2

D.^lA

The above measurements give us 53 x46x15x13 x 60 x 62-5 KQ _.„ , 331X)0 = 53 > 730 ' norSe power, with an efficiency of 85 per cent, for the turbine-power and of 95 per cent, for the electric-generating power 53,730 x 0-85 x 0-95 = 43,386-horse power available at the power-house. Dividing this power into four equal quantities of, say, 11,000 h.p. each, the percentage of loss for each quantity delivered in the four cities of Wellington, Auckland, Napier, and would be of an average of 15 to 20 per cent, (according to distances) for the transmission with wires of 0 - 2 in. in diameter. The up and down transformation of the current-tension from 50,000 to 200 volts would give a loss of 2 x 2 = 4 per cent. The total loss from the power-station to the centre of the towns can be averaged at 20 + 4 = 24 per cent, of the full load (according to the respective distances). The actual power delivered in each of the above-named cities would be not less than 8,750 h.p. for Wellington, 9,000 h.p. for Auckland, and 10,000 h.p. for New Plymouth and districts. It stands to reason that any amount of power taken from the lines between the power-station and the extreme delivery-point would proportionately reduce the loss and increase the available horse-power at the last point. Power-station. The power-station would be supplied with the current system of generators ; the tension would be of 2,200 or 5,000 volts, transformed into 50,000 volts tension for transmission purposes. The power-station would be constructed with, turbine dynamos of, say, 2,200 h.p., equal to 1,500 kilo-volt-amperes each, and sets could be added from time to time to supply the increased demand of power. All the sets would be available to run in parallel; the main lines would be constructed to carry the whole capacity allotted to each section (about 11,000 h.p.). This disposes of the power from the Huka Falls, but a far greater power is to be obtained from the rapids below these falls. Each one of these rapids has a fall of 150 ft. The same amount of water calculated in the Huka Falls passes through the rapids. We have, therefore, in each of the rapids a proportional power from 53 to 150, or 128,952 h.p. Taking the three powers together, we have 53,730 + 128,952 + 128,952 = 311,634 h.p. I must, however, draw attention to the fact that each rapid of 128,952 h.p. would, in proportion to the actual Huka Falls power, cost a higher proportional sum per horse-power for the initial cost, as the head-race would have to be carried along very rough mountain-sides; but, of course, the total amount of power obtained from each of the rapids, if able to be used up in the country, would greatly compensate for the extra head-race expense. The machinery cost would, of course, be the same per horse-power. In the Huka Falls no dam would be required,|{as the upper rapid makes a natural dam, and the 11 ft. of depth in C would deviate all the necessary water. The dams for both of the rapids would not be expensive, as they would only be of insignificant height, the present rocks making part of it, and plenty of rock material being at hand. With regard to the cost of construction of the first plant —that is, the Huka Falls —the following would be the rough and average prices of two units of 2,200 h.p., or 1,500 kilo-volt-amperes each : —f £ Two main pipes, complete .. .. .. .. .. .. 1,000 Two turbines, 2,200 h.p. .. .. .. .. .. .. 6,000 Two generators, 1,500 k.v.a. .. .. .. .. .. 8,000 One switchboard .. .. .. .. .. .. .. 500 Transformers .. .. .. .. .. .. .. 4,000 £19,500 Buildings and race .. .. .. .. .. .. .. £1,000 The lines to carry the whole power would cost about £300 per mile; therefore the initial cost would be,— £ 626 miles x 300 .. .. .. .. .. .. .. 187,800 Two sets turbine generators .. .. .. .. .. 19,500 Buildings and race .. .. .. .. .. .. 1,000 £208,300 To increase the plant about £10,000 should be added for each unit of 2,200 h.p. The consumers of power would buy their motors and pay for the installation. In the cities the current would be delivered at a reduced voltage of, say, 2,000 or 200 volts for power or lighting purposes. For railway purposes the current would be transformed by means of rotary transformers from 50,000 volts three-phase current to 550 volts direct current, or, as has been done with great success in the construction of the Jungfrau Mountain Railway, Switzerland, where three-phase current of 550 volts has been used, this system simplifying matters greatly, in giving better motors for the cars, having an easier start, and doing away with the rotary transformer stations, which means labour and cost saved, the current from the primary 50,000 volts three-phase transmission being simply reduced by ordinary transformers from 50,000 volts to 550 volts on the locomotive itself. I believe that the above deals with the whole of the preliminary report on the falls, and Fam quite at the disposal of the Government should any further information be required.