The Ships of Tarshish
Chapter XXIII. Descriptive and Dry, and may be Skipped
Chapter XXIII. Descriptive and Dry, and may be Skipped.
The two victors backed out, and were soon proceeding on their triumphant return. The tip-top and sub-tip-top military and naval officers, with Lord Malmsey Butt, were in the highest of spirits. With what different feelings did they commence their return journey to those with which they had started in the morning. As for Mandevil, he appeared like a prince among them, as they crowded round him with respectful compliments. Yes—Mandevil, calm and silent under the reaction after his late excitement, was being played second fiddle to by all these tip-top men, and by Lord Malmsey Butt, who had once watched him out of his office.
But as to Norval, who can describe his feelings? How he pitied himself as he thought of his pity for Mandevil. And yet he felt a pride when he thought how he had at once singled him out for admiration when he first saw him. Now, he thought he should never be able to venture upon his old familiar tone with him again, and felt inexpressibly gratified when Mandevil, as soon as he could escape from his distinguished party, came up to him, and, perceiving his humble countenance, slapped him on the back, as he drew him and Box to a retired spot, where they conversed in the old manner.
They were to proceed on an expedition that night. The Defence and Vindicator were run into their old inclosure, for the purpose of being fitted with some additional necessary adjuncts in connection with their next employment. While this was being done, Mandevil, with Box and Norval, remained at the Tarshish works, in a residence which he had there, and where he also entertained the tip-top naval officer and Lord Malmsey Butt, who had expressed their eager desire to accompany the expedition and watch the progress of events. Of course their conversation that evening almost entirely had reference to the day's work, and the wonderful "ships of Tarshish" by means of which it had been accomplished.page 94
The naval officer (as well as his lordship) was loud in commendation of the skilful manner in which the vessels had been handled, and also of the plan of battle.
"What does your lordship think of my new artillery and new projectiles?" asked Mandevil.
"First rate!" said his lordship. "One cannot fail to see that it will form an important element in all future harbour and coast naval warfare. As with Columbus and the egg, it is ridiculously simple when once practically indicated. All the events of to-day's fight have been a fresh exemplification of the saying that' extremes meet.' With our highest modern science, we are coming back to something like the old rude style of sea-fighting. Our rams are the old beaked ships re-introduced; while your hot oil and chemical fire are the jars of asps, and such like, of the Punic wars."
"Do you think," asked the naval officer, "that you could take your vessels a long voyage?"
"I do," answered Mandevil. "I do not say but that such voyages would be extremely tedious and uncomfortable; but the vessels are so strongly built that they would be perfectly safe. These vessels were never intended to act except along coasts and in harbours; and were that consideration alone to be kept in view, they need only cost half what these have, besides drawing considerably less water. But it was necessary to provide for all contingencies, such as being caught in a storm off a lee shore, or in offensive warfare having to cross the ocean, and for which requisite strength had to be given; and that has, as I have intimated, doubled their expense."
"Might I ask how much these two vessels have cost?" inquired Lord Malmsey Butt.
"As they now stand complete," said Mandevil, examining a memorandum, "they have cost together three millions eight hundred and sixty-five thousand four hundred and seventy-two pounds, seventeen shillings and sixpence halfpenny."
"Quite an exercise in numeration," said his lordship, laughing.
"The halfpenny be —— bothered," said Box.
"We'll make a present of it to Mr. Mantalini," said Norval.
"With all my heart," said Mandevil, "and the sixpence too, if you like."
At the united request of the party, Mandevil gave a description of his vessels, of which the following is the substance:—
Extreme length at water-line, 350 feet; extreme breadth ditto, 230 feet. The outline of section in plane of water-line an oval, being very much like that produced by the longitudinal bisection of a long-shaped egg, bluntest end foremost, with a slight sharpening of the stem. Bottom flat. Greatest breadth of bottom 220 feet. Draught of water with everything complete, except coals, 9 feet. Sides upright for 5 feet from water-line downwards. The remainder of depth rounded off to meet the flat bottom. Section of deck an elliptical arch, commencing at a foot above the water-line, when without coals (consequently commencing at more or less under the water-line when with coals), and having its crest 22 feet perpendicular height from base. Deck retiring at all points (stem and stern as well as sides), in an equal degree from the level of the water. About 80 feet of the crest (deck, lateral section) almost flat. No portion of the vessel above water presenting so steep an inclination as 45 degrees.
page 96and inner skins were screwed. (Note.—In order to procure these ribs of wood properly seasoned, all the timber-yards of the world within reach were quietly ransacked.)
The shape of the whole exterior—deck, sides, and bottom.
An inner skin of a uniform thickness of one inch.
An outer covering, of thickness varying as described.
The ribs of wood at the sides and bottom, to which the outer
And lastly, an interval of four feet between the inner and outer skins, of deck, sides, and bottom.
"And now," said Mandevil, when he had described so far, "I come to that feature in the construction of these vessels, upon which I most pride myself; namely, the manner of filling up the four-feet interval between the inner and outer skins, so as to conduce to the perfect rigidity and enormous strength required by vessels built at such utter variance, as to sea-going shape, with the old-established principles.
"Before I commenced this undertaking, I clearly saw that the limit had been pretty nearly reached in armour-carrying power, unless some new form of vessel were adopted, by which the proportion of superficial external area to Volume of the interior would be materially diminished; by these means acquiring steadiness, and above all, the essentially necessary quality of a light draught of water.
