Prev | Current Page 83 | Next

Bond, A. Russell

"The Scientific American Boy The Camp at Willow Clump Island"

A stick nailed to the
apex of each pair of spars served temporarily to brace them apart. The
center cross beam of the bridge was now suspended from the spars by means
of heavy galvanized iron wire (No. 14, I should say). The beam was hung
high enough to allow for stretch of the wire, making the roadway incline
upward from both sides to the center. Aside from carrying the floor of the
bridge, this beam was used to brace the inclined spars when the temporary
crosspiece was removed. The ends of the beam projected about thirty inches
beyond the bridge at each side, and they supported braces which extended
diagonally upward to the crossing ends of the spars. When this was done
the temporary crosspiece above referred to was removed. As the span
between the center cross beam and the banks was a little too long to
provide a steady floor, a couple of intermediate cross beams were
suspended from the inclined spars. The floor beams were then laid in place
and covered with a flooring of slabs.

Stiffening the Bridge.
[Illustration: The King Rod Bridge.]
[Illustration: The Bridge over Cedar Brook Gorge.]
The bridge was a pretty good one, except for a slight unsteadiness between
the center and either end.


Pages:
71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95