3 60 1 99-3 2 4,986 56-8 3,691 42-2 82 1 99-1 3 .. '. 5,229 60-3 3,448 39-5 82 1 991

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). 1 919 10-5 7,841 89-5 100 2 903 10-3 7,840 89-5 17 99-8 3 .. 936 10-7 7,746 88-4 v 78 99-1 4 104 1-2 2,290 26-1 6,366 27-3