Evening star., 1939-02-08
Dredge Starts Work
To Provide More
Land for Airport
Engineer Says GroveIIy
Field Will Have
Fine Foundation

Fine Foundation
The Pennsylvania. superdredge of
the American Dredging Co. of Phila-
delphia, stuck its snout into the
gravelly bottom of the Potomac
River off Hams Point this morning
and started pumping 1860 tons of
fill per hour to make the Washing
ton National Airport at Gravelly
Point.
The huge dredge, one of the larg-
est in the world, arrived here Satur-
day via the Delaware and Chesa-
peake Canal and moved into posi-
ton 1000 yards out in the river from
the levee thrown up to delimit the
area of the new air field. 1t could
get no closer and will have to "eat"
its way in toward the Virginia shore.
AS work started the cutter-con-
sisting of two wheels. the inner
larger than the outer and equipped
with knife blades between-much in
the manner of the paddles of
paddle wheel-was lowered to bot
tom, "a feet down, and the $500
horsepower steam turbines started
sucking up the bottom of the river.
875 Cubic Yards Per Hour.
The suction pipe terminates in the
center of the wheels and as the
knives loosen the river bottom the
= water, sand and gravel there is
sucked into its 34-inch aperture at
the rate of 875 cubic yards per hour.
More than 1000 yards away the
other end of the pipe, q feet in
diameter, discharge an ugly-looking
mixture in the still waters of the
levee already built around the air
port area.
1t will require 100000 cubic
yards of material to fill the Airport
Basin, Col r. S. Thomas. U. S.
Army Engineer for the Washington
area, said today as he watched work
start.
'"Those people who thought we
were going to make the airport out
of mud must be crazy" he said as
reporters listened to the rocks rat
tie through the pipe towards the air
field site.
"You see the river bottom here
Is all sand and gravel. In the geo.
logic past Four Mile Run was quite
a stream and it deposited huge
supply of good firm gravel all
through this section of the river.
That's why it's called Gravelly
point. The gravel area stretches
nearly all the way to Hams Point"
he said.
Slight Amount of Mud.
Just to prove his point he stopped
the dredge tender on the way
ashore at the levee already built up
around the airport site and demon
strated exactly what the material
looked like. 1t was composed of
cobble stone of considerable size and
graded down into coarse sand. Only
q slight amount of mud was admixed
This airport will have the best
foundation of any in the country ex-
cept Floyd Bennett Field on Long
Island" he said, adding that the
New York airport was made on pure
beach sand similar to that at Day.
tona Beach, Fla.
1t was early this morning that re-
porters and engineers from Col
Thomas Office as we'll as officials of
the Civil Aeronautics Authority
gathered aboard the dredge to eat
breakfast and watch work begin.
Until today dredging operations
had been confined to building the
levee around the airport site with
smaller War Department dredges.
The War Department has been
dumping fill taken from the Poto-
mac and Anacostia Rivers there for
years.
Later today the Civil Aeronautics
Authority announced a contract had
been awarded to the McWilliams
Dredging Co. of New Orleans similar
= to that held by the American Dredg-
ing Co.
Larger Dredge Due Next Month.
The George A. McWilliams. an
other dredge with an even larger
capacity than the Pennsylvania. will
arrive in Washington by March 20
to start work. 1t is at present work.
ing at Natchez, Miss.
: The McWilliams can pump ap-
proximately 100 tons of fill per
hour.
Contracts for both dredges provide
for three working periods of $500
hour each, with the right reserved
to discontinue work before the end
of the month If necessary, at the
termination of any of the 2,50O-hour
periods.
Cost OF the dredging, as contained
In the contracts. ranges from $125
to $l45 per hour.
Two other bids were submitted for
similar dredges, but the c. A. A.
has not as yet decided whether they
will be needed.