Battles with the Sea, R. M. Ballantyne [ereader iphone txt] 📗

overturned. The crew meanwhile having on lifebelts, floated and swam to the boat, caught hold of the life-lines festooned round her sides, clambered into her, cut the cable, and returned to the shore in safety! What more need be said in favour of the self-righting boats?

The self-emptying principle is quite equal to the self-righting in importance.

In every case of putting off to a wreck in a gale, a lifeboat ships a great deal of water. In most cases she fills more than once. Frequently she is overwhelmed by tons of water by every sea. A boat full of water cannot advance, therefore baling becomes necessary; but baling, besides being very exhausting work, is so slow that it would be useless labour in most cases. Besides, when men have to bale they cannot give that undivided attention to the oars which is needful. To overcome this difficulty the self-emptying plan was devised.

As, I doubt not, the reader is now sufficiently interested to ask the questions, How are self-righting and self-emptying accomplished? I will try to throw some light on these subjects.

First, as to self-righting. You are aware, no doubt, that the buoyancy of our lifeboat is due chiefly to large air-cases at the ends, and all round the sides from stem to stern. The accompanying drawing and diagrams will aid us in the description. On the opposite page you have a portrait of, let us say, a thirty-three feet, ten-oared lifeboat, of the Royal National Lifeboat Institution, on its transporting carriage, ready for launching, and, on page 95, two diagrams representing respectively a section and a deck view of the same (Figures 1, 2, and 3).

The breadth of this boat is eight feet; its stowage-room sufficient for thirty passengers, besides its crew of twelve men—forty-two in all. It is double-banked; that is, each of its five banks, benches, or thwarts, accommodates two rowers sitting side by side. The lines festooned round the side dip into the water, so that anyone swimming alongside may easily grasp them, and in the middle part of the boat—just where the large wheels come in the engraving—two of the lines are longer than the others, so that a man might use them as stirrups, and thus be enabled to clamber into the boat even without assistance. The rudder descends considerably below the keel—to give it more power—and has to be raised when the boat is being launched.

The shaded parts of the diagrams show the position and form of the air-cases which prevent a lifeboat from sinking. The white oblong space in Figure 2 is the free space available for crew and passengers. In Figure 3 is seen the depth to which the air-chambers descend, and the height to which the bow and stern-chambers rise.

It is to these large air-chambers in bow and stern, coupled with great sheer—or rise fore and aft—of gunwale, and a very heavy keel, that the boat owes its self-righting power. The two air-chambers are rounded on the top. Now, it is obvious that if you were to take a model of such a boat, turn it upside down on a table, and try to make it rest on its two rounded air-chambers, you would encounter as much difficulty as did the friends of Columbus when they sought to make an egg stand on its end. The boat would infallibly fall to one side or the other. In the water the tendency is precisely the same, and that tendency is increased by the heavy iron keel, which drags the boat violently round to its right position.

The self-righting principle was discovered—at all events for the first time exhibited—at the end of last century, by the Reverend James Bremner, of Orkney. He first suggested in the year 1792 that an ordinary boat might be made self-righting by placing two watertight casks in the head and sternsheets of it, and fastening three hundredweight of iron to the keel. Afterwards he tried the experiment at Leith, and with such success that in 1810 the Society of Arts voted him a silver medal and twenty guineas. But nothing further was done until half a century later, when twenty out of twenty-four pilots lost their lives by the upsetting of the non-self-righting Shields lifeboat.

Then (1850) the late Duke of Northumberland offered a prize of 100 guineas for the best lifeboat that could be produced. No fewer than 280 models and drawings were sent in, and the plans, specifications, and descriptions of these formed five folio manuscript volumes! The various models were in the shape of pontoons, catamarans or rafts, north-country cobles, and ordinary boats, slightly modified. The committee appointed to decide on their respective merits had a difficult task to perform. After six months’ careful, patient investigation and experiment, they awarded the prize to Mr James Beeching, of Great Yarmouth. Beeching’s boat, although the best, was not, however, deemed perfect.

The committee therefore set Mr James Peake, one of their number, and assistant master-shipwright at Woolwich Dockyard, to incorporate as many as possible of the good qualities of all the other models with Beeching’s boat. From time to time various important improvements have been made, and the result is the present magnificent boat of the Institution, by means of which hundreds of lives are saved every year.

The self-discharge of water from a lifeboat is not so easy to explain. It will be the more readily comprehended if the reader understands, and will bear in remembrance, the physical fact that water will, and must, find its level. That is—no portion of water, small or great, in tub, pond, or sea, can for a moment remain above its flat and level surface, except when forced into motion, or commotion. Left to itself it infallibly flattens out, becomes calm, lies still in the lowest attainable position—in other words, finds its level. Bearing this in mind, let us look again at Figure 3.

