Engineering Wonders of the World
Volume I

THE DEVELOPMENT OF TORPEDO CRAFT. 425 two funnels only behind the solitary mast, and that two 12-pounder guns, mounted one in the bows and one aft, constitute the arma- ment. She carries three torpedo tubes, all capable of bearing on either broadside. The turbine engines are on the Parsons system. A maximum supply of 40 tons of oil, suffi- cient to steam 1,200 miles at 12 knots, can be accommodated. The speeds varied on trial from 27| to 29 knots. It will be interesting to glance into the engine-room of a boat of this type. Its most striking characteristics are roominess and comfort. The machinery is probably no lighter than that which would have been in- Oil Fuel stalled if reciprocating engines had been used, but the gain in comfort, safety, and simplicity is enormous. Otherwise, the engine-room does not contain any features very novel to turbine-fitted ships. The boilers are of the Thornycroft water-tube type, and are fired by oil fuel only. The system is one which has been developed by the Admiralty, and appears to work with very great success. The oil used is a thick, treacly substance, thoroughly atomized before combustion, so that the boat runs without smoke or smell, and the two funnels remain so cool that the paint on them is never affected. Oil-burning adds a little to the weight of the boiler installation, as a certain amount of fire- brick must be used, and this more than counterbal- ances the ab- sence of metal fire-bars. The i m p o r t ant point in the adoption of oil fuel is, how- ever, the sav- ing in per- sonnel. So BOOM ACROSS PORTSMOUTH HARBOUR TO EXCLUDE HOSTILE TORPEDO CRAFT. {Photo, Russell and Sons, Southsea.) perfect are the mechanical devices fitted that it is said to be quite possible to run a vessel such as that under review with but one man in the stokeholds. In place of having to trim coal on to the stokehold floor, to shovel it into the furnace, and clean fires at intervals, the boiler attendant—he can scarcely be called a “ stoker ”—has only to manipulate his oil-feed and burner valves as required. The fire remains constant, and consequently the steam-pressure varies but slightly—this, of course, if the steam con- sumption by the engines be regular. The same regularity distinguishes the turbine engines themselves. In the old days of torpedo-boat trials a crowd of men hung around every moving part, and drenched the engines with lubricant to prevent overheat- ing. All this bother is avoided by the em- ployment of automatic lubrication, turbine engines, and oil fuel. The very latest types of fast small craft are due to the adoption of the internal-com- bustion engine for marine purposes. We possess a Yarrow built motor- vedette ; and Austria has Motor quite a fleet of small petrol- driven torpedo vessels capable of maintaining a speed of 22 knots. The British Admiralty are now looking carefully into the question of oil engines of various kinds with a view to utilizing them instead of steam in all small craft, and the evo- lution and de- velopment of this new type promises even better results than have been given us by the steam turbine.