The last of the large vessels disappeared from the brigade in 1890, and the river-service consisted of tugs and floats, the fire-engines or rafts being familiarly called by the latter name. This system, however, did not prove satisfactory; for, as the chief engineer pointed out, just before the appointment of Commander Wells, tugs being necessary to haul the floats, double the number of river-craft were employed, and there was a consequent increase in cost of maintenance. He suggested that both the propelling and the fire-engine machinery should be united on one vessel, but that it should be of light draught.
The new chief officer was consulted. Now, Commander Wells, who was then thirty-seven years of age, had enjoyed a long experience in the navy; and, moreover, had been used to torpedo-boats, which of course are comparatively light craft. Entering the Service in 1873, he was second in command of a torpedo-boat destroyer in the Egyptian campaign of 1882, and for three years was second in command of the Torpedo School at Devonport. At the time of his election to the chief officer's post of the London Fire-Brigade, he was senior officer of a torpedo-boat squadron. He had also been second in command of two battleships, and had partly organized the London Naval Exhibition of 1891. He was, therefore, likely to be thoroughly conversant with all the latest types of light-draught navy vessels.
He pointed out the great disparity existing between the brigade's tugs, which required nine feet of water, and the fire-engine floats, which needed only about two feet; and he prepared a rough plan of a craft on the model of shallow-draught gunboats. The chief engineer approving the plan, a design was prepared by Messrs. Yarrow & Co., in conjunction with Commander Wells.
This design, or one similar to it, is probably destined to revolutionize river fire-engine service. The class of material used would be the same as that employed for building light-draught vessels for her Majesty's Government; and the method of raising the steam would be, of course, by Yarrow's water tube-boilers, having straight tubes, and raising steam from cold water in fifteen minutes.
The design shows a vessel about 100 feet long by 18 feet beam, and the draught only about 1 foot 7 inches—i.e., five inches less than the previous floats, though containing its own propelling power. The engines, twin-screw and compound, would develop about 180 horse-power, and the speed range from nine to ten knots an hour, while no doubt much higher speed could be obtained if desired.
But the main feature is the ingenious use of the propellers. How can they work in such shallow water?
Briefly, the propellers operate in the two inverted tunnels, the upper parts of which are considerably above the water-line. When the propellers commence to work, the air is expelled from the tunnels, and is immediately replaced by water. Thus, a large propeller can be fully immersed, while the vessel itself is only floating in half or may be a third of the amount of water in which the propeller is actually working. The design thus combines maximum speed with minimum draught. Sooner or latter, it seems likely that some such system must be adopted for fire-floats used in protecting water-side premises; and so far the design promises to inaugurate a new era.
The boilers in the design also operate the fire-engine pumps, which would probably consist of four powerful duplex "Worthingtons," each throwing five hundred gallons a minute. They discharge into a pipe connected with a large air-vessel, whence a series of branches issue with valves connected with fire-hose.
But at the top of the large air-vessel stands a water-tower ladder, the two sides consisting of water-pipes. At the heads of the pipes are fitted two-inch nozzles, the direction of which can be varied by moving the water-ladders from the deck. Branch-pipes can also be led underneath the deck to either side of the vessel. Suitable accommodation is provided for the crew, and ample deck space is available for working the craft. She seems likely to give a good account of herself at any water-side fire to which she might be called.
Concurrently with this new design, arrangements were made to alter the London river-stations, and to some extent remodel the river organization. Previously, there had been five river-stations; but usually between fifteen and twenty minutes elapsed after a fire-alarm was received before a tug got under way with its raft or float. This delay was partly owing to the fact that the men lived at some distance, and also that a full head of steam was not kept on the tugs.