How our Great Sanatorium is Lighted.

New Zealand Graphic, Volume XXVIII, Issue XX, 17 May 1902, Page 962

How our Great Sanatorium is Lighted.

The Rotorua Electricity Supply and Sewerage Installation. Among the many improvements that have been and are being; made by the Government to add to the convenience and comfort of visitors to the popular tourist and health resort of kotorua, by no means the least important is the recently constructed drainage system and the lighting of the streets, sanatorium grounds, public baths, Government and private buildings, with electricity. The following brief description will, we have no doubt, be of interest to our readers, as we are able to illustrate it with copies of photos taken by Mr R. E. Fletcher, M.1.E.E., who has superintended the work on behalf of the contractors, the Brush Electrical Engineering Co., Ltd., London and Sydney.

The power required for driving the electric generators is obtained from the Kaituna River, the only outlet of Lakes Rotorua and Rotoiti. These lakes have a united area of between fifty and sixty square miles, and as they drain a large extent of country there is an enormous and never-fail-ing supply of water available- The generating station or power house is situated at the Okere Falls, near the outlet of Lake Rotoiti, a favourite resort of visitors to Rotorua, as it is one of the beauty spots of the neighbourhood. The Kaituna River at this point and for several miles further down, with its numerous falls

and rapids, runs through a deep winding gorge, with perpendicular cliffs, covered with luxuriant bush and free ferns. Very heavy excavations were necessary to form a site for the generating station, and a bench for the large flume that conveys the water to the turbines. Among our pictures is an interior view of the; generating station, or power house, showing the turbines, electric generators, switchboard, etc.

The turbines, of which there are two. are each capable of generating 100 1 orse-power. They are of the horizontal type, and work under a fall

of 14 feet. When developing their full power, each turbine requires about 5000 cubic feet of water per minute- Connected to the turbines by heavy leather chain belting, 20 inches in width, are the two electric generators, technically known as “ single phase inductor alternators.” Each generator has an electrical output of 50 kilowatts', which is equivalent to the electrical energy consumed by about 1600-8 candle-power incandescent lamps. A small continuous current dynamo is connected to the driving shaft of each of the generators, the current from which is used for exciting the field-magnets of the said generators, and for lighting the powerhouse and the attendants’ cottages. The bearings of the turbine and al-

ternator shafts are lubricated by ring- oilers, which keep a continuous stream of oil running through them; this causes perfect lubrication, great economy in oil, as the oil is used over and over again, and they will run for months without the slightest attention.

Between the two alternators is placed a very handsome switchboard, consisting of massive polished slate panels set in a wrought iron framework. Fixed on these panels are the various switches,safety fuses, regulating and recording apparatus for controlling the electric current supplied by the alternators, and for connecting either or both of them to the supply mains. A three-ton overhead travelling crane is provided for lifting various parts of the machinery for inspection or repairs. The Okere works are under the very efficient management of Mr. White, who, with his assistant, are the only two white men resident at Okere. The state of the works reflects the greatest credit on Mr. White, of whose unfailing courtesy visitors to Okere speak in the highest possible terms. The electric current is conveyed from the power-house to Rotorua, a distance of 13 miles, by means of two small bare copper cables about a quarter of an inch in diameter, which are supported upon large porcelain insulators, attached by means of a wooden arm to light iron poles. The poles really consist of railway rails, twenty-four feet in length,and weighing about 401bs to the yard. A telephone wire is also carried by the same poles, connecting the powerhouse with Rotorua.

The main line (above described) terminates at the pump-house in Rotorua, which is a neat and substantial bin ding, the first, and at p: esent, the only brick building in Rotorua.

The sewerage system at Rotorua !s a gravitation one —that is to say, the sewerage discharges from the various buildings into the drains and flows thence to a large underground brick and concrete tank situated near the pump-house. The pumps lift the sewage matter into a rising main, which carries it to two large filter beds situated about a mile and a - half from the township- Each pump is driven by an eight horsepower electric motor, and is capable of lifting 400 to 450 gallons of sewage matter pel’ minute. Although both pumps can, if necessary, work together, it is only intended to use one at a time, as one pump can empty the tank in an hour and ahaif, the second one being- intended as a reserve.

As me electric current is genera ted at a pressure of about 4000 volts at the power-house, for economy of transmission, it is necessary to reduce this pressure at Rotorua before it can be used for pumping or general lighting purposes. This is effected by means of what are technically known as transformers, two of wh ch van be seen, one on each side of the pump-house, distributing- switchboard. A very small quantity of current at high pressure passes into the transformers, and is there “'transformed,” or reduced to a conqiaratively

low pressure and large quantity. The two transformers referred to are used to supply low pressure current to the electric motors that drive the pumps. From the pumphouse the high pressure current is distributed to various parts of the township, for lighting the streets, sanatorium grounds, bath-houses, Government and private buildings. 'l’he copper conductors which carry the current are protected, with a. cover of India-rubber ami other insulating materials, and supported by large porcelain insulators fixed to wooden (totara) poles, which are painted white, with dark chocolate coloured bases, and present a very neat and pleasing appearance, and are a decided contrast to what is usually seen in the way of poles and overhead wires in most of our NewZealand cities and towns. The sanatorium grounds and streets of Rotorua are lighted by arc lamps, 21 in number. These lamps, of which one is shown in illustration No. 7, are placed at the intersection of the

BOW OUR GREAT SANATORIUM IS LIGHTED.

principal thoroughfares, railway station, and sanatorium grounds. The; band-stapd is also brilliantly illuminated with incandescent electric lamps, so that visitors may enjoy the cool of the evening in strolling about the beautiful grounds attached to the sanatorium, listening to the musie of the band, or to the open-air concerts held at frequent intervals during the tourist season.

