BY DEMAND FOR INCREASED SAFETY. 35 



— and that is no remedy. The precautions which should be taken must be such 

 as will not handicap the business unduly — and what is considered proper to-day, in 

 the present state of the arts and of public opinion, may hardly seem sufficient a 

 few years hence. The advancement which has been made in ocean navigation 

 in one century shows that many of the risks of former days have vanished. The 

 increase in the number of lives involved in any one accident is the real reason why, 

 at the present time, additional precautions are considered necessary. 



It is suggested, therefore, that the basis for further precautions in the struc- 

 ture of vessels should be the number of lives involved; and further, that greater 

 precautions should be taken for the lives of passengers than for the lives of an equal 

 number of the crew. 



Protection of the propelling machinery, which prevents loss of control of 

 the vessel, would seem to be of next importance to protection from foundering. 

 Double bottoms under machinery spaces to afford protection in case of ground- 

 ing, and, on vessels carrying a large number of passengers, wing compartments 

 to afford protection in case of collision, would seem in order. 



Protection from foundering in case of collision would seem to be obtained 

 in proportion as a greater or less length of a vessel's side could be open to the sea 

 without endangering the buoyancy or stability. Double bottoms would be of little 

 use for this purpose. Watertight decks near the water line in intact condition 

 would seem of no great benefit, as the damage would probably extend both above 

 and below this deck; and, in most cases, they would seriously interfere with 

 handling cargo. A fore-and-aft bulkhead at the center line would help to pre- 

 serve the buoyancy, but would probably destroy the stability. Wing bulkheads 

 spaced far enough from the side to be safe from injury by collision would be 

 prohibitive in handling ordinary cargoes, and could be adopted with advantage 

 in special cases only. Subdivision by transverse bulkheads is, therefore, the logi- 

 cal precaution to take. It is structurally simple, and transverse bulkheads inter- 

 fere very little, if at all, with the handling of any kind of cargo, provided they 

 are considered in the design of the handling appliances. Even lumber vessels can 

 be built with numerous transverse bulkheads. 



If it is determined that a vessel carrying a certain number of passengers and 

 crew shall be safe from foundering with a certain proportion of the length of 

 the side open to the sea, and it is attempted to obtain this result by transverse sub- 

 division, the accompanying diagrams. Figs. 3-1 1, Plates 25-29, will give an idea of 

 the conditions which will exist as calculaed for a hurricane deck coastwise passen- 

 ger vessel. The vessel considered is 370 feet long from stem to propeller post, 49 

 feet 6 inches beam, and 35 feet deep to hurricane deck. The collision bulkhead is 

 located at 6 per cent of the length of the vessel abaft the stem and the forward bulk- 

 head of the machinery space is 46 per cent of the length abaft the stem. The 

 vessel was assumed under two conditions of loading, one to give a draught of 18 

 feet 6 inches and the other to give a draught of 24 feet. 



The conditions as to draught and initial stability were first determined with 



