ENGINEER'S ANNUAL REPORTS FOR YEAR ENDED 31st DECEMBER, 1914.
Waihi, N.Z., 20th January, 1915
E. G. Banks, esq.,
I beg to report on the work carried out in the following departments for the year ended 31st December, 1914.
MINE ENGINEERING DEPARTMENT.
Pumping.—The draining of the No. 11 Level (1,300 feet) was continued, but it was only towards the end of the year that the water was reduced to normal flow.
A 23 inch plunger pump operated by the "C" pumping engine, was erected at the No. 11 Level, and started working on September 3rd.
The water having been reduced to normal in November, the 28 inch drawlift on the "B" pumping engine at No. 11 Level was taken out, and replaced with one having a diameter of 20 inches.
Development work on the No. 11 Level was somewhat retarded, due to a breakdown on the " B " pumping engine in August.
A dam was built in the No. 11 Level to control the water supply, and prevent the drowning of the pumps in case of a breakdown.
The " C " pumping engine now raises water from the 1,300 feet level to the surface, a portion of the water raised flowing- to the electric pumps at the 1,000 feet level. The electric pumps raise this water to the surface, and also the whole of the water from the " B " pumping engine, which latter engine raises water from the 1,300 feet to the 1,000 feet levels.
The water pumped to the surface during the year was :—
" C " pumping engine ... ... 295,349,600 gallons.
Electrically-driven pumps ... 313,166,067 „
Total ... 608,515,667
Our present arrangement enables us to utilise the electric pumps, which are driven by power received from Hora Hora, to the greatest extent.
A scheme has been formulated, and the necessary pumping gear is now on order, for unwatering the Mine at the deeper levels. This will be accomplished by means of Turbo-electric pumps, which, in conjunction with our existing electric pumps, will normally carry on the drainage. During times of excessive flow, e.g., when the water is cut in a new level, the steam pumps will be available to take the extra load.
The war has delayed the delivery of this new plant, and consequently development will be retarded.
A chamber was excavated at No, 4 Shaft for accommodating the new electric pumps and capstans for hauling the sinking pumps.
The engine at No. 4 Shaft has been converted into an electric winding engine, and the engine at No. 2 Shaft has been driven by compressed air (generated by power from Hora Hora), when sufficient air has been available.
In accordance with the Mining Act Amendment (1914), safety keps have been fitted to the pit head frames immediately below the winding pulleys, and gates or barriers to all the cages.
Air Compressing.—With the advent of the Hora Hora power, we have found it economical to extend the use of compressed air, and our plant is fully loaded. It is now proposed to increase our compressing plant, and utilise compressed air for driving our winding engines where possible. By this means an economy will be effected, and the first cost will be considerably cheaper than electrifying these engines.
Gas Power.—The gas plant was closed down on April 8th, from which date Hora Hora has supplied the necessary power.
Hora Hora Work.—The work in connection with the installation of the transformer plant and motors at the Mine was completed during the early part of the year. The transformer plant was tested at the beginning of April, and the first motor started on April 8th. Seven alternating current motors, having a total horse-power of 1,600, are in use.
The whole of this plant has run very satisfactorily.
VICTORIA MILL, WAIKINO.
Power.—The past year being an exceptionally dry one the amount of Power available from our races was small, and towards the end of the year almost negligible.
The water-race flumes and pipe lines have been kept in good order. Power was brought in from Hora Hora early in the year and the first motor started on February 4th.
By the end of February practically all the motors were in use. The following Motors are in commission :—
Alternating Current Motors, 20 ... 2,190 H.P.
Direct „ „ 7 ••• 98 ,.
Total 2,288 „
The whole of the Electrical Plant has been running very satisfactorily.
The Steam and Gas Plants are not in use now that we are receiving power from Hora Hora. These Plants are kept in good order and are available for use at any time.
Inspection of Machinery.—The Machinery both at the Mine and at the Victoria Mill has been inspected and approved by the Government Inspector.
W. P. GAUVAIN,
Waihi, N.Z., 20th February, 1915
HORA HORA HYDROELECTRIC WORKS.
Report for year ended December 31st, 1914.
E. G. Banks, esq.,
I beg to report on the work carried out during the year ended December 31st, 1914.
Hora Hora.—The early part of the year was occupied in carrying out final tests of the Main Station, the Transformer Plant, and the Transmission Line. Those tests having been satisfactorily concluded, the Station was brought into commission early in February and the load gradually increased until all the motors at Waikino and the Mine were in operation.
The plant has run very satisfactorily, and throughout the year no stoppages have occurred due to any defects in the Station.
Several minor alterations have been made since the plant started with a view to increasing the efficiency and to effect labour saving.
When the station was stopped during the Christmas holidays a careful examination of the whole plant was made with satisfactory results.
Owing to the abnormally dry year, the water in the river has been lower than ever before recorded, and a considerable amount of weed has come down, necessitating a good deal of work on the forebay screens.
The Groyne which was built out from the intake for 240 feet into the river has proved efficient, and with the present low state of the river it has been decided to extend this right across to the opposite bank.
The number of units generated during the year was 9,675,510.
Transmission Line.—Two stoppages were experienced during the year due to insufficient strength of the binding wires.
The breakages occurred on one particular section of the line during heavy north-easterly winds.
The line has since been rebound on this section with wire of a heavier gauge and permanent clips attached at intervals.
No Insulator trouble has been experienced.
At times heavy lightning discharges have occurred, but the lightning arrestor apparatus always effectively dealt with these and prevented any damage to the plant.
Telephonic communication is established between Hora Hora and the various Stations, and telephone huts are built on the Line every five miles.
General.—The whole of the plant has been working very satisfactorily, and a minimum amount of trouble has been experienced.
W. P. GAUVAIN,