Evening star. [volume] (Washington, D.C.) 1854-1972, 1903-04-10
THE HIGHWAY BRIDGE
DETAILS OF MODIFICATION OF
THE sCHERzER DESIGN.
Filed at the War Department. This
Afternoon-How to Come Within
the Appropriation.

The details OF the modification of the
Scherzer design for the proposed highway
bridge across the Potomac so as to bring
the limit Of cost within the appropriation
available for the bridge structure were
filed at the War Department this afternoon
and include the following suggestions:
First By changing the floor of the bridge
from asphalt and concrete to wood The
wooden flooring would have the following
advantages over the asphalt: 1t is much
lighter. consequently requiring much less
steel to carry 1t and less material in the
piers. In long bridge like this, the as
phalt and concrete pavement is very ex-
pensive to maintain because of the ex-
pansion and contraction of the steel from
temperature changes. The asphalt and con-
crete are rapidly destroyed and would have
to be repaired and renewed frequently. The
expansion and contraction of the bridge
has practically no effect on the wooden
flooring. The saving under this item will
be SO great that 1t will easily bring the
cost of the bridge within the available
amount.
Second. If further saving is necessary
or desired. it could be effected by decreas-
substructure. Concrete is now generally
used instead of granite for bridge piers. as
1t is now possible to make concrete which
is efficient and durable.
"A uTtneT saving COulO DE elIoCtcU
by cutting off the piles at a higher level
than originally specified. This would re-
duce the dead weight upon the piles and
decrease the number Of the piles necessary.
The bottom of the piers could be protected
by rip-rap. as is done by railroad COM
panies and municipal authorities. These
savings however. are not so essential be-
cause all the saving necessary can be made
by the change In the floor.
Reducing Width Of Channel.
Fourth. In our design we had a channel
for navigation $50 feet wide between pro-
lection tenders, while the government
channel was 100 feet wide on each side of
the protection pier. A reduction of the
width of channel from $50 feet would effect
a saving in the cost Of the movable bridge.
The maximum channel required in Chicago
Is 14O feet and $50 feet is only required in
very extreme cases for very large vessels
and very heavy navigation. For two street
car tracks and highway traffic, roadways
are usually made 80 feet wide. This road
way is made 40 feet wide. A saving could
be effected here If desired.
By employing our services In making the
designs, plans and specifications. co-operat-
ing with the engineers of the War Depart
ment, the government can build a first
class bridge within the appropriation avail
able. 1t would then not be necessary to
go back to Congress for an additional ap-
preparation. Our complete plans and speci-
fications could be on file within two months
after the order of the government, employ
in gour services. There would then be
wide competition because bridge building
companies and contractors would not be
compelled to make plans in order to bid.
In our work We would ask for no greater
latitude than we are allowed by the larg-
est muicipal corporations and railroad COM
panies, and by prominent consulting engi-
neers who employ our services.
AT the suggestion of Secretary Root, an
interview is being arranged between Mr.
Sherzer and Mr. D. H. Burnham in Chi
cago on the question Of Mr.. Burnham's
should conform exactly to the architectural
features of the railway bridge near it. II
Mr.. Burnham should see fit to modify this
recommendation suffici emily to allow the
proposed new bridge to be made an orna-
mental structure, it is believed the Secre-
tary will take steps to have a design pre-
pared in accordance with the new recon-
mendation.