TECHNICAL DESCRIPTION OF THE USS MAINE
From The "Maine", 1899

By Captain Charles D. Sigsbee

The United States Armored Cruiser Maine.

By Chief Engineer A. W. Morley

 

The following account of the Maine is drawn almost wholly from a paper by Chief Engineer A. W. Morley, USN, printed in the Journal of the Society of American Engineers, February, 1895, and entitled Contract Trial of the United States Armored Cruiser Maine.

The Maine, a twin-screw armored cruiser of about 6650 tons displacement, was built at the navy-yard, New York, from designs furnished by the Bureau of Construction and Repair of the Navy Department, and was the largest vessel built in any of our navy-yards. In external appearance and in arrangement of battery, she resembled the Brazilian ship Riachuelo but she was larger and had thicker armor and heavier guns. The machinery was built by N. F. Palmer, Jr., & Co., the Quintard Iron Works of New York City, from designs furnished by the Bureau of Steam Engineering of the Navy Department, the contract price of the machinery being $735,000. The contract price called for an indicated horsepower of 9000 for the main engines and the air and circulating pump engines, with a premium of one hundred dollars to be paid for each indicated horsepower in excess of the requirement, and a penalty of like amount to be deducted for each horsepower below that amount. Her keel was laid on October 17, 1888, and her hull was launched on November 18, 1890. The contract for the construction of her machinery was signed on April 3, 1889, and the engines erected in the ship and operated on August 31, 1891. An official dock trial was made on July 2 I and 22, 1893. She was commissioned September 17, 1895, and left the navy-yard, New York, on November 5, 1895, drawing twenty-two feet one inch forward and twenty-one feet eight inches aft.

The hull was constructed of mild steel, and all of the material used was of domestic manufacture. The outside keel-plate was five eighths of an inch, the inner plate, half-inch, and the vertical keel. a half-inch thick. The outer bottom plating was a half-inch thick, with a double sheer-strake; the plating of the inner bottom was five sixteenths of an inch thick. The frames were spaced four feet throughout the length of the double bottom, and three feet at the ends.

She was divided into two hundred and fourteen watertight compartments, and had a double bottom extending from Frame 18 to Frame 67, a distance of one hundred and ninety-six feet, and running up to the shelf for the armor belt. In the wake of the double bottom there were four longitudinals on each side, and under the engines and boilers intermediate longitudinals were introduced.

There were twenty coal-bunker compartments, ten on each side of the vessel, extending down from the protective deck, with wing bunkers at each end of each fire-room, extending inboard to the front of the boilers. The total capacity, in tons of forty-two cubic feet, was eight hundred and twenty-five tons. The bunkers were filled through trunks leading down from the main-deck, delivering directly into the several main compartments and to the wing bunkers, being so arranged that but little trimming of the coal was required until the bunkers were nearly filled.


DIMENSIONS OF HULL
Length between perpendiculars - feet
310
Length over all - feet and inches
324,4
Beam, extreme, at L. W. L. - feet
57
Draft, mean, normal - feet and inches
21,6
Area immersed midship section - square feet
1,077
Displacement, tons, at 21 feet 6 inches
6,650
Tons per inch
32.32
Center of buoyancy above baseline - feet and inches
12,3.5
Center of buoyancy aft of midship section - feet and inches
2,11
Center of gravity below C. B. - feet and inches
3,1
Transverse metacenter above C. B. - feet
12
Longitudinal metacenter above C. B. - feet
324
Coefficient of displacement, prismoidal - feet
0.596
Coefficient of displacement, cylindrical - feet
0.669
Coefficient of midship section - feet
0.878
Coefficient of L. W. L. - feet
0.747
Area of L. W. L. - square feet
13,560
Wetted surface - square feet
25,770

 

For a length of one hundred and eighty feet amidships there was a waterline belt of vertical Harveyized steel armor, extending from three feet above to four feet below the waterline, twelve inches in thickness from the top to one foot below the waterline, whence it tapered to seven inches at the bottom. The wood backing was eight inches thick, and the plating behind this was in two thickness' of a half-inch each, stiffened by horizontal angle-bars six by three and a half inches, and by plates five sixteenths of an inch thick, worked intercostally between the vertical frames,and connected with them by angle-bars two and a half by two and a half inches.

The bolts for securing the armor were two and eight tenths inches in diameter, with nuts and india- rubber cups and washers on the inner ends of the bolts. The wood backing was secured to the skin plating by bolts one and one eighth inches in diameter.

At the forward end of the armor belt there was an athwartship bulkhead of steel six inches in thickness, with the backing generally arranged as for the side armor.

