HOW TO BUILD A CATAMARAN.

BY F. S. C.

By this time, boys, you must be pretty well tired of winter sports—ice-boating, coasting, skating, to say nothing of cold fingers, frost-bitten ears, and red noses. There is no doubt but what you are as much pleased to see the grass looking a little green, and an occasional bud here and there, as older people. You perhaps have wished it might be spring for another reason, that is, to find out what was to be done with your ice-boat. If you remember, at the time the plans came out you were told to take particular care of your craft, as it could be put to good use in the spring. Well, with a few changes your ice-boat is to become a catamaran.

In the first place, you must unrig her. Take off the mast bench, side boards, floor, and stern pieces, and also the runners and rudder; then unfasten the runner plank, and move it back one foot six inches, and bolt it to the keel. Now call on your friend the carpenter, and get a plank of the same dimensions as the runner plank. Bolt that to the keel at the extreme end (one bolt will do). Have cut two pieces of pine plank five feet nine inches long, four inches wide, and one and a half inches thick; place them as in the plan. Replace the mast bench, and bolt it to the forward plank and sides as shown; bolt also the sides to the plank aft.

Perhaps it would have been better to have commenced with the hulls, and left the frame until afterward; but it makes very little difference, as it all has to be done. Now build the hulls. You must get four boards (white pine) twelve feet long, half an inch thick, and eighteen inches wide, not a check or a knot to be found even with a microscope. As you must be pretty well acquainted with the carpenter now, he will take particular pains to get the kind you want. Make the boards as in Fig. 1. At 1, 2, 3, 4 draw lines; cut the sheer line and the bow. The moulds (Fig. 4) 1 and 3 to be made of oak one and a half inches thick, and 2 and 4 of pine one inch thick. Take measurements carefully, as they are intended to remain in place, and not be removed after the hulls are formed over them.

The stern-post and stem are to be made of oak three inches thick, and rabbeted for the sides. Fasten the sides to the moulds with galvanized nails, and to the stern and stem with brass screws.

Square the tops and bottoms of the sides with a plane and straight-edge. But before you nail on the bottom of the hulls, cut a three-cornered piece out of the centre of the lower edge of each mould (see front elevation); this will allow the water to run from one compartment to another; for all boats must leak a little, you know; in fact, it is better for them—it keeps the seams tighter.

The bottom, which should be in one piece, may be nailed on. Put a little white lead on the lower edge of the sides; it will make the joints tighter. You must do the same with the stem and stern. Give the hulls a good coat of paint inside, and fasten bolts to moulds 1 and 3; you will see in the front elevation what they are for.

The deck may be cut and fastened in place; this is to be in one piece, half an inch thick. You may, if you like, put a three-inch ribbon of pine around the hulls. It is not really necessary, but it looks better; it gives more of a finish to it. In case you do this, the deck should lap over the ribbon, so don't cut the deck before you put on the ribbons. Give the hulls a primer of paint. You may now finish the upper frame. It is all done but the flooring. Use for this half-inch pine six inches in width, tongued and grooved; fasten with galvanized nails to the under side of the keel and side pieces. Put the frame on the hulls, and bolt the planks in their places. Now, if you like, you may launch your craft. After the launching let her lie a day in the water, which will give the wood a chance to swell. In the plan you will notice two squares on the decks. These are the hatchways, through which you may sponge out the water in case your vessel leaks; she will anyway the first day she is launched. In the steering gear of your boat you may utilize that which you have on hand, with some additions. In place of the rudder in the ice-boat, get a piece of oak eighteen inches long, with bolts at either end, and fasten to the old iron-work; a glance at Fig. 3 in the ice-boat plans will show you that it is the same. The rudders are to be made of oak one inch thick; the iron bands are intended to strengthen them, as well as to hold the eyebolts. Get the blacksmith to make two half-inch iron rods; these are to connect the rudders with the cross-piece. Fig. 6 will show you the detail.

Slip a small piece of gas-pipe over the rudder-post between the tiller and the keel (see Fig. 3). The tiller, fastened on with a nut on top, will keep the post in position; this is better than a pin running through it.

