with all the ease and accuracy of a rifled musket. It throws steel shells weighing from 1 to 6 pounds that do actually pierce the sides of any unarmored ship afloat at a distance of 1,000 yards, the shell exploding inboard. These guns can effectually silence a gun in an open port at a distance of 1,000 yards by keeping an easy, steady fire on it. From all this it follows that all guns must be protected. The old pivot-gun with its long sweep of dropped rail, must be condemned unqualifiedly. Were there no other reason, in the economy of shipboard, for putting topgallant-forecastles on our ships, the protection of the guns imperatively demands them. Let it be remembered that a fore-castle, like the traverse of an earthwork, protects the whole battery, fore and aft, in an end-on approach. Wherever the displacement of a ship will permit, the protection of the battery absolutely requires a covered gun-deck. On single-decked vessels other means of protection are designed, and it must be remembered that the defensive power calls for a weight that must be taken from the guns and ammunition. The allowance is at best but a small percentage of the displacement. If a ship is built for fighting, it is certainly bad policy to deprive her of the means of offense. We therefore consider it necessary to strongly protest against the reduction of the fighting power below that carried in foreign navies. In the batteries that we have recommended for adoption we have kept the total weight below the average allowed in European vessels. This weight averages 5.9, and in no case passes 6.2 per cent. But in the modified batteries these weights have been cut down over 1 per cent. We respectfully submit to the Board that no fighting vessel, whatever be her speed, steaming qualities, strength, or safety, is in a position to realize the benefits of her excellences if her ordnance falls below a weight of 5.8 per cent. of her displacement tonnage, except in the single case of utilizing her speed to escape from vessels which she should overmatch. Very respectfully, your obedient servants, H. L. HOWISON, Commander, EDWARD W. VERY, Lieutenant, U. S. N. REPORT OF THE SUBCOMMITTEE ON DESIGN AND CONSTRUCTION OF HULL. WASHINGTON, D. C., October 5, 1881. SIR: The accompanying drawings of a spar-deck flag-ship, a singledeck ship of war of the first class, a ship of war of the second class, and a gunboat, have been prepared in conformity with the instructions of the Board. The dimensions of the vessels as originally proposed have not been varied from, but a small increase in the estimated displacement was found necessary, and in order to obtain the high speed required it was absolutely necessary to allow a deeper keel aft to admit a propeller of the proper diameter; a temporary transter of guns and men on the deck we find can readily bring the vessels on an even keel when occasion requires. Allowing the vessels to have a topgallant-forecastle deck, not extending abaft the foremast, but which was not originally contemplated, has added somewhat to the weight. The ordnance officers of the Board not having originally proposed any armament, nor given any estimate of its weight, the constructors had to assume the number of guns which in their opinion the vessels could carry. This was necessary, because the number of guns determines the number of the crew and the consequent weight of provisions, water, &c. The estimated weight of the armament provisionally adopted by the constructor, corrected from the Ordnance Instructions of 1880, page 430, is, for the 24 guns assumed by the constructor for the spar-deck flag-ship, 292 tons; for the 14 guns similarly assumed for the first-class ship of war, 183 tons; for the 8 guns of the second-class ship of war, 103 tons, and for gunboat, 18 tons. The weight of the equipments of all kinds, namely, masts, rigging, sails, boats, anchor and cables, crew, provisions, water, tanks, casks, fuel for cooking, galley, cooking utensils, furniture, books, clothing, small-stores, hospital stores, officers' stores and baggage, and stores in the various departments was estimated by us in the usual manner, which experience has shown to be nearly correct. Estimating the weight of the hull, masts, boats, tanks, casks, and stores in construction department, and assuming the weight of the steam-machinery and coal to be as determined by the engineers of the Board, there will remain in the spar-deck flag-ship the weight of 919 tons for the armament and other equipments, consisting of