Shoddy ships sank invasion of Japan
22 January 2005
From New Scientist Print Edition.

ACCORDING to legend, the Kamikaze, or "divine wind", twice saved Japan
from subjugation by Mongolian invaders. But it now seems that bad
boat-building came to Japan's rescue.

A painstaking analysis of about 500 timbers raised from the remains of
the massive Mongolian fleet that sank in 1281 suggests wood for the
ships was recycled, and at least some of the ships were badly
constructed or not designed for the high seas.


In 1274, the Mongolian emperor Kublai Khan sent 900 ships to invade Japan. Resistance by the Samurai and bad weather forced the troops to retreat, and their ships were reportedly destroyed by the Kamikaze on their way home. Then in 1281, Kublai Khan gathered what should have been an overwhelming fleet of about 4400 ships from China and Korea. This time, strong winds struck before the troops could land, and most of the fleet sank off the island of Takashima, in southern Japan.

"There are historical documents that talk about how the winds were strong, and blew down trees, so it seems there was a typhoon in 1281,but we don't know how strong it was, or exactly what the impact of the winds was on the loss of the ships," says Randall Sasaki of Texas A&M University at College Station, who has studied the timbers.

In 1981, a Japanese team led by Kenzo Hayashida of the Kyushu Okinawa Society for Underwater Archaeology found the first remains of the 1281 fleet. None of the ships was even remotely intact. Only about a dozen of 700 or so boat fragments raised so far are longer than 3 metres. Most are between 10 centimetres and a metre.

Sasaki has now studied about 500 of these fragments, and worked out how the boats might have looked. He discovered that many of the timbers have nails very close together - with perhaps five or six in the same location. "This suggests the timbers were recycled to construct these ships," he says. "Also, some of the timbers were themselves of poor

Chinese documents suggest that many of the boats in the 1281 fleet were flat-bottomed river boats, which would have been unsuitable for use on the high seas. "So far, we have found no evidence of sea-going, v-shaped keels at Takashima," says Hayashida.

However, less than 0.5 per cent of the 1.5-square-kilometre site where the fleet sank has been studied. Sasaki hopes that future sonar and ground-penetrating radar studies will reveal the remains of many more ships for analysis.

From issue 2483 of New Scientist magazine, 22 January 2005, page 15