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should be so rigged unless it is decked over, partially at least, and properly ballasted.
Now I wish to suggest for the launches, two lug sails, dipping, the forward one being the larger, and with the seam abreast the foremast cut to the yard so that the forward part of the sail acts as a jib, and it really is not dipped at all; two masts and two yards are required only, and these would be of a size not excessive. These sails could be kept in the boat at all times and they, with their masts, are easily stowed or handled.
For cutters and whaleboats I am in favor of the sliding gunter rig, as I think it combines most advantages. The sails can always be kept in the boats and do not take up more room than any other rig. I think the whale boats should all be fitted with center boards. It has always seemed to me that our boats have too small rudders, at any rate it has been my experience that ships' boats work better when I have had the rudder enlarged. The sprit sail rig which is sometimes supplied for gigs and whale boats I think deserves the strongest condemnation : it is awkward, not easily reefed and very inconvenient to stow.
With regard to steam launches a great deal may be said, though possibly they were not intended to be included in the scope of the discussion. The same tests of fitness should be applied to these boats as to any other integral parts of the fighting whole. And I do not think this point can be urged too strongly, because it is too often slighted. The usefulness of these boats more than of any others depends upon their possessing certain qualities which fit them for battle, and every other consideration should be made subordinate to the one which would make them fit for battle service. They may be used for towing the other boats into action or for fighting with torpedoes at night. In either case they should be noiseless, as the success of an expedition may depend on the secrecy with which it is conducted. There is scarcely one steam launch or cutter in our service which fulfils this condition. I think I may safely say that there is not one which was made in this country. I do not believe that there is a single Engineer Officer here present who will say that such a thing is impossible; in fact we all know it is not. And yet why is such a vital consideration neglected ? On a quiet evening one of our steam launches can be heard nearly three miles off, and this one objection would militate seriously against the fitness of the boat for such duty. If it is possible to do away with this objection let it be done. If it is necessary to use fan blowers, let us have them; if it is necessary to have more grate surface, let us have it; if it is necessary to exhaust into a larger aperture, let it be done, but, at any rate, stop the noise. And moreover the steam launches or very few of them are built or fitted for work at sea. We are not going to use them always in smooth water: if one of our vessels meets an enemy at sea and can lower a fast launch with a torpedo, then we shall be two to one. But that launch must be strong enough to hold its engines and boiler with steam up before it is lowered, it must have steel protection for its men from musketry fire, in the shape of turtle-back or shields; it must be able to use salt water, it must be able to work in a considerable sea. I have no doubt that we can have such a boat if it is demanded. Why should we not have some now to try, to see what we may want in the future? The Chairmen has said something about the rig of catamarans. I think that as they are made now of india rubber and sometimes kept on deck and sometimes below, they are, when on deck, only a good substitute for a life buoy, and that the principal part of the rig should be bread and water secured to the raft in a water-tight box. If the discussion permitted something might also be said about life saving appliances. This part of the subject is well worthy of consideration. Few of our ships can float their whole crews in case of accident, and it seems to me that we ought to try to have all boats fitted with detaching apparatus and in addition to have collapsing boats or bridge rafts so that in an emergency all hands can be fvated. But above all things let us remember that our boats are intended for fighting and that every detail of build, rig or equipment should be in harmony with that object.
P. A. Eng. KAFER:- The man-of-war boat which will be of the greatest use in time of war is the steam propelled boat, be it either launch or cutter, and it is well worth while to devote a part of the time allotted to the discussion of the rig of boats to the consideration of the question whether we have the steam launch or cutter best adapted to the demands of naval service.
The object of a steam launch is not the same as that of the sailing launch--to be able to transport men and guns--but to float the motive power necessary to tow a number of boats carrying men and guns, at a fair rate of speed. To do this the hull must be as small as possible, or the maximum motive power should be placed in a hull of given size. The nature of the service limits this size, in length, to about thirtyfive feet, and as a fair rate of speed is desired this length also limits the breadth. Moreover to obtain the best results the draught should be very nearly constant; but this is impossible where the launch is made to carry men and guns. Therefore it may be assumed that in order
to have a constant draught and displacement, the steam launch or cutter should be of sufficient size to carry its machinery and necessary supplies, and these only. I have said that the length is limited to about thirty five feet, for beyond that a boat cannot be hoisted to the davits or swung on board conveniently. Were it not for this, it would be better to build a steam launch larger so as to make its lines finer; this would decrease its resistance and make it more efficient for towing or for speed.
A steam launch or cutter should be decked over whenever possible, so as to make the boat safe in any ordinary sea; safety being the first requisite of such a boat. Again, the machinery should be simple in design and of sufficient strength to stand the rough usage to which it is generally subjected.
