THE MELBOURNE MONITOR CERBERUS.

Grey River Argus, Volume VI, Issue 367, 21 May 1868, Page 2

THE MELBOURNE MONITOR CERBERUS.

(From the Engineer-, Feb. 7.) We this week lay before onr readers a twopage engraving of the powerful ironclad monitor Cerberus, now building on the Tyne, by Messrs Palmer, of Jarrow (the builder of the ironclad frigate Defence and the Indian trooper Jumna), from the designs of Mr E. J. Reed, the Chief Constructor of tho Navy. Thi» design is based upon the breastwork principle, propounded last year by Mr Reed in a speech on the turret system at tbe Institution of Civil Engineers, the object of adopting the central armor-plated breastwork being to protect all the principal apertures into the ship to a height of 10ft. or l'2ft. above the water, aud thus to add greatly to the security of these low-decked vessels. The pnly apertures through the low deck in this ship outside of the armor breastwork are three skylights, for giving light and air below in a direct way when in harbor. Each of • these skylights is surrounded by armor, and provided with au armor-plate cover for use in action. The ship, although of moderate dimensions, wijl be coated with very thick armor, and will carry four eighteen -ton guns, at a speed of about nine knots. Instead of sending the Cerberus to Melbourne under escort, it is, we believe, the intention of Major Posiey, R.E., the representative of the colonial Government in this country to have her fitted under Mr Reed's direction with a temporary deck and jury-rig, and navigated to Melbourne like an ordinary ship. The presence of this formidable ship in the port of Melbourne will, in our opinion, tend more to its security and immunity of attack than threo times its cost expended in land defences. She is the first monitor proper laid down, we believe, in this country, although Messrs Napier are engaged .upon another. The dimensions of the vessel ore as follow :— ft. in. Length between the perpendiculars 225 0 ' — Length of keel for tonnage 193 7| Breadth, extreme and for tonnage... 45 0 Depth in hold ... 16 li Bnrdeu in tons, 0.M., No. 2107 23-94. The nominal power of her engines ia 250---horse power, and she will be propelled by twin screws. She will sit on an even keel, with a draught of water of 15ft. Cm.; and be steered by a balanced rudder, which is well protected by the overhanging stem. Her freeboard is 3ft., the side being covered with armour from stem to stern, and $o about 4ft. belp.w the water-line. This armour is in two strakes, the upper one being Bft. and the lower one 6in. thick, each tapering towards the extremities of the vessel to SJin. and 4in. respectively. The teak backing is worked horizontally between two outside stringers, and the whole secured to two thicknesses of fin. plating. Her frames are 3ft. apart, excepting in tbe double bottom, which extends from the armour shelf on one Bide to the armour shelf pn the other through tbe whole length of the midship bor^^ghere the frames are 4ft, two flat plates, vertical keelframi b, fore and the

armour plates, 3ft, Gin high, with strong watertight covers. The breastwork stands upon the midship part pf the upper deck, and is 112 ft long, 34ft wide, and Oft deep, having circular ends, which aie protected with 9iu armour in wake of turrets. Elsewhere Sm armour is placed ou the sides of the breastwork ; the frames are 3ft apart, and well secured to the upper deck beams. The top of the breastwork is nrotecte I ia protected with two thicknesses of plating upon the ordinary Irmsvevse ucams, excepting where the turrets run through it. and also where -the funnel, airshaft, &c, enter it. Besides theso, the breastwork encloses two small engines for working each turret, a steering wheel, cooking ranges, and the hatchways leading directly down to the ammunition, as well as those leading to the fore and after parts of the lower deck, where the crew are berthed. The turrets,, two in number, one at each end of tho breastwork, and about sft 6in above it, are constructed to fight tyro eighteen-ton guns, and may be turned either by manual or steam power. The turrets are protected in front, by lOin and in the rear by 9in armour, extending down a short dist-uice within the breastwork. The teak backing is woilfed horizontally between stringers, which are outside of the two thicknesses of 4in skin-plating, and the tops of the turrets are protected by 4in plating upon the beams. A flying deck, 20ft. wide, js worked above the turrets for the whole length of tbe breast work, and tho communication from the latter to tbe Hying deck takes place through water* tight iron trunks. All openings in this and other decks are protected from a vertical tire. The pilothouse is supported from the top of tbe breastwork, an I extends to 4ft. above (hs flying deck. The sides of the pilothouse ire protected with 9in. armour, the teak b: eking being worked as before described, and upon two thicknesses of £in. planking without internal frames. The davits an 4 other outriggers for boats &c , will admit of being lowered, bq as to clear the range of the turret guns. The fresh air for ventilating the vessel will be admitted by means pf the air shaft, tbp a^h-shoot, and the openings in the decks over the stoke-hole. A fan at the bottom of the air shaft, and another at the fore-end of the b'dler room, will I >e. worked by steam, and will drive the air forward through main pipes under the lpwer deck, ancj. aft through similar pipes at tho upper part of shaft Eassac>e, and from these pipes branches will c led wherever required. Tbere are seven watertight transverso bulkheads continued fci the upper deck, and having watertight doors in them, either at the lower deck or in tbe bold.