CENTERBOARDS.

In all decked canoes of classes A and B, which include probably two-thirds of the canoes used in America, sailing qualities have of late been considered as of even more importance than paddling, and the sailing powers of these boats have been developed to an extent never thought of by the first canoeists. Almost the first quality in a sailing boat is its lateral resistance, by reason of which it can be sailed to windward, and to secure enough in a canoe one of two things is necessary, a fixed keel, or a centerboard; the lee board being too clumsy a device to be of use in a canoe, though at one time occasionally used. An exception may be made here to the double leeboard used on the Canadian canoes, which may be handled on an open canoe, but will not answer for a decked one. There are a number of considerations on both sides of the question of keel vs. centerboard, and as no general rule is possible, we will notice the leading points on either side, leaving the canoeist to decide for himself after weighing them.

First - efficiency; the two are about equal as to lateral resistance and handling if the keel be rockered, otherwise the centerboard boat will turn more easily, and the double board is decidedly better than the keel when running free. Second - strength and weight; the keel boat will be stronger and lighter than any centerboard boat can be, but the latter can be built strong enough without being too heavy. Third - durability; the keel is not liable to accident and derangement as all boards are, and there is less danger of leakage, while the boat will stand more rough usage. Fourth - expense; the keel will cost usually from $15 to $25 less than a board of proper construction. Fifth -convenience; the keel boat gives more room inside, but will not stand upright on shore as the flat-bottomed centerboard will, which is a great disadvantage in landing, sleeping on shore and in packing stores aboard, and sometimes dangerous in running aground. On the other band, a flat keel, as now built for centerboard, allows the canoe to rest in an upright position when on land, a very great convenience.

Whatever style of board may be adopted, to secure the best results it must be placed as nearly as possible in the proper position; but again the question of accommodation comes in. The best position for a board is, in most boats, with the center of its immersed portion a little forward of the center of lateral resistance of the hull and the center of effort of the sails; but in a canoe, in order to obtain room for sitting and sleeping, the board must be considerably forward of this if a trunk is required for it, and it may be moved forward without much harm, provided the aftersail is reduced in consequence. The only detriment to this plan would be that while the boat would balance properly on a wind with the board down, she would need a larger mizzen when in shoal water with board up. To avoid this disadvantage two plans are adopted, either to place the board well forward and add a second board aft, or to use a folding board that will not require a large trunk, and may be placed in any part of the boat. Of the latter class of boards there are several varieties, all of them patented. The question of weight in a centerboard is also an important one. Most sailing canoes require some ballast, and in this form it can be carried lower than in any other way, as a drop of 18in. below the keel is allowed by the rules. The weight being so low down will make the boat much stiffer than inside ballast can, and its value will be found when running, as it will steady the boat greatly. The extra weight is of little account in handling, as the boards may be lifted out on landing so that the canoe and trunks will weigh no more than a canoe with fixed board. Several instances have occurred of canoes with heavy boards capsizing under racing sail until water poured into the well, but coming up safely and continuing.

The double board plan presents many advantages for a canoe, the center of the boat is entirely clear of trunk, lever or gear, leaving plenty of room for sleeping; with two boards, if properly worked, the boat may be handled to perfection in tacking, the canoe falling off quickly when the forward board is raised, and luffing when it is lowered and the after one raised, while in running free the after board steadies the boat greatly. The objection on the score of weight is but small, as both boards may be lifted out easily, when the weight of the two trunks is no more than that of most folding boards, while the boards themselves are ballast in its best shape. The smaller or after board will weigh from 7to 12lbs., the forward one from 15 to 60lbs., as desired, or for light winds it may even be made of wood. These boards are also made so that a portion of the weight may be removed, as will be described further on.

The first point of importance in building a centerboard boat is the trunk for the board. In a boat of any size, a sloop or catboat, of 16 ft. or upward, the trunk would be composed of two pieces of oak called bed pieces as long as the trunk, and for a small sailboat, 2x4in. placed on edge and bolted to the keel on each side of the slot, strips of canton flannel, painted with thick white lead, being laid between them and the heel. At each end of the slot are "headledges" also of oak, 2 or 3in. wide, in a fore and aft direction, and as thick as the width of the slot, which should be large enough to allow for the board swelling when wet. The slot being cut in the keel the headledges are driven into it at each end and a rivet put through each and the keel, then the bedpieces are put in place with the flannel between and bolted down to the keel, rivets being also driven through their ends and the headledges. The sides of the trunk are made of dry pine from 1 to 1-1/2ins. thick for a sailboat, riveted at the ends to the headledges, the seams between the sides and the bedpieces being caulked.

