THE Brennan Torpedo.

Te Aroha News, Volume V, Issue 218, 3 September 1887, Page 3

THE Brennan Torpedo.

A secret is a secret no longer when ib becomes ki-owu to move than one person, and the accept anco by the Lords of the Admiralty, mUiscd by tho Royal Engineers, of Mr lirennan's invention has been speedily followed by a disclosure of the details <■• its working; parts, and of the mechanic "i 'or which special originality is claimed. >lM >c invention, made in 1876, has required ' \<- years lo mature and five more to vendor . ' practical value, its originality andmeiii being so highly recognised that the invent i>r n-ceived a gratuity of £5,000, and an aumi'il sum of £1,000 till his torpedo \vas perilled. He now enjoys the satisfaction <i' seeing his work passed as complete, and i lie substantial reward of £110,000 as pay hum! for tho exclusive right of manufacture in i upland. The pir i.uy difference between the Brennan and tho Whitehead torpedoes, both buill on the nuno lines, those of a fish, are that while the latter is an uncontrolled projectile dischaiged from a ship, and furnished with uu automatic steering apparatus, tho former is a captive torpedo, intended as an auxiliary weapon of harbour defence, launched and guided from the shore. It is not the first invention of the kind its most notable predecessor being the Lay, adopted by the Russian Government some 10 years ago, but apparently since discarded. American and other inventors ha\e been puzzling their b.ains o\er a controlled locomotive torpedo for the last decade, but although the SimsEdison, the Nordenfeldt, and the Patrick inventions have attained a certain degree of completeness, not one of them has complied with all the conditions required. Should the Brennan ratify the judgment of the Home authoiities, it will be a source of no little pride to Australians, and possibly go far to convince other nationalities that some good can come out ot Nazareth. The gicat diileienco between the Brennan toipedo and its rivals lies in its unique means of propulsion. Whereas the SimsEdison and the Nordenfeit are driven by electiicity, generated in the one case by a dynamo at the starting point, and in the other within the torpedo itself ; tho Berdan, with gas produced by the burning of rockets : tho Lay and Patrick, with compressed cat bonic acid gas; and the Ericcson, like the Whitehead, with compressed air — the propulsion of the Brennan is effected by means of a powerful engine on shore rapidly unwinding two slender wires, 18 W.(J,, with a breaking strain of G cwt to 7 c\\ t, and weighing 331b per mile, from two drums within the torpedo. The unwinding of these coils of wire gives a rapid impetus to the two propeller shafts with which they are connected, just in the same manner as a rotary motion is imparted to a schoolboy's peg top by the string round it when rapidly drawn off, and through them to i the screws which drive the projectile. Thus the beautiful mechanical paradox is afforded by the fact that the faster the stationary engines aic driven, and tho harder they are apparently hauling the torpedo to shore, [ with the greater speed is she progressing in the opposite direction. The strength of the wires, which must of necessity be light, is a matter of the utmost importance, for I should either snap the cruise comes to an end. The length of wire required to be wound on the reels is three times that of the j joui ney. Thus if the vessel against which tho torpedo is directed is a mile away, each drum lntbt, be provided with 3 miles of wire, or b" miles altogether, weighing in all 196 lbs. The torpedo can be neither dragged back nor turned round, though she may be deflected for 30 to W degrees either to starboard or port. To retrieve her, therefore, a steam laanch must be employed. The dimensions of the Brennan torpedo are 2."> feet, by 3 feet by 2^ feet ; her weight, fully equipped for a 2 mile run, is 25 cwt ; siieed 20 miles an hour, and range from 1£ I to 2 nrile>.