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8 UNITED STATES STEAM RAM KATAHDIN. A good deal of curiosity has been excited as to the appearance and details of construction of the United States steam ram Katahdin, as a result of the Con- gressional action permitting her acceptance. The Ka- tahdin was built by the Bath Iron Works, of Bath, Me., and on her trialtrip failed to make 17 knots an hour, the speed demanded by the contract. After careful in- vestigation, however, it was found that this was not at all the fault ofthe builder, but that her peculiar model almost precluded this speed on any degree of power. The indicate horse power was considerably in excess of requirements, and on bhese grounds the Katahdin was accepted. The Katahdin is the product of many years of re- search and careful investigation by Admiral Ammen of the Navy. Her builders have had to contend with sev- eral serious drawbacks in getting her near to the con- tract speed of 17 knots an hour. Her lines are not such as to allow of a free throw-off of the water as she goes along; in fact, as one old salt said about her the other day, ‘‘she papers the whole Atlantic ocean ahead of her.’’ She is of the whaleback typ2, aud in some respects— those of low freeboard and heavy hull protection—re- sembles the common idea of the monitor. Intended to ram the enemy and in that way to do the most possible damage, her whole offensive power is concentrated in her formidable ram head of cast steel. Virtually the vessel is an immense automatic aquatic _ _ projectile of 2,183 tons, driven by a double set of trinle- expansion engines at the rate of nearly 17 knots an hour, and able to deliver a blow of 56,000 foot-tohs. The structural bracing of the vessel has been carefully de- signed to insure great strength, and an equal distribu- tion along the axis of the whole body of the shock of the impact, the piganlike form of the hull facilitating that end. From’ the collision bulkhead to the stern the vessel has an inner bottom, and between the inner and outer bottoms and the inner skin and deck armor the craft is divided into more than a hundred ‘water-tight compart- ments, and,by flooding certain of the compartments of the double bottoms the vessel is submerged to her fight- ing ‘rim. To shield herself from the blows of the enemy, the Katahdin will depend upon the deflective power of her curved armor, which tapers from the out- board strake in toward the center line from 6 to 2% _ inches, and upon her limited exposure of hull, the con- ning towers, ventilators, and smoke pipe being the most important targets for an enemy’s fire. The four six- pound rapid fireguns are to repel torpedo boats. The armor throughout the vessel is of nickel steel. All the hatches leading below through the armor deck are to be protected by battle plates, and the smoke pipe and ven- tilators are to have inclined armors six inches thick. The conning-tower, which is placed well forward, to give a commanding view in fighting the ship, is to be almost eighteen inches thick. The vessel’s principal dimensions and special features are: 250 feet 9 inches onload water line; 43 feet 5 inches breadth, extreme; 15 feet mean draught; 239.88 tons total coal bunker capacity. The engines are of the triple-expansion type, one set actuating each screw, and in separate water tight compartments, with THE MARINE RECORD. cylinders of 25 36 and 56 inches, having a stroke of 36 inches, and a piston speed of 150 revolutions a minute. There are two main double-ended boilers 13 feet 8 inches by 22 feet 6 inchcs, and one auxiliary single-ended boiler 13 feet 8 inches by 11 feet 7 inches, giving a total grate surface of 354 square feet and a total heating sur- face of 13,190 square feet, the Gla e pressure to be 160 pounds. Some idea of the difficulties experienced in getting the required speed out of her may be had from the fact that the engines of the Katahdin have already deve- loped nearly 6.000 horse power. This is an enormous horse power for a vessel of her size, and had the lines of her hull been of even an ordinary nature, or conduced to speed in the least degree, no difficulty would have have been found in driving her ahead at a much higher speed than that required. It must be remembered, however, that while most of the faster cruisers could undoubtedly walk away from the Katahdin in a straight-away run, it is very unlikely that they could be manceuvered at close quarters so quickly as to avoid her if she attempted to ram. As at first constructed the bow of the vessel consisted of the ram in its naked wickedness, but it was found on the first trial that the slope down to the water’s edge tended to throw a good deal of water upon the deck, and so a false bow has been added, which covers the ram and brings the bow up above the water. When the vessel is submerged to her fighting trim she buries the knuckle of her heavy armor deck plating a foot below the surface, and, as an old Jack Tar ex- pressed it, ‘‘Blow me, if she don’t carry her water-line on deck!’’ In action she is intended to strike fairly UNITED STATES STEAM RAM KATAHDIN. head on, the sharp edges of her side to cut like an opster knife into the enemy’s plating below the water line. The possible consequences of a mass of such proportions rushing at a foe have been shown with awful impres- siveness in the case of the ill-fated Victoria. In all but speed the Katahdin comes fully up to her From Harper’s Weekly. Copyright, 1894, by Harper & Brothers SECTIONAL VIEW OF THE KATAHDIN. contract requirdments, and in this she falls very little short. The report of the trial trip states that the time occupied by the ram in making the run west of 17 knots was 1 hour 5 minutes and 33 seconds. The run back was madein 1 hour 0 minutes and 44 seconds, the total time for the round trip being two hours 6 minutes and : 17 seconds. When the tidal corrections were applied to the course it was found that the distance actually — traveled by the Katahdin was 33.91683 knots. - The board divided this by the time consumed and found that the true mean speed of the ram was 16.1146 knots Lier % hour. : The mean draught of the ram when she left New Lon- | don was 15 feet. ‘The coal consumed during the trial lightened her somewhat, and upon her return it was found that her draught was 14 feet 8% inches. During the run there was a moderate surface sea but no swell. The vessel neither pitched nor rolled. She carries her helm amidship. During the entire trial the tide was ebb, setting to the eastward, and was slightly stronger onthe return run. The board is enthusiastic about the — turning qualities developed by the ram. Its report states that at the end of the second run, and before the speed of the vessel was virtually diminished, the helm. was put hard over both ways, the time from hard-a starboard to hard-a-port being 17 seconds. The steer- ing geer is thoroughly efficient and works smoothly and easily, and the vessel turns promptly and rapidly. On the first run the mean of the revolution of the starboard engine was 151.5 and port 146. The average revolutions of the starboard engines were 146.49 and port 143.5. The mean steam pressure on this run was 168 pounds and the average 166.5 pounds, and the mean air pressure to 1 inch of water was 2.4 and the average ~ 1.35. On the return run the mean of the revolutions for — the starboard engine was 150, average 148.49, and the mean for the port was 145, average 144. The mean steam pressure was 168 pounds and the average 167.1. The air pressure to 1 inch of water was 2.4 mean and 1.7laverage. The Katahdin returned to New London under natural draught, making between 13 and 14 knots. Crossing the sound she encountered a moderate sea. Her rolling motion was very slight and easy, the seas breaking completely over her hull. In concluding its report the board say that they found that the vessel is sufficiently strong to carry her armor and armament, equipment, coal supply, stores, etc. Her hull, fittings, equipment and machinery are strong and well built andin strict compliance with the pro™ visions of the contract. The board find that in a num- ber of minor instances the ship is not fully completed and enumerates a number of small articles with which she must be supplied before she can be considered finished. The report states that the ram is noticeably free from vibrations at full speed. Her minimum heel- ing angle at full speed with helm hard over was found to be 1%°. The board was especially pleased with the ventilation of the ram. Although she is covered entirely over by a plated deck the air inside was thoroughly pure. The report states on this point that the “ventilating system appears to be exceptionally efficient.’? Chief Naval Constr. Hichborn directed that the Katahdin be sup- plied with her present system, and the board pays con- siderable attention to its good qualities. The RECORD is indebted to the Army and Navy Jour- nal for the illustration of the Katahdin, for which it was especially prepared from a photograph. The cross section here shown was kindly furnished es y ed by Harper and