When the prohibition of shifting ballast came into operation, it was only reasonable that yachtsmen and yacht builders should devise some plan to enable the yachts to continue to carry the enormous spars and sail areas that shifting ballast had called into existence. The shot bags that had been shifted from bilge to bilge were permanently located in a solid form in the bottom of the hull, and metal keels—generally of iron—became fashionable. Then lead keels were timorously introduced; but the man who owned a yacht that would not stand up without a lead keel was regarded with a feeling which was a mixture of contempt and pity. Indeed, lead ballast generally was contemned, and when a yacht first appeared with " all lead ballast," many so little understood the subject as to predict that she would " get caught some day, and sink like a stone." This comical prediction, so far as we know, has not been verified, and "all lead " for racing vessels is now commonly employed as ballast. There seems to be no limit to the proportion of ballast to be carried outside, and, whilst the general practice during the last three or four years has been to put about one fourth of the ballast outside, on the keel or in the garboards ; we have seen as much as four-fifths of the total ballast put outside some 10 and 5 toners. Generally we agree that the employment of a lead keel has advantages ; and probably the practical failure of one or two attempts which have been made to balance a bad type of vessel—built to evade the effects of a tonnage rule—by the aid of weights stowed very low, will check any evil influence the unlimited employment of lead as ballast might be supposed to have.
In some remarks on ballast, in " Yacht Designing," the following occurs : " The principal advantage of using lead as ballast is that, owing to its greater specific gravity or smaller bulk for any given weight, it can be stowed as a whole in a lower position in the hull than a similar weight of iron, and thus bring about a lower position of the centre of gravity of the vessel, which simply means that, with any given weight, greater stability can be acquired by using lead as ballast than by using iron. Next, as the centre of gravity of a vessel can be brought so mach under command by the use of lead and lead keels, advantage has been taken of this to decrease the displacement for any given linear dimensions, and thereby increased fineness of lines has been obtainable. In this respect the employ ment of lead as ballast has had a beneficial effect. It has enabled naval architects to design vessels equal in accommodation to those of much greater cubical contents, that necessarily had to provide a large space for ballast, and at the same time to nearly equal in initial stability and speed the broad shallow vessels which are deficient in internal accommodation." In order to get the centre of gravity of the ballast as low as possible, the practice is, in most racing yachts, though not in cruisers, to distribute the weights in a fore-and-aft direction ; and in order that as much weight as possible can be got into a metal keel, the latter is frequently made to reach five-sixths of the length of the vessel, measured from the heel of the keel. For smooth-water sailing nothing but clear gain, so far as stability is concerned, will result from having the weights well distributed in a fore-and-aft direction; but the case will be different among waves, no matter whether the ballast be lead, iron, quicksilver, or pumice stone. The longer the radius of gyration and the greater the metacentric height are made, the more violent will be the pitching and scending motions among waves, and the vessel will dive, and be very wet and uneasy. But, on the other hand, if the weights are much concentrated, the vessel, whilst diminishing the momentum that caused her to plunge into a wave or " dive," will be extremely lively, and probably rise to every wave crest, large or small. The vessel with the longer radius of gyration will not so accord with the waves ; and, although she may be " carrying her canvas better," yet will she so bury herself, that to sail her must be a work of great difficulty and even danger to spars. In moderate weather, and among comparatively small waves, the case might be somewhat different, as the momentum acquired would be unimportant, and the fore-and-aft motions of a vessel with a long radius of gyration would consequently be slow ; whereas, a vessel with her weights much concentrated would tend to keep time with the waves, or would be what is termed " lively," and the sails would not "sit" quietly. This is particularly noticeable in little boats,
and often among small waves better results are obtained by stowing the weights well fore-and-aft. As a general rule, the best place for the ballast is in the middle third of the length of the vessel ; and if one third, more or less, of the ballast takes the form of a lead keel, the latter should not be greater in :enz....e ti-an cf t'ne le of the vessel on the load water-Lime.
Varkus cf ba:s.s.r...z have &c at time to time been adopted or pr_p=sed, ar_d we have see-r. ballast should be slung, or that it have bear-.: psi-, It need scarcely be pointed out that moving-balast *tn.: ng wares be a very had thing, as the momentum acquired by the banast wog:a in effect augment the general momentum of the vessel : and farther, if the ballast were " slung," it would shift to leeward upon the vesysel being heeled by a wind force, and would be in effect like trimming ballast to leeward instead of to windward. The most ingenious and elaborate plan yet adopted in the way of ballasting is that introduced by Messrs. Harvey and Pryer ; it consists of lead floors with angle iron inserted ; lead keelson, with lamps of lead underneath it between the floors moulded to fill the spaces, and a lead outside keel. This plan was very successfully tried in the Seabelle; she is wonderfully stiff, and is said to be easy among waves; at any rate, she has on two or three occasions done so well against a heavy head sea that there cannot be a doubt on this point, and it may be concluded that her ballast plan has had no detrimental effect upon her qualities as a sea boat.* So far as small are concerned, it is unusual now to have wood cross floors and keelson, for two reasons firstly, because it is almost impossible to get grown floors for vessels with sharp bottoms, or great "rise of floor" as it is termed ; and, secondly, because the throats of wood floors and the keelson occupy a space which is much better filled by ballast. The keel of a ten-tonner in " siding " or breadth is more than double what it was before the era of lead keels, and this great breadth is resorted to partly that a heavy lead keel may be carried, and partly that the strength lost by the absence of floors and keelson may be compensated for.
The upper edges of the wood keel between the frames are sometimes cut away, in order to give additional space for ballast ; in fact, every care is taken that all the crevices are filled, and that the ballast is cast so as to be stowed as much like a solid mass as possible. Some ten years ago a plan was introduced of running about half the ballast into the vessel hot; and certainly this plan so far fulfilled its object, that the ballast was solid, and all the small spaces were filled.t But the plan was objected to for the reason that if anything went wrong With the frame of the vessel, or if the ballast required shifting, it was such a very great labour to cut the solid mass out. The best plan is to have two-thirds of the ballast cast from moulds, in blocks of from 2cwt. to 4cwt., as may be convenient, and the remainder in ingots, square and triangular in shape, of lcwt. and icwt. each. Some loose ballast will always be required to trim the vessel in a fore-and-aft direction, and the large blocks, whilst they are difficult and dangerous to move, cannot be " stowed " if shifted from the places they were moulded to fill. The moulds for the lead ballast should be made very exact, so that the lead blocks fit between the frames without loss of space. At the same time, care must be taken that the blocks do not rest on the plank.
Sometimes in small vessels the spaces between the heels of the timbers and the keel are filled with concrete (made of shot and cement) up to the level of the top of the keel, hogging piece, or keelson. If this plan is adopted, all the surfaces of the spaces should be well tarred, and the concrete should be well worked into every crevice, otherwise the damp may rot the heels of the frames and the plank, or foul bilge water may accumulate.