THE MAPLE.

MATERIAL OF HULL.

The material, to be open-hearth mild steel, shall stand satisfactorily the tests adopted by the Light-House Board and specified in detail hereinafter.

Depth of hold from top of beam to top of keel-plate....

GENERAL DESCRIPTION.

Ft. In.

164 O

155 0

30 0

11 10

The vessel will be built with a double bottom, constructed as per plan and specification, extending from frame No. 53 to frame No. 65. This double bottom will be divided into two separate water-tight and independent compartments, each provided with a sufficient number of manholes properly constructed and so located that access can be had at all times to both compartments for cleaning and other purposes. The detailed description of the construction of the double bottom will be found under its proper head, the different compartments to be tested with a hydrostatic pressure, not less than that corresponding to a head of water of 15 feet. There will be seven water-tight bulkheads dividing the parts of the vessel above, and forward, and abaft the double bottom, into eight water-tight compartments. All water-tight compartments in any part of the vessel to be provided with effective appliances for draining and emptying, also for sounding and for the escape of air. The vessel will be built with a flat-plate keel in double thicknesses, provided with one outside bilgekeel on each side of the vessel, constructed as shown, and extending for about 75 feet. The run of these keels shall conform with the natural run of the water when the vessel is in motion. The plating will be run in inside and outside strakes, perfectly fair, and the shell-plating shall be neatly and smoothly fitted up and riveted. All plates in the shell of the vessel, the keels, the bulkheads, the bulwarks, and wherever directed by the superintendent in charge, shall be machine planed; no other method of fairing the strakes or preparing edges for calking will be allowed. Under the main deck will be located storeroom, trimming tank, lower quarters aft, fitted with ten berths; three staterooms, pantry, lockers, table, etc. Forward of these quarters and in the succession named will be located the engine room, extending to the superstructure deck; the boiler rooms, the coal bunkers, the cargo hold, trimming tanks, crew space with twelve berths, lockers, wardrobes, washstands, table, etc., chain lockers, and the forepeak, which will be fitted up as a storeThe main deck house will be constructed as shown on plans, and extend from about frame No. 4 to about frame No. 53, and in it will be located inspectors' quarters, consisting of cabin, two staterooms provided with iron bedsteads, one pantry, and one bath room, every room fitted complete; two staterooms for two quartermasters and for cook and steward, entrances to upper deck and lower quarters aft, engine room, donkey boiler room, water-closets for crew, and bath room for officers, crew's wash

room.

room, the upper boiler room, galley, room for steam steering engine, lamp room, and ice room, two hoisting engines, located as shown. Cargo hatch, necessary eleats, fairleads, bitts, ringbolts, freeing ports. scuppers, anchor beds, anchor windlass, and all other small fittings needed for the proper handling of the vessel, cargo, buoys, boats, anchors, etc., will be located and fastened as shown, and as will be directed by the superintendent in charge, whose decision in such matters shall be final. On the superstructure deck aft will be located a deek house with chart room fitted as a stateroom, with burean, desk, iron bedstead, etc., and entrance from main deck, also a forward house with pilot house and staterooms for master and chief engineer, as shown. This superstructure deck will be surrounded by a strong and neatly-built rail of galvanized-iron piping. On this deck will be located three boats, necessary ringbolts, bitts, chocks, fairleads, lead box, cleats for fenders, for fastening, and for all other purposes required by the service. Two hard-wood stairs will lead to the forward deck and one to the deck aft.

The vessel will be rigged as a two-masted schooner, as shown on the plans and as will hereinafter be described and specified.

DOUBLE BOTTOM.

The vessel will be fitted with a double bottom, extending from frame No. 53 to frame No. 65, constructed as shown on plans. Inside height of this double bottom, in the clear between plates amidships, will be about 36 inches. The vertical center keel plate will run from end to end of the double bottom and will be tapered forward of frame 65 to the height of the keelson, and it will form the center keelson for the length of the double bottom. The frames in the double bottom will be run continnously from center to the height given under the heading "frames." The reverse bars shall be cut between the girders and at the margin plate, where they will be dispensed with for a sufficient distance to allow the margin plate to be properly worked in, and to make the double bottom water-tight at the sides or bilges. As a compensation for the cutting of the reverse frames at the side, there shall be put in doubling frames, same size as the ordinary frames, riveted back to back to frames proper. The lower and upper angles connecting the vertical keel plate and side girders to inner skin and floor plates shall be continuous. The reverse bars in clips between the girders are to be secured thereto by means of small plate knees large enough to take three rivets on each side, and they are to be strengthened by vertical angles where, in the opinion of the superintendent in charge of the work, it may be deemed necessary. The plans, together with the specifications, shall govern the construction of the double bottom, and two ballast compartments shall be formed of same, as shown on plans.