rigging, sails, awnings, anchor and cables, crew, provisions, water, fuel for cooking, galley, cooking utensils, furniture, books, clothing, small-stores, hospital stores, officers' stores and baggage, and stores in the various departments. In the first-class ship of war there will similarly remain 642 tons for the same purposes; in the second-class ship of war, 398 tons; and in the gunboat, 93 tons. The weight of the armament above estimated can only be increased by means of an equal reduction in the equipment or in the quantity of provisions and stores to be carried, for to reduce the steam-machinery and the coal will be a vital injury to the vessels in regard to their speed and ability to keep the sea under steam. Should the surface of the sails be reduced by one-third, there would be a gain of 76 tons in the spar-deck ship, 62 tons in the first-class ship of war, and 48 tons in the second-class ship of war; with this reduetion of spars there could be a small reduction in the anchors and cables. If the vessels be more deeply immersed in the water to enable greater weights to be carried, their speed will be proportionally decreased and their general usefulness impaired. The cost of the hull of the spar-deck ship, with masts, boats, tank and casks and stores, we estimate at..... Same, first-class ship of war.. ...... $728,000 00 514,000 00 358,000 00 90,000 00. We are of opinion these vessels, as now submitted, will fulfill all the conditions originally required by the Board as sea-boats and fast steamThey are sufficiently large, and it would be injudicious to increase their size and cost. Respectfully, Rear Admiral RODGERS, JOHN LENTHALL, Naval Constructor (retired). Naval Constructor, U. S. N. Naval Constructor, U. S. N. President of Board. REPORT OF THE SUBCOMMITTEE ON DESIGNS OF ENGINES AND MACHINERY. NAVY DEPARTMENT, October 5, 1881. SIR: In accordance with the instructions of the Board, its committee on machinery has designed the machinery required to give the respective four classes of vessels ordered by the Board the speeds required. In making these designs, the committee adopted horizontal backaction compound engines, with steam-jacketed cylinders, surface condensers, and independent expansion valves on each cylinder. The boilers adopted are the ordinary cylindrical boilers, with return tubes above the furnaces, and having a strength capable of carrying a pressure of 90 pounds per square inch. The screws are all fixed, four-bladed, and have uniform pitches; one screw for each vessel. All the machinery is below the water-line, and is otherwise protected from shot by the coal, which has been placed in bunkers arranged for the purpose, and for convenient delivery upon the fire-room floor. For the spar-deck ship the engine consists of three cylinders, each of 75 inches diameter and 5 feet stroke of piston. The boilers are sixteen in number, arranged in two groups of eight each; each group having a separate chimney, making two chimneys in all. The fire-room, which is in the fore-and-aft direction of the vessel, is 9 feet wide for the after group of boilers, and 8 feet wide for the forward group. The two groups of boilers are separated on each side of the vessel by a coal bunker 6 feet wide. Each boiler is 12 feet in diameter and 9 feet in length; it contains three cylindrical furnaces 3 feet in diameter, with grates 6 feet in length. The aggregate grate surface is 864 square feet. The screw is 22 feet in diameter, 34 feet pitch, and 34 inches length. The coal is carried in bunkers arranged on the starboard (but not on the port) side of the engine; between the boilers and the engine; between the two groups of boilers; in a hold forward of the boilers and below the lower deck; between the boilers and the sides of the ship; and along the sides of the lower deck for the entire distance occupied by the engine and boilers. The weight of the machinery will be 900 tons, and its estimated cost is $403,200. The weight of coal carried is 960 tons. For the first-class sloop of war, the engine consists of three cylinders of 65 inches diameter and 5 feet stroke of piston. The boilers are twelve in number, arranged in two groups of six each, each group having a separate chimney, making two chimneys in all. The fire-room, which is in the fore-and-aft direction of the vessel, is 9 feet wide for the after group of boilers, and 8 feet wide for the forward group. The two groups of boilers are separated on each side of the vessel by a coalbunker 4 feet wide. Each boiler is 12 feet in diameter and 