LIFEBOAT MAGAZINE ARCHIVE

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Lecture on Life-Boats

I.—Preliminary Remarks, IN a country bounded on all sides by the sea, whose earliest associations are connected with it, through the medium of which it has derived its civilization, its wealth, its grand political status, and probably to a great extent the energy, enterprise, and indomitable spirit of its inhabitants;— in a country whose almost innumerable ships ceaselessly traverse every sea, and are harboured in well-nigh every port on the globe we inhabit! —and, above all, in a country whose shores in every winter's storm are strewn with the wrecks of its ships and the corpses of its sailors;—in such a country it may well be presumed that an instrument devised to save the helpless castaway from an untimely end will be an object of general interest.

Such an instrument is a life-boat! I feel therefore under no other embarrassment in offering some explanations on its character and specialities than that which arises from the fear lest I should not do justice to so important a subject.

I propose, successively, to explain the general principles on which life-boats are constructed as compared with other boats—the peculiar properties of the principal descriptions of life-boats now in use on the coasts of the United Kingdom— the character of their equipment—and the system under which they are provided and managed in this country, especially those belonging to that noble institution to which I have the privilege and happiness to be attached—the NATIONAL LIFE-BOAT INSTITUTION.

II.—Distinctions between Ordinary Soots and Lifeboats.

—Properties of Life-boats: Extra buoyancy, telf-discharge of water, stability, self-righting, internal capacity, speed, weight, strength of build, material, §*e.

Although the word life-boat has not in itself any definite meaning, it is pretty generally understood as signifying a boat especially constructed for saving lives in storms and heavy seas, when ordinary open boats could not attempt to do so except at the imminent peril or certain destruction of those within them.

What, then, are the causes which make ordinary open boats unsafe in rough seas? And in what manner are those causes removed in life-boats? The principal causes of a common open boat being unsafe in a heavy broken sea are, its liability to fill with water and swamp from a wave breaking into it or by its upsetting, and loss of stability from all water within it falling to one side with every motion of the boat. It is therefore obvious that the chief requirement of a life- * Delivered by Capt. J. R. WAED, R.N., at the Royal United Service Institution, Jan. Uth, 1862.

boat is the counteraction, as far as possible, of these defects.

Extra Buoyancy.—The first essential property, then, in a life-boat is what is termed extra buoyancy ; which property is in a greater or less degree common to all life-boats, excepting to some of the so-called life-boats which, to meet the requirement of a loosely-worded clause in an Act of Parliament, are placed on the decks or hoisted up to the sides of many of our merchant vessels- Extra buoyancy may intelligibly be defined as the excess of floating property in any body immersed in a fluid, the expression of which in pounds indicates the number of pounds' weight of any other body that it is capable of floating in addition to itself. Thus a log of fir timber, the specific gravity of which wood is about half that of water, will float with only half its-body immersed, the remaining half representing its extra buoyancy. A piece of dry fir wood has therefore extra buoyancy about equivalent to its own weight.

This important property in a life-boat should be sufficient in amount to enable it to be loaded with people, and nearly filled with water, without its then being so deeply immersed as to be unmanageable.

Extra buoyancy in all our coast life-boats is now chiefly obtained by occupying a sufficient portion of the interior with enclosed water-tight compartments or boxes. These compartments, by being placed along the sides of a boat, and at its extreme ends, are made to serve the further purpose of adding to stability, by confining all water that may be shipped to the central part of the boat, where it is in some boats made to perform the office of ballast.

The mode in which this property is applied to the different descriptions of life-boats will be best explained by diagrams and models.

In Plate I., representing transverse sections of the five principal descriptions of life-boats in use in this country, the air-tight compartments which form the extra buoyancy are marked A.

It will be observed that in figs. 1, 2, and 3, this extra buoyancy occupies a large portion of the interior of the several boats, so that if filled with water they would evidently still float buoyantly; whilst fig. 4 represents a section of a tubular boat, which, having no interior corresponding with that of an ordinary-shaped boat, can contain no water.

Fig. 5 is a section of one of WHITE'S ship's lifeboats.

It has not so much extra buoyancy as figs. 1,2, and 3, but has sufficient for an ordinary ship's life-boat.

By the proper application of this principle, we have then not only an insubmergiblc boat, but the possession of other valuable properties, which are so mingled with it as to make it difficult to separate the one from the other. Thus, as in figs. 1, 2,Ely. 1 311 g . 4 .

PI. a.

3, and 5, by occupying the interior space along the sides of a boat -with air-tight compartments, the water within her is, in varying degrees, prevented from falling over to the lower side; and lateral stability in a rough sea is thereby much increased.

