When the Great Britain was launched on July 19th, 1843, she was far larger than any other ship afloat and was revolutionary in many aspects of her design. Why was this? What commercial or technical reasons were there for the construction of such a ship, many of whose features were to set new standards for all later ship-building?
The Great Britain represented a bold attempt by a British company to compete on a totally fresh basis in the North Atlantic passenger trade, where the United ‘States had held a near monopoly for thirty years. With fast sailing packets of 300 to 500 tons the Americans provided a reliable service on regular dates, and this was just what was required by the merchants and shippers of New York and Liverpool. For this regularity, too, the first-class passengers themselves were prepared to accept indifferent conditions, while below them in the poorer accommodation travelled emigrants from Europe the beginnings of the stream which later in the century would eventually swell to the flood that filled the continent of North America.
The United States’ virtual domination of the transatlantic trade continued until the Great Western Steamship Company of Bristol, inspired by its chief engineer, Isambard Kingdom Brunel, decided to try to out-build the Americans with larger ships and by using the new development of steam. With his first ship, the Great Western, launched in 1837 and of 1,320 gross registered tons, Brunel proved that it was possible for a steam ship with paddle
wheels to make regular voyages back and forth across the Atlantic without running out of coal. And her speed, reliability and comfort quickly eclipsed the sailing packets.
As confidence in the Great Western grew, so did Brunel’s ambition. His next step would be to build a sister ship, rather better and faster as a result of the lessons learned with the first one, though she would still be constructed of wood and driven by paddles. She would be called the City of New York.
This was not, however, quite how events turned out. As the design work proceeded, the proposed new vessel gradually got bigger. It had after all been one of Brunel’s most historic contributions to marine engineering to announce his categoric support for the view, hotly disputed at the time, but quite correct that:
‘The resistance of vessels on the water does not increase in direct proportion to the tonnage. The tonnage increases with the cubes of their dimensions while the resistance increases at about their squares. so that a vessel of double the tonnage of another capable of containing an engine of twice the power does not really meet with twice the resistance. Speed therefore would be greater with the larger vessel, or the proportion of power in the engine and the consumption of fuel may be reduced.’
It was not surprising, therefore, that the vessel grew so dramatically in size, that when eventually launched she had reached 2,936 gross tons, or more than twice the tonnage of the Great Western.
During this process, however, there had also been two fundamentally important new developments. The first was in 1838 when a little paddle-wheeler called the Rainbow visited Bristol. What intrigued Brunel about her was that she was built of iron. So he sent two of his colleagues. Captain Christopher Claxton and William Patterson, to join her for the rest of her voyage to Antwerp, and on their favourable report decided that his own great new ship must be of iron too. Then, since no firm was prepared to tender for such an unusual vessel, including, as it had to. larger paddle-wheel engines than had ever been built before, the Great Western Steamship Company itself took on the job. And, as the weight was thought to be too great for a traditional slipway, a fresh dry dock was constructed in Bristol, and special construction machinery installed on the quayside.
The second change of plan was even more radical than the first. In May 1840,
ten months after the building of the big ship had actually started, another small experimental vessel, the Archimedes, arrived in the harbour and gave demonstrations of her novel screw-propeller, designed by Francis Pettitt Smith. Again Brunel was fascinated, and this time he chartered her for six months for experiments of his own. As a result he became convinced that he must alter the motive power of his own new vessel. Her engines would now be swung round by 90 degrees. and she would become the world’s first ocean-going, propeller-driven ship. Her name was changed to Great Britain. A building committee was set up, consisting of Brunel, Claxton, and a Bristol engineer. Thomas Guppy. William Patterson, in whose yard the Great Western had been built and who with Brunel had drawn the lines of this new ship, was to supervise her construction in the dry dock known as the Great Western Dock, which is where the Great Britain lies today.
