§ The value of the "Hecla" torpedo depôt ship as an adjunct to our principal squadrons has been most thoroughly demonstrated during the last ten years. The "Hecla," as is well known, was purchased from the Mercantile Marine and adapted as a torpedo depôt and store ship; she was also equipped for carrying a number of second-class torpedo boats. A careful study of the work done by the "Hecla," and the conditions now regarded as essential in a vessel capable of doing similar work, preceded the preparation of the design of the vessel about to be laid down at Portsmouth. This design is altogether novel in character, and has been worked out in the utmost detail during the last two years.
§ The "Vulcan" may be briefly described as a swift protected cruiser, lightly armed, with a large coal endurance; fitted with special appliances for lifting and carrying a considerable number of the largest type of second-class torpedo boats; while, in addition, she will be equipped with laboratory, workshop, a powerful torpedo armament, a large supply of torpedoes, stores, submarine mines, and electrical appliances of all kinds. She will he capable of protecting herself against all except the largest class of cruisers; her speed will exceed that of most cruisers and all armoured vessels. She will be a base of operations for a torpedo boat flotilla or the torpedo boats of a Meet; have the means of repairing torpedoes, torpedo boats, and their machinery; be a practice ship for all kinds of torpedo work—submerged and above water—and will carry all the gear required for submarine mining operations on a large scale.
901| The principal dimensions are:— | |
| Length | 350 feet. |
| Breadth | 58 feet. |
| Displacement (about) | 6,600 tons. |
| Speed (with full coal supply)— | |
| On measured mile | 20 knots. |
| At sea (continuous steaming) | 18 knots. |
| Radius of action— | |
| Speed of 10 knots (about) | 12,000 knots. |
| Speed of 18 knots (about) | 3,000 knots. |
§ Armament:—
- 8 36-prs. (quick-firers).
- 12 3-prs. (quick-firers).
- 4 to 6 Torpedo-tubes.
§ The protective steel deck will extend throughout the length, and over machinery, boilers, &c, will have a maximum thickness of 5 inches, and a minimum of 2½ inches.
§ Hydraulic power is to be applied throughout the vessel on a large scale, for lifting the boats and doing all kinds of work.