Again, as shown in figs. 1 and 3, by placing the greater part of the extra buoyancy beneath a water-tight deck, means are provided for self-discharge of all water falling into the boat above the deck, through the instrumentality of connecting tubes between that part and the open sea below.

And again, as in fig. 2, by attaching large buoyant wales, or fenders, or pads, as they are variously termed, round the exterior sides of a boat, both lateral buoyancy and resistance to sudden heeling over, and thereby lateral stability, are increased.

Lastly, by occupying the extremities at bow and stern with enclosed air-compartments, the properties of self-righting and longitudinal stability are provided.

Self-discharge of Water.—Since, however, notwithstanding great extra buoyancy, it would be inconvenient and unsafe for so large a quantity of water to remain in a boat as often falls into one from a single broken sea or surf, another requisite property is at once apparent, viz., that of self-discharge or self-relief of water. Indeed, without this property, the full advantage of that of extra buoyancy is not realized, as without it all water breaking into a boat must remain in her, and become a shifting cargo, settling more or less on one side or at one end with her every motion.

Having then already the property of extra buoyancy, nothing more is needed, in order to effect the self-discharge of all water above the level of the outside sea, than to have a sufficient number of open holes in the bottom of the boat. Through such openings, all water shipped from above must then pass out by its own gravitation, until lowered to the outside level.

In some descriptions of life-boats, as in figs. 1 and 3, self-relief of water is total, unless they are very heavily laden with passengers or other weights; in others, as in fig. 2, it is only partial, a large quantity of water below the outside level remaining in the central part of the boat, where it serves as ballast.

In figs. 1 and 3, the watertight deck before alluded to, which is there shown by the line B, forms the inside floor of the boat; it is laid with considerable sheer,—i.e., curved upwards at bow and stern, so that all water over it should settle to its central part. Between this central part of the deck and the floor of the boat below, passing through the intermediate space, tubes of metal are fixed, varying in size and number in different boats, and open at both ends; thus opening passages between the space above the deck and the sea below the boat, but excluding all communication with the space between the deck and the floor —just as a chimney open at both ends passes from a ground-floor to the exterior of a building above the roof through intermediate apartments, whilst excluding communication with them.

These tubes vary in size, from three to six inches in diameter. The smaller they are, the more are required. As a single wave breaking into a boat will often fill her to the thwarts, there should be a sufficient number of relieving tubes to clear her of that quantity in twenty or thirty seconds. These relieving tubes in all the old classes of boats, as above stated, are open at both ends, and therefore freely admit the ingress of water from below, as of its egress through them from above. To remedy this defect, which is not an unimportant one in some boats, an ingenious self-acting valve has been invented, which valves are fitted in all the life-boats on the plan of the NATIONAL LIFE-BOAT INSTITUTION. It is a simple plate, fitting the tube at its upper end, and made to turn on an axis on one side of its centre, as does an eccentric wheel. It is so balanced as of itself to remain shut, and on the slightest pressure of water from below, to shut still closer, whilst, on water falling on it from above, the pressure on the larger division of the plate, being necessarily greater than on the smaller, opens it downwards.

Valves, unless self-acting, and of very simple construction, are objectionable; but these are found to answer admirably, and some which have been ten years in use are still efficient, and have never got out of order.

In the Norfolk and Suffolk water-ballasted lifeboats, fig. 2, Plates I. and II., which have no decks, there are merely holes in the floor, with large plugs to them. There are two of these holes, with corresponding plugs, at every thwart. The plugs have long handles, similar to those of common spades, so that the men sitting on the thwarts can insert or withdraw them at pleasure. Being large, powerful sailing boats, and very heavy, it is a great convenience to be able to handle them on the shore without the weight of the larger portion of their ballast: they are therefore launched empty; but as soon as they are clear of the beach, and before entering the heavier part of the surf, the plugs are withdrawn, and the water admitted until it rises to the outside level. The water thus let in varies in amount from four to seven tons in different boats.' Through the open holes, the water within, after a sea being shipped, will alwayssubside to the level of the outside water, all below that level remaining as a constant quantity. In some life-boats, as in fig. 5, and in all other ships' life-boats now in use, no provision is made for the relief of water except by baling. It must be acknowledged that all such boats are without one of the most requisite qualities of a good lifeboat.

In the tubular life-boat, fig. 4, it will be seen that this property is attained in the greatest perfection, as, having no open interior, no water can lodge within her.

Stability.—The next quality of essential importance is lateral stability, or resistance to upsetting sideways. Stability may be obtained by three modes:—1st. By great breadth of beam; 2nd. By occupying the interior with air cases, as described already, in such a manner as to leave no space for water to remain in the interior, into whatever position the boat may be thrown, or to so confiue it to her central part that it cannot fall much to one side above the centre of buoyancy; 3rd.

