University of Wisconsin Digital Collections
Link to University of Wisconsin Digital Collections
Link to University of Wisconsin Digital Collections
The University of Wisconsin Collection

Page View

Godfrey, Kneeland, Jr. (ed.) / The Wisconsin engineer
Volume 59, Number 4 (January 1955)

White, Richard N.
The Mackinac Straits bridge,   pp. 20-22


Page 20


  -U. S. Steel Photo
   Fig. 1.-Two main steel towers rise majestically 552 feet above water from
piers founded on rock approxi-
mately 195 feet below lake level. These main towers support cables for a
center span of 3800 feet, second only to
the 4200 feet of the Golden Gate Bridge in San Francisco. The total length
of the bridge and approaches is
26,195 feet, while the suspension bridge, 8,614 feet from anchorage to anchorage,
is the longest in the world.
The
Mackinac Straits
Bridge
A GREAT MAN-MADE LINK NOW BEING BUILT BETWEEN
UPPER MICHIGAN AND THE LOWER PART OF THAT STATE
                by Richard N. White, ce'56
          A Short History of Bridges
  Undoubtedly the first bridges were formed by
-Mother Nature-fallen logs across streams, natural
arches formed bv erosion, and similar devices. Man
soon came to imitate these structures, and then started
to improve on them and devise new and different types
of bridges. India was the birthplace of the modern sus-
pensionl bridge an(l the cantilever bridge. Mesopotamia,
in 4000 B.C., produced the first true arch bridge; and
the Romans, who usually needed many bridges in a
short time, built the pontoon and timber trestle bridges
during their military conquests.
  After Rome the Church became the chief bridge-
lbuilders because of the unruly order and dangerous
traveling conditions. As the Renaissance came into
being, Leonardo da Vinci drew plans for portable and
bascule bridges, and Palladio first used the truss, which
is the framework of most modern bridges. Many large
masonry arch bridges were being constructed at this
time, especially in Paris. It was also in the Renaissance
period that the bridgebuilders became known as civil
engineers and gained stature in the eyes of the public.
  It was not until the 18th century that bridges were
designed using some type of scientific analysis. The
first engineering school was headed by Jean Perronet
who has been called the father of modern bridgebuild-
ing. A few years later iron and wrought iron came into
use as a building material, and many new wrought
iron truss type bridges were constructed. However,
during the 1870's and 1880's about 25 railroad bridges
THE WISCONSIN ENGINEER
2()


Go up to Top of Page