DOUBLE-SCREW STEAMSHIP.

Colonist, Volume VI, Issue 554, 13 February 1863, Page 2

DOUBLE-SCREW STEAMSHIP.

Tmb trial of this vessel, which took place on the Thames, was attended with an unusual degree of interest, in a public arid official sense, from the fact that the peculiar form of the vessel's construction and the disposition of her propelling steam power, if successful on trial, combined the requisites required for our smaller ships of war, such as corvettes of the Chanticleer and Rinaldo class, and smaller craft as gunvessels of six guns and less, inasmuch as she was the representative of a class of ship capable of carrying a heavy armament of guns, with a large engine power, at alight draught of water, possessing at the same time a power of manoeuvring in a small space such as could not, under any circumstances, be possessed by a vessel with the ordinary single screw.

So important, in fact, was the result of the Flora's trial considered by the Admiralty that their inspector of machinery afloat, Mr- John Dinnen, was present officially to report the result for the information of the Board.

The Flora is an iron vessel of 400 tons, 160 feet in length, 22J feet in breadth, and 15J feet in depth, having two independent engines and screws with a collective nominal horse power engine of 120 horses, the screws working under each quarter, and consequently before the rudder, in lieu of the present system of one screw astern and abaft the rudder. The diameter of the cylinders is 26 inches, with a stroke of 21 inches. Each screw has a diameter of 7 feet, with a pitch of U£ feet. The boilers comprise two tubular, working at 301b. pressure, and one high pleasure, working at 50!b. The high-pressure boiler is intended to be used for producing a steam blast in the chimney and to dry the steam (by admixture) from the two common boilers. The vessel is schooner rigged, and without yards or any extra weight aloft, and, for her size, has a very handsome appearance on the water, giving promise of being a real siesm clipper —a promise wh eh her performance under steam during the day fully confirmed, for, if her tonnage and horse-power are faiily considered, there can be no doubt the Flora is the fastest screw ••tennship afloat. Her builders are Messrs Dudgeon, of Milhvall (both of hull and engines), and the success of the ship is a fitting tribute to an enterprising mercantile firm. There is nothing new in the idea of the use of two screws in the propulsion of ships, as our old floating iron«cased batteries are each fitted in the same way, but are worked by one motion from the engines. A small vessel in the Clyde works two screws also, with two rudders, the idea, as acknowledged by the adapter, having been taken from the model exhibited in the Exhibition of 185 Lby Mr A. Sturdee, the present master shipwright's assistant at Portsmouth dockyard. The Flora, however, is the first vessel that has been fitted with two screws and engines working separately and independently of each other; and herein lies the value of the principle in a military point of view, as giving a ship a means of rapidly revolving under steam and changing her position to any required point.

The weather was fine, considering the season of the year; the atmosphere sufficiently clear to carry out the proposed experiments, with the wind at N.E., on leaving Gravesend somewhat light, but as the mouth' of the river was reached freshening until it reached a force of between 4 x 5. The ran from the Nore to the Mouse Light was made in 31 rains. 40 sees., the tide being high water, slack on passing the Nore. This gave the ship a speed of 14-16 knots—an exceedingly favorable result. The ship's head was then brought round, and her course laid for the Nore, on reaching which preparations were made for making the important tests of the day—the capabilities of the ship in answering her helm and engines in making circles. The first experiment was made with both engines, going ahead at full speed, and the helm hard over, when the first circle was made in 3 mm. 14 sec, the second in 3 mm. 13 sec, and the third in 3 mm. 16 sec, the diameter of the circles being about three lengths of the ship, and lessening each time. In the second experiment one engine and screw worked ahead, with the other going astern, and one circle was made in 3 mm. 39 sec, and another in 3 mm. 46 sec. In making these circles the action of the ship's hull was extraordinary, the central part being stationary, and both ends moving equally ; the circle was made on a pivot from the ship's midship section.

The vessel was then put in a straight course, stopped, and from a state of rest the engines were started, one ahead and the other astern, the circle being completed in 3 mm. 55 Bee, and the diameter of the circle being as before, within the ship's length. The vacuum throughout the trials was steady at 25 inches.— Evening Mail.

Our old friend Capt. Thomson, with the ship Derwentwater. arrived in harbor on Wednesday afternoon, Jan. 7, after a very long and tedious passage of about 120 days from land to land. She sailed from Gravesend on sth Sept. She brings a good cargo for Canterbury (about 801) tons); also some valuable fowls from the Sydenham Palace Poultry Exhibition, of 1882, consigned to Dr. Lillie and Mr. Moore, of Glejaniark. They comprise good specimens of the Dorking and Spanish kinds; also a line lot of pigs, of the Berkshire breed, and four valuable merino rams for Major Coote. She has also a small number of cabin and second cabin passenger*. It appears that Capt. Thomson expected to leave homo a month earlier for Lyttelton, and was desirous to be out in time for the regntta. He brings with him a fine four oared racing gig, built by Wylde, of London.— Lyttelton Times,

The following are the passengers in the ship Ida Zeigler, ship, 800 tons, A. Reynolds, for London. Miss Rowson, Mr and Mrs Scotland, Mr and Mrs Werner and family, Mr and Mrs Farmer, Mr and Mm Tutty, Captain Brown, Lient. Wamjh, Lieut. Baynton, Mr and Mrs Chamberlin, Captain and Mrs Barton and family, Miss Tyhurst, Mr and Mrs Fairburn and family, Mr Jenkins, Mr Milner, Mr and Mrs Oarleton, Mr and Mrs Williams, Messrs Galca, Dittrich, Silva, and Da Costa, Mr and Mrs Corbett, Rev VV. Calvert, Master McEwan, Master J. McEwan, Messrs Smith, Gimes and Pike, 98 rank and file, 8 women, 15 children, and 15 mtivea.—Aucktander.

The barque Empress of India, from London, arrived in port. She brings a general cargo. Part of her cargo is consigned to Picton, whither she proceeds on discharging the portion intended for Otago. As previously reported, she sailed from London on the 13th Sept.; was forty-five days on the Line, having during that time experienced light contrary winds. An un fortunate accident occurred in the course of the pasnage, by which Mr Frederick Todd, the second officer, lost his life. lie was engaged forward, when he was canied overboard by the bowsprit shrouds, and though life-bcoya were immediately thrown to him by Captain VVilkin, and one of the boats was lowered in two minufes' time, and was almost within arms length of him, he sank before he could be saved. Except Mrs Wilkin and child, the Empress of India bringa no puwcngew,— Otago Daily Tims, Jan. 9,