The Manitowoc Story
As described in Part 1, just prior to America’s entry in to World War II, the United States launched a rearmament programme. As a result, in 1941 Manitowoc was awarded major contacts to built 28 submarines said to be valued at over $6 million apiece. During their assembly, the company needed a 60-ton crane, but a crane of this capacity could not be found, so Manitowoc engineers upgraded two of its model 3500 cranes to lift the required loads. The cranes worked perfectly and the upgraded machine became the model 3900, primarily marketed as a heavy-duty lift crane. Later it was available as a dragline with a 4-yard bucket on an 80-foot boom, but with its long and wide undercarriage, it was not suitable to work as a shovel.
In designing the 3900, much thought was given to shipping such a wide and heavy machine. Its crawlers could be disassembled from the undercarriage using its own crane boom and, as with other Manitowoc machines, it featured a self-removing counterweight. This incorporated a patented back hitch where the boom hoist cables were hitched
