“Once again, how will the winds and the waves affect this leviathan mass, when they chance to be in their surly and ungenial moods? A connected mass of 27,000 tons is not as easily heaved as a cork or a cockle-shell; but the storm-winds and the storm-waves of the open ocean have a tremendous power. What will they do then, with this stupendous morsel, when they have it fairly within their clutches? The heaviest hurricane-wind blows with a force that would act upon a square foot of resisting surface with a pressure equivalent to a weight of 40 lb. Such a wind could only heel the leviathan with its full load out of the perpendicular to the extent of six inches even if it struck it quite on the side! The waves of a fresh sea run about 100 feet long. Those of a moderate sea are 300 feet long. Of such the leviathan would take two at once, and would preserve the while almost an even keel. The highest storm-waves ever seen on the wide and deep ocean are only 28 feet high from trough to crest, and 600 feet long from trough to trough. Of course the leviathan would still take two at a time, when the crest of one was near to the bow, and the crest of the other near to the stern. Under the most unfavourable circumstances such waves would not disturb the horizontal equilibrium of the deck line to the extent of more than five degrees.... The captain of the leviathan will have a cabin for himself, situated conveniently near the centre of his domains, on the mid-deck, and between the huge paddle-boxes. But placed here like a spider lurking in the centre of its web with outstretched attentive feelers, he will have to use his telescope to see what is going on at the bows and stern; and the old contrivance for issuing orders, the speaking trumpet, will be altogether out of date and valueless in his hands. His voice, even with this aid, would hardly be heard half-way to the stern. He will have to signal his directions to his officers by semaphore arms by day and by coloured lamps by night. He will also have electric-telegraphs ramifying to the engine-rooms, and to other places to which it may be necessary that his instructions should be instantaneously communicated. The compasses will be placed aloft on a staging reared forty feet above the deck, to remove them from disturbing influences inherent in the vast masses of iron below; and it is proposed that strong shadows of the needles shall be cast from a tube, so that the steersman may at once watch these shadows, and so follow exactly the movements of the compasses as they traverse. It is also proposed to carry a perpetual moonlight diffused around the ship, emanated from an electric light planted on the foremast head.
“Up to the present time £350,000 has been expended upon this wonderful construction, and by the time the vessel is ready for sea, this sum will have been augmented into nearly £800,000. It will, however, be understood that there is a fair capacity in the vast vessel for yielding a revenue ample enough to render the undertaking a commercial success, notwithstanding this great cost, when it is borne in mind that if the fares for a single outward or homeward passage to India or Australia for the three classes be fixed only at £65, £35, and £25 respectively, the passage-money alone for the voyage out and home would amount collectively to something beyond £300,000 if all the berths were occupied. It is an interesting fact that naval engineers fix the amount of tonnage required in a steam vessel designed for any particular voyage by a very simple standard; they consider that one ton of burden is needed for every mile to be traversed; hence it is that this vast steam-ship has been made capable of carrying 25,000 tons. It is intended to go in every voyage 25,000 miles: it is a distance equal in extent to the circumference of the world.
Caricature of the “Great Eastern,” from a Contemporary Print.
“It is estimated that this great vessel with 5000 tons of merchandise and her complement of 4400 living beings would still be able to store enough coal for her consumption during a complete circumnavigation or a voyage out and home.”
The iron plates used in the construction of her hull weighed 10,000 tons and to fasten them together required three million rivets. Her length was 680 feet, breadth 82¹⁄₂ feet, depth 58 feet, and displacement 27,384 tons. The paddle-engines were of 1000 nominal horse-power and worked up to 3411; and weighed no less than 836 tons. The four cylinders weighed when finished 28 tons each, they were 74 inches in diameter and had a stroke of 14 feet. Each of the two right-angle cranks was driven by two cylinders, inclined at a mean angle of 22¹⁄₂ degrees from the vertical. Each paddle-wheel was worked by a complete double-cylinder engine and could be revolved without the other if necessary. Four double-ended tubular box boilers supplied steam for the paddle-engines at 24 lb. pressure. They were each 17¹⁄₂ feet long by 17 feet 9 inches wide, and 13 feet 9 inches high, and had forty furnaces and 4500 square feet of heating surface. Each boiler weighed fifty tons and contained about forty tons of water. Her first paddle-wheels were 56 feet in diameter, but these were damaged in some rough weather, and the next pair, only 50 feet in diameter, were much stronger and equally serviceable in the matter of speed and lasted out the ship. Her calculated speed under both screw and paddles was 15 knots and under the wheels alone seven knots. She certainly never approached the fanciful speeds predicted for her by the newspaper enthusiasts, and it is only fair to her builders and designers to say that these prophecies did not originate with them.
The engines for the screw propeller by James Watt and Co. were horizontal and direct-acting, and were of 1800 nominal horse-power and 4886 horse-power indicated. They weighed 500 tons. Six double-ended tubular rectangular boilers gave steam at 25 lb. pressure. The propeller was a four-bladed cast-iron screw 36 tons in weight, and of 24 feet diameter and 44 feet pitch. The shaft of the propeller weighed 60 tons and was 150 feet in length. So as not to interfere with her speed when the screw should not be working, two small auxiliary engines were fitted to keep it revolving when disconnected from the main engines. Her speed under the screw alone was about nine knots.
Her longitudinal bulkheads were carried to the uppermost deck, which was perfectly flush and extended from one end of the ship to the other. An iron deck connected the head of each longitudinal bulkhead with the ship’s sides and this, being at the greatest possible distance from the bottom of the girder, was in a position to contribute most to the longitudinal strength. The Britannia Bridge over the Menai Straits has its top and bottom flanges of cellular construction, and Brunel practically repeated this formation in the Great Eastern, by making both the bottom and the upper deck cellular.
The launch of the Great Eastern was arranged for November 3, 1857, and it was not till then that it became known that this was to be the vessel’s name and not Leviathan. The vessel moved only a few feet and then stuck. One of the causes of the hitch was that the ship was being launched sideways, thereby greatly adding to the difficulties of the operation. Another attempt a few days later did not move her an inch. On January 11 she was got a little nearer the water and the next day was moved a little farther; she was finally launched at the next spring tides at the end of the month.
