SUBMARINE NAVIGATION 



777 



America, no successful results were arrived at, 

 but in 1886 a submarine boat was built at Stock- 

 holm by Nordenfelt. She was driven by steam, 

 and ran 16 miles at a speed of 5 knots, but was 

 only immersed for five minutes at a time ; she 

 descended, however, some 30 feet, and this was 

 repeated several times. A similar boat was con- 

 structed for and bought by the Greek govern- 

 ment. Two others somewhat larger were built by 

 Nordenfelt for the Turkish government, and were 

 tried at Constantinople in 1887; they were 100 

 feet long, 12 feet in diameter, with a displacement 

 of 160 tons, and when not immersed had a speed 

 of 12 knots, travelling a distance of 100 miles 

 without recoaling ; they had a crew of six men, 

 and descended successfully to a depth of about 50 

 feet. A still later Nordenfelt boat was tried at 

 Southampton, also in 1887 ; she was 125 feet long, 

 with a diameter of 12 feet, a displacement of 230 

 tons, and indicated 1000 horse-power with a speed 

 of 15 knots when not immersed ; with her cupola 

 awash, however, this speed was reduced to 5 

 knots. Although these boats at the time seemed 

 to answer all expectations, further experiments 

 would seem to have shown that they could not 

 be depended upon for real practical work, and 

 the original boat, after lying some time at 

 Copenhagen without finding a purchaser, was 

 finally bought and broken up as old iron in 1891. 

 By the choice of steam as his motive 

 power the inventor created diffi- 

 culties not easily to be overcome, 

 and prevented the satisfactory de- 

 velopment of that type of boat. 

 One result of this choice was that 

 the boat, when proceeding without 

 communication with the atmo- 

 sphere, was entirely dependent 

 upon the energy developed by the 

 boiler. That this method of ac- 

 cumulation is disadvantageous is 

 clear from thermo-dynamic prin- 

 ciples, which show that from a kilo- 

 gram of water of 200 centigrade, 

 when it is cooled to 121 C. by the 

 withdrawal of steam, only 2000 

 m.kg. of work can be obtained. 

 Then not only is the great weight 

 of the engines and boiler a dis- 

 advantage, but the continual radiating heat from 

 the boiler renders a prolonged stay in one of these 

 boats impossible when under the surface. An 

 attempt has since been made in England with the 

 Honigman natron-boiler, but with no better re- 

 sults ; and later inventors have adopted electric 

 accumulators with electric motor and engines as 

 the motive power. Experiment shows that as 

 much as 8000 m.kg. of work can be developed per 

 kilogram of accumulator weight. In 1888 a boat 

 called the Nautilus, designed by a Mr Campbell, 

 was tried in the West India Docks. She was 60 

 feet long, with a beam of 8 feet, was driven by 

 electricity, and fitted witli two impulse tubes for 

 Whitehead torpedoes. The trial was fairly suc- 

 cessful. 



The nearest approach to a workable submanne 

 boat was made in two boats built in France, 

 named the Goubet and Gymnote, and in one, the 

 feral, built at Cadiz. After exhaustive trials, 

 a fair measure of success was obtained ; and in 

 1897 the French navy had four such boats. The 

 Peral, so called after her designer, a lieutenant 

 in the Spanish navy, was first tried at Cadiz in 

 May 1889. According to the official reports, with 

 250 accumulators on board she attained a speed 

 of 7 knots, and it is believed that with 616 

 accumulators a speed of 11 knots would be 

 reached. She covered during two trials some 120 



miles without exhausting all the electricity in 

 the accumulators, answered her helm well, and 

 no difficulty appears to have been experienced 

 in sinking or again rising to the surface, al- 

 though it appears to have oeen found necessary 

 to rise to the surface before venturing to alter 

 course. A torpedo, of which she is fitted to carry 

 three, was also successfully discharged at a target 

 400 metres off, while during the six hours she 

 remained closed up, the air on board remained 

 perfectly sweet. In the case of the Gymnote and 

 the Goubet, with which since 1889 a series of trials 

 have been carried out at Toulon and Cherbourg, 

 the results have been much the same. No diffi- 

 culty was experienced in sinking and rising to the 

 surface, yet they ran on a perfectly straight course ; 

 and when it was wished to turn, the boats were 

 brought to the surface, and placed on their new 

 course before again sinking. When they were 

 moving at a depth of some 15 feet below the 

 surface no trace of their course could be perceived 

 on the top of the water, although in the case of the 

 Gymnote at Toulon she was clearly visible and all 

 her movements followed from a captive balloon 

 some 150 feet in the air. The Goubet has a displace- 

 ment of about 2 tons, is 16 feet 5 inches long, 5 

 feet 10 inches deep, and with a beam of 3 - 5 feet ; 

 outside the boat at the stem she carries a torpedo 

 charged with 110 Ib. of dynamite ; she carries a 



Section of the French Submarine or Surface Boat Goubet, built 1888 : 



a, the electric accumulators ; 6, tanks for compressed air ; c, d, pumps ; e, e, engines ; 



/, cupola ; 0, the safety or emergency weight, which, in event of pumps or machines 



breaking down, can be detached, when the vessel at once rises to the surface. 



When proceeding on the surface only the cupola, /, is visible above water. 



detachable keel weighing 900 kilograms, the drop- 

 ping of which, in the event of tiie pumping-oufc 

 arrangements at any time breaking down, would 

 enable the vessel to immediately rise. Her crew 

 consists of only two men. She is fitted with 

 reservoirs for compressed air, electric accumulators, 

 and motor. The Gymnote is a boat about as large 

 again. In spite of the relative success which has 

 attended the trials of these three boats, the experi- 

 ments seem to have revealed certain practical 

 difficulties which render it problematical if sub- 

 marine navigation can ever be carried on with any 

 degree of safety or certainty. It has been shown 

 that at a depth of only some 50 feet it is impossible 

 to distinguish objects more than 25 feet off, and that 

 even the electric light fails to illuminate objects at 

 a greater distance in the gloom which obtains at 

 this depth ; the colour of the water at this depth is a 

 deep green, and red objects are completely invisible. 

 Navigation under these circumstances must always 

 l>e dangerous. In the French and Spanish experi- 

 ments a given course seems to have been steered 

 with mathematical accuracy by means of the 

 gyroscope, but to deviate from this course would 

 appear at present to be difficult without those in 

 the boat losing all knowledge of their whereabouts, 

 and thus being forced to come to the surface to 

 reconnoitre ; and the slow speed at present attain- 

 able, not exceeding 7 to 8 knots, also militate* 



