Ballast in yacht design, measurement and rating
Carrying no cargo, every pleasure vessel, even those of moderate cruising rig, must depend on ballast for stability – the power to carry sail. It is interesting to know that the yachts of King Charles were ballasted with lead-musket balls from the Royal Arsenal; a better use than firing them at his subjects or his cousin of France. But his subjects were not so fortunate and the ballast first used in yachts, as well as in revenue cutters, smugglers and fishermen, was that which was cheapest and most conveniently at hand – stone from the beach. As lines were fined down in the search for speed there was less space below the floor for so bulky a material, and it was displaced by heavier substances, ores, copper dross, and kentledge in the form of discarded iron. About the middle of the nineteenth century the old kettle-bottomed sections with flat floors and bluff bows were replaced by much finer models, with midship sections appropriately termed "peg-top", and fine, if not hollow, bows. While these yachts had but little internal space for ballast, at the same time they called for a large quantity to balance their great sail plans, and the subject of ballast was for thirty years the most vital issue in yachting.
At this period the usual form of ballast was cast iron, molded to fit between the frames, as in the yacht America, though lead was used when the purse of the owner permitted such a luxury. In the more extreme racing craft, such as Thought, Vesper and Cygnet, of pure "peg-top" section, not only was lead employed, but it was carried on the locker on the weather side or on a specially constructed ballast shelf well up on the side, the cabin being gutted as in more modern days. Shifting ballast, introduced in England in 1826, was prohibited in 1856.
No modern product of photography can produce such fascinating pictures as the paintings and lithographs of the fifties depicting cutters with huge swaggering topsails, the yards crossing the topmast like the sails of a felucca. How the hulls stood up under them is as much of a mystery as how the spars themselves stood? The barring of these great kites led to the lengthening of the standing spars and the increase of lower sails, with new demands on stability met only by shotbags to windward.
With the prohibition of shifting ballast a new problem arose, and experts were divided on various details; the comparative merit and cost of iron and lead; the effects of these heavy metals on the speed of a vessel, apart from the question of stability; the structural effect on a yacht’s hull of a part or all of this metal below the wood keel; and the effect of this weight on the motions of the yacht. In his treatise "Yacht Architecture", published prior to 1850, Lord Robert Montague discussed the subject as follows: "Wherever the ballast is stowed, it should, above all things, be placed upon springs; in order to make it a ‘live’ and not a ‘dead’? weight. Why, in the chase, do they sometimes put a shot in each hammock, and make every man hold a shot in his hand? To make the ballast live weight. At Malta there was a race between little sailing boats; one boy slung his ballast under the thwart of his boat, there was a slight tumble in the sea, the boat joggled up and down, but forged away from all the rest and won the race. Why was that? The true-blooded Yankee, a famous cruiser, was one of our 10-gun brigs, but her ballast had been taken out and stowed upon broom stuff (which gave it spring) and light tops were substituted for our heavy ones. Instances might be multiplied to show the advantages of live weight."
That good old cruising salt "Vanderdecken" (William Cooper, pseud.) in 1873 devoted one chapter of his "Yachts and Yachting", London, Hunt and Co. to the subject of ballast. He pointed out the need for weight in small bulk and suggested that the best ballast would be gold, or “platina"; a suggestion re-echoed 30 years later by George L. Watson. Rejecting these for financial reasons, he suggests lead as next in order, but adds: "Few yachtsmen are so flush of cash as to ballast their vessels entirely with lead." Going to the question of outside ballast, he admits the advantage, but is afraid that it would rack a vessel and stop her way, with the added disadvantage of the increased friction due to the depth of the keel in water of increased density. His summary was that while the general impression of yachtsmen was in favour of outside ballast, it was still an open question, "with much to be said on both sides." By way of final warning he adds: "We should remember that the more metal we cram into a yacht’s intestines, the more we destroy her buoyancy and elasticity in a seaway." The cost of lead is quoted at £25-10 and iron from £4-10 to £6 per ton; and for those who cannot afford such luxuries he recommends sulphate of barytes (Barium sulphate, BaSO4), in powder form, and in stout canvas bags, as "almost equal to iron."