Hanging the rudder and necessary fixtures, as well as the rigging, had better be done on land; that is, after she has been launched, and hauled up again.

You will need a new mast twelve inches longer than the old one, as well as a new gaff and boom; make them eighteen inches longer than the old ones. The topmast should be four feet long from the mast-head. The mainsail should have a new piece sewed on the leach, eighteen inches long, at the head and foot. The jib should be eighteen inches longer on the foot. The shrouds must be heavier than those used formerly, and be run out to the ends of the plank. No jibstay is needed, but a small rope sewed to the leach will be necessary. The bobstay should run from the end of the bowsprit, thence to the plank under the same, and be trussed in the middle with a piece of oak (see front elevation).

You might make a spreader for the topmast, say of eighth-inch wire, with an eye at either end; run the topmast shrouds through these eyes, and then to where the shrouds are fastened.

Those parts of the ice-boat which you have not used for this craft put carefully by until the next cold snap, which will doubtless not occur within the coming six months.

Now you are ready, boys, to paint up. Having examined the hulls carefully, and being thoroughly satisfied that there are no leaks, you may get out your paint-pots and go ahead. Draw the water-line mark, and paint the bottoms red, the sides light buff or French gray, and the ribbons black; the deck, the same as the hull; the frame you may varnish, although it would be better to paint it.

Get your boat in the water now, hoist your sails, and, with a fine breeze, take your first sail in your catamaran. You need have no fear of capsizing, but your boat may do what they call "pitch pole," that is, dip its nose into the water, and go completely over. We are in hopes, however, that this one will not act so.

In making the drawings for this catamaran the supposition is that you have an ice-boat, and that you utilize certain parts of said boat in the new construction. New timber is used in whatever radical changes are made, and under no circumstances do you cut any of the old timber, but lay it away until the next cold snap. The construction of this craft from your ice-boat has necessitated a rigid frame-work, preventing the independent movement of the hulls. In a catamaran properly built the hulls should move independently; and for those boys who have not an ice-boat, or prefer, if they have, to lay it aside altogether, additional drawings are made. The changes are only in the manner of fastening the hulls to the frame-work—the arrangement of the keel and bowsprit, an additional mould in either hull, a crown to the deck, and a slight difference in the iron-work and position of the tiller.

The keel, K, of white pine, four inches wide, an inch and three-quarters thick, and eight feet long, runs twelve inches beyond the after cross-beam; instead of being on top, it is hung underneath the beams, and bolted to them by half-inch links or eyebolts. The ends of the cross-beams are fastened to the moulds in the hulls (Fig. 1 will show you how), with a rubber washer on top; this will give elasticity. You will observe that these are used wherever there are bolts, with the exception of those in the keel. Fig. 2 gives the detail of the stanchions (of oak, one by three inches) for keeping the hulls on an even keel, and at the same time allowing a limited rolling motion; the other end of the stanchion is bolted to an extra mould in the hulls, marked R M and L M. You notice the difference in the positions of the same (see Fig. 1 and plans in Plate I.); Fig. 2, Plate II., explains why. The detail is given (Fig. 5, Plate II.) of rubber washers, links, etc.; this is drawn quarter size. Mast bench of oak an inch and a half thick and six inches wide. If you like, instead of pine for cross-beams, oak can be used, an inch and a half thick, but only four inches wide, and, if it is possible, get them with a slight curve upward.

Instead of nailing the floor to the bottom of the side pieces, lay a four-inch plank of oak on the cross-beams, G, Fig. 1, and fasten the floor to that. Make it three-quarters of an inch thick, instead of half an inch, as in Plate I. This will prevent the floor going through when you happen to get in a rough sea, and your craft gives all over. The side pieces should be bolted to the cross-beams with half-inch bolts, with washers of rubber underneath; one bolt is sufficient in each end of the side pieces, running through the middle of the cross-beams.

With these alterations, in connection with Plate I., there is no reason why you should not have a comfortable craft, and no doubt you will get through the summer creditably, and without a wet jacket from a capsize. As for a "pitch pole," that should not occur, as your craft, when afloat, will be pretty well down by the stern.