March 20, 18S5.] 



♦ KNOWLEDGE 



239 



THEJIIXTER-OCEANIC SHIP 

 RAILWAY. 



(Continued from p. 219.) 



AS said before, the road is designed to be almost exactly 

 straight, since there will be no curves having a radius 

 less than twenty miles, for the carriage is 400 ft. long, and 

 rests upon wheels which, as already explained, are not set 



Fig. 7. — Plan of Floating Turntable. 



on tracks swinging to a common centre. There are only 

 five places in the whole line where it is necessary to deviate 

 from a straight line, and at each of these places a floating 

 turntable (see Figs. 7 to 9) will be built. These turntables 

 in design resemble pontoons, for they rest upon water, and 



its bearings. These turntables may be made to serve 

 another purpose : by their means a ship can be made to 

 run oil" on a siding, so to speak, where she can be scrupod, 

 painted, coppered, caulked, or otherwise repaired without 

 removal from her cradle, and thus be saved the heavy 

 expense of going on a dry-dock. 



The locomotives for hauling the ship carriage over the 

 Isthmian railway will not differ from those in ordinary 

 use. The big freight engines of the day have no difficulty, 

 as we know, in drawing freight trains of a total of 1^,000 

 tons ; and, as the ship carriage moves along three tracks, it 

 would be easy, if such a course were necessary, to i)lace 

 three locomotives in front of it and three behind. The 

 time estimated in crossing from ocean to ocean is only 

 sixteen hours. 



The cost of the ship r^ilvvay, as computed by expert 

 engineers, will be about 800,000,000, or §75,000,000 at the 

 outside. 



A careful estimate has shown that it would not be un- 

 reasonable to look for a gross tonnage of .5,000,000 tons in 

 1888 for any passage across the Isthmus. Four dollars the 

 ton would be but a moderate charge — the Panama railroad 

 demands fifteen dollars a ton : this would give 820,000,000 

 as gross receipts. Now, it has been estimated that 10 per 

 cent, of this would pay all working expenses, thus leaving 

 §12,000,000 as net profit, or 12 per cent, on a capitalisation 

 of 8100,000,000. 



The Tehuantepec ship railway is a private enterprise 

 that does not ask a dollar from the Government, and there 

 will be little trouble in its construction if the Government 

 does not, by legislation or by committing itself to the 

 Nicaragua Canal tcheme, injure its prospects and defeat its 

 aim, which is to furnish a cheap, rapid, and s^fe passage 

 for ships acro.ss that narrow strip of land which heretofore 

 has proved an eflectual barrier to aspiring canal builders. 



If Mr. Eads' plans are not thwarted, there is reason to 

 believe that ere long the graceful masts and trailing yards 

 of majestic ships will be seen to mingle with tropic palms 

 in the mountain fastnesses of the Cordilleras, on the ship 

 railway. 



Fig. 8.— Sectional View of Floating Turntable. 



will be strong enough to receive the carriage and its burden. 

 The turntable pontoon will be firmly grounded upon the 

 circular bearers of the basin, when the carriage is run upon 

 it, by the admission of water. This is pumped out by a 

 powerful centrifugal pump, the water being drawn through 

 the cylindrical pivot of the pontoon, which is hollow, and 

 discharged into the basin. When the pontoon has been 

 made sufficiently buoyant to be turned easily upon its pivot 

 by steam-power, the ship carriage is then quickly pointed 

 in its new direction. The valves then permit the water to 

 enter once more, and the pontoon table again rests upon 



In our illustrations. Fig 2 thows an elevation of the 

 adjusting of the screw standard for supporting the vessel 

 on the pontoon, the detail of these standards being given in 

 Fig. 5. A is the standard, having a head-plate with uni- 

 versal joint, its top cushioned with rubber or canvas, to 

 prevent damage to the ship ; B is an adjusting nut, which, 

 when the rams are down, stops the descent of the jack by 

 contact with the toj> side of the main girder C, on which 

 they will rest, D being the top cf the hydraulic jack of the 

 pontoon, the number of these jacks used being better shown 

 in Fig. 4, a perspective of the floating pontoon. E F G, in. 



