Evening star. [volume] (Washington, D.C.) 1854-1972, 1930-05-18


~ AIRING engineers are now put
ting the finishing touches on
Americas first international
- traffic tunnel, which links De-
troit with Canada. An old
dream comes true as the $26, 900 900
tube Is projected under the Detroit
River, the first of the kind to be de-
signed and built. The subway will in
troduce new efficiency to modern trans
portation and blaze the way to economy
in the movement Of the great fleets Of
motor cars which now congest the De-
troit area and border city district.
This is the first tube to be built on
dry land, noated to the site and sub
merged to the bottom Of the river 1t
is to span. It Is one of the first tubes
to be projected and completed in
America within the estimated cost.
Moreover, it is the first river tunnel
projected and completed by private
initiative. All others have been con-
structed by municipalities or States.
Windsor Residential Center.
Even since motor cars made Detroit
a metropolitan district. resulting in
such q congestion of traffic as to rem
der 1t necessary that large part OF the
population reside on the opposite side
of the river, In Canada, and necessitat-
ing the movement each year OF more
than 100000 motor cars and 18,000,-
600 persons back and forth across the
waterway, engineers have visualized a
day when . modern tunnel would span
the river. Detroit has grown by more
than so per cent in the last decade.
while the development on the Windsor
side of the river has been 100 per cent.
Into the picture came Frederick Mar
tin, dreamer, worker and windsor SAL
walton Army man. He visualiZed the
method and obtained the necessary en-
cheering assistance to insure success.
He sold" the idea to private interests,
complete the project.
The construction has been carried on
without interruption of traffic on the
Detroit River, one of the most con-
gested waterways in the world.
The engineers adopted new idea in
tunnel building quite in contrast to
the burrowing methods previously EN-
ployed. Work was started in January,
1929, and 1t Is expected the tunnel will
be opened for use in a few months,
since the engineers are ahead Of sched-
ule. Experts say o new method has
been evolved at Detroit that will revo-
lutionize tunnel construction.
New Methods Described.
Maj. Burnside r. Vale is chief en-
gineer In charge. Our method differs
from those previously used" Maj. Vale
says. Previously engineers have sunk
their segments-if they did sink them
by simply filling them with water or
sand and water. We place no additional
weight inside the tube, but sink 1t by
simply pouring cement on the outside
until 1t comes down to the surface Of the
water. Then we speed it on its way to
the bottom Of the river by adding enor-
nous concrete blocks that weigh 5000
pounds.
when the divers have gone down
and bolted the segment to the next
one, all we need to do is to knock out
the wooden bulkhead, and there we
have another water-tight link in our
tunnel
Each Of the tunnel segments is $50
feet long and has an inside diameter
of 81 feet and an outside measurement
of 35 feet. The sections were built OF
24-foot strips of heavy sheet metal
Joined together by means of the new
electrical and welding process, thus In
surfing one-piece segment OF great
strength and alright.
These giant steel tubes were fabri-
Gated at Ojibway, Ontario, six miles
from the tunnel site. After the joints
had been tested by Use OF powerful hy-
draulic machines to make sure that
each section was watertight, wooden
bulkheads were built into each end
and the great 450-ton tube was
launched into the river, much as q
ship is handled. Then tugboats took
hold and towed the great tube to the
dock OF the Steel Corporation, where
about 1900 cubic yards OF concrete
we're poured into the forms TO make
the outer lining.
When this had been completed, the
huge tube weighing about 5000 tons,
was towed to the site. Air was pumped
into the shell to make the cargo buoy
ant for the trip.
Steel Towers Erected.
Upon reaching the site of the tunnel
steel towers were erected at either end
of the tube. These assisted the engi-
neers in getting the range in shooting"
the heavy charge s5 feet to the trench
that had been excavated for 1t In the
bottom OF the river. When the signal
was given the air valves were opened,
and the heavy load shot to the bot
tom. This called for the precision Of
Swiss matchmaker, since there was
only an inch allowance for error, yet
the engineers did not need this, so
accurate was their n1Arksfi1anBhip.
THE preparation OF the trench across
the river for the reception Of the tubes
consisted Of dredging as nearly as pos