Rainbow, launched in New York in 1845 to sail in the China trade for the firm Howland & Aspinwall, was a clipper, a type of sailing vessel designed to sacrifice cargo capacity for speed.
An early clipper ship
Rainbow was an early clipper ship. It was built in 1845, in accordance with John W. Griffiths' ideas, and followed by Sea Witch the next year. Both of the vessels are cited as being highly influential in subsequent U.S. merchant hull design. Though initial opinions were that Rainbow would sink during its first trip, its subsequent success led to a rush to adopt the new design in shipbuilding across Boston, New York, Philadelphia and British manufacturing companies.
Its design was created around the concept of sacrificing cargo capacity in favour of speed. As per Griffiths' ideas, it featured a lengthening of the bow above water, a drawing out and sharpening of the forward body, and the greatest breadth further aft (further aft than earlier designs, not further aft than forward). These modifications had the effect of minimizing water resistance. He allegedly formulated his design after studying the lines of the owner's previous ship, the Ann McKim.
Design and construction
Clipper bow
Rainbow was launched in 1845. She created a sensation while still on the stocks because of her concave or hollowed lines forward, which opposed the tradition and practice of shipbuilding of the time.
"The sharp model of Rainbow gave rise to a great deal of discussion while she was on the stocks in course of construction. It was generally admitted by the recognized shipping authorities of South Street, that she was a handsome vessel, but whether she could be made to sail was a question on which there were varieties of opinion."
"Her bow with its concave waterlines and the greatest breadth at a point considerably further aft than had hitherto been regarded as practicable, was a radical departure, differing not merely in degree but in kind from any ship that preceded her. One critical observer declared that her bow had been turned " outside in," and that her whole form was contrary to the laws of nature."By 1930, looking back on the clipper era, the bow appeared much less shocking than it did at the time. Cutler writes,“The Rainbow represented a certain departure from fast-sailing models of her day but she was far from being a radically new type ... However, her appearance as she gradually took shape on the stocks aroused so much criticism that her owners delayed her completion for more than a year. She was, perhaps, the first ship of the extremely hollow bow type, and in spite of the fact that very similar lines had been incorporated in pilot boats for years, old wiseacres grumbled that her bows were 'turned inside out.'"
Hull
"Perhaps it was the ongoing philosophical contest between the proponents of the traditional flat-footed vessel, as staunchly favored by Nathaniel B. Palmer, and those who were swayed toward the sharp-bottomed vessels championed by John W. Griffiths in the form of Sea Witch and Rainbow, both vessels of remarkable performance and far-flung reputation."
"In 1841, John W. Griffeths [sic], of New York, proposed several improvements in marine architecture, which were embodied in the model of a clipper ship exhibited at the American Institute, in February of that year. Later he delivered a series of lectures on the science of ship-building, which were the first discourses upon this subject in the United States. Mr. Griffeths advocated carrying the stem forward in a curved line, thereby lengthening the bow above water; he also introduced long, hollow water-lines and a general drawing out and sharpening of the forward body, bringing the greatest breadth further aft. Another improvement which he proposed was to fine out the after body by rounding up the ends of the main transom, thus relieving the quarters and making the stern much lighter and handsomer above the water-line."