9 feet in length; it contains three cylindrical furnaces 3 feet in diameter, with grates 6 feet in length. The aggregate grate surface is 648 square feet. The screw is 20 feet in diameter, 2 feet in length, and 32 feet pitch. The coal is carried in bunkers on the starboard (but not on the port) side of the engine; between the boilers and the engine; between the two groups of boilers; in a hold forward of the boilers and below the lower deck; between the boilers and the sides of the ship, and along the sides of the lower deck for the entire distance occupied by the engine and boilers. The weight of the machinery will be 760 tons, and its estimated cost is $340,480. For the second-class sloop of war, the engine consists of a high-press ure and a low-pressure cylinder; the former having a diameter of 48 inches, with a 3-foot stroke of piston; and the latter having a diameter of 65 inches with a 4-foot stroke of piston. The boilers are ten in number aud form a single group; all deliver their gases of combustion into the same chimney. The fire-room is 9 feet wide and extends in the foreand-aft-direction of the vessel. The boilers are arranged in pairs, on opposite sides of the fire-room, and facing each other. Each boiler is 9 feet in diameter and 9 feet in length, and contains two cylindrical furnaces 3 feet in diameter, with a 6-foot length of grates. The total grate surface is 360 square feet. The screw is 16 feet in diameter, 2 feet in length, and 25 feet uniform pitch. The coal is carried in bunkers arranged on the starboard (but not on the port) side of the engine; between the engine and boilers; in a hold forward of the boilers and below the lower deck; between the boilers and the sides of the vessel, and along the sides of the vessel, on the lower deck, for the entire distance occupied by the engine and boilers. The weight of coal carried is 575 tons. The weight of the machinery is 550 tons, and its estimated cost $246,400. For the gunboat, the engine consists of a high pressure cylinder of 24 inches diameter, and a low-pressure cylinder of 40 inches diameter; stroke of piston for both, 30 inches. The boilers are four in number, 9 feet 4 inches in diameter, and 8 feet 6 inches in length. Each boiler contains two cylindrical furnaces, 3 feet in diameter, with grates 6 feet in length. Total grate surface, 144 square feet. The boilers are placed in pairs, each pair facing the other, with an athwartship fire-room between them, 9 feet wide. The four boilers have one chimney in common. Between the boilers, on each side of the fire-room, is a fore-andaft passage 4 feet wide, and over each of these passages is a hatch 6 feet long by 4 feet wide, for ventilation. The screw is 10 feet in diameter, 15 inches in length, and has a uniform pitch of 163 feet. The coal is carried partly forward and partly abaft the boilers, and weighs 160 tons. The weight of the machinery is 160 tons, and its estimated cost is $71,680. The four accompanying general plans, drawn to scale, show, for each vessel, the arrangement of the entire machinery, and coal-bunkers, hatches, ladders, &c., together with the dimensions of the spaces occupied. We are of opinion that the machinery submitted for the four classes of vessels will give the required speeds; that it is well adapted to the vessels, can be properly placed in them, and will prove satisfactory in its working when constructed. Very respectfully, your obedient servants, B. F. ISHERWOOD, Chief Engineer, U. S. N. CHAS. H. LORING, Chief Engineer, U. S. N. CHAS. H. MANNING, Passed Assistant Engineer, U. S. N. Rear-Admiral JOHN RODGERS, U. S. N., President of the Advisory Board. REPORT OF THE SUBCOMMITTEE ON EQUIPMENT OF VES SELS. WASHINGTON, D. C., October 4, 1881. SIR: The committee to whom was referred the subject of equipment of vessels submit the annexed table of weights and costs of outfits, stores, &c.; also, weights of provisions and clothing for 100 men for three months. Very respectfully, P. C. JOHNSON, Captain, U. S. N. R. D. EVANS, Commander, U. S. N. M. R. S. MACKENZIE, Rear-Admiral JOHN RODGERS, U. S. N., President of Advisory Board. Lieutenant, U. S. N. Weights and costs of outfits and equipment of proposed vessels. Weight of provisions and clothing for 100 men for three months. Pounds. 26, 625 5,063 200 264 8,000 40,752 16, 830 00 15,000 10,856 24,700 00 3,428 2,741 1, 802 00 2,241 6, 602 1,063 24 21, 049 5, 993 08 5, 504 15,795 80 00 1,760 008, 250 00 7,800 00 1, 602 99 986 38 4, 517 31 221, 887 200, 838 Total weight..... 31,888 |