The Truth About the Bulkhead System.* 



By CAPTAIN CHAS. A. CHADDOCK, Master Mariner. 



These diagrams were prepared for the information of the Iiilernaiional Jury at the Paris Exhibition of 1900, and met 

 with their unanimous approval. At the close of the Exhibition the diagrams were sent per Embassy Bag to H.M. Secretary 

 of Slate for Foreign Atl'airs, London, and thus brought to the oflicial notice of the Government. 



Attention was first called to the subject matter by a paper I read at the Rooms of the Mercantile Marine Service Associa- 

 tion, Liverpool, on Tuesday, Xov. 9th, 1897. In effect, I pointed out that while bulkheads were sometimes instrun-:cntal in 

 preventing ships sinking, they enormously aggravate the dangers by causing the ship to sink in the shortest possible time 

 after striking submerged objects. They also cause the ship to take up angles greatly nnpcding the launching of boats, even 

 if time were available therefor. The diagrams prove in the clearest possible light how the dangerous angles set up by the 

 bulkheads, after the ship is damaged, may be counteracted. The weight system also demonstrates the danger in merchant 

 ships of lilting longitudinal bulkheads, as with a he.avy list the boats on one side only would be available for passengers. 

 These diagrams demonstrate that .accidents at sea which now result in dreadful loss of life can be reduced to a question of 

 altered weights, whereby the ship and lives on board may be saved. The mnxinumi of insecurity is here illustrated by 

 applying the weights to turn the ship like the beam of a scale, to tirst demonstrate the form of craft which will sink in the 

 shortest time. 



Fin. r is a skeleton hull fitted with a partition in 

 or near the centre of the ship, to confine the inrush 

 of water to one end. This device is designed to pur- 

 posely cause the ship to take up the most disastrous 

 angles in the process of sinking and to sink in the 

 shortest possible space of time, and in a manner to 

 ensure the greatest loss of life. 



The result of an accident to Fig. i by collision or 

 striking some submerged danger in the fore part or 

 bow is illustrated by the severance of the cord holding 

 the weight C. The turning movement commenced by 

 the severance of the weight C is now continued in the 

 weights A and D up to the point of bursting strain, 

 when the partition must give way and the ship sinks, 

 when less than half full of water, as indicated in the 



Fig. 2 is the form of ship which will take the longest 

 time to sink. .She has no internal obstruction, and the 

 water has the full range of the ship's hold ; conse- 

 quently she fills up evenly throughout her length. 



Fig. 2A illustrates this ship nearly full of water. 

 The weights have been gradually reduced, and she is 

 now on the point of sinking. As she sinks the remaining 

 air will blow off the upper deck hatches. This is how 

 ships sank in the old days of wooden hulls. l'"illing up 

 evenly before sinking, and abstaining from taking up 

 dangerous angles, thus enabling seamen to save the 

 lives on board. 



Fig. 3 represents the introduction of bulkheads 

 originally designed to prevent the ship sinking it she 

 runs into another vessel. 



Fig. 3A represents the same ship after collision, the 

 jagged line at the bow indicating the fracture on this 

 and other figures. The compartment is now full to 

 water level ; the only alteration is that the weights 



* The value of bulkheads and water-tight decks has been 

 under discu^<ion both in ihc American Commission and over 

 licre. In America the Senate C'ommission reported in favour of 

 Hecks being made water-light. Mad the 7';Ai««: been cinislruclcil 

 with real bulkheads and with .1 walerlighl deck she wiiuld not 

 have sunk. 



B and C are slightly increased and A slightly 

 diminished. 



Fig. 4 represents the extension of the bulkhead 

 system, which is now applied throughout the ship, 

 ostensibly to prevent the ship sinking if another vessel 

 runs into her. This figure is a scale drawing of a 

 passenger and cargo steamer, as constructed by an 

 eminent firm of shipbuilders. She is fitted with eight 

 bulkheads, three principal decks, and five cargo hatch- 

 ways (marked //). These hatchways are covered by 

 wooden hatches laid on in sections from above. 



In Fig. 4A the ship has struck some submerged 

 danger and fractured her hull in the region of Nos. i, 

 2, and 3 bulkheads. The incoming water rushes up 

 at once in an immense volume, having free access to 

 all air spaces between the three decks, as the wooden 

 hatches cannot offer the slightest resistance to the 

 water pressure. The accident is indicated by the 

 severance of the cord holding the weight C, thereby 

 depressing the bow, in which the weight A now assists, 

 by operating as a lilting force to the stern. As No. 4 

 bulkhead, in or neai the centre of the ship, arrests the 

 flow of the water and causes it to level up in the one 

 end inly, we are now in the identical position of Fig. i, 

 illustrating a ship purposely designed to take uyi the 

 most dangerous angles, and to sink in the shortest 

 possible time with the greatest loss of life. 



Fig. 4ri is a deck view of Fig. 4A to demonstrate the 

 difficulties of saving life after accident. Fig. 4c 

 illustrates the water rushing up through the hatchways 

 and bearing down upon the side to which the ship 

 lists. This list is first started by an ordinary roll .setting 

 the water inside the ship in motion, and its weight 

 bearing against the side of the ship is likely to cause 

 her to turn completely over (sifleways), a.s her stability 

 is now fast disapjiearing owing to one end rising com- 

 pletely out of the water. 



liili-r alia. Fig. 411 illustrates precisely what hap- 

 pened in the case of the loiinderiiig ol the La liourgogne. 



During this lime the vessel is rapidly filling in one 

 end only. Hy the lime she rights (sec Fig. 4D), which 



