Whale back
Walrücken (English Whaleback ) was a type of ship that in the period from 1889 to 1898 mainly due to the two yards of the ship's designer Alexander McDougall was built. The name is derived from the characteristic round shape of the hull, reminiscent of the back of a whale, of these ships and barges , which were mainly designed for bulk transport on the Great Lakes .
Form and structure
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The aim of McDougall's development was a vehicle that was as insensitive as possible to the effects of sea and wind with a large loading capacity and shallow draft. The background to this direction was the towing formations to be created from the "whale backs", which were initially developed as barges, and their towing vehicles had to get by with low engine power at that time. A conventional design of the barges with larger attack surfaces for wind and swell led to a rapid reduction in speed in bad weather conditions. The basic shape of all whalebacks was therefore a cylindrical hull, which was stronger at the top and bottom, slightly less flattened on the sides and tapered to a point at the ends of the ship and pointed slightly upwards, which reminded a little of a snout , and was nicknamed pig boats (English Pigboats).
The hatches were arranged in the narrow flat area on deck. Furthermore, rounded deckhouses and platforms were attached to accommodate winches and deck equipment. In the case of the self- propelled whale backs, there were versions with a front and rear bridge , whereby the machinery was always to be found in the stern. The design turned out to be inexpensive to build, extremely seaworthy, but also inconvenient and difficult to use. The hatch covers were still flush with the hull of the ship in the first constructions, but this led to problems with the resulting leaks in the case of torsion and was therefore later replaced by a solution with conventional hatch kumming .
history
McDougall's original design, patented in 1881, was a barge without a superstructure. In the patents that followed in 1882, 1888 and 1890, machines, superstructures, lifeboats, winches and capstans were successively added.
The first whale back was built in 1887-1888 as Barge 101 according to Alexander McDougall's plans by the Robert Clark Shipyard in Duluth , Minnesota , with the stern and stern of the barge from Pusey & Jones Shipbuilding Company in Wilmington , Delaware . In the following year, with support from New York financial circles, McDougall succeeded in founding the American Steel Barge Company in Duluth, which built two more whaleback barges in 1889 . In 1890, the Colgate Hoyt was the first steam- powered whale back , which at US $ 120,000 cost slightly more than twice as much as the previously built barges and reached a speed of 16 knots .
Then, by 1898, another 18 cargo steamers, 20 barges and one passenger steamship of this type were built on McDougall's American Steel Barge Company in Superior . The only passenger ship, the Christopher Columbus , was built in 1893 to carry visitors from Chicago to the World's Fair . Only two whale backs were created without McDougall's involvement. On the one hand the C. S. Wetmore , which was built at a shipyard on the American Pacific coast, and the Sagamore , which was launched at the shipyard William Doxford & Sons in Pallion , Great Britain . The Meteor built as Frank Rockefeller is the last vehicle of this type to survive . The Meteor was in service until 1969 and has been a museum ship in Superior since 1973.
Individual evidence
- http://www.abouthegreatlakes.com/whale.htm
- http://www.marmuseum.ca/duerkop.html ( Memento from November 8, 2007 in the Internet Archive )
literature
- Rolf Schönknecht / Uwe Laue: Ocean freighters of the world shipping , Volume 2, transpress VEB Verlag für Verkehrwesen, Berlin 1988, ISBN 3-344-00282-1
