The Topeka state journal. [volume] (Topeka, Kansas) 1892-1980, 1902-01-04
RAILROAD NEWS.
Rock Islands Great Feat of
Bridge Building.
Great Canyon Spanned in Six
Months Time.
BUILT BY TOPEKA MAN
w. II. Cannon Superintended
the Construction.
Crosses Canadian River in Midst
of Desert.
SUNDAY.

One of the greatest engineering feats
in railway bridge building in the west
was accomplished in the construction
of the bridge shown in the cut by the
Rock Island railway over the Canadian
river, in New Mexico.
The bridge as shown is 1863 feet IN
length, and spans the river at a height
of 135 feet at its highest point 1t Is a
single track structure supported on six
steel piers, and consists of seven spahs
so feet in length and six spans 50 feet in
length, the shorter spans having The
same length as the tops of the towers
in the direction of the length of the
bridge. The structural work on the
bridge includes 1,110,000 pounds of soft
Steel and was built by the American
Chicago branch of the American Bridge
company, under the supervision of w.
r. Cannon, of Topeka, superintendent
of bridges and building of the Rock
Island
In the locality in which the bridge is
built timber is very scarce, and to have
employed false work in the erection OF
the SuperStructure would have neceSSi-
tated considerable expense and time in
bringing the materials to the site. In
view of these conditions it was decided
to dispense if possible with the extern
sive false work which would have been
required in a bridge of this height. Ac-
cordingly a new method was employed
in the raising of the superstructure
used on a bridge of this size. Two
cables were stretched ten feet apart
from one side of the gorge to the other,
and on these trolley systems were fitted
up for conveying the materials to be
used in the towers from cars to their
proper positions on the bridge. The
cables used were l 900 feet in length II
inches in diameter, and were stretched
by means of hosting engines. They
were anchored on one side in solid rock
and on the other by means of four
12x12 inch timbers placed back of six
piles driven into the ground
The pull on the anchorages was estima-
ted at $4,000 pounds. To these cables a
platform was attached, having a. back
ward and forward movement along the
cables and Which at the same time
could be made stationary in any posi-
ton desired. In the building of a tower
this platform was fixed a short distance
beyond the site and served as a means
Tor holding the pulleyS through which
We're run. A separate trolley was used
Tor each cable and was so designed that
the structural material could be run out
from the embankment or completed
portion of the bridge to the tower I'M
der construction and there raised or low
cred as desired. When tower had
been completed, two men were sent out
to the platform where the device grasp
ing tie cables was IOosened and the
platform pulled along for work on the
next tower and there fastened By the
use of this method, no false work
whatever was necessary, and there was
provided rapid and very satisfactory
means of conducting the work After
the towers We're completed, the Orders
were placed in position in the usual
way by the use of a traveller The tray-
eler used was run on rails spaced 10 feet
center to center and laid on either side
OF the rails of the track. 1t was equip
ped with 25-horsepower hosting en-
CINE and two booms 60 feet in length
The platform on which the hosting en-
CINE rested was - feet above the rails
leaving an open space 1OX13 feet
through the traveller, through which the
girders and structural material were
brought forward to be carried by the
booms or trolleys to their positions on
the bridge.
In the construction of the substitute