The dotted double line about the middle of the boat, extending from stem to stern, represents the floor of the boat, on which the men’s feet rest when standing or sitting in it. It also represents, or very nearly so, the waterline outside, that is, the depth to which the boat will sink when afloat, manned and loaded. Therefore, the boat’s floor and the ocean surface are on the same level. Observe that! The space between the floor and the keel is filled up with cork or other ballast. Now, there are six large holes in the boat’s floor—each hole six inches in diameter—into which are fitted six metal tubes, which pass down by the side of the cork ballast, and right through the bottom of the boat itself; thus making six large openings into the sea.

“But hallo!” you exclaim, “won’t the water from below rush up through these holes and fill the boat?”

It will indeed rush up into these holes, but it will not fill the boat because it will have found its level—the level of ocean—on reaching the floor. Well, besides having reached its level, the water in the tubes has reached six valves, which will open downwards to let water out, but which won’t open upwards to let it in. Now, suppose a huge billow topples into the boat and fills it quite full, is it not obvious that all the water in the boat stands above the ocean’s level—being above the boat’s floor? Like a wise element, it immediately seeks its own level by the only mode of egress—the discharging tubes; and when it has found its level, it has also found the floor of the boat. In other words, it is all gone! moreover, it rushes out so violently that a lifeboat, filled to overflowing, frees itself, as I have already said, in less than one minute!

The buoyancy, therefore, of a lifeboat is not affected for more than a few seconds by the tons of water which occasionally and frequently break into her. To prove this, let me refer you again to the account of the Constance, given by its gallant coxswain, as recorded in the third chapter. He speaks of the lifeboat being “buried,” “sunk” by the wave that burst over the bow of the Stanley, and “immediately,” he adds, “the men made a grasp for the spare oars!” There is no such remark as “when we recovered ourselves,” etcetera. The sinking and leaping to the surface were evidently the work of a few seconds; and this is indeed the case, for when the force that sinks a lifeboat is removed, she rises that instant to the surface like a cork, and when she tumbles over she recovers herself with the agility of an acrobat!

The transporting-carriage is a most essential part of a lifeboat establishment, because wrecks frequently take place at some distance from a station, and prompt assistance is of the utmost importance in all cases of rescue. It is drawn by horses, and, with its exceedingly broad and strong wheels, can be dragged over any kind of road or across soft sand. It is always backed into the surf so deep that the boat may be launched from it, with her crew seated, and the oars out, ready to pull with might and main the instant the plunge is made. These first strokes of a lifeboat’s crew are of immense importance. Want of union or energy on the part of steersman or crew at this critical point may be fatal. The boat must be made to cut the breakers end-on, so as to prevent her turning broadside on and being rolled back on the beach. Even after these initial strokes have been made successfully, there still remains the possibility of an unusually monstrous wave hurling the boat back end over end.

The boat resting on its carriage on the sands (Figure 1) shows the relative position of the two. It will be seen, from that position, that a very slight tip will suffice to cause the bow of the boat to drop towards the sea. As its keel rests on rollers, comparatively little force is required to launch it. Such force is applied by means of ropes attached to the stern, passing through pulleys at the outer end of the carriage, so that people on shore haul the ropes inland in order to force the boat off its carriage seaward.

Once the boat has got fairly over the surf and out upon the wild sea, her progress is comparatively safe, simple tugging against wind and sea being all that has to be done until the wreck is reached, where dangers of another kind await her.

I have now shown that the great qualities of our lifeboat are—buoyancy, or a tendency not to sink; self-righting power, or inability to remain upside down; self-emptying power, or a capacity to discharge any water that may get into it; and stability, or a tendency not to upset. The last quality I shall refer to, though by no means the least, is strength.

From what has been already written about lifeboats being hurled against wrecks and rocks, it must be evident that the strength of ordinary boats would not suffice.

In order to give them the requisite strength of frame for their tremendous warfare, they are built of the best Honduras mahogany, on what is known as the diagonal plan—that is, the boat has two distinct “skins” of planking, one set of planks being laid on in a diagonal position to the others. Moreover, these planks run from one gunwale round under the boat to the other gunwale, and have a complete layer of prepared canvas between them. Thus great strength and elasticity are combined, so that the boat can stand an inconceivable amount of battering on wreckage, rocks, or sand, without being destroyed.

That this is really so I will endeavour to prove by referring in the next chapter to a particular instance in which the great strength of one of our lifeboats was powerfully illustrated.

It may be added, in conclusion, that the oars of a lifeboat are short, and so made as to