OLD GAOL SMASHED

Evening Post, Volume CXI, Issue 73, 27 March 1931, Page 11

OLD GAOL SMASHED

DEMOLITION PUZZLE

NOT WHOLLY SUCCESSFUL

BUT BACK WELL BROKEN

: Commenced in tho 'eighties as the first wing of a. central prison for New Zealand, and built wondrous strong and ugly by prison labour, tho Mount Cook gaol stood until last evening as Wellington's most unwanted building. At 7 o'clock 50 charges of explosives wcro fired simultaneously and five thouand tons of brickwork of tho heaviest type crashod down. So solid was the construction, .however, that only about a quarter of the gaol was thoroughly smashed. Still, this first grand collapse was sufficiently successful to render comparatively simple the complete demolition and rapid clearance of the site to enable tho first work on the Art Gallery and Dominion Museum buildings to bo commenced. A GRAND EXPERIMENT. Tho peculiar construction —the amazing construction, in fact—-of the old gaol presented a first-rate problem in demolition, of which, in the opinion of those who tendered for the job, there were two most likely solutions. One ■was to tackle the work from the top, knocking it down piecemeal; and tho other, which was adopted by tho successful contractors, Messrs. M'Millan and Son, and carried out by Mr. Charles Carlsen, a sub-contractor, was to shatterthe lower walls on the western side, leaving tho eastern wall untouched, in tho hope that the whole building would cant over to the open spaco on the western side and would smash itself by its own weight. Even though the attempt was not fully successful, it would seem that the method adopted will bring far quicker final results than jfcho piecemeal.method could have done —and time means money. NEARLY 3,000,000 BRICKS. : The exterior suggested a brick castle, Sour stories high, packed from side to side and end "to end with cells, but this was not so. ' The colls were arranged tone cell deep, along the outer walls ■only, and between them was a great open hall, with, high above, a .brick arch, nearly 3ft thick. Why a 3ft brick arch nobody knows, for no cat burglar could have climbed out, and certainly no. one wanted to break in, but thero, the arch was. At their bases the outer walls were as much as 6ft thick, but dwindled down to 4ft or so at the upper floors. The interior ceil walls wevo of comparatively-flimsy construction, say, 2ift of solid brick .work, ' yet strong enough to turn a dinner knife or nail file smuggled in -by tho possible gaol breaker. ■ The inner walls of tho cells were carried on ■a. series of immensely strong arches, and thus there wero four parallel lines of fouudation supports, the two outer fift. thick wall bases and tho arches ■below the inner cell walls. A careful calculation made by one of the tenderers indicates that nearly three million bricks and fif- '■', teen hundred cubic yards of mortar, ' partly lime and partly cement, went ■ to the building of this architectural monstrosity. ■Under Mr. Carlson's plan the western outer wall base was cut out to leave a iniuimum.. of brick pier supports, the two lines- of arches wore similarly reduced and tho pillars so left were bored.to-receive tho charges. The eastern -.outer wall was left as it was, for ;it.was calculated that the pull of the rest, ■ of. the building would sco to it. Tue-archj too, could be left to look after ils own- smashing. A LONG WAIT, BUT WORTH IT. The cutting down of the piers to minimum safe thickness took longer than'-was expected and tho "drop" was postponed from; day to day. The time finally fixed.was 4.30 yesterday aftorrioan, but at that time there was still a good deal to be dove in placing and wiring up the 50 charges in the piers for electrical firing, and it was not till ""1 p.m. that the ' shots_ wero fired. Though the contractors did not want to do Wellington out of a really first rate show —and it was a great show—they simply. could not advortise the hour, for flying bricks tiro uncomfortable. Somehow tho news got about and there were two or three thousa7id people- at Mount Cook by 6 o'clock. The light failed completely by 7 O'clock, but if-anything the building was the more impressive for that. Very courteously tho contractors held tho firing of the charges until Press photographers had got going a big magnesium flaro to attempt a night photograph, and then slio went! REFUSED TO TIP. Because Hit; 50 individual charges '"were small (three sticks of cruptito inch) ihe. explosion was seemingly very light, aud neither it nor the crashing building caused any appreciable- earth tremor. The attempt to tip the whole building 'failed, but the two ends swelled outwards aud came down with a roar. A cloud of dust so thick as to completely block out the light from the magnesium' flaro (that was the end of ihe photography) hid the remains of •the building and ground immediately, .-inr 1 when it had dropped after a few minutes it was seen that tho central part of tho western wall was still apparently as stubborn as over, and that tho eastern wall was unbroken. This morning, bright and early, tho contractors wero at Mount Cook to see what had been clone, and wcro pleasantly surprised after the disappointing appearance in tho gloom of last evening. Tho eastern wall was found intact, both ends of tho western wall were completely smashed aud ready for the lorries, but tho central part of this v.-011,-. a good half of its length, had t-.imply dropped vertically about nine feet., in one ugly mass, and there it- is to-day, waiting for more- charges. The ■brick arch, of course, was well shattered. Could the same job bo tackled again, there is no doubt that it could bo done- thoroughly ■successfully, for a lot was learned, but' some things can only tic dono once. MORE SUCCESSFUL THAN IT APPEARS. . The central .mass weighs probably "000 or 3000 tons, and to drop that weight nine or ten feet and to find it Btill standing is to be greatly astonished. ■ It says 7nuch for such bricklaying as was dono by men with plenty of timo before them. The eastern wall, though its.inner piers were well shattered, did not cave in, as the falling masses from tho arch and 'end buttresses wedgn down iiiid-held it in pome sort of stability. It appears tn.be perfectly stable, in fact, but, Mr. Carlsen thinks otherwise. "it. didn't, quite come oil'," he told 71 "J'ost." reporter this morning, "but it's not halt' a bod job. That big block on the west is'cracked in ti dozen directions, and the next charges will bring it. down, well broken up. Tho eastern wall will probably not be tackled until some, of the wreckage is shifted .from the front." In a pood -many years' e.vponcnc.c of work with explosives, sail ; Mr, Carlsen, he had. trickled some, tough proposit-iunp, but the old gaol was in .its our? class. lie had never ■ had any doubls about gelling the building down with light charges, and.-though Iho ii'"st. plan did no I. work mil altogether lo timntaljlo, the ba<'k of the jol> hart been well broken.