END OF SHEERLEGS

New Zealand Herald, Volume LXXI, Issue 21958, 15 November 1934, Page 13

END OF SHEERLEGS

DEMOLITION TO-DAY ■> SPECTACLE AT DEVONPORT TO BE DROPPED IN HARBOUR A well-known Auckland landmark for the past 25 years, the sheerlegs at the Devonport naval base, will disappear this morning. Punctually at 10 o'clock the huge structure will be dropped into the water, and the descent and the splash should provide a unique spectacle .

' Standing between Calliope Dock and the jetty where the cruisers berth, the steel tripod rises to a height of-. 156ft'., and the total weight is about 100 tons. The cost of the structure was about £30,000, and it has been used six times. Describing the erection of the sheerlegs in 1909, a man who was engaged in the work at that time, and who will also take part in their demolition to-day, said the task was a most difficult one and occupied about six months.

Manufacture in England "The legs," he said, "were manufactured at Home and assembled at tho site of the base.. They were spread out in the form of a Y and, joined in the centre by the pin and blocks. The rear leg went as far back as the hill. The next stage was the erection of a sheerlegs 90ft. high, consisting of baulks of timber. When these were wired together and dogged, the legs were each 4ft. square in section. ' 'To lift these into position another set of sheerlegs had to be made use of. These were 50ft. high and measured 15in. by loin, in section. When the former were set up a sling was placed round the rear leg of the steel structure, a short distance from the pin and blocks, and the whole was lifted up 80ft. by means of a winch on either side of the cups at the base of the two front legs. It was kept in that position and the purchase was then laid along the ground to the base of the rear leg, which was thus propelled forward until the apex was at the correct height and the connection could be made to the screw. The legs were actually raised in one day, although the proper hinging of the two front ones and other adjustments took some time." Preparations Completed Since Monday workmen of the Auckland Harbour Board have been making preparations for the demolition of the tripod. Yesterday afternoon these were completed. A "cushion" of timber, shingle, sawdust in bags, and old motor tyres was in position to take the shock of a portion of the rear leg, which will fall on the wharf; a sling had been attached to the apex, and concrete had been chipped away from the base of the two front legs. In addition, the rear leg had been driven forward to give the structure an overhang of about 40ft. over the water.

About seven or eight minutes before 10 o'clock to-day two men wTll burn through the straps at the base of the rear leg, and as soon as this has been completed the weight of the structure will precipitate it into the water. It is hoped to make its descent coincide with the sounding of four bells on H.M.S. Philomel.

The sheerlegs will afteflward be lifted by the floating crane Mahua and placed on four pontopns, which will be towed to a position near the vehicular ferry wharf at the eastern reclamation. There they will remain until cut up and sold for scrap metal.