In his later book "The Yacht Sailor", "Vanderdecken" discusses the use of shot bags and pig lead in racing; he suggests the use of two or three tons of shot, in double bags, not too large, and fitted with stout rope handles; as, 1f too heavy, they will kill the ballast shift. These are to be kept on the floor when making short tacks, but piled up to windward on a long tack; and moved as seldom as possible in order not to kill the way of the yacht. By way of final injunction, "In belts of calm and veins of wind, a hammock hung to a handspike laid athwart the skylight coamings, half filled with shot bags and kept on a gentle swing fore and aft, I have seen productive of astonishing results."
The advent of the lead keel
The question of shifting ballast was disposed of in Great Britain by positive prohibition in 1856, but there still remained the question of the practicability of an outside metal keel. There is mention of a yacht Wave, built by Steele of Greenock in 1834, with a metal keel, but no record has been preserved. The cutter Cymba, of 53 tons, built by the second Will Fife in 1852, had three tons of lead in her keel, with 20 tons inside; incidentally, she was fitted with standing rigging of galvanized wire, then a novelty. The American schooner Onkahye, built for John C. Stevens in 1839, is said to have had an iron keel, and about 1850 the great sloop Maria, also owned by the Stevens family, had a padding of lead outside her planking, said to have been five inches deep at the keel and diminishing to a shim edge at the bilge.
Even the most experienced builders hesitated in placing any material proportion of the ballast outside the wood keel; partly from fear of the effect on the structure and partly from fear of the effect on the motion of the vessel. In 1852, when Count Batthyany purchased the schooner Flying Cloud, of 53 tons, he ventured to place two tons in her keel. In designing the cutter Kriemhilda, of 104 tons, and 80 feet on the waterline, for the same owner in 1872, Michael Ratsey, one of the leading builders of his era, placed but 41% of her 52 tons of ballast on her keel. This was in five short pieces, scarfed together, and held by dovetail side plates as well as throughbolts to her wood keel.
The thwartship strain on a yacht’s keel is a negligible quantity, being taken care of by the floors and the garboards. The vertical strains, however, are of prime importance, whether afloat or grounded, and the bulk of wood was placed in the depth rather than the breadth. The keels of old vessels were of the same parallel siding as the stem. This was determined by the thickness of wood between the inner faces of the rabbets necessary for the fastenings, plus the thickness of the plank ends. Such proportioning of the keel made it impossible to place any great bulk of iron or even lead below the keel. The yawl Florinda, designed and built by Camper & Nicholson in 1873, of 125 tons, carried, when built, 3% tons of lead outside, the siding of stem, keel and sternpost being about 9 inches. Later, 4 1/5 tons were added and at a still later date the total was increased to 23 tons. In order to carry this bulk of lead on so narrow a keel, a part was in slabs, bolted to each side of the wood, thus making a broad base below which the remainder of the lead was bolted.
As the use of outside lead became general, the width of the keel amidships was increased to five or six times the siding of the stem and sternpost into which it tapered. About 1876 John Inglis, the noted Clyde shipbuilder, himself a yachtsman, built the 5-tonner Hilda, with what is termed, in the case of the Cape catboat in America, an "alligator" keel, wide in the middle and tapering to the ends. Vertically this wood keel was shaped, as was the lead keel beneath it, to the tapering form of the bottom of the yacht. The great yawl Jullanar, built in 1875, had five tons of lead in her keel, with a wood shoe beneath for its protection. Much of her ballast was in the form of cast-iron floors of 5 to 6 hundredweight, with projecting side flanges to keep the inside lead from the planking. In a little cutter designed for his own use in 1871 young George Watson ventured to place all of her ballast in an outside keel.
In designing and building the schooner Sea Belle, of 142 tons, in 1874, John Harvey, one of the leading designers of his day, went to much unnecessary trouble and expense in devising a system of inside ballasting to secure the lowest possible position of the lead without straining the hull. The floors were of angle iron, bent to shape, with lead cast around them to the required siding and molding; the keelsons were of iron beams encased in lead, and blocks of lead were hung from them by iron straps.
Between 1875 and 1880 the transfer of weight from inside to outside progressed rapidly even in the larger yachts, in spite of the opposition of the older builders. In his masterpiece Van- essa, of 20 tons, built in 1873, "Dan" Hatcher, one of the greatest of the old-school builders, placed but 214 tons outside, with 14 inside; in the 5-tonner Freda, a very successful yacht of 1876, he placed but 40 per cent outside.
