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THE HONGKONG WEEKLY PRESS AND
in front that the effect of a collision is of course minimised. It is also necessary to mention that in the old days the speed of the ships was very much less than it is now, and that the ships were mostly of wood, which resists more effectively than the thin plates of steel used at the present day. A fiddle bow usually damaged only the upper part of the ship, and before the water line could be reached the force of the blow had spent itself. The ships of to-day travel at a high rate of speed; they have great dis- placement and their vertical bow is so strong and so sharp that the moment collision takes place the skin of the ship is penetrated from the gunwale to the waterline, and an immense rush of water into the vessel is the result. Let us go into the details of the collision so that we can ascertain whether any remedies can be applied to lessen the danger. I shall try to be as brief as possible, but, in order that you should better understand, let us look at the matter from every point of view. The first and best remedy which one can propose is to avoid a collision altogether, and certainly every improve ment in the rules of navigation is very im- portant, but the conditions under which seamen have to navigate are sometimes so difficult that it is perfectly certain that collisions will take place in future, notwithstanding any rules that may be proposed in order to make naviga tion as safe as possible. The second remedy is to minimise the effect of collisions, and au
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[January 30, 1896.
trustworthy in this respect. If the collision Is there not a striking difference in the result of takes place upon one of the main bulkheads, the two cases I have just mentioned? While two compartments are filled with water. In in one case the ships continued their practice order to avoid this I propose that each main as if nothing had happened, in the other the bulkhead should be supplied with extra small damage was very great and if the Elbe had watertight compartments at the side of the been in the place of the Pamiat Azova she would ship, from ten to twelve feet wide. Then have gone to the bottom. In order to demon- the collision would only affect one bulkhead of strate the difference between touching the skin these small compartments, and the result would with a ram which is without a buffer and a ram be that instead of two big compartments being with a buffer I made some experiments a few filled with water only one big compart. weeks ago on board my flagship Emperor Nicho ment and the little one would be flooded. lai. Vice Admiral Buller, Rear-Admiral Hoff. The fourth remedy for preserving the safety of mann, Commodore Boyes, and many captains the ship consists of a means whereby leaking were invited to witness them. A model re- may be stopped. Twenty-five years ago I pro- presenting a ramming vessel was moved by a posed the use of collision inats; one of them was weight so as to ram a model which repre- exhibited at the Vienna Exhibition and every sented the amidship section of a ship. A small mau-of-war of every nation has themhow. Lately buffer of a quarter of an inch thickness of I have improved this apparatus, but although cotton cloth was made which could be adjusted they are invaluable on men-of-war I do not
to the ram. When the blow was dealt without think they will be ever accepted for inerchant the buffer the ram easily penetrated the skin ships, because in order to use them to advantage of the other model and the ramming vessel the crew must be regularly drilled. I do not made an inroad of three-quarters of an inch, say the mats are useless for commercial ships, and cut a hole two inches in length, which in but there are now more important improve. reality means eight feet. When a similar ex- ments which have prior claims toļour attention. periment was made with the buffer on the ram Now I returu to the second remedy. The gen- an inroad of only a quarter of inch was sufficient eral opinion is that the colliding blow is so very to arrest the progress of the vessel, and the powerful that nothing can minimise the effect skin was only slightly bent and not penetrated. of it; but I can give proofs that even when the This experiment is analogous with what hap- force of the blow is comparatively slight the pened in the two before-mentioned cases. It skin of the ship is penetratel. It is a matter shows that the model experiments, if properly this point I shall speak afterwards in detail. of fact that the vertical stem acts as a knife carried out. are very useful in testing the The third remedy is to have watertight bulk- and that very little energy is required to pene application of new improvements. Does it heads, so well disposed and so strongly built trate the skin of the ship which is run into. not also show that something can be done that they should localize the inflow of water. We know, for instance, that the Cruthie, the to minimise the effect of collision? What It was at the beginning of my service that I steamer which sank the big ocean liner Elbe, is the reason, then, that up to now nothing has commenced to study this question, and some- was of very small dimensious, and struck when been done to minimise the effect of collision ? thing was done in the Russian navy to make she was going at a very moderate gate of speed. We see improvements in every branch of ship- the bulkheads more efficient. I shall not trouble Everybody knows that the Elbe went to the building. Why, then, is such an important you with the details of this most important bottom in a very short space of thue aud only item as this left without due attention? There branch of shipbuilding. but I venture to lay a few of the passengers and crew were saved. is something which interferes with this most before you one single proposition which, in my I was a witness of a similar case in the Bos- necessary improvement. I believe I shall not opinion, will produce a great improvement in pherus. A Russian steamier, Azore, touched hurt anybody's feelings if I say that the main this matter. I wish to draw your attention to à big French mail steamer, the Porence.
