"The steering powers of the boat have next had attention from Messrs. Yarrow, and they have sought to remedy the defective steering common to these large quick-speed torpedo craft. To do this they have fitted the vessel under notice with two balanced rudders, one of which is placed forward about 10 feet from the bow, and the other in its usual position at the stern with the screw abaft it. Both rudders are connected with the same steering gear, and are operated simultaneously by one steersman. The forward rudder can be raised out of the water into a casing inside the boat if desired by means of a screw cut on the upper part of its spindle. By the same means, by unscrewing the collar on the spindle, the rudder can be released and dropped into the water should the necessity arise for so doing, by reason of its becoming fouled or damaged. In trials which have been made with this double-steering system, it has been found that when steaming at high speeds the forward rudder has a much greater control over the motion of the boat than the stern one. The reason assigned for this is that at high speeds the forward part of the boat is lifted out of the water, and consequently offers a diminished side resistance to any turning motion brought to bear upon it.
"The boat in which these improvements have been introduced is 86 feet long by 11 feet beam and 5 feet 6 inches deep. She is fitted with compound engines having 22 inch and 12-1/2 inch cylinders, with a 12 inch stroke, and making 520 revolutions per minute when running at full speed. She is propelled by a three-bladed screw 5 feet 6 inches in diameter and 5 feet pitch. Put through some evolutions with the view of testing her steering powers, the double rudder arrangement was found to answer exceedingly well, and she turned a circle of a diameter equal to about three times her own length in 1 minute 15 seconds. She turned equally well either going ahead or astern, and in fact her steering capabilities were satisfactorily demonstrated. The new arrangement for carrying off the smoke also answered very well, with the exception that the heated gases occasionally swept the deck, which objectionable result will be avoided in future boats."
These boats are to be armed with spar torpedoes, and with the Whitehead fish torpedo, the cradles and fittings for which are shown at [Fig. 161].
The Fastest Vessel in the World.—Another type of torpedo boat, of which one of the same dimensions has been built by this firm for the English government, is shown at [Fig. 162]. This vessel is as yet the fastest vessel in the world. The trials with this boat were made in March of this year, and were as follows:—
| Runs. | Time, | Knots per hour. | Knots per hour. | |||||
| Min. | sec. | |||||||
| First | 2 | 37 | = | 22·93 | Mean of first pair | = | 21·35 | |
| Second | 3 | 2 | = | 19·78 | ||||
| Third | 2 | 33 | = | 23·53 | Mean of second pair | = | 22·05 | |
| Fourth | 2 | 55 | = | 20·57 | ||||
| Fifth | 2 | 30 | = | 24·00 | Mean of third pair | = | 22·23 | |
| Sixth | 2 | 56 | = | 20·45 | ||||
giving as a mean 21·93 knots per hour, or 25-1/4 statute miles. The boat was fully equipped for active service, i.e. with a load of 6-3/4 tons on board. It was found during the trial that at speeds of 17 and 19 knots the vibration of the boat was considerable, but when running over 20 knots it was hardly perceptible; the excessive vibration taking place when the revolutions of the engines became a multiple of the natural vibration of the boat.
Torpedo boats are at the present time being built by this firm for the English, French, Spanish, Austrian, and Italian governments.
Russian Torpedo Boats, built by Mr. S. Schibau, Prussia.—Mr. S. Schibau, of Elbing, Eastern Prussia, in 1878 constructed ten torpedo boats for the Russian government, similar to the one shown at Fig 163.
These boats are each 66 feet long, and 11 feet 3 inches beam. They are built of steel plates about an eighth of an inch thick. Their engines consist of three cylinder compounds, with surface condensers; and they run at 380 revolutions per minute, at full speed, driving a screw 4 feet in diameter. They have been variously armed, some with the spar, some with the Whitehead fish, and some with the Harvey towing torpedo. Their speed is about 18 knots per hour.
Messrs. Herreshoff's Torpedo.—Messrs. Herreshoff, of Rhode Island, U.S.A., have also constructed several torpedo boats. One of these, built for the English government, is shown in section at [Fig. 164]. This boat is 59 feet 6 inches long, 7 feet 6 inches beam, and 5 feet 6 inches deep; she draws about 1 foot 3 inches of water.