1YA Mast—Highest Structure In The Southern Hemisphere

Radio Record, Volume VIII, Issue 23, 14 December 1934, Page 12

1YA Mast—Highest Structure In The Southern Hemisphere

Looking Over the Plant at Henderson ©

Specially Written for the

"Radio Record"

transmitting plant is housed, I chuckled over a story that I had been told a few days before in. Wellington. "I got about half-way up the mast and took one look at the ground below. «That was. enough for me-I yelled like a kid to be taken down again," said O N the way out to Henderson, where the. new 1YA

the teller of the story. Pooh! Newspaper men ‘~were made of stouter stuff than that, It: would be the top of that: mast for me or nothing! It was nothing. When I _ stood directly beneath that huge _ steel structure hovering more than 500ft. in the air, I took such a sudden liking for solid earth that a king’s ransom would not have persuaded me up the frail ladder that seemed to go upwards — like Jack’s’ beanstalkfor ever. By way of making excuses,I might add that the Wellington man had been taken up

in a sort of bosun’s chair, which probably wasn’t so bad as climbing up tle tallest ladder in the Southern Hemispheve. Yes, that’s something that the contractors at Henderson are very proud of-the new mast is the tallest structure south of the Line. Already -Aucklanders, especially those living up the Bayswater end of the harbour, have come to-regard the mast. as an integral part of the Waitemata’s coastline. There is only one mast, known as the umbrella type, and. it is similar ‘to those in use'in several modern ‘transmitting centres in Europe. Actually this 65-ton piece of steel is a marvel of modern engineering, and the engineers on the job deserve a word of praise for the excellent and speedy way in which they carried out the job. The entire weight of the mast is carried on-a pivot nine inches in diameter (shown in the close-up picture of the base on this page), but so exactly are the stay-wires adjusted that there is not the slightest possibility of -the mast: getting out of plumb. It is triangular in shape, with-the guy-wires running out from the

three corners. These wires are securely attached to 50-ton blocks of concrete so that, even when winter winds do blow, ; the mast will stand as firm as the Rock of Gibraltar, Bach { base has three guys running to it, and there are lighter guys running down from lower altitudes. From the _ topmost point of the mast three aerials descend, running out-

ward for some distance and then being brought back to the tuning house, a small eight-by-eight shack at the foot of the ‘mast. There is an important earthing system, too, the wires being buried a foot underground ) and radiating from the mast for 200ft. at angles of 10 degrees. Near’ the base, too, are seven porcelain insulators above which the mast narrows to the nine-inch pivot mentioned earlier in the story. The building of the mast created plenty of interest, and the drive to Henderson has_ become a popular one

with motorists. On a recent Sunday there were nearly 800 people outside the Broadcasting Board’s property, craning ‘their necks at the great inanimate object towering skyward. . The pieces of metal comprising the mast are each 17ft. 6i long and were each hoisted separately and screwed up as the mast proceeded to creep into the blue. ms.% reporter from the ‘Auckland Star’ went right to the top of the mast and got a good story,"' said the man in charge of the work. . "But I’ll bet, when he was sitting 500ft. up in the air, that he was praying to God he was down again!" The little eight by eight concrete building at the foot of the mast is known officially as the aerial tuning unit, and it is from the equipment in this shack that the sound is finally transmitted -to the aerials. Although the actual weight of the steel in the mast is 65 tons, the "pull down" of the staywires almost doubles that weight on the single support at the base,

The transmitter building is attractively earried out in eream concrete with the Broadcasting Board’s symboltwo masts among high hills-adorning the front entrance \ and carried out in blue, brown and green, ‘The exterior style of the building is similar to that of the studio building in Shortland Street, except that one is in concrete and the other in brick. Inside the main entrance are the offices and storeroom accommodation, while a door leads on into the transmitting hall, a fine lofty room 63ift. x 50ft. The transmitters stand in an imposing row along one wall and look vaguely mysterious and exciting to the layman. Engineers were busy adjusting these transmitters, and blue and red lights winked wickedly from various points on their black surfaces. The equipment has beeu installed by pimalgamated Wireless (A/sia), Limited. The line amplifier room is the kernel of the works, the room Where the sound is received from the studio in the city and sent on its way to the aerials. This room has been specially prepared, and the walls have been treated with bronze gauze set in concrete so that the sound may travel round and round the walls instead of coming into the room and upsetting transmission. The floor and ceiling have been similarly insulated. In case of an emergency a programme can also be transmitted from this room. Beyond the transmitter hall is a large engine room, 24ft. by 684ft., and here are kept a benzine engine and a generator in case of a power failure. The Waitemata Electric Power Board, too, has installed extra equipment in the grounds of the transmitting station to deal with the extra load that Will be imposed when the station is fully operating. . And now, after months of hard work, the most powerfr ‘station in Australia and New Zealand is about to come ou the air, May its term of office be a long and happy one.