The protective deck, constructed in two layers of one inch each, extended from the armored bulkhead to the after-end of the side armor, whence it sloped below the waterline with a thickness of three inches.

There was an armored conning-tower built of steel, ten inches thick, elliptical in shape, from which an armored tube four and a half inches thick extended down to the armored deck to protect the steering-gear, voice-tubes, electric wires, and connections of the engine-room telegraphs.

There were two revolving turrets, each fitted with two ten-inch breech-loading rifled guns, placed high enough to admit of their all being fired simultaneously on a line parallel with the centerline of the ship, each having an unobstructed fire through an angle of 1800 on one side, and through an angle of 640 on the opposite side. Each turret had eight inches of Harveyized steel armor, with plate backing, frames, etc. The revolving parts of the turrets, and the spaces for working and loading the guns, were protected by a fixed barbette of mild steel armor twelve inches in thickness, fitted to a wood and steel-plate backing, and secured by bolts and nuts, as described for the side armor. The turrets and guns were worked by hydraulic gear. Besides the turret guns there were six six-inch breech-loading rifles, two mounted forward inside the super-structure-deck firing directly ahead, two abaft the cabins firing directly astern, and one on each side on the central superstructure-deck.

The ten-inch and the six-inch guns could be fired in broadside, throwing a weight of projectile on each side of about twenty-four hundred pounds at one discharge.

The six-inch guns were worked by hand on central-pivot carriages, and were protected by steel shields two inches thick.

The secondary battery consisted of seven six-pounder Driggs-Schroeder rapid-fire guns, four one-pounder Hotchkiss, four one-pounder Driggs-Schroeder, and four machine-guns (Gatling).

There were four tubes for Whitehead torpedoes, two on each side, discharging directly from the berth-deck.

The ship's motive power was supplied by two vertical, inverted-cylinder, direct-acting, triple-expansion engines, in watertight compartments separated by a fore-and-aft bulkhead. The high-pressure cylinder of each engine was placed aft and the low-pressure cylinder forward, the latter being so arranged that it could be disconnected when working at low power, and the high- and intermediate-pressure cylinders used under economical condition as a compound engine.

The diameter of her cylinders was as follows: high-pressure cylinder, thirty-five and a half inches; inter- mediate-pressure cylinder, fifty-seven inches; low-pressure cylinder, eighty-eight inches; stroke of all pistons, thirty-six inches.

Her propellers were made of manganese bronze, and were four-bladed twin screws. The diameter of her propellers was fourteen feet six and a half inches, and their pitch, as set on her trial trip, starboard, 16.08 feet; port, 16.114 feet.

She had eight single-ended steel boilers of the horizontal return-fire tube type, with three corrugated furnaces in each boiler and a separate combustion chamber for each furnace. The boilers were placed in two equal groups in two watertight compartments, with a central fore-and-aft fire-room in each compartment. There was one smoke-pipe, oval in cross-section, for each group of boilers. The boilers had 573.84 square feet of grate surface. She was provided with a force-draft system in each boiler compartment, for which she had two Sturtevant blowers. Located in the after-part of the ship, well below the protective deck, was a combined hand-and-steam steering-engine of Williamson Brothers' patent. The steering-engine was capable of putting the helm hard over from amidships in ten seconds when the vessel was making a speed of seventeen knots. It could be operated either at the engine or from the conning-tower, the pilot-house or the bridge. She was provided with steam-capstan and-windlass, excellent distilling apparatus, electric plant for lighting and minor purposes, and with an ice-making plant and, in connection therewith, a cold-storage compartment. For turning the turrets, hoisting ammunition, and loading and working the turret guns, she was provided with a hydraulic pumping plant. Large and small, everything counted, she carried fifteen boats, including two steam-launches or cutters.

The official trial for horsepower took place on October 17, 1894, in Long Island Sound. The Maine left her anchorage off New London Light at 12 M., and proceeded out through the Race, and when on Watch Hill was turned and headed to the westward in order to make as nearly as practicable a straightway run for the four consecutive hours' trial required by the contract.

The trial began at 1:30 P. M., and ended at 5:30. The weather conditions were not very favorable, for throughout the entire run the ship was steaming against a strong head wind and sea, which increased in force to the end of the trial. The ship was remarkably steady, and at the maximum speed of the engines very little vibration was noticeable.

The speed was very accurately obtained for a portion of the trial, while running over the official measured course laid down for the trial of the Ericsson The average speed for this 25-mile course was 15;95 knots, or, with a mean allowance of 1.5 knots for the strong head wind and tide, 17.45 knots.