BALLAST TANK AFT.

Beams in ballast tank to be angle steel, 3 by 2 by inches, fitted to each frame and secured thereto by knee-brackets of proper size and thickness. Plating at center to weigh 10 pounds per square foot, reduced at sides to 8 pounds. Round wronghtiron manholes with water-tight cover to be fitted as shown on plans. All trimming tanks to be thoroughly water-tight, and tested by hydrostatic pressure not less than that corresponding to a head of water of 15 feet, and to the satisfaction of the superintendent in charge of the work.

BULKHEADS.

The bulkheads to be arranged as per plan, to be built thoroughly water-tight, and to be tested by a hydrostatic pressure not less than that corresponding to a head of water of 15 feet from the bottom of the keel. The bulkheads shall be fitted with patent radiating stiffeners, the distance between the stiffeners decreasing toward the bottom, and also toward the center line of the vessel. The plates shall therefore not

be increased in thickness in the lower part of the bulkhead, but be of a uniform thickness of 9 pounds per square foot. The stiffeners shall be in size equal to the frames.

Double frames shall be fitted at all the water-tight bulkheads, and both edges of both frames shall be planed for calking. To prepare such edges by chipping after fitting of the shell-plating will not be allowed. The whole shall be made thoroughly water-tight by calking only, except in such places where, in the opinion of the superintendent in charge, hempen stop-waters, dipped in red lead, may be used as an extra precaution. Seams of plating to run horizontally, the plates to be lap-jointed, planed, and calked water-tight. Around keelsons and stringers will be fitted shoes of angles strictly conforming with the shape of angles, corners, etc., on one side and a plate on the other. Liners for the outside strakes at water-tight bulkheads shall extend from the frame forward to the frame abaft the bulkheads; they shall be planed, fitted tight, and be calked. Suitable sluice valves to be fitted on all watertight bulkheads, and to be worked from the upper deck. Liners and stiffeners to be put in where necessary. The coal-bunker bulkheads to be built as per plan, the plates to weigh 7 pounds per square foot. It is the intention that the bulkheads and all water-tight compartments in the vessel shall be tight against the pressure specified, and that the bulkheads shall be built strong enough to withstand any pressure due to the complete filling of any room or compartment below main deck. Care shall therefore be taken that such a result will be obtained and tests will be made by the representative of the Light-House Board to such an extent as will satisfy him that the intention of the contract has been fulfilled.

LOWER CABIN AFT.

Will be fitted with ten beds with drawers underneath, beds and drawers to be constructed of pipes, tees, elbows, and wire netting, as per plan; four air ports 10 inches in diameter will be fitted on each side with storm covers of cast iron working on hinges; necessary shelves, hooks, etc., to be fitted where required; all woodwork white pine; doors in staterooms to be arranged in panels; all locks and fittings for doors, drawers under beds, etc., to be of brass. The entrance to these quarters will be from main deck on starboard side in engine room, as shown, and will be built perfectly water-tight into the water-tight bulkhead; lockers to be fitted as shown and as will be directed.

CREW SPACE.

The crew space will be located as per drawing, and will be fitted with berths for 12 men, constructed of pipes, tees, elbows, and wire netting; under each of the lower berths there will be two drawers of wire, fitted with lock and keys of brass; six wardrobes will be built as shown, 15 inches in clear above deck, and a table having an ash top and sufficiently large to seat 12 men will be furnished. This table will be made to slide up on stanchions and properly fastened underneath deck beams when not in use; necessary clothes hooks to be provided; special care to be taken to provide proper ventilation and good light. Draining holes to be cut in the flooring where directed. There will be four air ports on each side, of metal, and 10 inches in diameter in clear, with rubber packing and cast-iron storm covers working on hinges. To each bed will be furnished one mattress, one pillow with cover, one mattress cover, two cotton sheets, and two blankets. The crew space will also be provided with good substantial outfit of crockery, cutlery, glass and table ware complete for 12 men; also fourteen wooden stools.