Economy in fuel is also one of the chief requisites of a good launch; but to gain this to any extent while maintaining the average speed now attained, it would be necessary to increase the size of the boiler to correspond to the increased grate surface required. With a natural draught the consumption of coal will not be more than ten pounds per square foot of grate surface which will give about a 21 horses power. To consume even this amount of coal, an artificial draught may be necessary, and assuming that 25 indicated horses-power is required to propel the launch at a speed of eight knots per hour it will take a boiler with ten square feet of grate to furnish the steam. Such a boiler would be a large one if constructed after the design of the boilers at present furnished to uaval steam launches. To get the requisite power from a small boiler, it is necessary to use an artificial draught, increasing the consumption of coal per square foot of grate surface and making it necessary to carry a much larger fuel supply. If the draught is increased by discharging the exhaust steam into the funnel, there is the disadvantage of being unable to supply to the boiler the water which might be furnished were the exhaust steain condensed in a surface condenser. When the exhaust steam is used to increase the draught it is necessary to carry fresh water in tanks, adding to the weight to be carried. With a condenser and natural draught, the boiler might be much larger without increasing the weight to be carried above that of boiler and water in tanks.
The noise caused by the exhaust steam, discharging directly into the funnel, to which objection has been made, may be obviated by discharging the exhaust into a closed tank, and keeping an almost continuous flow from it into the atmosphere.
The machinery of a steam cutter may be made fairly economical and within the limit of weight for boiler, engine, water and fuel, by having a keel condenser and air pump, a boiler with circulating water tubes and by using a noiseless blower to increase the consumption of fuel.
Passed-Assistant Engineer MANNING. Some of the gentlemen who have spoken this evening have objected to the type of machinery at present in use in our steam launches, on account of the noise it makes, which would render the boats useless as torpedo boats when the operations were to be secret, as they would announce their approach by the noise of the exhaust. Another strong objection to the present type is the expense and trouble of keeping them supplied with fresh water for their boilers. The question as to whether the Herreshoff system of machinery, which would avoid both these troubles, would not be preferable to our present type, has, I think, been very fully answered in the negative by Mr. Isherwood's recent report on that subject.
In order to avoid the noise of the exhaust, which in our launches, 'as in locomotives, is used as a blast to urge the combustion, we must condense the exhaust steam, and urge the combustion by means of a fan blower which could be driven directly from the shaft, or by the independent steam pump with which our launches are always fitted. The condenser could be of the type used so successfully by Herreshoff, being merely a copper tube running nearly twice the length of the keel, outside the vessel, thus saying the fresh water to return to the boiler. It is not usual, at present, to carry steam on any of our lauuches at much over one hundred pounds per gauge, but this could readily be increased to three times that pressure, and in that way the weight of machinery considerably decreased, with a probable increase of wear and tear. The weight of the present type of machinery makes our steam launches wet and uncomfortable, not to say unsafe, in a moderate sea way; and so any method of reducing the weights would be advantageous. In this respect, the weight of the fan blower and tube condenser would be less than the present fresh water tanks and the mean amount of water carried in them. As economy of fuel is not a matter of much importance in such craft, I think we will some day have a small boiler which will successfully use the liquid hydrocarbons as fuel, which would reduce the weight of both boiler and fuel. No one will deny that our present type of launch is a vast improvement over that of the first ones we ever had, which were twin screws, built in England, and used off Charleston and elsewhere as picket boats during the war; but no improvements have been made in the last ten years, during which time very considerable advances have been made in steam engineering. It is a mistaken idea that three hundred pounds pressure of steam is any more dangerous than one hundred, and the extra two hundred pounds costs very little in heat, comparatively speaking. As to the boats themselves, they should be of steel, and with sufficient air tanks to float them, even when waterlogged.
NEV YORK BRANCH.
MARCH 18, 1880.
Lieut.-Comd'r CHADWICK, U.S. N., in the Chair.
Lieut. NoYES. I suppose the universal criticism on our boats is that they are built for speed under oars and nothing else. Certainly, the long list of victories over the men-of-war boats of other nations in pulling races shows them to be superior in that respect, but there are a few other qualifications more valuable, in my opinion. First, I count capacity for carrying especially valuable, in view of the use of men-ofwar's men ashore under arms. In this our boats are very faulty, for in the effort to make them speedy and with handsome lines, the necessary beam and high free board are lost sight of. As striking instances of this, I can cite the cutter of the Juniata bought at the Navy Yard, Toulon, in 1871 ; pulling twelve oars, it could carry as many men and arms as the sixteen oared cutters four feet longer, of the Richmond. These two may be taken as representing the different styles of French and American building. Again, the launch of the Juniata could not float the howitzer, ammunition and crew for which she was fitted. Second: the weather lines under oars or sail are too fine. Under oars, our single banked boats lack the necessary free board to pull dry in rough weather; they are too fine forward and they carry too many oars. Under sail, they are too long for their beam to work bandily, too crank to carry sail, and, having no keel nor centre-board, they fall rapidly to leeward.
Our launches have the same faults, being built for speed solely. They are too fine forward and too low and are wet and leewardly in