402 Her Majesty's Ship "Sultan" 



former, or hydraulic, method is successful if the ship's bottom 

 can be made sufficiently water-tight; the latter, or pneumatic 

 method, is successful if her deck can be made sufficiently air- 

 tight. In the great majority of cases it is much easier to get 

 at the ship's deck and close her hatchways than to get at her 

 bottom and repair a leak. Consequently in most cases the 

 adoption from the first or the pneumatic method would afford 

 the greatest prospect of success. It is necessary, however, 

 that the deck should originally, or by strengthening, be capable 

 of resisting the upward pressure of the air, which by its reaction 

 forces the water out through the leak. In the case of men-of- 

 war and most modern first-class merchant steamers, which are 

 built with iron decks, this condition is fulfilled by their original 

 construction, which makes their hold space comparable to a 

 boiler, with this difference that the hatchways are not fitted 

 to resist pressure from within. It is therefore necessary to 

 close the hatchways by solid beams pressed up against the 

 under surface of the deck or lower edge of the combing. In a 

 man-of-war this is comparatively easy, as the hatchways are 

 comparatively small. When all the openings of the deck have 

 been made as tight as possible and all communications with 

 the damaged hold have been closed, air-forcing machinery of 

 very moderate power will speedily force the water out and keep 

 it out. All its work is effective, while in the case of water 

 pumping only the residue, after the pumps are throwing more 

 than can enter by the leak, is available. One steamer with 

 air-forcing machinery of the power of the pumps of one of the 

 salvage steamers would, with the resources of the "Sultan" 

 herself and the other ships of the fleet, have cleared her fore- 

 hold of water and enabled her to be towed off. 



It is impossible to say what damage or straining the 

 "Sultan" may have experienced in the process of being lifted 

 off the rock by a tempestuous sea, but the pneumatic method 

 remains as available as before. It is unlikely that her iron 

 deck has been seriously damaged; she is lying with her upper 

 works above water; it will therefore be necessary to employ 

 divers for closing the hatchways, where formerly carpenters 

 would have been sufficient. The difference in the conditions 