By ballast. There is a limit to the application of each of these modes, which requires careful consideration.—1st. Great breadth of beam, in proportion to length, is a certain mode of securing great stability, but it adds to weight, above the centre of buoyancy, and by increasing the area of the " midship section," entails loss of speed, requiring proportionally greater propelling power.

It also prevents the application of another important property—that of self-righting in the event of being upset.

The widest rowing life-boats are those of the north country, or Greathead plan (fig. 1, Plate !•), some of which have 10 J and 11 feet beam to 30 feet length. The Norfolk and Suffolk boats (fig. 2) have also great beam, the largest having 12 feet to 46 feet length; they are, however, exclusively sailing-boats.

In sailing-boats, increase of beam can be very well given, as greater power of propulsion can be obtained by enlarged sails; but in rowing-boats this power can only be had by using longer oars, with two men to each, which thereby incurs the risk of an unnecessary number of lives. In one of such boats twenty-two men out of a crew of twenty-four perished at Shields by her being upset in the year 1850.

2nd. A most valuable means of adding to the stability of a life-boat, as intimated under the last heading, is by occupying its sides with buoyant cases. By an examination of Plate II., the relative properties of different life-boats in this respect will be readily perceived. It will be noticed that the north country life-boat (fig. 1) is possessed of this property to the fullest extent; as, if thrown over with one gunwale to the water's edge, there will only be space for a very small quantity of water to lie in her at the level of the outside sea, and that little but slightly on one side of the centre of gravity.

The continuation of the side air-cases to the gunwales, as in those boats, is, however, in another respect detrimental, by occupying space which is valuable for the stowage of wrecked persons.

In fig. 2, a greater quantity of water is retained, but the larger portion of it is on the windward or higher side of the centre of buoyancy, where it serves the purpose of ballast, and thereby adds to the stability of the boat.

In fig. 3 there is space for a larger quantity of water, some sacrifice of this important quality being made, to enable the scarcely less valuable property of self-righting to .be brought into play, which great side buoyancy, placed high, would prevent.

In fig. 4 it is evident that no water can remain in any position.

In fig. 5 a large quantity of water might lie on one side of the centre of buoyancy, but the loss of stability arising therefrom is counteracted by large side buoyancy, placed high.

Ballast.—There remains the third principle of stability—ballast. Ballast may be either solid or liquid. Solid ballast is most frequently applied in the shape of an iron keel, in which position, at the lowest part of a boat, it acts with the most powerful leverage. Iron keels in life-boats vary from 3 to 17 cwjt. Ballast formed of wood, and of cork enclosed in water-tight cases, is also used in the self-righting life-boats of the NATIONAL LIFEBOAT INSTITUTION, of nearly equal weight to the iron keel. Thus a 10-oared boat 32 feet long has an iron keel of 9 cwt. and nearly the same weight of wood, or of cases of cork stowed beneath the deck.

It is difficult to gome persons to imagine that wood or cork can partake of the nature of ballast.

In fact, however, any substance heavier than air may be used as ballast, a pound of cork being as as much ballast as a pound of iron or lead. The advantage of employing a ballast of less specific gravity than water is, that in the event of a boat being stove in and the spaces below the deck filling with water, the extra-buoyancy of the material then comes into play, and prevents the boat from becoming so deeply immersed as to become unmanageable.

In February, 1858, the NATIONAL LIFE-BOAT INSTITUTION'S life-boat at Tonghal, in County Cork, in launching, got stove on a rock, and a hole was made in her floor as large as a man's head: she became at once much more deeply immersed, and the water rose to five or six inches above her deck, the spaces beneath it having filled with water; nevertheless she proceeded on her mission of mercy; her gallant crew rowed her two miles to a wrecked Austrian ship, and in the midst of a very high surf which frequently broke over and filled her, she took fourteen men from off the vessel's bowsprit and conveyed them safely to the land: had all her ballast been of metal, she would undoubtedly have become so deeply immersed after being stove, that she could not have proceeded to the wreck, and all those poor men would have perished.

As, however, a large quantity of fixed ballast causes great extra labour and difficulty in land transport and launching, water-ballast is occasionally employed. It is sometimes enclosed in water-tight tanks, but more frequently, as in the Norfolk and Suffolk boats, is unconfined.

In consequence of the liability of enclosed tanks to leak from decay or injury, and of the water thereby spreading over the whole floor of the boat, water-ballast has been discontinued in most rowing life-boats. I am however of opinion that, if properly applied and secured, it would be free from any risk, and might often be employed with much advantage.

With the exception of three or four of the old boats on the north country plan, which still retain water-tanks, the only boats in the United Kingdom now ballasted with water are the Norfolk and Suffolk boats, fig. 2, already alluded to.

