Discoveries and Inventions of the Nineteenth Century

by Robert Routledge

Fig. 68.—Bessemer Steamer.

Another very novel and curious invention connected with steam navigation was the steamer which Mr. Bessemer built at Hull in 1874. This invention also was to abolish all the unpleasant sensations which landsmen are apt to experience in a sea voyage, by effectually removing the cause of the distressing mal de mer. The ship was built for plying between the shores of France and England, and the method by which he purposed to carry passengers over the restless sea which separates us from our Gallic neighbours was bold and ingenious. He designed a spacious saloon, which, instead of partaking of the rolling and tossing of the ship, was to be maintained in an absolutely level position. The saloon was suspended on pivots, much in the same way as a mariner’s compass is suspended; and by an application of hydraulic power it was intended to counteract the motion of the ship and maintain the swinging saloon perfectly horizontal. It was originally proposed that the movements should be regulated by a man stationed for that purpose, where he could work the levers for bringing the machinery into action, so as to preserve the saloon in the required position. This plan was, however, improved upon, and the adjustments made automatic. It may be well to mention that it is a mistake to suppose that anything freely suspended, like a pendulum, on board a ship rolling with the waves, will hang vertically. If, however, we cause a heavy disc to spin very rapidly, say in a horizontal plane, the disc cannot be moved out of the horizontal plane without the application of some force. A very well-made disc may be made to rotate for hours, and would, by preserving its original plane of rotation, even show the effect of the earth’s diurnal motion. Mr. Bessemer designed such a gyroscope to move the valves of his hydraulic apparatus, and so to keep his swinging saloon as persistently horizontal as the gyroscope itself. Mr. Bessemer’s ship was 350 ft. long, and each end, for a distance of 48 ft., was only about 4 ft. from the line of floating. Above the low ends a breastwork was raised, about 8 ft. high, and 254 ft. long. In the centre, and occupying the space of 90 ft., was the swinging saloon intended for first-class passengers. At either end of this apartment were the engines and boilers. The engines were oscillating and expansive, working up to 4,600 horse-power, which could be increased to 5,000. There were two pairs of engines, one set at either end of the ship, and each having two cylinders of 80 in. in diameter, and a stroke of 5 ft., working with steam of 30 lbs. pressure per square inch, supplied from four box-shaped boilers, each boiler having four large furnaces. The paddle-wheels, of which there were a pair on either side of the vessel, were 27 ft. 10 in. in diameter outside the outer ring, and each wheel has twelve feathering floats. The leading pair of wheels, when working at full speed, were to make thirty-two revolutions per minute, and the following pair of wheels move faster.

Entrance into the Bessemer saloon was gained by two broad staircases leading to one landing, and a flexible passage from this point to the saloon. The saloon rested on four steel gudgeons, one at each end, and two close together near the middle. These were not only to support the saloon, but also to convey the water to the hydraulic engines, by which the saloon was to be kept steady. For this purpose the after one was made hollow, and connected with the water mains from powerful engines, and also with a supply-pipe leading to a central valve-box, by means of which the two hydraulic cylinders on either side were supplied with water. Between the two middle gudgeons, a gyroscope, worked by a small turbine, filled with water from one of the gudgeons, enabled Mr. Bessemer to dispense with the services of a man, and thus completed his scheme of a steady saloon, by making the machinery completely automatic. The saloon was 70 ft. long, 35 ft. wide, and 20 ft. high. The Bessemer ship proved to be a total failure, and never went to sea as a passenger boat.

On board of some modern war-ships where speed is essential, and where the engines are driven at a very great number of revolutions per minute, as in the case of torpedo-boat catchers, the vibration throughout the whole of the vessel becomes extremely trying, not only for the nerves of the crew, but for the security of the structure itself. The cause of this vibration and consequent strain and loss of power is not far to seek. The cylinders of marine engines are always of a large diameter, 6 feet, 8 feet, or even more sometimes, and the pistons and piston-rods are necessarily of great strength and corresponding weight. Now, at every half revolution of the engines, this heavy mass of piston and piston-rod, though moving at an exceedingly high speed in the middle of the stroke, has to be brought to a standstill, and an equal velocity in the opposite direction imparted to it. A large portion of the power is therefore uselessly expended in stopping a great moving mass, and reversing its motion. All the force required to do this reacts on the vessel’s frame. Many attempts have been made to construct rotatory steam-engines, and some hundreds of patents taken out for such inventions, which in general have a piston revolving about a shaft; but the great friction, and consequent liability to wear out, have prevented their practical use.

Lately, a method of using steam on the principle embodied in the water turbine has been developed, and within the last six or seven years has found successful application in propelling electro-dynamos at very high speeds. In the steam turbine there are no pistons, piston-rods, or other reciprocating parts, the effect depending on the same kind of reaction that is taken advantage of in the water turbine (which has a high efficiency in giving out a large proportion of energy), and the power is applied with smoothness and an entire absence of the oscillations that would shake to pieces any vessel that an ordinary steam-engine could propel at the same rate.

The advantages of the steam turbine have been proved by the performances of a small experimental vessel lately built at Newcastle, and appropriately named the Turbinia. She is only 100 feet in length, and 9 feet in breadth, with a displacement of some 44 tons. Now the highest record speed for any vessel of that size is 24 knots per hour; but the Turbinia, in a heavy sea, showed, at a measured mile, the speed of 32¾ knots, which is believed to be greater than that of any craft now afloat, being nearly 37¾ miles an hour, or equal to that of an ordinary railway train. Besides that, it has been found by experiment, that an arrangement of the blades of the screw propeller more suitable to high velocities will enable a still greater speed to be obtained. The weight of the turbine engines of this vessel is only 3 tons, 13 cwts., and the whole weight of the machinery, including boilers and condensers, is only 22 tons, with an indicated H.P. of 1576, and a steam consumption of but 16 lbs. per hour. The weight of the turbine is only one-fifth of that of marine engines of equal power; the space occupied is smaller; the initial cost is less; not so much superintendence is required; the charges of maintenance are diminished; reduced dimensions of propeller and shaft suffice; vibration is eliminated; speed is increased; and greater economy of fuel is secured.

THE RIVER AND LAKE STEAM-BOATS OF AMERICA.

The chapter on “Steam Navigation,” in the foregoing pages, has dealt mainly with the progress of the ocean-going steam-ship, from the establishment of regular transatlantic services down to the building of the splendid liners, the New York and the Paris, and we have recorded, in addition, the performances of the pair of hitherto unsurpassed sister ships, the Campania and the Lucania. The importance and interest attaching to steam navigation is, however, by no means confined to ocean-going vessels, and the chapter demands a supplementary notice of the great developments of the steam-ship in other parts of the world than Britain, more particularly where great rivers, navigable for hundreds of miles, and lakes, spreading their waters over vast areas, present conditions of traffic and opportunities for adaptation to an extent that could not be required within the range of Britain or British oceanic lines.