The Tenmasen was built in the Fall of 2002. This boat was one of two that I built with Mr. Kazuyoshi Fujiwara from September, 2002 through January, 2003. This research project was underwritten by the Freeman Foundation, and also included a third boat that I built later in 2003 with Mr. Seizo Ando.
Tenma, or Tenmasen, is a name that is used throughout Japan to refer to small cargo boats or ship's boats. The term probably refers to horses used to transport goods along the post roads in the Edo Era (1603-1867). Because Tenmasen also carry cargo this etymology seems reasonable. The boat that Mr. Fujiwara and I built was quite small. Some distinguishing features of smaller Tenmasen of the Tokyo region are the wide, flat gunwales, which provided a space for a man to walk from the bow to the stern pushing a pole. These boats were often poled through narrow canals, their hulls piled high with cargo such that the gunwales were the only space left for their crews.
Mr. Fujiwara's father and grandfather were boatbuilders, and they built very large cargo boats that were towed by tugs. Despite their enormous scale they were still called tenamasen. Our small boat represented traditional construction: athwartship beams in lieu of frames in the hull, the use of fire to bend the planks, and a great deal of copper plating - while adding unique design motifs to the boat - actually served an important purpose. The copper plates covered nail heads and seams in order to prolong the life of the boat. This use of copper in boats is found generally in cities, disappearing as one moves further out into the country, no doubt a result of the high cost of this material.