2004-08-12 22:31:00 (UTC)

Cool Article

John and I both enjoy reading science and technology
magazines--everything from Nature to Science to
Discover. One of our favorites is New Scientist where I was
delighted to find this article.

The Sheep That Launched 1000 Ships
New Scientist, Vol 193 Issue 2457 July 24, 2004, Page 52
By Nancy Bazilchuk

In 1990, two researchers probing the roof of a 12th-century
stone church in northern Norway made a remarkable find:
stuffed into a gap between the roof and walls were the
tattered remains of a 650-year-old woolen sail. Although
maritime archaeologists had long suspected that Vikings
plied the oceans in ships with woolen sails, this ragged
piece of cloth offered the first definitive proof. When the
pair joined forces with traditional handcraft expert Amy
Lightfoot to weave this reproduction, they hoped to learn
how such a sail would perform on the open sea. But copying
the old sail yielded far more than just cloth. Lightfoot
found herself exploring the very warp and weft of Viking
life. Viking voyages were only possible, she realised,
because of their sheep - and the women who stayed behind to
spin the wool.

THE Gulatingslovi, a Norse law dating from about AD 1000,
was very clear on the subject of sails: "The man on whom
responsibility falls and who lives near the sea, shall store
the sail in the church. If the church burns this man is
responsible for the sail..." Norse sagas describe a ship's
sail as a prized possession, crucial to the defence of
Norway's long coast against rival clans and foreign
invaders. Indeed, every settlement was responsible for
providing and outfitting a leidangskip, a communal boat for
defence, and for keeping its sail safe.

Since the middle of the 1800s, maritime archaeologists have
been able to study a series of well-preserved Viking ships,
either excavated from grave mounds or raised from the bottom
of fjords. What they were missing was a sail: such old cloth
rarely survives in the environments that preserve wood. But
after delving into old documents and laws, Jon Godal of the
Norwegian Craftsmen's Registry and Eric Andersen from the
Viking Ship Museum at Roskilde in Denmark decided old sails
might be preserved in an entirely different sort of place -
old churches. They struck it lucky in the church at
Trondenes. Crammed into the seam between the walls and the
roof, they found a fragment of sail. It may have once been
stored in the church for safety, but it ended its days
blocking the wind instead of filling with it. Laced into one
corner was an eyelet that clearly identified it as part of a

Amy Lightfoot, head of the Tømmervik Textile Trust in Hitra,
Norway, had been researching and documenting the traditional
handcrafts of coastal Norway and the Shetland and Faroe
Islands for the Norwegian Craftsmen's Registry since the
late 1980s. She had studied coastal peoples' use of a tough,
lanolin-rich wool to knit garments and weave vadmal, a thick
woolen cloth used to make durable clothing. She knew, too,
that woolen sails had powered Norwegian boats well into the
1800s. When the Coastal Museum in Hitra decided in 1991 to
build a replica of a Norwegian coastal boat first used
locally in the 1300s, it decided that it should have a
woolen sail based on the newly discovered fragment from
Trondenes, and that Lightfoot was the only person with the
expertise to weave it. There was only one catch: the
knowledge needed to produce such an object had disappeared
with the sails themselves. "No one had made sails since the
middle of the 1800s. We couldn't talk to anyone about it,"
says Lightfoot. "But people still made vadmal, and we could
talk to them about that."

