Three gunboats, the Nashville, the Wilmington, and the Helena, were ordered in 1893. The Helena, Nashville, and Wilmington were light-draft gunboats for river service. The Nashville was schooner-rigged, and was interesting because of her peculiar machinery arrangements. She had twin screws and two sets of quadruple expansion engines.She had two types of boilers, cylindrical and water-tubular. Aside from these novel machinery arrangements, the features of the Nashville were as follows: Length, 220 feet; breadth, 38 feet 3 inches; complement, 150 men; At her normal draft of 11 feet her displacement is 1,371 tons.
The Nashville was a draft twin-screw gunboat designed for the usual duties of cruising naval vessels. In coast work her moderate draft of water will enable her to enter many ports from which most men-of-war are excluded on account of their greater draft.She is schooner-rigged, with two smoke-stacks, and her total coal-bunker capacity is 390 tons.
The main battery consists of eight 4-inch breech-loading rapid-fire guns, four of them being on the upper deck, four of the same in armored sponsons on the gun deck; four 6-pounder Hotchkiss guns, two 1-pounder rapid-fire guns and two Gatling guns. One fixed torpedo tube was mounted in the bow, and a searchlight was placed just above the pilot-house and forward of the foremast.
She was able to cruise without re-coaling for long periods at moderate speed, using her cylindrical boilers only, being able rapidly to increase her speed to its extreme limit by starting fires under her remaining boilers. No attempt had been made to secure over 14 or 15 knots an hour, that being sufficient for the duties required of such a vessel. The engines driving the twin screws are of the quadruple-expansion type, so designed that the low-pressure cylinder can De disconnected when the vessel is cruising under ordinary circumstances. When running at full speed the high-pressure cylinders receive steam from the Yarrow boilers directly, while the two cylindrical boilers supply steam to the receivers between the high and first intermediate cylinders. At moderate speed, the low-pressure cylinders being disconnected, steam can be supplied to the two triple-expansion engines so formed by either of the batteries of boilers. The cylinders of these were arranged in fore and aft lines, with the low pressures towards the bow. The purpose is to disconnect these big cylinders by a shaft coupling when the vessel is on ordinary cruises, making the engines triple expansion, and as thus arranged they can be worked with small consumption of coal at about eight knots speed. By coupling the low-pressure cylinders with the others the speed may be run up to fourteen knots, though at the expense of much more coal. At cruising speeds an economy closely approximate to that of careful merchant steamers is expected. Her smoke-pipes are very tall, reaching almost to the top of her masts.
In the launching of the Nashville and the Wilmington was a peculiarity deserving of especial mention. It was believed to be the first cuse where two warships were launched on the same day from a single set of ways. The vessels had been constructed one ahead of the other, tandem fashion, upon a continuous decline, the Nashville nearer the water, with her bow a few feet from the Wilmington, both vessels taking the water stern foremost. This arrangement was due to the fact that the works of the contractors, in accordance with modern notions, had been installed for the erection of ships of the largest size, the building slip^ being of sufficient length to accommodate a vessel 500 feet long, while the combined length of the Nashville and Wilmington was only 485 feet. Not only was ample space available for both ships, but it was also possible to deliver in position all the material used in their construction by a single crane, which travelled alongside on a track So feet above the ground. This great crane, with a lifting capacity of 60,000 tons at the end of the 125-foot arm, also served an adjoining similar slip. The Nashville had to travel only 250 feet before floating freely, but the Wilmington's stornpost had 280 feet to slide before reaching the water and 175 yards altogether before she was fully floated.
The light-draft United States gunboat Nashville made her official trial on Long Island Sound on May 4, 1897,and earned for her builders, the Newport News Shipbuilding and Dry Dock Company, a bonus of near $60,000, her speed greatly exceeding that which was guaranteed, and for which the Government will reward her constructors. Her average speed throughout her trip was 16.7 knots, while but 14 knots was required. The course was laid from Stratford Light to Horton's Point, a distance of 30 miles in a straight line, and return. There were six stake boats, consisting of the tugs Leyden and Narkeeta, the lighthouse tender Cactus, and the torpedo-boats Stiletto, Porter, and Ericsson, which were anchored at distances of five miles along the course. The total time consumed in the run was three hours and forty-seven minutes. After the speed test the gunboat was put through several tests to show her seaworthiness, all of which were successful.
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