PATENT SLIP

Wellington Independent, Volume XVI, Issue 1703, 28 February 1862, Page 3

PATENT SLIP

(From the " Daily Times)

In view of the increased shipping at Dunedin port, it becomes a very grave question what is to be done with vessels which, whether from natural causes or from accident, require repair. Vessels coming loug voyages, say from England or America to Australia generally require some overhauling before returning, but at present there are no facilities for effecting anything of the kind in Dunedin. It is quite likely, indeed, we may almost say, certain, that a great many vessels will shortly be laid ou direct from Lomlou, Liverpool, and Glasgow, to Olago ; and other parts of the world will contribute their share to swell the total. It is hardly necessary to point out how a large trade always arises in connection with a shipping port. Besides the business connected with the supply of stores, the outfits and expenses of passengers, form considerable items of emolument. What would Southampton be but for tbe immense passenger traffic that it enjoys. If we would have Dunedin anything but a mere hailing place on the road to Melbourne, we must provide accommodation to ships so that they will not require to visit the neighbouring colony for repairs, or to refit.

At present, Dunedin is wholly deficient of anything of the kiud. It has neither a slip on which to haul vessels requiring repair, nor shipwright's yards.. It is scarcely possible to exaggerate the importance of supplying these wants.

A merchant in town has kindly placed at our disposal the subjoined extracts from cor respondence on the subject of the supply of a patent slip. The writer is Mr. W hite, of Thus. White and Son, a firm which has supplied slips to the Governments of Russia, Holland, Cadiz, Pesth, Pernambuco, Valparaiso, Sydney, Hobart Town, Hong Kong, and many other places. It is satisfactory to observe tuat the cost would be comparatively a light one. Their slip for Rotterdam for 1,000 ton vessels' cost about £8,000, inclusive of all charges. At Portsmouth, one for 800 ton vessels cost £6,000. Such a sum, considering the objects it will effect, is comparatively trifling. Even supposing the Government bad to find it, the slip could be let at a rental that would yield good interest on the amount of the cost. We direct particular attention to the extracts from Messrs. White and Son's letters, which we add. extracts from letters received prom messrs. White and Son. " The slips are' easily laid down, either upon l piles, as at Forton and Goaport, or in concrete as at the Camber, Portsmouth ; or rock cut direct to the slope or incline, just according to the soil or the material cheapest and at hand ; rise and fall of water of no cousequonee. I have laid them where there is none, or only four feet as in Holland, 10 feet at Cadiz, 14 feet here, 30 feet at Bristol and Liverpool. No damworlt is necessary where there is length of promises; wo place the whole in a field as it were, and cut a channel to it. I have just shipped a 1500 ton to Bombay, and 1000 to Pernambuco."

•'The price of machinery, rails, chairs — in short every part of iron -work finished at the factory is as follows: — 500 tons capstan-purchase, worked by horses or men, i' 1,000; 450 feet cradle, if made here, but can be made with you where timber is cheap and save freight. If a steam-engine be required, .£250 extra, including connections, bevel wheels, &c,"

"We use hydraulic for the largef^ncfTfESi do so generally; but I am not anxious to piojdse them abroad, because of the difficulty of rejurj and the superior engineer to work them, whereas a wheel machine for the smaller slips like rains is not at all liable to derangement, and a duplicate of two or three wheels (about £100) would secure a clip abroad/or an age. For larger sHpB hydraulics are beautiful; I send one to Bombay, — they add 20 per cent, to the cost before mentioned.

" 1000 tons, £3680, with additions and proportions for hydraulics to the foregoing; 15Q0tons(my Bombay all complete), cradle 250 feet, engine double patent hydraulics, £6040; additional length, £3 par foot ; foreman to lay down, £20 per month ; the foundations^ ways, &c, depend upon locnl cirenmstances. Labour and materials,the Camber cost £1500 ; Forton and Gosport the same ; Cadiz — ironwork and foundations £6000."

" The premises I always seek are a field, say 500 to 800 feet long. Above the water excavate; here lay the whole down and then dig away the bank which has been left, of about 30 feet as a dam; this prevents all dam work which might be necessary if you run out into the harbour or river. Rise and fall is of no consaquence aft?r ; the slip ia thus laid" • ' ■

" 1000 tens slip at Rotterdam, also at Cadiz, cost for iron work, machinery, cradle, frieghta, and charges — £3500 for my work ; frieghts and charges, £500; insurance, £120; foundations, timber piles or concrete, £3000 ; sundries, £500, say £BUO. Our slip here, 800 tons, cost for foundations, ironwork, machinery, &c, complete for use, £6000. My shipment for the Oregas Patent Slip Company for 1500 tons, the steam engine (20 horse power), machinery, cradle, and all ironwork. £5,C40, and my engineer has gone out to be the engineer of the company, and to lay it down and work it."

"If you select a site describe it to me, let it be clear, if yon can, of shifting sand or rolling beach, as in this case the little channel would be always filling up. Dig a hole as deep as you can, and say what the strata ia. Have you any piling thereabouts, and how do they drive? What have you for piles? they should be 10 or 19 inches through, and if clay, 28 or 30- feet long, if timber is smaller have more of them. . . ~

"Concrete formed of nine parts clean shingle, two of rough sand, two of lime, 'forms in a three four or feet bed, an excellent foundation,— such ia our Camber Slip j mine at Gosporfc, was piles ; Rotdam and Cadiz, piles ; Birkenhead, on the plain red sandstone ; or three little walls of masonry\if stone ia easier got at ; in short, anything local circumstances furnish, and any place will do " " Springy land offers no obstacles, as to docks." 11 We have no sets of drawings. Slips differ bo much in size and inclination, — sdme being laid at one foot descent, others in one foot to twenty-five inches; at Haslar, one in thirty-five inches, all of which makes great difference in power and strength of the iron-work. All my contratc with Government, companies and individuals are at the service of any Agent in London to inspire the confidence you need at such a distance. 1 '

"I am adopting a screw and. wheel ; I think or abroad it will be strong, safe, and of more tpwer than the pinion."