About 80 miles northwest of Des Moines, Iowa, lies the small
town of Manson. Nothing much has ever happened there, unless
you count the time 74 million years ago when a giant meteor
crashed nearby. Actually, calling it "giant" doesn't do it
justice: The meteor was 1 1/2 miles across, weighed 10 billion
tons, and was traveling at 45,000 mph.
Compared with that, the second biggest thing to hit town was
almost puny — it measured 60 feet in diameter and 53 feet
in height, weighed 42 tons, and moved down the road at a mere 5
mph (1, 2).
Still, the people of Manson can be forgiven for making a fuss
over something that — comparatively speaking — was
not so big. After all, no one was around when the meteor
landed, but a lot of folks were there to see the round barn
with a dome-shaped roof being hauled onto the grounds of the
camp at Twin Lakes Christian Center.
Built in 1920 by a traveling carpenter named Charles Knapp, the
barn was donated to the camp by a local farmer. The original
owner used the lower level to house draft horses and dairy
cattle, and the upper level (3) to store hay. At the time,
round barns were popular because they required much less lumber
to build than rectangular barns of the same volume.
Considering how windy it can be in such a flat, treeless area,
it's amazing how little framing this barn contains.
Curved laminated rafters run up from the walls and end at a
wooden compression ring (4); the unsheathed walls are stiffened
by a series of let-in diagonal braces. According to an engineer
who consulted on repairs, the purlins account for 80 percent of
the roof's strength.
Perhaps it's all a matter of perspective. The barn may be small
compared with that meteor — but it probably looked real
big to the guys who used 54 squares of cedar shingles to reroof
it several years back. — David
Frane, with special thanks to Mark Parlee and Joel
Rude for providing photos and information