That the residents of Rotorua have not been long in availing themselves of the advantages of the electric light, may be gathered from the faet that already there are about the equivalent of 1040 8-candle power lamps installed by private users only, while in the various publie baths and Government offices the number amount to the equivalent of 600 8-candie power lamps, or a total of about 1640 8-candle power lamps. As there are still a good number of applicants for the electric light who have not yet been connected on to the supply mains, it is more than- probable that before the coming winter is fully through the generating plant will be working at its full capacity, so that to meet the rapid and increasing requirements of the town the Government will have to seriously consider the question of. erecting additional generating machinery, for which, as already mentioned, there is an almost unlimited supply of water power. The electricity is supplied to. the various consumers by meter, at the extremely moderate rate of sixpence per Board of Trade unit, of 1000 Watt Hours. This moderate charge, combined with the safety, cleanliness and general convenience of the electric light, is cauusing many of the hotel and board-ing-house keepers, who commenced with having the light only in the principal rooms and passages of their establishments, to have it installed throughout their premises. A FLOOD AT WHANGAROA AND ITS CONSEQUENCES. (See illustrations page 964.) The following excellent and vivid description gives a lively idea of the damage caused by the recent floods at Whangaroa. Some photos illustrating the same will be found on page 964. It will be noticed the writer treats the really serious misfortune with a brave and whimsical philosophy, happily characteristic of the New Zealand temperament: On Thursday morning I could hardly see to sweep the bedrooms—-it was raining so heavily. After dinner the creek began to overflow, and our back yard filled up, but we didn’t think much of that—it had happened before. Father and the boys were away, and the tide was full, so everything was as bad as could be. An immense puriri tree, branches, roots and all, and trunk about four feet through, eame bowling down the creek, turning, round and round quite gaily (so you can imagine the quantity of w T ater coming- down), and of course it. stuck against the workshop, and the other stuff gathering round it soon made a solid dam, and turned all the flood into our back yard. In a few minutes the w-ater was up to the step of the kitchen door. We shut it, and put a box in front, then went into the diningroom and looked through the window. The water began to bend the door in below the latch—it was about two feet up the outside—then bang! the door flew open, and there was a crash and jingle, over went the dressers with all the crockery. The dining-room door- soon burst open. Mother was swept off her feet ami carried along the floor (and it was very cold water, I can tell you). Then we retreated to the passage, which is a step higher, and began picking up little things in those rooms and throwing them on to the higher furniture, but as the flood followed us and promptly turned over all the things, it was wasted labour. The piano was the only piece of furniture that kept its feet, buf the water came up ovjr the keyboard, so it

is spoiled. There was a terrific current through the passage, and we stood on the stairs, and every now and then dived after some particular treasure that went flying past. We heard awful sounds from tue verandah—such unearthly cries. I went out to see what it was, and there was Tom (cat), on the verandah rail, surrounded by water, screaming with fear, his eyes glaring, his black fur on end; he looked like an imp of Satan. We found the poor mother cat drowned, with her kitten, such a dear little fat kitten. I was sorry for that. (And a coop with eight half-grown chickens we have never found yet.) Well, while I was outside the water got behind the door and shut it, and that was ten times no 'better. Do you hink we could get that door open again? Not much. Fortunately father and the boys swam and waded in just then, and, between us all, we opened it. All this time, I am ashamed to tell you, I was laughing; there were a lot of funny things happening, really, and it was the only way I could keep from howling. The water roared so that you could hear very .little else; it lifted the oilcloths and drove sticks through them (they are just rags now). When the flood began to go down the rooms w-ere paved a foot deep with up-rooted ferns, broken branches, tussocks, clay, clothes, bric-a-brac, mud and eels (we really had several inside), and cockroaches, wetas, and stinking black bugs. They had to cut a hole in the floor of each room to send the rubbish through. The garden was buried entirely, only the tops of the highest shrubs showing; the back yard was filled up to the diningroom window ledge with stones, trunks of trees, etc.; the bed of. the creek was between the house and post office; that and dark-room and workshop floorless, my negatives all gone bung, my camera wet, but saved, nearly everything in darkroom lost. I seem doomed to losses by water. The 'kitchen floor, sank under the weight of mud and stones, the stove came out of the fireplace, and the windows were broken by the branches being driven through them. We hal nothing left. Father estimates the damage to house and yard at £3OO. All the men In the place are now digging out creek and back yard; all the women endeavouring to get the mud out of the house. It will cost thousands to| (repair the road—.such terrible landslips all along. The whole side of the hill has come and sat down on the sawdust outside the hall. There are tree-ferns and all sorts there now.

But the poor Bramleys had their house flattened out on a landslip, so they are worse off than we are. “Well, things is always someway.”