Evening star., 1926-04-18
Five Months of Digging.

This alone is long operation. 1t was
estimated by G.. A. Follett, resident
| representative of the contractor.
| that 1t will require about five months
to complete this operation so the first
cement may be laid. All of the piers
viii be concrete up to point three
feet below low tide, and then con-
crete faced with granite to the
spring line.
The steel piling for the cofferdams
is being received in the Potomac
Park yard. ready to be placed by the
derricks so that the pile-driving
Each piece OF steel piling interlocks
with it's adjoining one, and the whole
is faced with timber to- withstand the
heavy pressure Of water
While 1t will take months to corD-
plete the first abutment, operations
will not be confined to this. The
construction Of the cofferdams in
the river will begin as soon as the
two river dredges are completed at
their anchorages just off the sea wall
of the Potomac Park yard.
1t was estimated by Mr.. Follett that
the operations viii begin on two of the
eight piers which will stand in the
river proper within the next three
river will be abutment piers. because
they will carry the weights OF the
bascule BRIDGE draw span that
opens In the center, the roadways
lifting in the air.
One year from next September. If
no unforeseen difficulties develop, this
work will be completed, and the work
of connecting the piers and abutments
by the roadway spans will be started.
The contract for this work, however,
has not as yet been let.
Railroad Yard Needed.
In connection with the work on
the bridge, O. small railroad yard is
to be constructed on the Virginia
shore for the easy handling of
materials for the contractor, and bids
were opened last week for the spur
line which will connect with the
Rosslyn branch Of the Pennsylvania
Railroad which runs close by.
OF in the distance, viewed from
Potomac Park, two great Army engi-
neer dredges, the Talcott and the
Dalecarlia (the latter SO named be-
cause It Is constructed of machinery
taken from the Dalecarlia Reservoir
gagged in one of the greatest engineer
ing operations in this section of the
country. There. almost silently. day
after day they have been sucking
down one-third of Columbia Island
and, pumping 1t as liquid mud into
the levee, where It is allowed to settle.
the water running off into the river
again. For the first time In this
vicinity, it was said. levee building
machines are being employed. They
are scooping up earth around the
island and building the 20-foot high
leyee, forming a sort OF crater into
which the dredges are pumping the
rest OF the island.
Change in Channel.
This change in the contour Of the
| island is made necessary incident to
the construction of the bridge In
order that the present Georgetown
channel of the Potomac River may
be moved so that 1t will pass under
the center Of the bridge, where the
bascule span will be located. This
work will be finished in June, when.
| II was estimated by II. III. James, OF
| the District engineers office. 25OO.OO
| cubic yards Of mud will have been
moved in the work Of rebuilding Co
| lu,nbia Island and forming the founda-
ton for a great playground for the
District.
Some idea of the labor-saving work
of these machines may be obtained
from the fact that one of them will
move and place on the islands 5000
cubic Yards of earth in day of is
hours, whereas one man can move
only about cubic yards a day. Each