BUILDING A WARSHIP.

Wairarapa Age, Volume XXXII, Issue 3148, 27 March 1909, Page 3

BUILDING A WARSHIP.

AN ENORMOUS WORK. THE IMPORTANCE OP PLANS. In the building of battleships, experimental work is practial]v continuous and the great naval constructing firms devote such sums as £IOO,OOO annually to research and jnvt'iuioi:. In the construction oi' a modern warship, apart altogether frcjn the evolution of dpsigns. ths j re ate over 10.000 drawings require;). Of these 6,000 are for the. hull, 3,50(J for the machinery, and 500 for gun mountings, etc. The aim of the design can only be reached by absolute exactness in working to these plans and by the cartful weighing of every item tu the last bolt and nut. Experience, therefore, is essential to success in the preparation of the detail drawings, and the exact calculation of strength of metal aloys and ether manufactures. 'ihe exactness with which the work in the moulding loft is done influences every subsequent operation, both as regards rapidity of construction and efficiency of result. The flour of the ioft is a great drawing board on which is mapped out to full.size, the plates, beam?, and frames of the hull. From these lines are prepared templates to represent every rib of the ship, as well as the beams which bind the hull together to secure ridigity. Template making has greatly developed. Previously the builder waited till the framework uf the ship was erected before commencing the shell and deck planting work, but now templates are made for practically all the plates excepting those at irregular parts, ard it is possible to commence the formation of plates and the punching of holes for rivets as soon as the templates have been made. Each item constituting th°. 4,OCQ to 5,000 tons of steel in the hull thus proceeds contemporaneously, and this is why the launching of the Triumph and Dreadnought and other ships in seven or eight months from the commencement of operations was rendered possible. Plates are bent' to the desired angle by powerful hydrauli: machinery, the pressure being lrom I,ooolb to 1,5001b per square inch. On the building berths tt>e units are fitted together by bolt and nut preliminary to the riveting, and the fitting of the parts is a test of the accuracy of the work in the moulding loft, at the bending slabs and in the machine shop where frames and plates are sheared to size and punched. The rapidity of the work depends on tin accuracy of these processes, and in the casj of the cruiser Rurik, for tha Russian navy, as much as 300 tons of metal, exclusive of armour, was fitted in a week. As much ae 200 tons of armour has been fitted in a week on battleships. The riveting is now done by hydraulic power and by pneumatic tools. Hydraulic a-r.d electric cranes of great power are provided at all the construction docks. Lifting grabs take up heavy loads while cranes move along the long gantry at 600 ft per minute. Heavy loads, such as armour plates, are lifted at the speed of 125 ft per minute.

The construction of the boilers, engines, pumps, and -ill the hundred odd engines required for tuj sl ip, proceeds simultaneously with ihe ►■uil .ing of the hull. 11k builtrs are partly made to templates in the methoJ described, and speeinl machinery is used far the construction of water-tube boilers. With electric crane power many boilers are put in position before the vessel is launched. Centralisation has meant much in the construction of the machinery ai,d especially in the castii.g ur forging of large units lor reciprocaling and turbine machinery., with due repaid to the progress cf other units. Many of tinse moderate Hiz»i forgir.gs weigh as much as 15 tons and experience in the tensile quality of metals and various alloys enables stress to be conteracted with minimum of weight. It has tnus been possible to material'!y reduce the weight, of warthip machinery so that 15 b.p. is eloped per ton of machinery by natural taught ships as compated with 10 h.p. 10 ye rs ago. The 19,71)9 i. h.p. machinery of the Kurik was erected in eight months, and was fitted on board, ready fur steaming in live months more.

The greatest importance, from a mechanical ingenuity point of view, attaches to the oarbette mounting for thj guns in the primary armament. Few, indeed, r<.-ali?e the work involved in tne ordnance machinery, which extends from the bottom of the ship tj the breech of the gun. Yet weights are measured by the ounce, as every addition not absolutely essential, not only calls for increased power to drive the snip but atfects the sj.eed of nnuiipiildting the gun, The grjat firms of Vickers and Armstrong have done f-plei.did service by their ingenious work in ordnance rnacidnery. The ord' a ice manufacturing resources they have at their dispoasl have never yet been fully utilueo hy the British Government. It would take volumes (.escribe the woncers cf modern o'dnance machinery and how great masses of over 400 tons can be revoived at a speed of 80ft per minute > d Vfrt te hronght t'- a s4np within an almost immeasurable unit of time, and without the slightest shock. This m-i eox woiK is i one to the onethousandth part cf an imh, so that some idea of the precision required may lie gained. G'unmouiil ing turn'aides weighing I,']() tort; arc lifted board in one piece by the great The turntable, which has two platforms, the upper for the gun

. vat kij, ~ (j firii g pear, and (he tower t<r Mmiriunitioti hoisting :md training machinery, has also sus,"l"" it the iimmiv iiion hoists. The barbette has a roller path made S" it v.fi that, 'here is rot. wt any point, a variation of a I,oooth part of irvii, a'.u 011 ii trie turnahle carrying the gun and all machinery for elevating, loading and firing is

hv mechanism. But so weH balanced is it that it may u_ wuiKeu uy nana, wlihough the moving weimt is over 400 tons.