HARBOUR WORKS. THE CLYDE-QUAY WHARF.

Evening Post, Volume LXXVIII, Issue 129, 27 November 1909, Page 9

HARBOUR WORKS. THE CLYDE-QUAY WHARF.

NEARING COMPLETION. The Clyde-quay wharf, the first structure of reinforced concrete of the kind in Wellington Harbour, is rapidly nearing completion. Quietly, without the Qpise of caw, hammer, and planing machine, the work has progressed. Tho piles havo been driven, the massive beams and struts and braces, interlocking with each other, have been raised on their foundation, and to-day the last stage of the concrete decking at the very end of the wharf will be laid. Superficially, then, th; work will be complete. It was commenced with the driving of the first ferro-concrete pile on the first of February last. The whole wharf should be open for business by the first of February next. It is a strange piece of engineering to one accustomed to the long-sheathed wooden pile, the bolted beams of solid ironbark, the. covering of Muntz metal, the nuts and screws,, the sawn timber, and the grooves cut with the adze^-all ,the concomitant circumstances of the building of a wooden wharf. The scheme of things is entirely different, tho pynciple of construction is different, the workers are different. A Post reporter visiting the Clyde-quay wharf to-day found about forty men hard at work. .For all the noise they made, it might have been Sunday. A little sawing of odds and ends of wood for the casing of the concrete, a little scraping of shovels mixing gravel and cement, a trundling of light wheelbarrows — and that was all. The men were not carpenters or axemen. They were men of the shovel and tamping iron, of the wheelbarrow'and scraper. They were covered from head to foot with thx- greenish dust of cement. The mixers of concrete working behind a wooden wind screen wore blue glasses to keep the stinging dust blown by the southerly from their eyes. The landward part of the wharf is already finished except for the laying of wooden blocking and the erection of the crane bridge. It is like a wide stone highway, with low parapets on each side. On these are the bollards — not the great blocks of wood on the King's and other wharves, but curious cast-iron things with a top like a ham-mer-headed shark leaning outwards. These are bolted securely right through the concrete. There will be forty-four of these bollards, twenty-two to each side. Steal rods about two inches thick in groups of four project at intervals along the centre of the wharf. These are tor the crane bridge — a novelty on a novel wharf. It will bo some twenty feet high, running the whole length of the wharf, and carrying two rails. On each of these the cranes sit back to back with their feet travelling along rails at the edge of each side of the wharf, and their arms projecting over the side convenient to tho ship's hold. They will be driven by electricity, another new departure in Wellington Harbour. SIZE OF THE WHARF. The wharf* is 600 ft long and 63ft broad. It will be clear of buildings, except for an office v.ith a weigh-bridge at the shoreward end. It runs parallel witn other wharves due north and south. How it is built will be impossible to see after to-day, when the skeleton of stsel, or tha little bit of it exposed at the extreme end of the wharf will be covered with its flesh of concrete. II will then be an enormous monolith from the tips of the piles driven a dozen feet or more into tho bed of the harbour to the surface of tho wharfway and the travelling crane bridge and the flagstaff. All are linked together with rods and wires of steel. These were visible this morning. They looked like the side of some gigantic cage laid flat. Bent rods hooked together with vertical extension rods from the deep-seated piles, each of which carries four, like bones embedded in flesh. Smaller wires lash these rods together indissolubly. Continuity of strength is the essential in the reinforcement of coneiete. There must be no weak spots — no weakest links in the chain of steel. Among these rods men were discharging bairow loads of liquid concrete, like a thick porridge. Other men poked and puddled, and tamped it securely among the steel-work with which it is to form, when it sets an unbreakable bond. So it was with the nanipet. in the unfinished parts the network of rods and wires was still open to view. Soon it will be boxed in and filled with the liquid material that solidifies into the hardest stone. It takes some threo weeks to set properly. All woodwork is taken away, when no longer needed. It is not possible to get a complete idea of the wharf from the iop. One must see its underside to realise the extraordinary solidity of its construction. First there are the piles and their extensions carefully linked together. From them spring the cross-beams and the diagonal struts. Transervo braces in the shape of Maltese crosses join tho piles of tho wharf from side -to side. It is like looking at the foundations of tho catacombs to fee these enormous stone 'beams and columns and trusses. One would think they would carry the weight of Wellington on their backs. They are strong. The Auckland wharves, built on the Hennebique system, are much slighter, and there have been complaints of the exposure of steelwork. Mr. W. Ferguson, late engineer to the Wellington Harbour Board, took no risks in designing the Clyde-quay Wharf. It is as rigid and substantial as a coral reef, to which, indeed, it bears gome resemblance. IN CASE OF A COLLISION. What if a ship bumped into this immovable mass? Well, she woula get the worst of it. To prevent damage to wharf and vessel the Clyde-quay wharf is protected all along the line by a spring fender. Ordinary wooden "piles pitched outwards a little guard the outskirts of the concrete structure, which has an overhang of about four feet. These, linked together by beams along the top and chained to the concrete at their back, form a spring fender. A vessel mooring touches tho fender first. It springs in and touches perhaps the concrete in event of extra pressure. Little- or no harm is done to vessel or wharf. Thus eveVy precaution has neen taken against accidents of this description. Against wind and wave the wharf will have to stand an ordeal, too, for it is in the most exposed part of Port Nicholson, exposed to northerly and southerly alike. Will it stand it? It ought to do. The 3000 odd tons of concrete, tha 500' tons of steel all united to stand to the best advantage should weather out any gale, and meet even the worst of earthquakes. The wharf will not decay. The older it grows, the stronger it becomes. Reinforced concrete improves with age. The wharf is a new departure, and its behaviour will be watched with interest. The contractors are Messrs. M'Lean Bros., who have the dry dock alongside and the Otira tunnal also in hand. The clerk of the works, who looks after the interusts_of the Harbour Board, is Mr. G. W. Atkinson ; the superintendents of the work are Messrs. N. W. M'Lean and J. M'Dermott. It is anticipated that the work will be completed early in the New Year.