In 1850 several boats were designed for mail service in any weather for a run not exceeding sixty miles and on which sleeping accommodation was not required. One of the best of the type was Her Majesty, built and engined by Robinson and Russell in 1850 for the Portsmouth and Ryde station. She was an iron paddle-steamer. The engines had two oscillating cylinders 27 inches in diameter with 30 inches stroke, and made 58 revolutions per minute. Her tubular boiler, 9·75 feet long, 11·25 feet wide, and 6 feet high, developed steam at 20 lb. pressure. The heating surface was 1234 square feet. Engines, boilers, and water weighed 30·5 tons. The paddles were 11·16 feet in diameter and each had nine fixed floats. There were three masts and the sail area was 64 square yards. Her speed was 12·8 knots; displacement, 93 tons; length, 127 feet; extreme beam, 26 feet.
The steamer Crœsus, for the Australian trade, launched at Mare’s yard, Blackwall, in June 1853, for the General Screw Shipping Company, was the largest vessel yet built for the firm. She was of 2500 tons, with engines by Messrs. G. and J. Rennie, of 400 horse-power.
Messrs. Maudslay, like Messrs. Penn and other eminent engineers, had been in the habit of having the ships for which they contracted built by other firms, while they themselves supplied the engines. They decided to do their own shipbuilding, and accordingly opened a yard at East Greenwich. The first vessel launched there was the Lady Derby, of 530 tons gross, built for the General Iron Screw-Collier Company.
Those were the days when Thames shipbuilding was at its zenith. While trade was good, freights high, and shipowning was profitable, shipowners did not mind paying high prices for their vessels; but as the north-east coast, the Mersey, and the east and west coasts of Scotland developed their iron shipbuilding facilities, and by reason of their proximity to the coal and iron fields were able to obtain these commodities at lower prices than the Thames shipbuilders could secure them, they were able to underbid the Thames shipbuilders and secure the industry, with the result that there is now but one shipbuilding establishment of importance in the Thames equipped to turn out a large warship or liner. Its competitors and neighbours of half a century ago vanished one after another. Some have passed out of existence, others have become merely repairing yards, and two or three have gone elsewhere and prospered. The one survivor is the Thames Iron Works and Shipbuilding Company, which, on the site made historic by Mr. Penn’s enterprise, proudly endeavours to hold its own and maintain the traditions of the river.
Mare’s shipbuilding yards on the shores of Bow Creek, near its entrance to the Thames, started in a very small way, but within seventeen years it extended until it was employing nearly 400 hands. In 1845, a large portion of the Essex side of the yard was a marsh, covered with water at high tide. By 1854 it was one of the principal shipbuilding yards in the world. The wages of the workmen at Blackwall averaged for eighteen months £5000 per week, and some weeks it was £1600 more. The yards of Messrs. Green, Messrs. Scott Russell, Messrs. Dudgeon, Messrs. Maudslay, Messrs. Samuda, Messrs. Yarrow, and Messrs. Thorneycroft, to mention only a few, besides a host of smaller builders, employed their thousands of hands; but never a keel is laid there now. The banks of the river which rang to the stroke of the shipwrights’ hammers are silent; the slips are unoccupied or devoted to other uses, the furnaces are cold; the machinery is sold or dismantled, and fragments of it may yet be seen rusting ingloriously on the scrap-heap. Dawn now brings no activity to the shipbuilding yards of the Thames, and dusk adds nothing to their stagnation. Steam-ship repairing work is nearly all that London river sees now. If, as sailors say, ships have spirits that return to the yards where the vessels were built, when those ships are lost or broken up, there must be many homeless phantoms haunting the banks of the historic stream, seeking rest and finding none, and perchance, as did certain of the ships they represent, going down the river with the tide never to return: a ghostly fleet bearing many mysteries which shall not be solved till the day when the insatiable sea is called upon to surrender all it has taken captive.
The general superiority of iron screw steamers over those of wood led to the introduction of a number of types designed to meet the requirements of special trades.
James Hodgson, who, in addition to the Sarah Sands, built the Antelope, the first iron screw steamer to leave Liverpool for the Brazils, introduced the tubular type of iron vessels. The Carbon, a vessel of this type, was built by him for the Eastern Archipelago Company in 1855. In the construction of this boat he proposed to dispense with the ordinary side frames altogether.
He stated in his synopsis that calculations of the strength of thirty frames, in a ship that had answered exceedingly well, showed that a partial bulkhead or frame projected from the side of the vessel to the extent of only 20 inches was more than equal in strength to the thirty frames, if it were supported on two bearings at a given distance and weighted on the upper side in the middle. This frame, of 20 inches deep, would carry more than the whole of the thirty frames, and when the bulkhead was extended across to the other side of the ship there would be a great preponderance of strength in favour of the bulkhead. But, in dispensing with frames, it might, in some cases, be necessary to increase the plating for the sides, to give some additional strength. Since the strength of the materials increased as the square of the thickness, the addition of one-eighth to five-eighths of an inch plate increased the strength to resist a blow sideways, or in a lateral direction, by nearly 50 per cent. The strength of the vessel was further increased by placing the bulkhead in the widest part of the ship, amidships, and by other bulkheads placed midway between the midship bulkhead and the bow and stern, should it be deemed advisable; and also by the interposition of stiffening plates. Other strengthening means were also recommended. The vessel would be, he contended, “capable of sustaining a considerable pressure, either externally or internally, having round, swelling, or convex sides, with a ridge or rib on the lower side which answers the purpose of a keel.”
Vessels of this type were expected to be much more economical to build, and no more expensive to run than those built on the ordinary lines. It was disputed whether a tubular vessel being without frames, floors, &c., would be strong enough for all purposes. An accident to Mr. Hodgson’s tubular cargo vessel, The Carbon, however, seemed to justify his contentions, for she stranded badly when being launched, so that her stern was submerged at high water. She was towed up the slip again, and refloated, and it was found that only two plates required repairs. The Carbon was running until quite recent years in the east coast coal trade to London.
Another important development in construction was due to Mr. J. Scott Russell, who has been described, like Sir I. K. Brunel, as a man before his time. Mr. Russell’s services to steam navigation in his exposition of the wave-line theory of ship construction were of incalculable benefit to the science. His object was to diminish the resistance offered by the water to the passage of the ship, and the modifications he made in the lines of the hull not only effected this to a very remarkable degree, but also increased the seaworthiness and speed of the vessels. He designed a number of small vessels suitable for special trades or to meet particular requirements.