|
The Fenian Ram was a three-man boat. The operator sat in a kind of bucket seat perched over the engine. On the port side, the large flywheel revolved, driving an eccentrically fastened rod that operated a compressor mounted forward over a high-pressure air tank. On the starboard side, a second eccentric drove a similar compressor. Two upright levers served as controls, joy-stick fashion: the left one controlled the rudder; the right, the diving planes. The second member of the crew served as engineer. His task was to regulate flow through the numerous valves as required, check the gauges for pressure, or blow the fixed ballast tanks if an emergency required such action. Holland had masterfully designed the Fenian Ram to assure longitudinal stability, a problem that plagued contemporaries such Goubet and such later rivals as Garrett and Nordenfelt. This was achieved by meeting two fundamental requirements which he always set for himself: a fixed center of gravity and a constant reserve of positive buoyancy. The long, tapered bow and stern each held a sealed compressed air reservoir calculated to assure positive buoyancy. Between each reservoir and the crew's central control room, separate water ballast compartments were provided. The central location of these tanks proved a decided advantage. The after tank was always kept full when running submerged in order to prevent any disturbance from the motion of water within it. The forward tank was kept "nearly full, allowing a little to compensate for changing weights," including oil consumption and projectiles expended. This arrangement was far ahead of its time and enabled Holland to maintain a fixed center of gravity and the longitudinal stability he rightly felt to be essential.12
A third member of the crew was the gunner who operated the sole piece of armament on board the Ram. This consisted of a pneumatic gun constructed of a nine-inch tube. Approximately eleven feet long, the gun tube ran through the center of the forward air reservoir. Its breech of heavy iron casting was centered in the forward water-ballast tank, opening by means of a hinged door into the control compartment. With the pointed bow cap screwed down into a watertight position, the gunner's task was to undog the inner door, load a six-foot projectile into the tube, shut the inner door, turn a crank which opened the bow cap, reach down and unscrew the balance valve sending a four-hundred-pound air charge into the breech, and thus fire the projectile. Water rushed in to fill the tube. The gunner cranked the bow cap closed. Then he blew the tube, forcing the water into the ballast tank that surrounded it and restoring the fixed center of gravity13
12. Holland, "Notes on Fenian Ram," p.7. It was rumored that Goubet's little boat, launched in 1883, lost its longitudinal stability whenever the operator thrust his arm forward,. Nordenfelt later experienced the same instability in his Turkish boats. 13. These descriptions are based on the Delameter Iron Works' final drawings of the Fenian Ram, dated 7 February 1880 (General Dynamics Corporation, Electric Boat Division, Groton, Conn., Negative No. 1513), and on Holland's notes. |