I El, 1915. 



THE INDIA RUBBER WORLD 



479 



buoyant margin of safetj of 500 pounds. The greater the 

 pressure impelling water into .i passageway, such as a leak, 

 the faster the water will flow, and thus the hazard increases 

 as a submarine goes deeper and any part of her structure 

 yields so that the sea can work it-, way inward. Then 

 the greatest care must he exercised to prevent leaks and to 

 see thai everything is sound and strong enough to withstand 

 ill -..('- crushing force within certain limit- In the United 



The conning-tower forms a separate compartment placed 

 hi tup of the main pressure-resisting hull of the submarine. 

 In order to isolate this space, in case of accident to the tower, 

 there is a second manhole with bronze top in the floor of this 

 [rational turret, and here, again, the passageway can be 

 sealed by drawing down the lid upon a thick gasket of rubber. 

 1 'tic "i thi has its lower end in this chamber, 



and the man at the wheel uses this instrument in sti ■ 



A\ Inboard. Longitudinal View of a Modern Submarine. 



-I \" Flasks. 8 Storage Batteries. Bll — Water-tight Bulkheads. C — Conning-tower. D — Safety Drop Kiel. E — Engines. 



H Hatches. M — Electric Motor. Controlling Room. P — Periscopes. 5 — Superstructure. T — Torpedo. 7 7' — Torpedo Tube. 



Mates navy all oi till' later undersea boats ate required to 

 he water-tight at a depth of _'<»l feet, and are actually tested 

 liy a submergence of that extent before they are accepted by 

 the government from their builders. 



Now, the general reader knows that a submarine must seal 

 itself up tight before it sinks below the sea's surface, yet 

 there must he openings to the env> loping water, but openings 

 susceptible oi perfect control. Again, the submarine would be 

 as near-sighted as a human diver plunging into the water but 

 for the optical cunning of modern periscopes. These observ- 

 ing instruments reach above the waves when the subaqueous 

 craft is far enough beneath the surface to be secure from 

 the shot and shell of a foe. 



But the reader of this publication may be impatient to 

 know how india rubber helps to make the submarine efficient 

 and how it aids the crew to hold out the insidious sea. Let 

 us start at the beginning by following a craft like one of the 

 German U-boats in her various manoeuvres. While running 

 on the surface, or while alongside the dock, we see that she 

 has a circular hatchway on top of her conning-tower and 

 two or three more of these at points along the crest of her 

 curving deck. The hatch in her conning-tower is the last 

 one to lie closed before the boat submerges. The others are 

 for the general passage in and out of her crew and for the 

 loading of stores, ammunition and torpedoes. In order that 

 these openings, when sealed, shall he absolutely watertight, 

 an annular ridge in these heavy metal covers settles deeply 

 into rubber gaskets of the best sort. 



Now all modern submarines have tun hulls, one that is 

 strong enough to withstand the sea's pressure at any de- 

 signed working depth and the other which constitutes an 

 envelope or superstructure to which the sea has full access 

 when the craft is submerged. This superstructure or outer 

 hull gives the boat its ship-shaped form, which makes the 

 vessel more seaworthy and capable of being driven at high 

 -p. ed when traveling on the surface. In tins latter condition, 

 i. c, "light" trim, water must he kept out of the superstruc- 

 ture or double hull space lest the submarine be made hard 

 to handle by the surging of such water in partly filled spaces. 

 Accordingly, all of the openings in this outer body or shell 

 are made tight by seatings of rubber. In the l T -boats of the 

 German navy this double hull space is used extensively for 

 the Stowagt of fuel, and as the oil is consumed In the engines 

 water is admitted to make up the deficit, SO that the tanks are 

 always filled and no air pockets are left for the sea's pressure 



to push against and to crush at the deeper operative depths. 



toward his target when the boat is below the surface. In 

 order thai the observing instrument may he rotated and yet 

 not leak, it passes up through a stuffing box packed with 

 rubber. That certain of its lenses shall not be fractured by 

 an ordinary jar. they, too, are set in beds of soft rubber, and 

 that the steersman may not bruise his cheek-bones and brows 

 when looking into the periscope there are rubber cushions 

 attached to the eye pieces. The other periscope, reaching up 

 from the controlling room below the conning-tower, dupli- 

 cates the features we have just described save that it passes 

 through a second rubber-packed, water-tight stuffing 

 its way up through the main hull or floor of the conning-tower. 

 Before we take up the propelling motors of one of these 

 U-boats, let us have a glimpse at the how and the stern 

 torpedo tubes. Generally, before leaving her base, the sub- 

 marine places a torpedo in each of her tubes; and that 

 these rather delicate weapons shall not rust there, the tubes 

 are kept dry until just before the commander is ready to expel 

 them. Therefore, each torpedo tube must have an outer and 

 an inner door. These doors are firmly seated against annular 

 gaskets of heavy rubber. To launch the torpedo, the outer 

 door is releasetl and swung clear; the tube fills with water 

 from the sea. and at the desired moment compressed air is 

 „ . blown in at the rear of 



the tube — the pressure 

 being sufficient to force 

 the torpedo out and to 

 trip the little lever 

 which sets the engine 

 of the "steel fish'' go 

 ing. The torpedo itself 

 is divided into three 

 parts — the w a r h c a d 

 containing the explos- 

 ive, the middle body 

 holding the pent-up 

 compressed air for pro- 

 pulsive purposes, and 

 the after section con 

 taining the motors to 

 operate the twin set 

 and the steering and 

 depth -regulating mech- 

 anisms. The forward and after parts are joined to the central 

 bodv and made water-tight against rubber collars, and rubbet 

 gasket? and packing figure elsewhere in this sinister instru- 



Cros 



Section View of Submarine 

 Hull. 



,/ — External Hull. B — Internal oi I' 

 sure -resisting Mull. K — Valves Admitting 

 or K\i'< Mr g Watei Ballast, W — Super- 

 Sum* " i ing Ft ameu 01 k 



Of Slipi l \ cut-- in thi 



structure l>3 which thai space is filled or 



1I1 .,11 <-.i automatically :ts the Laurent! Sub- 

 ■'( \\ ater Bal 

 last Tanks. 



[lave 1 ubber ^.- 