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reason why ships are not improved in this way the fact that everything on board a ship is tested speed of the Azore at the moment of collision is the false supposition that they cannot be before she is taken from the hands of the ship was not more than two or three knots, but her improved. I believe this is really due to pre- builder. Capstans, radder. engines, cranes, stem made a hole in the skin of the Provence, judice; at any rate no scientist has yet proved winches-everything in fact is fosted in order and the latter immediately went to the bottom. this supposition. It is everybody's fault that to ensure that the whole of the fittings are quite. I may give another example which occurred less this prejudice exists. Quand tout le monde a tort sound and capable of performing the work they thau'a year ago, also in my presence, in the tout le monde a raison. Where there is a are meant for. Watertight bulkheads are PI. harbour of Chefoo, when a forpolo catcher of prejudice there is no progress, and the first cluded from this examination. If you ask a ship. 480 tons displacement aud of a very light thing that we have to do is to remove the builder if he tried the bulkheads he will answer construction touched the cruiser Pamiot Actre ulice. As soon as we believe that ships can Yes; and he is perfectly right, hause he and although the stem of the torpedo catcher | be improved in the desired way they will is obliged to test them with the fire hose. If. was of very delicate construction the hole be improved in & very short time.
after collision, bulkheads were not subjected to a more severe trial of their strength, then of course it would be all right, but unfortunately, when a compartment is filled with water the pressure which the bulkhead is subjected to is very heavy, and I think the only way to be absolutely certain of the strength of the bulk- heads is to try them under similar conditions to those in which they will be after the com- partment is filled with water. Allow me to give you an example. Now only few manu- facturers know how to make guns strong enough to resist the immense pressure of powder, and nobody dare wake with inferior metal for the simple reason that every gun is put to a very severe trial before it is taken from the hands of the makers. If this condition were not insisted upon anybody could make a gun which would resemble the very best specimen, but it is certain that the first time the gnu was fired it would be blown to pisces. If we cannot accept guns, capstans, winches, &c., without trial, why then do we accept bulkheads without trial? I propose that when a ship has been fitted with eugines, boilers, watertight doors. and everything else which canunt he damaged by water, # trial of the bulkheads should take place by filling the compartments with fresh water to the upper part of the bulkheads. This trial ought to be made in. the presence of competent officials. who should certify that the bulkheads are strong enough to with stand the full pressure of water, and that they are watertight. This trial over, the ldiers, cylinders, pipes., &c., can then be covered with the usual non-conducting composition and the cabin fittings put in their proper place. Probably all this work will occupy a week or so. but the loss of time will bo amply compensated ofr by the ship being guaranteed absolutely
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made was big enough to permit of the entrance of a fall man. Had there been no belt of armour at the waterline an immense rush of water into the vessel would have followed, It is a known fact that two years ago a torpedo boat of 70 tons displacement went into a mán- of war and the skin of the latter was penetrated. I believe the examples which I have given are sufficient to prove that, however slight the blow is. the skin of the ship collided with is of a certainty damaged, and a rush of water follows. It is believed that nothing can be done to minimise the effect of collisions because the blows are so very heavy, but this loes not mean that nothing can be done in case of only a slight shock. I may give an example which will prove that two ships may collide without damage being sustained by either. Thirty years ago Admiral Boutakoff wished to give his captains the opportunity of ramming exercise. Two gun hoats of 300 tons were employed for this purpose, and each boat was entirely surrounded by a huge fender two feet in diameter, made of very light trees and branches hound firmly together so as to present a yielding shield. This protection was sufficient to preserve the one vessel intact when rammed by the other. It is true that the speed of the ressels was never higher than six knots, but I saw myself that the concussion at the moment of ramming was so great that not one of the men on board could keep his feet This proves that from the moment one ship touched the other to the moment when the vessel was stopped the colliding ship made a progress of may be only one foot. But in the case of the Pamiat Azord the crew of (Le torpedo cafeler were not in the least affected by the force of the blow. This shows that the resistance of the ship's side when the skin is penetrated is very small in comparison with the resistance of the skin before penetration.
It is taken for granted that the energy of a blow which is developed by one ship striking another is so very great that no means can be devised to absorb it without injuring the ship's skin. Let us see if this is so. A big ironclad of 10,000 tons ramming at five knots speed gives a striking blow of 15,000 foot tons, while the muzzle energy of one 12-inch projectile is 20,000 foot tons. You know very well when you propel the projectile with this energy one way the gun and the carriage are thrown with the very same energy into the opposite direction. Should no- thing be arranged to withstand this blow a lot of damage would necessarily follow. But hydraulic buffers easily absorb this energy in a space of two feet, and really the shock is scarcely felt on board the ship. If it was a question of absorbing the energy of the big ironclad striking perpendicularly on some firm solid block strong enough to receive that blow, then an ordinary 12-inch gun's buffer fixed on the ram would take the whole energy of the 10,000 ton ship striking at the speed of five knots. This example shows that the energy of the blow is not so very enormous. Generally speaking a collision never occurs when the boats are going full speed. Engines are always reversed before the collision takes place and that diminishes the speed consider- ably. Experiments show us that if the big- gest ship in the world was going at full speed ahead she could be brought to rest three minutes after the engines are reversed from full speed ahead to full speed astern. I have pointed out that the skin of the ship struck is penetrated because of the hatchet like action of the stem of the striking vessel. Should the fore part of the ship be flat the skin of the ship collided with would be battered in, but not broken. The effect of the collision would be damage more or less serious, but there would be
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