Even the simplest sail is a highly complex tensile
structure. The fabric must be heavy enough to withstand
strong winds and strain from the rigging, but not so heavy
that it slows the ship or is difficult to raise or lower. It
must be elastic, so that it fills with enough wind to form
an area of low pressure in front of the sail, but not so
elastic that it forms irregular pockets. The sail's form
must also be correct: too flat and it won't propel the boat,
but too bowed and the boat won't manoeuvre in the wind. The
trick to achieving this balance lies in the strength of the
different threads, the tightness of their twist, and their
interlacing and watertightness. The discovery of the
Trondenes sail meant that, for the first time, these
intricacies could be examined in Viking-age cloth.
Microscopic analysis of the sail showed that its strength
came from the long, coarse outer hairs of a primitive breed
of northern European short-tailed sheep called villsau (Ovis
brachyura borealis). Small flocks can still be found from
Finland in the east as far as Iceland in the west. Norwegian
coastal farmers had long favoured this breed, which could
thrive on the limited amount of forage, chiefly heather,
found on the Norwegian coast. Villsau were extremely hardy:
they did not need shelter in winter, nor extra food to
survive outdoors throughout the year. The result was less
work for the farmer and, because the sheep were always
outside, a wool saturated with water-repellent lanolin.
When it came to making a sail for the Coastal Museum's boat,
the Sara Kjerstine, Lightfoot was able to provide a limited
amount of villsau wool from a flock of 25 sheep she kept
herself. The remainder came from a modern relative called
the spelsau. Both types of wool had to be worked by hand to
preserve the lanolin and to separate the long, strong outer
hairs from the weaker inner wool. Following tradition,
Lightfoot and her colleagues "rooed" or pulled wool from the
villsau in midsummer. This was not a trivial undertaking:
the Sara Kjerstine required an 85-square-metre sail that
consumed 2000 kilograms of wool, a year's production from
2000 sheep. To prepare the wool for spinning, the outer
hairs had to be separated by hand from the inner fleece.
That job took Lightfoot and three helpers six months.
Spinning the wool into 165,000 metres of yarn and weaving
the sail took another two-and-a-half years. The Sara
Kjerstine made her maiden voyage with her woolen sail in 1995.

After finishing the Sara Kjerstine's sail, and a second,
50-square-metre sail for a group of Danish Viking ship
enthusiasts, in 1997 Lightfoot joined forces with the Viking
Ship Museum at Roskilde. The museum wanted a woollen sail
for the Ottar, a replica it was building of a Norwegian-made
Viking cargo ship. This time Lightfoot took a short cut:
instead of rooing the wool, it was sheared. Still, she and
her colleagues had to spin 188,000 metres of yarn for the
90-square-metre sail. The sail took three years to complete
and the Ottar set sail in August 2000.
As Lightfoot spent endless hours working the wool, she
thought about the enormous amount of time and material
needed to produce just one sail. Outfitting a fleet seemed
nearly impossible, and yet the Danish king Knut II is
believed to have had more than 1700 ships at his command
when he laid plans to oust William I from England in 1085.
"You think about the Vikings' western expansion, and you
look at all the wool it took," she says. "And you think,
maybe the sheep had something to do with their expansion."
Sheep and women - women with their drop spindles, looms and
infinite capacity for work. "Unless there were women ashore
making sails, Vikings could have never sailed anywhere,"
says Lightfoot. But there was more. Each sail required so
much wool that Vikings had to perfect their sheep husbandry.
In Norway, they managed the landscape to feed more sheep by
burning the heaths.

Historical and radiocarbon data from as early as 1400 BC
show that Norwegian coastal farmers kept sheep and burnt the
heather. Villsau must eat a rich variety of grasses in the
summer to gain the weight they need to survive winter on
heather. The sheep themselves encourage new fodder,
suppressing new growth of heather and enabling nourishing
summer grasses to flourish. Fire augments the process by
keeping down the heather and preventing the invasion of
young pines that would eventually turn good grazing land to

Lightfoot's three woolen sails have provided some unexpected
insights into the handling of Viking ships. For example,
woolen sails power Viking ships about 10 per cent faster
upwind than modern sails, and can be sailed far closer to
the wind than anyone guessed. In September, the Roskilde
museum's latest ship, a reproduction based on the Skuldelev
2 wreck, is due to make its maiden voyage to Ireland.
Ironically, this ship won't have a woolen sail. "It's too
expensive," says Andersen. Unlike the Vikings, the museum
doesn't have huge flocks of wild Norwegian sheep to produce
the wool it needs. Nor does it have an army of women to spin
and weave its sails.