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450 tue of increasing the stability of the vessel after damage, provided this oc- curs below the deck. It is equivalent to treating the compartments under the deck as ballast tanks and filling them with water. As long as the ship can afford to lose this buoyancy, and the transverse subdivision ensures this, the vessel has more statical stability than she possessed before the. damage was received. Should the deck be broken the vessel is no worse off than if she was provided with transverse subdivis- ion only, and, even then, the deck may not be punctured in all the transverse compartments affected. - Horizontal Subdivision It has already been pointed out that horizontal subdivision is not necessary in intermediate and cargo boats, and it is not suggested that it is essential in all passenger vessels. In large liners the necessity or otherwise of horizontal subdivision must be considered on the merits of the individual vessel. Decid- ing factors will be amount of stability in sea-going condition, ratios of beam to draft and depth to draft, and dis- tribution of the cargo. From a practi- cal standpoint it should not be diffi- cult to make the lowest passenger deck watertight. This would entail water- tight cargo hatches, a matter that could easily be arranged in view of the moderate size of these in first class passenger vessels, or a simpler solution could be found in the provision of watertight cargo trunks extending to the bulkhead deck. Steel trunks are not uncommon in these vessels at present, and watertightness could easily be se- cured. would have to be made watertight up to the bulkhead deck. The holds below the lowest passenger deck would; in effect, become deep tanks with expan- sion trunks as in oil carriers, except that the heavy scantlings provided in the latter, for regular carriage of oil, would not be required. It is obviously impracticable to provide a _ watertight deck over the machinery compartments, the solution there would be found in making the lowest continuous deck, or the one above it, watertight, and carry- ing the machinery casings from _ it, watertight to the bulkhead deck. Large Initial Stability As an alternative to horizontal sub- division, large initial stability could be provided to prevent the negative sta- bility from becoming excessive in the damaged condition. In certain cases, however, the initial stability would re- quire to be much in excess of that necessary for safe and comfortable In addition, the hold ventilators. THE MARINE REVIEW sea-going, and would not be tried on that account. On first consideration, it might appear that shallow draft steamers of the cross- channel or river type would be very un- stable after receiving damage. The large ratios of beam to draft and depth to draft would apparently form the basis for this conclusion. Examina- tion shows that the actual state of af- fairs is otherwise. The bulkhead deck is, with very few exceptions, the one next below the weather or strength deck, and these depths are only a small proportion of the length of the vessel. The actual ratio to depth (to bulkhead deck) to draft is accordingly not so large as it appears to be when the depth to the weather deck is taken, 'In addition although the vessel carries no carge, the interior fittings, outside the machinery \ compartments, being fairly uniformly distributed, can be looked on as homogeneous cargo in so far as they effect the question. .The initial stability of these boats is gen- erally large, especially in those carry- ing a large number of passengers. The result is that this class of vessel maintains ample stability after being bilged, and transverse subdivision can be made sufficient to meet all con- tingencies. In warships all three methods of sub- division are adopted, with the result that the vessels are divided into a very large number of small watertight com- partments. This enables a vessel to re- main afloat after sustaining consider- able damage by gunfire, and in some cases by torpedo explosion. The latter is proved by the fact that the Cressy remained afloat for about an hour after being struck by the first torpedo. The damage, however, inflicted by a torpedo explosion in cruisers of this type will generally be excessive, as borne out by the rapid sinking of the three cruisers, on account of the absence of protection against this form of attack--protection which cannot well be provided as in battleships and battle-cruisers. It is safe to say that the horizontal water- tight decks and flats in the Cressy, Aboukir and Hogue were broken by the force of the explosions, and these gone, consideration of the ratios of beam to draft and depth to draft indi- cates that the stability took a large negative value. . The conclusion to be drawn from the above considerations is that it is un- necessary and undesirable to introduce legislation for the provision of hori- zontal subdivision in merchant vessels. Vessels in which this method of sub- division would be beneficial are few and far between, and it would be unfair to penalise the majority for the minority, Nevertheless, cases do arise where December, 1914 horizontal subdivision should be adopted and a little invéstigation would deter- mine its necessity or otherwise--Liver- pool Journal of Commerce. * Slides in Panama Canal A large slide on the east bank of Culebra Cut, Panama canal, directly north of Gold Hill, moving between 5 p. m., Wednesday, Oct. 14, and 9 a. m,, Thursday, Oct. 15, carried about 725,000 cubic yards of earth and rock into the Canal prism, and blocked the channel for '1,000 feet to the passage of vessels larger than towboats causing the suspen- sion of traffic. This occurred two months, to the day, after the official opening of the canal to commercial traffic. The big dredges were working at Cucaracha slide, south of Gold Hill, at the time the slide started, and with com- mendable foresight on the parts of Messrs. Comber and Macfarlane steps were taken to move them northward; but for this action the results secured could not have been accomplished, as the condition of the channel was such that loaded barges could not be passed through the slide. The dredges were worked under triple shift. The 15-yard dipper dredges Gamboa and Paraiso, and the 5-yard dipper dredge Mindi, be- gan excavation at the north side of the slide during the night. of Oct. 14-15, while the -mass was still in motion. The dipper dredge Cardenas was added to the fleet on Oct. 15, and during the. 16th an extension of discharge pipe was laid from a point opposite Cucaracha slide, which allowed the pipe line suction dredge No. 86 to take part in the work. The channel was cleared sufficiently by noon of Tuesday, Oct. 20, to allow the passage during the afternoon of seven vessels, which had been delayed at the south end of the canal. The ves- sels had been taken to Pedro Miguel Lock and moored alongside the ap- proach piers and within the lock. The actual passage of the seven through the cut occupied about four hours; they followed each other at intervals of about half an hour, propelled by their own power, but passing the slide under the control of a tug fore and aft, to hold them to the course. A good story is told in Newcastle to the effect that a shipowner upon hearing that the British Admiralty wanted a boat of a certain size for a certain port, offered his vessel at a pretty stiff rate. The admiralty simply asked the name of the boat and owner from the broker and forthwith com- mandeered her, leaving the owner to speculate what rate the admiralty court will eventually award him. i ier Nil ila aaa hala kis ial a ig ot eet ah ¥