These latter boats deserve especial notice. They are only eleven in number, nine of them being exclusively sailing-boats varying from 39 to 46 feet in length, and from 10} to 12 feet in breadth.

As they are unmanageable in a heavy sea under oars, and as they have often to work to windward against the heaviest gales to the rescue of the crews of vessels wrecked on the numerous outlying banks which exist off that part of the coast, it is indispensable that they should be heavily ballasted, and have considerable draught of water, to give them good weatherly qualities. In order, then, to make this requisite provision, without involving too much weight for convenient launching, they are provided with water-ballast, in addition to having iron keels. This water is let in by the same apertures that serve for self-relief of water, the plugs which close them not being withdrawn until the boat has got off the beach. The water thus let in is of very large amount, being in the largest boat of this class not less than seven tons—which water is not retained in an enclosed tank, but left to fill every unoccupied space up to the level of the plane of flotation. By the representation of a cross-section of one of these boats in fig. 3, Plate I., it will be seen that this unoccupied space is chiefly confined to a narrow channel of about one-third of the boat's width.

Cross air-cases at bow and stern, to the level of the thwarts, also confine it lengthwise. The average area of these channels is about 20 feet long by 4 feet wide, in which the water lies to an average depth of 2J feet, in amount equal to about 200 cubic feet, or 5f tons.

A great quantity of water also settles between the large timbers of these boats, beneath the side and end air-cases, which cases are moveable separate boxes, and cannot be made to fit so closely as to fill up those spaces. These boats have also iron keels varying from 12 to 17 cwt.

At first thought it would appear highly dangerous to have so large a quantity of water loose within a boat: the truth is, however, that the safety of the principle consists in the largeness of the quantity, taken together with the circumstance of its being cut off from access to the ends and sides of the boat. If these boats were less heavily ballasted, they would be more lively, rising and .falling with every motion of the sea, and the water within them would be constantly in motion towards the lowest level; but thus heavily weighted and propelled by powerful sails, they cut deeply through every sea instead of rising to it—they, in nautical phraseology, make much worse weather of it than a lighter and a more lively boat would do; heavy bodies of " green sea " break over them so as sometimes to altogether submerge their crews, and to hurl them from one end of the boat to the other, but their stability is so great that fee boatmen have unbounded confidence in them; and they are protected against being washed overboard by * ridge ropes " rove through iron stanchions round the boat, fixed in the gunwales.

The only boat of this doss which lias ever upset was the Southwold life-boat in February, 1858, the then most recently-constructed beat of the class. She was taken out, through a rather high surf, for the quarterly exercise of her crew. On returning to shore, before entering the surf, the crew injudiciously inserted the plugs and pumped out about two-thirds of the water ballast. They then ran her under sail, with too much way, into the surf, when, a sea overtaking her, threw her stern up; the ton and a half of water still in her then rushed to the bow, which became completely submerged, and, broaching-to across the surf, she immediately upset. Her masts broke off on eoming in contact with the ground, and not being a self-righting boat, she remained keel up. Her crew of 15 men, all having on their life-belts, in accordance with the rules of the NATIONAL LIFEBOAT INSTITUTION, were saved; but three gentlemen —who had gone off as amateurs, and had refused to put on life-belts which had been offered to them—were drowned, although one at least of them was known to be a good swimmer. Had this boat been full ballasted, the sea would probably have broken over the stern instead of lifting it, and the accident would not then have occurred.

In this life-boat—in consequence of the crew having withdrawn their confidence from her after the accident, and as they also thought she floated too deeply in the water—the water-ballast channel was at my suggestion filled in with portable solid blocks of fir timber up to the level of the former water-ballast, she being thus provided with fixed ballast of half the weight of the former water.

Since that alteration she has given every satisfaction to her crew. I have thought this circumstance deserving of mention, since the question as to the relative merits of water and solid ballast will, I have no doubt, continue to be s disputed one.

Although, however, this principle of ballasting with a large quantity of unconfined water has on the Whole answered well in the large sailing-boats above referred to, I consider it to be inapplicable to rowing-boats, which, being of smaller size, and only slowly propelled against high surfs, would be liable to be thrown so much out of a horizontal position as to cause the water to settle at one end, as in the Southwold boat, and thereby endanger upsetting. I feel sure that I have many times been through heavy surfs in the self-righting rowing life-boats of the NATIONAL LIFE-BOAT INSTITDTION, which would have proved fatal to any rowing-boat so ballasted. It is also a serious drawback to such boats that their crews, whilst rowing, must sit with their feet in the water, which in a protracted service in cold weather, cannot but be very trying to them.

( 7b be contained.).