EQUIPMENT AND OUTFIT.

Steam-steering gear.-The vessel shall have a steam-steering gear of the Globe pattern; the engine shall be fitted complete with drum; hand-steering and steam-steering wheels of proper size and neat finish; all chains, wire ropes, blocks, and fair

leads shall be supplied and fitted; the whole shall be arranged in the most convenient manner ready for actual use for steering by hand or by steam, and to the satisfaction of the representative of the Light-House Board.

Anchors and chains.-The following anchors will be supplied by the contractor: One bow anchor, 1,600 pounds; one bow anchor, 1,400 pounds; one stream anchor, 500 pounds; all with iron stocks; also 90 fathoms 18-inch stud chain, and 75 fathoms 18-inch stud chain; necessary chocks, etc., to be made and fastened in their proper place. The chains shall stand in every respect and satisfactorily Lloyd's tests. Hoisting engines.-The contractor shall furnish and fasten in places indicated on plans one double 104-inch cylinder steam-hoisting engine, of Copeland & Bacon's New York, pattern, and one single 6-inch cylinder hoister of the same make.

The hoisters shall be leaded under and strongly fastened to deck and deck beams. They shall be provided and fitted with all valves, pipes, connections, etc., necessary in actual service, to the satisfaction of the representative of the Light-House Board.

DRAWINGS.

The contractor will furnish the Light-House Board with a complete set of drawings or tracings (no blueprints will be accepted, except in such cases where, in the opinion of the Light-House Board, a blueprint would fully answer the purpose) of all parts of the hull, machinery, pumps, rigging, and general arrangements of same as assembled in the vessel and as actually constructed; also weights of boilers, engines, pumps, shafting, propellers, etc., where possible to be given in detail. Such drawings, weights, and other data to be delivered to the Light-House Board within thirty days after the final trial trip; also a model, 4-inch scale, suitably mounted.

ENGINES, BOILERS, AND APPURTENANCES FOR TWIN SCREWS.

General description.—There will be two right and left handed cast-iron screw propellers, one under each counter, of about 6 feet 9 inches diameter and suitable pitch, each screw to be driven by an inverted-cylinder surface-condensing two-cylinder fore-and-aft compound engine, the cylinders to be 16 inches and 31 inches in diameter, with a stroke of 24 inches.

Screw propellers.-To be of cast iron, each about 6 feet 9 inches in diameter, of suitable pitch, and provided with four blades. They are to be secured to shaft by means of longitudinal keys and held in place by nuts screwed on and locked in place. The starboard propeller will be right and the port one left handed. The shaft casing will enter about 1 inch into the propeller boss and be fitted water tight; each boss will be finished at the after end by a composition cap bolted on water-tight. The propellers will be cast as smoothly as possible and have all roughness removed.

Boilers.-There are to be two cylindrical single-ended steel return tubular boilers, located as shown on plans, 11 feet 9 inches diameter outside the smallest course of shell, and 12 feet long from outside to outside of ends.

There are to be two Fox's patent corrugated furnaces in each boiler, 40 inches in diameter inside; corrugations to extend from the front end to the back tube-head and secured thereto by means of a single seam of rivets, of diameter and pitch to suit the thickness of the plates. The corrugations of furnaces are to alternate. The back connections will be about 36 inches long at the bottom and about 33 inches at the top, increased in a direction parallel with the length of the boiler, and the side sheets are to be carried eccentric to the shell, so that the distance between the shell and said side sheet will be about 4 inches in the clear at the bottom, increasing upward to a distance, in the clear, of about 63 inches at the height of the top row of the tubes. The crown sheet is to be horizontal and stayed by means of wrought-iron girders, properly spaced, and formed at the ends to have bearings on the front, back, and crown plates, and have a clear space of not less than 2 inches between the crown sheet and the bottom of the girders.