Editor’s note: There were no photos with the original article, but we have added some to complement the text.
Southland Times, 24 Dec 1912, p 6
THE SINGING SPARK
AWARUA WIRELESS STATION.
AN IMMENSE STRUCTURE.
For about two months the giant main mast of the Awarua wireless telegraph station has been slowly reaching further into the heavens and it has long been visible from many parts of the town. To say that the mast is four hundred feet in height does not convey a sufficiently clear idea of the immense height to which it readies.
Standards of comparison by which a true idea of the altitude of the platform at the top of the mast might he conveyed to those who have not had an opportunity of viewing the structure at close quarters are rare, but it will be sufficiently clear to use comparison of the Invercargill water tower. The tower might be passed beneath the lowest guy or staying cable of the mast without fear of touching anything.
One hundred and sixty feet from the ground level at the point where it comes into contact with the steel framework of the mast, this guy appears to be only a small distance from the ground and the second set of guys stretch out from the same anchors to a point far above again.
Both sets of guys are anchored into the same bases. That is to say, that from each of the three angles of the mast there are two chains of steel rods one above the other, and each two are led into one of three immense concrete anchors. These lie out from the tower some distance and they all resemble in appearance lean-to buildings with a gable entrance. Each one is of an estimated weight of three hundred tons, so that the lower mast is stayed against the weight of even the most furious storm.
The guys enter at different angles a long sloping slot in the front of the anchor structures and then come together just before they emerge into a deep cellar where, a heavy steel girder is placed across the opening at the lower end of the slot mentioned. This is stayed off from the concrete by steel rods, and heavy glass disc insulators are also placed between the upper face of the girder and the concrete. The lower spans of the guys are led together to a coupling below which there is a heavy steel bar which passes through the girder and by the screwing of a huge nut the tension of the guys may be regulated.
The whole arrangements give the impression to a layman that the main mast could not carry away unless it uprooted one of the three hundred-ton anchors, and such a possibility can be dismissed at once.
In order that the cellars mentioned may be kept dry so that the mechanics might go below to examine the base of the whole staying gear the contractors have had to sink enormous ditches to drain the sodden ground, and in this work they have been seriously handicapped by nature of the soil through which they had to cut. Working to a depth of ten feet they frequently encountered streams of running sand which, besides filling in the ditch, caused the banks to fall in. By continued activity it has now, however, been possible to overcome the original difficulties and this part of the work has been carried out satisfactorily.
From outward appearances the casual observer would come to the conclusion that the concrete anchors are solid. Such a conclusion would be in part erroneous. True, the anchors are of solid concrete below the ground level and they sink to a considerable depth but above the ground level the abnormally thick walls hide a cavity. This cavity is supposed to he filled with dry sand, and in order to comply with the specification as to dryness the contractor has been compelled to go to considerable trouble. The sand available is wet and it must be dried before it is emptied into the cavity. A Southland Times reporter, who visited the station yesterday, saw the sand being heated on an arrangement of sheets of corrugated iron which formed a primitive oven and from this drying table the sand was shovelled into buckets and emptied into the cavities for which it was intended.
There is still another difficulty with which the contractors are faced and this is of a far more important nature. Consequent upon the inability of the Railway Department to supply trucks, the concrete blocks for the buildings are not coming to hand as they should and work in this respect is being retarded. The gangs of workmen are being kept employed at other work which in the ordinary course of events would have been done at a later date, but the essential parts of the work are held up and of late no progress has been made with the construction of the walls of the building. The blocks being used are manufactured at the local reformatory, and it is believed that there is a good supply available, but those most concerned state that it is impossible to get them on to the ground.
Although these difficulties have occasioned some trouble they have, however not been so serious as to cause any suspension of the constructional work. All hands have been kept busy and there appears to be any amount of work still to be done.
THE MAIN MAST.
To return to the main mast some very interesting features are now noticeable. As is well known a wireless tower must rest on a glass base, which acts as an insulator. The main mast at Awarua is said to weigh about one hundred tons, and all that weight centres down to a small pivot in the base of an inverted pyramid of steel which forms the lower end of the structure.
The girders at each angle of the mast do not touch the concrete pillars beneath them which are provided merely as jacking bases for use in case of repair. They will have to he used before the installation can be passed as complete.
As already indicated the structure rests on glass. In all there are nine glass discs in the base and these are divided into three sets, each of three discs, which arc separated by triangular metal plates. The discs are placed at the angles of the metal plates and in the centre of the topmost plate rests the pivot mentioned above.
On account of some movement in the structure two of the glass discs have cracked, and they will have to he replaced before the station can be opened. In order that this may be done it will be necessary to lift the hundred-ton mast structure and the utility of the concrete pillars will then he demonstrated.
“CLIMBING THE POLE.”
The novelty of surveying the world at large from an elevation of four hundred feet is attractive, and a few intrepid spirits have made the ascent. The workmen on the contract have no time or energy for such a climb during the week, and at least a few of them have journeyed to the scene of their labours on Sundays and have reached the top without trouble. A plain upright steel bar ladder runs up the inside of the tower, and not a few young fellows have made the ascent of late.
Unfortunately the lattice work, of which the ladder is a part, was being painted yesterday, and when the reporter paid his visit the wet paint reached to a height of one hundred and sixty feet. The prospect of besmearing his clothes with paint deterred the pressman from making any attempt to climb the mast, but it is possible that an account of what may be seen from the top will he obtainable later.
No word has yet been received by those in charge of the work as to what type of mast is to be used for the twelve outer masts to which the wires of the plant will run out from the central mast. It is said that they will be eighty feet in height and will he set in a circle at a radius of 925 feet from the central mast. The wires of the installation will not roach the whole of that distance, but will be joined to cables which will run out to the eighty foot masts. The necessity of placing the masts so far out therefore is that the receiving wires must be kept at a certain elevation, and were the poles set in further the drop from four hundred feet to eighty feet would impair the efficacy of the plant.
On account of the impossibility of getting concrete blocks the engine room and storage battery room is not being proceeded with in the meantime, but the other structures are well on the way to completion. The main building in which are situated the high tension room, operating room, and telegraphist’s room as well as quarters for the staff is being rapidly brought to completion.
One wall, separating the high tension room from the operating room, still languishes uncompleted on account of the concrete block trouble, but otherwise the work is going ahead satisfactorily. The flooring is now being put down and it is anticipated that the plasterers will be able to commence their work early in the New Year. At the rear of the main building is situated the oil and fuel storehouses and these also are nearly finished.
On the whole it may he stated that excellent progress has been made, but it is stated that a good deal remains to be dune before the station commences to flash messages from seventeen hundred to five thousand miles around the earth. The work commands interest on account of the modernity of the wonderful invention and the progress of the installation wl doubtless be watched with eager interest.
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