Car Frames: “Head On” 1938 Chevrolet Box Girder Engineering
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Construction of Ranger (a J-Class America’s Cup racing yacht), trains, and bridges are used to demonstrate engineering principles used in Chevrolet automobile frames.
NEW VERSION with improved video & sound:
Public domain film from the Library of Congress Prelinger Archive, slightly cropped to remove uneven edges, with the aspect ratio corrected, and mild video noise reduction applied.
The soundtrack was also processed with volume normalization, noise reduction, clipping reduction, and/or equalization (the resulting sound, though not perfect, is far less noisy than the original).
A box or tubular girder is a girder that forms an enclosed tube with multiple walls, rather than an I or H-beam. Originally constructed of riveted wrought iron, they are now found in rolled or welded steel, aluminium extrusions or pre-stressed concrete.
Compared to an I-beam, the advantage of a box girder is that it better resists torsion. Having multiple vertical webs, it can also carry more load than an I beam of equal height (although it will use more material than a taller I beam of equivalent capacity).
The distinction in naming between a box girder and a tubular girder is imprecise. Generally the term box girder is used, especially if it is rectangular in section. Where the girder carries its “content” inside the box, such as the Britannia Bridge, it is termed a tubular girder. Tubular girder is also used if the girder is round or oval in cross-section, such as the Royal Albert Bridge.
Where a large box girder contains more than two walls, i.e. with multiple boxes, it is referred to as a cellular girder…
Ranger was a J-class racing yacht that successfully defended the 1937 America’s Cup, defeating the British challenger Endeavour II 4-0 at Newport, Rhode Island. It was the last time J-class yachts would race for the America’s Cup…
Construction
Harold Stirling Vanderbilt funded construction of Ranger, and she was launched on 11 May 1937. She was designed by Starling Burgess and Olin Stephens, and constructed by Bath Iron Works. Stephens would credit Burgess with actually designing Ranger, but the radical departure from conventional J-class design was more likely attributable to Stephens himself. Geerd Hendel, Burgess’s chief draftsman, also had a hand in drawing many of the plans.
Ranger was constructed according to the Universal Rule that constrained the various dimensions of racing yachts, such as sail area and length. Often referred to as the “super J”, Ranger received a rating of 76, the maximum allowed while still adhering to the Universal Rule.
Ranger was scrapped by 1941 or 1946 – sources differ…
Construction of a replica of Ranger was started at Danish Yacht Boatyard in early 2002 and was completed in late December 2003. The original designs were used as the basis for the new boat but were updated to conform to the latest safety regulations and the requirement of the owner to cross oceans in comfort…
The J-Class serves as a rating for large sailing yachts designed between 1930 and 1937. Reserved for a wealthy elite of yachtsmen, these boats were used to compete with the best sailing talents in three races of the America’s Cup…
The 1930s
The J-Class is a development of Nathanael Herreshoff’s Universal Rule for racing boats. It was established in 1929, two years after it was agreed amongst American yacht clubs that the International Rule would be used for 12-metre class boats and smaller. As a result the Universal Rule was retained for large boats in the United States and the 1930s America’s Cup regattas were all raced in the J-Class.
Following Sir Thomas Lipton’s near success in the 1920 America’s Cup, he challenged again for the last time at age 79, in 1929. The challenge drew all the novelties developed in the previous decade on small boats to be ported onto large boats, and pitted British and American yacht design in a technological race. Between 1930 and 1937, the improvements brought to the design of sailboats were numerous and significant…
