PROGRESS IN MARINE ARCHITECTURE.

Auckland Star, Volume XXXIX, Issue 102, 29 April 1908, Page 6

PROGRESS IN MARINE ARCHITECTURE.

What for many years must remain the goal of marine architects was laid down more than twenty years ago by one of the most prominent ship designers of the day. Sir William Pearce had just designed the Umbria and Etruria, which shattered all previous records by crossing the Atlantic at an average speed of nineteen knots, and in an address delivered shortly after to one of the learned societies of Glasgow he declared that he was ready, then and there, to produce a vessel which should accomplish the voyage at a speed of forty knots. If this could be done it would reduce the Lusitania's time by 50 per cent.

It is not surprising that Sir William Pearce's statement was received with a good deal of scepticism. Even in these days the realisation of such a feat seems sufficiently far off, and in ISSS twin screws were only just coming into prominence, while the turbine; for marine purposes, at all events, was unknown. The difficulties to be overcome were, therefore, tremendous, and in order to combine the requisite horse-power with a capacity for paying its way as an ordinary cargo and passenger ship, it would, said Sir William, be necessary to give the vessel a length of 1,500 feet and a beam of 150 feet —just about twice the. dimensions of the Lusitania The cost of such a ship would have been fabulous.

The progress of the last twenty years, and most of all the adoption of the turbine as a marine engine, enable us to look upon Sir William's boast with more credulity than was possible when he made it. If for the next thirty years we advance at the same proportionate rate as we have done for the last twenty, a forty-knot liner should be crossing the Atlantic in three days by 1940.

The evolution of marine architecture has been phenomenal. The last wooden liner was built in 1850, and the last iron liner in 1883. The last paddle ship was the Scotia, of 1864, and the Etruria, of 18->5, vMg the last single-screw ship Now that thVturbine has so completely vindicated itself, it cannot be many years before we come to the last of the reciprocating engined ships, and, with the unhampered development of the turbine, forty knots will be comparatively easily realizable.

There is at present no sea-going ship afloat can do more than thirty four knots an hour. The torpedo-boat destroyers' Viper and CJobra, the first- _o__-bine-engined war ships ever -____,-• each

did well oyer thirty-sis: knots;/but were; both lost at sea, and since those disasters; the Admiralty has"been content with comparatively moderate-speeds. There is nofr : building; however, a destroyer" whichbids fair to break all records. The Swift, a vessel of 1,800 tons—four times the; size of' the average destroyer—now com--pleting at the works of Cammel, Laird; and Co., at Birkenhead, has, a contract speed of thirty-six knots. This alone is sufficiently remarkable for a vessel of her size, but it is an open secret that the builders and designers hope to get fortytwo or forty-four out of her. The displacement of the Swift is little more than a twentieth Of the Lusitania's, but her engines will develop 30,000 horsepower, as compared- with the liner's 72,000, and she will cost as much as four or five ordinary destroyers. . Of course, the Swift could not cross the Atlantic at thirty-six knots, or any-; thing like it, since her oil-carrying capacity is limited to 130 tons, but the naval architect, if left to himself,, have no difficulty whatever in producing a ship capable of doing it The trouble with, such a ship would not lie with the naval architect, but with the-civil engineer. Waters now traversed in perfect safety by the Lusitania and her sister would become perilous, all existing wharves and docks would be useless, and frequent docking is vital to a ship which is to maintain her speed.