DIMENSIONS OF DOCK

Evening Post, Volume CX, Issue 40, 15 August 1930, Page 10

DIMENSIONS OF DOCK

ADJUNCT TO THE PORT

Tho decision to proceed with the construction of the Jubilee. Dock, (as it has already been named by the board) was arrived at at a meeting' 'of th« Harbour Board on 29th January last, when authority was given tothe general manager (Mr. J. Marehbanks) -;to -arrange for the preparation of designs and specifications. Previous to the meeting, the board authorised.the construction of tho reinforced concrete wharf at which the dock will lie, at tho Kaiwarra end of the harbour. Th« actual site is at tho end of the Thorndon sea wall. The construction of the big floating hospital is estimated to take the better part of a year, if! not more, and then the towing out of the unwieldy craft will probably occupy six months, so it will probably be at least eighteen months before the dock is here. , • '

Tho lifting power of the dock will be 17,000 tons. It will measure -527 ft ia length over, the pontoons; -533 ft m length over tho keel blocks, and 584 ft in length' over the platform. The'overall width will be 117 ft 6in. -■ The width of tho entrance will be BSft, which: will enable a vessel of 80ft. beam to doek f The depth of the dock will be not lesi than 24ft over the- keel blocks: at ":l6tr water. ThG dock ; itself 'will -draw 44ft when sunk to its lowest1 depth to put the vessel in. These dimensions are slightly greater in some respect* than ' those. decided. on on 22nd' February, 1928, showing that the board tais determined that the dock .'shall bi» thoroughly up to date- with.-the iv- ■ creasing requirements ■of 'the vport, but there will be an ample depth of water on the proposed site, with & .; little dredging. ■ ■ ■■ ■>. - . The pumping .will be done by- electrio power. The compartment valves will be operated by the- electro-pneumatic system from a central valve house. Tha dock will be attached by four-;mooring booms to a reinforced concrete;wharf, which will be built outside, the'breastwork'at the northern end of'the Thbrndon reclamation. There will be "longitudinal moorings f ore ■-and-.aft, and gangways will be provided for access for material from tho wharf to the dock, laid both to the top level' of th» idock and to the working level below. lEleetrie. capstans to assist in the berthing; of ships will be provided; and four sets of mechanical side-shores;; \.Aji electric ..crane, capable of', 'lifting ...tw.o. tons, will run on rails extending dow.n one side of the dock. Electric-driven air compressors will be installed, and other subsidiary appliances, 'but th» dock will in no way resemblo' a workshop, as no machine tools will ber installed. . .........:,.

ITS CAPACITY;

> - 'ilhe capacity- of the dock,, unllkc^that of a graving dock, is! increased by th 9 fact that the size of the vessel that can be accommodated depends purely ou the lifting capacity of the dock, as the ship has not to fit in at the ends, which project. The Jubilee Dock, With'its 17,000 tons', lifting capacity, .should therefore be capable of handling J iaost of the big overseas liners ; coming licre, which average; 10,000 tons, with"'a'--few of 12,000 tons, and exceptionall^ instances of 16,000. Vessels liWithe Carinthia (which visited Wellington, some time ago) are' not : sufficiently numerous to justify the added expense in dock construction. It must be* borne in mind that, while there willJhe a good deal of work for the dqc.k;;jtn the ordinary way, and" a certain; amo.unt of revenue to offset the iexpenditure,vsuch. docks rarely - pay harbour;, authorities, and are put in.; purely as- a- convenience to visiting . shipping, -and •■ as ; %.safe- ! guard in the case, of. .serio.us; . disablement to ships, which would ■ prevent them effecting .temporary: Repairs enabling them to pursue their voyages. While the board will not find rtho .dock a paying proposition, however,'•at. wiU gain in the added tonnage to the routes bythe added security .offered, and the city willl gain, by-the; docking of 'large ships here, both-in-the work given to the } engineering firms and- the money spent . in the city by, crews and on materials. . •. ; • . ■

Dredging by a Priestman-dredge. oa .the site of the dock was in progress ia April last, when it was ■ estimated -that the bottom would have to be-deepened by ,2ft to 2ft 6in. ' A start-was ■ also made with the making: of the concrete piles, of which 350 would be required, for the approach wharf and the dock wharf itself. ■ • ' ' :