Air Supply and Ventilation.—Compressed air is stored aboard the vessel with means of allowing a supply of air into the interior of the vessel. Ventilators are provided for the circulation of outside air throughout the vessel; the gasoline vapours from the engines and all noxious gases are carefully excluded by suitable devices, while safety valves are provided to prevent the pressure to the vessel from exceeding that of the atmosphere.
Pumps and Pumping.—All tanks and compartments are connected with the pumps, the valves are located to allow of quick manipulation, and pumps with independent means of operation are furnished in duplicate. The tanks can also be emptied by flowing out.
Navigating Apparatus.—In communication with the interior of the vessel there are bells and speaking tubes, while there are provided gauges, indices, and clinometers for indicating pressure, depth, positions, quantities, and weights.
Two compasses are carried, each compensated and adjusted. It is said that the first of the British submarines exhibited certain defects in its compasses, which it was thought were due to the steel conning tower. This was replaced by a brass construction, and on being tested the compasses acted more satisfactorily. After a few trials a new steering-wheel was fixed in the boat close to the conning tower, which could be worked from above and below alike.
The first British submarine was launched on November 2, 1901, at Barrow without any ceremony, although representatives of the Admiralty were present. The trials were placed under the direction of Captain R. H. S. Bacon, D.S.O.
Before launching “No. 1” was by means of a floating dock placed on the gridiron. A crew of six men were put on board, and she was then hermetically sealed for three hours, air being supplied by compressed air cylinders. The trial was quite successful, and the men suffered no inconvenience. On her first “sea trial” “No. 1” started from the floating dock and proceeded along the Devonshire and Buccleuch docks and back to her moorings. On subsequent trials she attained a surface speed of 10 knots.
The first submersion trials of “No. 1” were carried out on February 5, 1902. She went under water with some officers of the Hazard t.g.b., the mother ship to the submarines (Captain R. H. S. Bacon, D.S.O.) on board, and most satisfactory results were obtained. Her appliances for the purification of the air were used to maintain atmospheric conditions without any need of her cylinders of compressed air being requisitioned. The first deep sea trials of “No. 1” took place at the beginning of April last in the Irish Sea. The submerging was accomplished in less than six seconds. From the “awash” conditions she suddenly disappeared and then came again into sight some yards’ distant with great rapidity and ease, and the diving was continued at intervals for several hours at a time without any perceptible hitch.[[10]]
[10]. Mr. Arnold Foster, in the House of Commons on May 29, 1902, said that the submarines had been a pronounced success, performing all that could be expected from them in the way of evolution and manœuvring.
Submarine “No. 2” was launched on February 21, 1902. Certain alterations were made in her construction, rendered advisable by defects which had been discovered during the testing of “No. 1.” “No. 3” took the water on May 9th, and “No. 4” on May 23 last.
During April last No. 42 t.b. was commissioned at Portsmouth as tender to the Hazard t.g.b., and was sent to Barrow for a series of experiments with the submarines.