A Guide to Motor Boat Design and Construction - A Collection of Historical Articles Containing Information on the Methods and Equipment of the Boat Builder. Various
the wheel invariably suggests a compass, as one seldom sees the one without the other just in front of it, in a stout binnacle, screwed to the deck. For motor boats the best rig, to my mind, is a permanent compass mounted on one of the aft panels inside of the cabin, with a pane of glass so that the skipper at the wheel outside can see it day and night by simply glancing through his binnacle pane. This is also the cheapest rig, and one which you can feel reasonably certain will stay well lighted and be protected from the weather, which the small brass binnacle, with its dinky lamp, will not stay or be. Assuming that you elect to locate your compass in a permanent box on the aft port cabin panel, set the rhumb line true fore and aft and screw the fixture in place just under the panel window pane. The rhumb line is a fixed black line which you will find inside the bowl of the compass and represents the fore and aft center-line of the ship with respect to the rotating compass card. By the rhumb line you lay your course in degrees and minutes on the card as taken off your chart bearing. Simply keep your rhumb line on the point on the card which represents your bearing and you will “arrive.”
In almost any cruise you will need a set of charts covering the various landfalls you will make, giving all buoys, lights, soundings, etc. By writing to the U. S. Coast and Geodetic Survey you can get a book giving all the charts for the Atlantic, Pacific and Gulf coast lines. These are numbered and you order the ones you want from the diagram maps in the book. The charts cost about 50 cents apiece and are very complete and up to date. If your boat draws any water at all, do not attempt to go beyond the limits of your chart without picking up the course on another. We once tried that on a river showing only five miles back from the harbor chart. Fifteen years before I had often navigated that river so I followed the old bend regardless of the fact that many a large schooner was now sailing down some new channel cut through the marsh. I didn’t know where the new channel went, but I was sure of the bend, so I followed the familiar old course. Suddenly there was a crash for’d and our cruiser hurdled up into the air. Something solid drummed along our keel and out astern, and we found ourselves afloat in that new channel with our rudder jammed fast. We had hurdled clear over a sheet piling breakwater, two feet below water at mean low tide, with our 35-foot cruiser going ten knots an hour. A tap on the rudder with a machinist’s hammer freed it and we got under way again, but it was a ticklish business thereafter without any chart!
As stated before, the chart gives soundings at mean low tide, in fathoms in white waters and in feet in stippled shoals and shore beaches. Where fore, in picking out your anchorings in a cruise be very sure to take the tide into account and allow at least four feet under your keel at dead low tide. This is because if any sea gets up you will touch at the trough of every wave and pound the skeg off her unless you have at least a few feet clear below it in still water at low tide. To get your depth you need an exceedingly important little item of equipment, the “dipsey lead” which is “tar” for the deep sea sounding plummet. A seven-pound billet will do for any motor boat. Bend on it a length of stout braided “banks” line and let it be at least fifty feet long, as there will come times when you have got to put down the hook in mid-channel and hence will be curious about the depth. For taking anchorage or “feeling your way” soundings, stand up on the starboard bow and swing the lead out into the pickle, about twenty feet ahead, using an underhand swing. Don’t attempt to whirl the lead in grand circles as you’ve seen them do on big ships going seven or eight knots in five fathoms of water. You’ll only hang the plummet on some innocent bystander’s ear, and will make a landlubberly exhibition of yourself in general. It isn’t easy to heave the lead like an old salt. No trouble about the other stunt!
Mark your lead line in feet, with a brass clip at two feet below your boat’s draught, a red flannel rag at 10 feet, a white bunting rag at 15 feet, a leather tag at 20 feet, etc. There is no use adopting the regulation nautical markings of the lead line as they are far too coarse and too deep to be of much use for a motor boat. The different tags, however, are good to adopt as they show the depth as well by night as by day. You can easily feel the difference in the tags and measure the exact point on the line from the nearest tag with your arm even on dark nights.
A highly important but not much appreciated “fittin’ ” (before launching) is the bilge pump. First, when your boat is being built, see that the lead holes (“limbers”) under the ribs fore and aft are all clear and have not gotten choked up with chips and sawdust. Choose a handy point for the bilge well and have a permanent bilge pump put in near it with a permanent suction to the well and a discharge overboard. No well-built motor boat should leak much, but as they gradually grow old they leak a little more every year; and the stern gland of the screw shaft lets in more or less water throughout the season, since its packing will, get worn and hard. It is well worth while, to simply have to work a handle whenever a peep at the bilge well tells you that she has made a few inches of water. The little brass bilge pumps sold for motorboats throw a wonderfully voluminous jet of water,—out of a clear, clean pailful of it. But handling dirty bilge-water is another matter, and these pumps usually stick before the first ten strokes are made. Then there is nothing for it but unscrew the pump and get the chip or grit out from under the ball check-valve, or else free the ball itself, which often sticks on its seat. Put it together again, and observe how nicely it will stick once more in the next three strokes. Besides which, some one has to hold the rubber hose over the side or else it is sure to squirt on the boat cushions, and another boy will have to put in time holding down your temper for you while you struggle with the pump.
Under the head of fixtures and fittin’s comes the signal mast and the awning. The signal mast is a very natty and handy addition to any motor boat, but nothing will make you look more like a landlubber, a gardener, and a cabbage-planter than a signal-mast badly stepped, badly raked, or improperly stayed. Wherefore make a scale drawing of your boat and experiment with a pencil and rubber as to height and step of your signal-mast before cutting any holes for it. It wants a neat yard arm hung in a rope bridle above the shroud withe, and the permanent halliard pulley-blocks are at either end of the yard. Your club flag may fly from the starboard block on the yardarm, with blue peter on bow pole and yacht ensign astern; or else the house flag takes the yard arm, the club flag, the bow pole, and the ensign the stern. The port pulley-block is for signalling.
As regards the awning, let it come forward over the extension trunk cabin by all means, as even a foot of cool shade under the awning will keep the cabin from becoming a sweatbox. All the awning rail equipment should be stout and securely bolted to the deck, as it is the very thing which collides most frequently with dock string pieces, sail craft’s bow-sprits, steam-yacht boat-booms, etc. A good rig is of one-half-inch galvanized piping, forming a hand-rail clear around the awning with short 16-inch stanchions to the cabin deck and long ones to the main deck around the cockpit. The awning is a few inches short of this rail all around, so that it can be stretched taut by a lashing around the rail. This latter should stop a foot back from the edge of the cabin eaves, so as to provide a runway for’d and should leave at least seven feet of clear deck for’d to give room for handling the anchor gear.
CONSTRUCTION OF THE HULL
BOATS, MOTORS, AND CRUISING HINTS
CONSTRUCTION OF THE HULL
THE construction and design of the hull will very much depend upon the type of service to which the boat will be put.
A boat intended for river use, for instance, would be of much lighter construction than a boat which had to contend with heavy weather at sea.
The boats usually offered to the public and built by our leading boat builders are the result of considerable research on the part of naval architects, who have been up against many difficulties.
It will be seen that to design a craft for either river or sea work would present little difficulty to those experienced in the work, but to design a craft that will be clean running, giving an absence of wash, for river use, and at the same time be safe and reliable at sea, is no simple undertaking.
This problem has been tackled and overcome by designers, and the pleasure craft offered to the public to-day are not only clean running and economical, but can be safely taken to sea in even very bad weather.
So much headway has been made and the confidence of the public