"To this form of vessel there are several objections, each of the principal of which I will take up and examine in turn. But, generally speaking, it will be found that these objections apply to the case of ocean-going ships, while these vessels are intended solely for harbour and coast fighting; and were the proof required to be thrown on the other side, to show why there should not be a class of ships exclusively for harbour and coast fighting, there would be no necessity for further argument. But as such vessels, though not intended for ocean-fighting, may sometimes be required to cross the ocean, and as they might be caught in rough weather off a coast which would be as bad or worse than in the open sea, and as traditional bias is always great, I shall go into it more at length. The objections based on mere traditional bias, I shall dispose of by mere argument; the more valid objections I shall prove, I hope, to have been overcome by novelties and specialties of construction, and, far above all, by excellence of execution. This last I imagine to be the direction in which modern enterprise must look for scope, theory having long ago been pretty well exhausted.
"The first objection I shall consider is, that of want of speed. This is an objection resulting from traditional bias nurtured in the times when sailing-vessels only were used. In the old times page 97of sailing-vessels, these broad ships would have been out of the question, for the simple reason that, after having cost so much money, they could not proceed from one harbour to another without the almost certainty of being wrecked. And this was the point upon which I imagined (and I think to-day's events have proved me right in my opinion) that the merits of steam had been overlooked, with respect to its enabling us to have a class of broad vessels solely for coast and harbour fighting.
"But to proceed with the argument. When once possessed of invulnerability, speed is not necessary for harbour-fighting. Besides which, propelling power being equal, speed only means slow turning, and quick turning is a more valuable quality than speed in contracted spaces.
"The objection of want of speed in coasting is more serious, for a ship requires speed to get off a lee-shore as much as for anything. This, I hope, has been obviated by the specialty of construction, and by the enormous propelling power possessed by these vessels. At any rate, from barometrical signs, I think we shall be able to put them to the proof to-morrow: at the same time, I have the utmost confidence. Their speed is about six knots. This I consider sufficient to carry such vessels, offering, as they do, scarcely any surface against winds or waves, off a lee-shore in any gale. Of course, only that amount of speed would be utterly vain in the case of an ordinary vessel, with its mass of rigging and high hull for winds and waves to act against. Another thing, too, has to be borne in mind. The retrograde motion caused by winds and waves is not like that produced by a current. In the last case, the whole water, with its particles, moves bodily along. To make head against each acceleration of such opposing force, the propelling power has to be increased in geometrical progression. But in the case of the retrograde motion, produced by winds and waves, the increase of propelling power required to make head against each increase of opposing force is in a much more direct proportion to the latter.
"The next last serious objection is the immense strength required by these broad vessels. In the ordinary traditionally-shaped vessel, narrow and long, strength is much more easily attained, for all the supporting parts being closer to one another, are more easily knit together. Then the shape of the hull above and below water allows the vessel to yield before the shocks of the page 98sea, and so avoid damaging strains. The weakest part of the old vessels is longitudinally, as is to be expected, because the strengthening and binding parts are at an unfavourable angle. Accordingly, it is common to hear of vessels having 'broken their backs.' How much more difficult the position to solve must be when there are two backs to break,—a lateral as well as longitudinal. These difficulties we have endeavoured to overcome chiefly by excellence of execution, and by some novelties of construction, the principal of which is the manner of filling up the four-feet interval before mentioned. Whether we have overcome the difficulty, will most likely be proved to-morrow; but, I must say, I have no fear in the mean time. The interval, then, of four feet between the inner and outer skins is filled by steel hexagons of a least diameter of 18 inches. These hexagons are united side by side to one another, each by several screws. The four-feet interval is thus something like a honeycomb. The ends of the hexagons abut on to the inner and outer skins, each individual end carefully shaped to coincide with the rounding of their (the skins') surface. These abutting ends are secured to the plates in this manner:—From the end of each hexagon, running down the middle of each of its sides, a half-cylindrical hollow is indented in the making. Then the hexagons being firmly screwed together, and the sides of each opposite half-hollow coinciding, a hole is produced, in which a female screw is formed. All the screws used in the vessel have tapering heads accurately turned, and the corresponding holes in the plates are accurately drilled to fit them. Each screw is screwed in till it wedges itself tight. The head is then cut off flush. This sort of method stands jarring better than nuts and bolts. Besides the purpose of strengthening, this system of hexagons serves to localize and detect leaks. A thin sheet of gutta-percha being placed between the skins and the abutting ends, keeps the uninjured parts water-tight. On the inside a small perforation is made, opposite the bottom of each hexagon, for the purpose of detecting leaks. Except at the sides (where the thicknesses vary, some reaching to three-quarters of an inch), the steel hexagons have a uniform thickness of a quarter of an inch. In addition to this system of hexagons, which conduces so greatly to the strength and rigidity of the ship, we have in various directions steel tubular girders and braces of a large diameter.
"I have now," continued Mandevil, "told you of the principal page 99peculiarities of construction which occur to me. When our vessels get into the open sea, they don't rise to the waves like ordinary vessels, but the water breaks over them, like it would over a large raft. "There is one objection I have not thought worth considering, —though I did consider it before commencing the enterprise,—namely, the expense of these vessels. I thought, what is the good of frittering away two millions on half a dozen inefficient vessels, when, spent on one, it may be the means of averting an evil fate from a kingdom to whom the spending of a couple of millions is like the loss of a drop oat of a bucket."