25-Foot Cabin Cruiser Part I
The engine for which the 25-foot boat was designed is a two-cylinder, two-stroke, rated at 6-hp. and the weight allowed for same is 350 pounds. Therefore, if you do not use one of these engines you at least should bear in mind that in order to get the best results; you should install an engine of about the same weight and power, irrespective of whether you desire a two or a four-stroke engine. Do not install a high-speed, high-powered engine if you want a cruiser, and bear in mind that this craft is not designed for a speed boat. Eight (8) miles an hour can be depended upon with the outfit mentioned, and that is speed enough for so small a cruiser.
Construction Plan Of 25-Foot Nock Cabin Cruiser
It is almost a moral impossibility to cover all the details in the specifications even though they are much more comprehensive than such as I should furnish to a practical builder, but I will try to explain as closely as possible how to proceed.
Lines Of 25-Foot Nock Cabin Cruiser
When you have laid down the lines full size, you can proceed to get out the moulds. For this you will need about 100 feet of hemlock, spruce or some such material. Saw to shape and don't forget that the lines are to the outside of the plank, therefore if you mark your moulds the same as the lines, you will have to take off 3/4 of an inch around same, as these moulds arc to represent the inside of the planking and the planking is to be 3/4, of an inch in thickness. Of course you can take this amount off the outside when you lay down the lines if you prefer, and by doing so, you will save yourself considerable labour.
Body Plan Of 25-Foot Nock Cabin Cruiser
A practical boat builder seldom uses all the moulds, but would probably use Nos. 2, 4, 8, 16, 20 and 22, and spacing them 4 feet apart except the two end ones, you can proceed in this manner and have good results provided you use good strong battens to make a fair curve and hold the frames in place without bending the battens.
Plan of One-half Transom
The lines as laid down usually show but one side of the mould as both sides should be alike, therefore you will find it easier to mark out one side of the mould on a piece of board, fasten this to another pieсe and saw the two of them out at the same time; this applies especially to the case if a band or jig saw is available. Mark and cut out all your moulds in this manner and then proceed to fasten them together. There are many different methods in vogue, but one that is about as good as any for the amateur is to put the cross pawls in such a position that the lower edge of all of them sets to the sheer line on each mould. Where more than two pieces of wood are used to make a mould, you can cleat them together, taking care to keep the cleat well in from the edges in order not to interfere with the frames, etc., if any of them should be close to the mould. Cleat the lower part of the moulds with a piece of spruce or some such material about 2x2 inches, so that you can use this to fasten the mould to the keel. If the cross pawls are set true, it is a great help in setting up, as you can level same, and again I would call your attention to the necessity of marking the centre line on each mould. I believe that in a case of this sort it is also a good plan to mark on the moulds the waterline, for by so doing you can easily ascertain whether the moulds are all set up correctly or not before starting to put on the battens. The practical builder could tell this at a glance, but it is not always so with the amateur. When you have completed your moulds, you can proceed to mark out the keel. For this you will need a nice piece of oak, about 21 feet long, 3 inches thick and 12 inches wide; carefully smooth the sides and mark out on same the shape, and the stations, cut to the lines and after carefully trimming the keel run in a line through the centre of the upper side, and, with your square, mark the stations across the top. Select a good piece of oak for the stem, mark the shape on same and cut to the lines. It is a good plan to make a thin wood template of the stem as you can use this template to mark out the shape and also the rabbet line. To do this, you can bore a number of small holes along the line of the rabbet, and with a drill or awl you can easily reproduce this on one side of the piece of wood you have previously cut to shape, reverse the template and mark the other side, draw a centre line, down the face of the stem and a line 3/8 of an inch on each side of same, which allows 3/4 of an inch for the face of the stem. Trim from the rabbet line to these two outer lines and then proceed to cut the rabbet, using a fid (Fig. 3) to get the bevel. If you want to get the rabbet on the stem absolutely correct you can do so by marking on same the waterline and cutting the rabbet to the exact bevel, but I do not think you would save much time by doing this, for when the stem is in position and you start to place the battens, if the rabbet line needs fairing in places you can easily accomplish same, having the battens to work to.
If the engine you decide to use is of the dimensions as the one called for on the plans, you can rest assured that the line of the shaft will not differ, and therefore you can proceed to get out the shaft-log. For this you will need inches, and inasmuch as it might be a difficult matter to procure oak 30 inches wide, you will probably have to use two narrower pieces and bolt them together, or, if you prefer, you can use mahogany for the transom. There is little or no difficulty in obtaining this material 30 inches wide, but it would cost a trifle more than oak. The plans show one half the transom with all dimensions marked on it. You can set this out direct on one of the pieces of stock for transom if you desire, and saw it out and mark the opposite side for same. Or you can saw the two pieces at one time with a band saw. Trim carefully to shape and get out a couple of cheek pieces of oak 1 inch thick and about 3 inches wide; set these almost out to the edges of the transom and fasten with galvanized screws these pieces are to be trimmed to form a back rabbet to fasten the ends of the planking to, and you will probably have to fair them to some extent when you start to put on the battens.
You can now proceed to set up the frame. Draw a chalk line on the floor where you intend to set up the boat and to the edge of this line set up 4 pieces of spruce 3x4 inches, each piece to be one foot longer than the height on the table of offsets of base line to keel bottom, at stations 2, 8, 14, and 20. Nail a strip of wood to the sides of these upright, so that the upper edge will represent the base line, and if the floor is level, it will be one foot above same. Set this strip of wood level, using a long spirit level to ascertain that neither end is high. The forward side of these posts will represent the stations Nos. 2, 8, 14, and 20, and you can measure up on from the upper edge of the strip representing the base line and see that the dimensions correspond to the heights of keel bottom above the base line on table of offsets. These uprights must be well braced forward and aft and also at the sides in order to keep them upright and sustain the weight of the boat. It is not necessary to obtain any special size stock for these braces, as most any stock from 1 to 2 inches thick will serve the purpose if properly fastened. Set the keel on the uprights and ascertain that it is in the right position; measure from the base line to the waterline on stem and see that it is 2 1/2 feet above the base line as per plans. Plumb the stem and securely brace it from overhead if possible. If you are sure that it is correct, you can fasten some wooden cleats to each side of the uprights and also fasten to the keel.
The knee and transom can be fitted and fastened, using plenty of fastenings but taking due care not to get any nails or screws where they will interfere with the rudder port, which will have to be bored and time spent looking out for this will mean a saving in the end, as nails and screws are apt to spoil an auger or bit. Place your level against the side of the knee and when vertical, stay the transom either to the rafters or some other convenient place. Then take your chalk line and stretch it from the centre line of the transom to the centre line of the stem, haul taut, and drop a plumb-bob from same. If the point of the bob touches the line on the centre of the keel you can rest assured that the stem and stern are in line, but do not be satisfied with one trial, try the plumb-bob at different points and if any of them are out, sight along the side of the keel and if this is not in a straight line fore and aft you must brace it until it is perfectly straight and the plumb-bob must intersect the centre line at any point. When you have it correct, you can fasten the stays or braces strongly, so as to keep it in position.
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