Such a construction is too heavy, and, besides, unnecessary in a light boat; the headledges.(a a) are retained, but no bedpieces are put in. The headledges will be from 3/8 to 3/4in. thick, according to the thickness of the board, and 11-1/2in. wide, of spruce. They are set into the keel (b) as shown in Fig. 11, and also in plate on next page. The sides of the trunk are of well-seasoned and clear wood, usually white pine, although mahogany is more durable. A tongue is planed on the lower edge, 1/4in. wide and deep (see Fig. 11), and a corresponding groove is ploughed on each side of the slot. The sides are 5/8in. thick on lower edge, for a large board, but may be tapered down to 3/8in. at the top, as shown, to save unnecessary weight. Some care and neatness is required to make tight work; the sides are tongued on their lower edges, then fastened together, side by side, with a few small brads, and cut to the same shape; then the insides are painted, a strip of brass being first screwed to the inside of each to prevent wear, then they are carefully adjusted, with the headledges in place between them, and a few screws put in temporarily to hold them while riveting. They are then fastened together by copper nails through sides and headledges, about 1-1/2in. apart, the nails being also riveted over burrs. Two or three pieces of wood, as thick as the headledges, are now laid in the trunk to prevent it or the keel from coming together in planking, and are not removed until the boat is finished, or the trunk may close slightly. Now the grooves in the keel are painted with thick white lead, the trunk is driven down into place and clamped fast, rivets are put through the keel and each headledge, then the holes are bored for the screws. These latter are of brass, 3/16 to 1/4in. diameter and 3-1/2in. long. The holes are bored full depth with a small bit, then a larger one is run in for a distance equal to the shank of the screw, the latter is screwed firmly in and filed smooth. In fastening such work all joints that are painted must be thoroughly fastened while the paint is fresh, or they will leak.

The after trunk will come on the deadwoods, and it may be necessary to set in a solid bedpiece, on which the trunk is set, as above, the sides, however. being thinner.

Trunks are sometimes made of galvanized iron, but are liable to rust and are not as good as wood. If the sides of the trunk are thick enough holes are sometimes bored through them from top to bottom and bolts driven down through the keel, preventing them from splitting. In canoes the trunks are usually open on top, so that the boards maybe lifted out.

The after board may be of zinc, galvanized iron or copper 1/8in. thick, about 15 to 18in. long. It is hung by two strips of brass 5/8x1/8in., or even thinner, one on each side of the board, to which they are fastened by a rivet through both and the corner of the board. At the top they are both riveted to a small handle, by which they may be lifted out. A braided cord is used to raise and lower the board, being spliced into a brass eye in the after upper corner. This cord runs over a brass pulley fitted on deck, which is also movable.

The heavy boards are usually of plate iron galvanized, and are from 1/8 to 1/2in. thick, the latter weighing 60 pounds. A square board. as is usual in sailboats, would bring too much weight at the top, to avoid which that portion of the board within the case is cut away until only an arm, sufficient to steady the board in the case, is left. The board is first cut to shape out of boiler plate of the required thickness, then it is filed smooth at all corners and angles and reduced to a thickness of 3/16in. at the upper after corner where the lifting gear is fastened, and at the lower forward corner where the pin hole is. Next the board is galvanized and then it is ready for the fittings. Sometimes cast-iron is used, but it is liable to break. The Pearl canoe has two boards of Muntz metal, one of 68 pounds for racing.

Another form of board, in which the frame work is of wrought iron, with sides of sheet iron, leaving a space inside in which a plate of lead can be inserted, is shown in the (link to appendix) Appendix. By this device a light or heavy board can be had, while the weight is divided for carrying. If the board be fixed in the canoe, a brass bolt is put through it and the trunk, on which it turns, but the usual plan is to fit the board to lift out. The board is hung from a brass rod, or between two brass strips (f f), as described for the small board, the top having a handle (g), and also a catch to prevent the lifting rod from pulling forward. A small brass chock (h) is screwed to the inside of the trunk to prevent the lifting rod slipping aft. A rivet is also put through the keel to retain the lower end of the rod. If the board does not weigh over thirty pounds it is raised and lowered by a single pennant of braided cord. Two brass plates are rivetted, one on each side of the board, at its upper after corner, and a brass thimble in which the lifting line is spliced, plays on a rivet through their upper ends. A pulley is placed on deck, from which the cord leads to a cleat.

For a heavier board a purchase must be used, a chain made of flat links side by side, is fastened to the centerboard by two large links, a rubber ball is then slipped on to the chain to act as a buffer, and a single brass block is lashed to the end of the chain. The deck pulley (k) over which the chain runs has a sheave with a square groove to take the chain, and is also fitted so as to slide into place on deck, or be readily removed, without taking it off the chain. A brass block is also lashed to the lifting rod at deck, and the line is rove by making one end fast to the tail of this block, leading through the other block, on the chain, and back through the first block, thence to a cleat. By taking hold of the chain near the pulley with one hand, and of the lifting handle with the other, the pulley may be disengaged and the board readily lifted out.


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