The Washington times., 1914-01-28
TIMBERS IN EARTH
MAKE STREET SINK
Canal Is Likely to Be the Only
Solution of Permanent Re-
pair of Condition.
Continued from First Page.)

Continued from First Page)
wrong with the tunnel: and the only
building whose foundation is affected by
the operation of trains through the tun-
mel is the House Office building. Despite
the utmost pains to insure that thaI
building would be perfectly solid at the
point where its foundations rest on the
roof of the tunnel. il has been found
that a seismograph in the southeast
part of the House Office building re-
cords vibrations when trains pass
through the tunnel.
man handling the SelSmCgTGph, who
didn't know there was a great railroad
tunnel far down in the bowels of the
hill. would suppose that an earthquake
vas in progress.
Street Keeps Sinking.
But, while Capitol. Library and the
Office Buildings are perfectly safe. and
the tunnel Itself is solid enough to last
for centuries, the earth above the tun-
enl persistently sinks and carries down
the surface of First street.
1t will be recalled by those interested
in the remarkable engineering feats
connected with the tunnel construction
that the double-traCG car line on First
street was operated throughout the
time when the tunnel was beng made
Immediately under it. The center line
OF the tunnel and the center line of the
CSI track are coincident for a distance
S6 four blocks.
The street railway company was I'M
willing to suspend or remove its tracks,
Rnd the contractors for the tuLfel were
compelled to handle their bOrinEs in
such fashion that they should not in
terfere with the surface.
Most of the engineering authorities
favored building the tunnel by the
open-cut method; that is, digging
from the surface down, section at a
time, building the tunnel, covering it,
end going on to the next section But
this was impossible in view OF the |
protests against disturbing the sur
face, and the engineers then accepted |
the plan of boring directly through |
the hill.
A Timber Tunnel
In doing this the plan was adopted |
OF constructing a temporary timber |
tunnel to sustain the earth above |
while the workmen were building the |
permanent masonry arch. So when |
the task was completed there was |
double tunnel, the permanent ma sOnry |
structure and around and above II !
the temporary timber structure.
The work being constructed in sec |
tons of twenty feet, the earth was
packed, as tightly as possible, in the !
zone Of about five feet between the |
masonry arch and the wooden struc-
ture. But, however they would try !
10 do it, the WOrlSmen found it impos-
sible TO restore the original condition
After the work was completed, the
earth between the wooden and the ma
sonry arch inevitably fell away. The |
masonry arch has now begun TO de-
cay, and the earth above is falling
down into the space between the tim
bers and the masonry structure.
That is what is making the trouble
at the surface Of First street The
District government and the Washing
ton Railway Company are both suing
the Pennsylvania railway, which built
the tunnel, for damages and to re- |
, Quire a restoration of proper surface
conditions. In turn, the Pennsylvania
IS suing the construction company thac
rut in the tunnel Tor It: and the series
Of litigations gives promise Of being
: long time reaching settlement.
An Urgent Need.
Meanwhile there is urgent need that
the surface work be attended to. En-
gineers insist that the one safe and per
Inanent way 20 10 this is to open up
the entire line Of the tunnel across
Capitol Hill; to bare the roof of the
masonry tunnel; take out the timbers
composing the old protective structure,
and then put back the earth.
Doing this would, in effect, repeat the
whole experience OF disorganizing and
ripping up Capitol Hill. which has been
in an almost perpetual condition of
chaos in recent years. II was thought,
At the time. that a great trimph had
been achieved when the railroad tunnel
was built by the boring process; now.
IL seems, the troubles that were avoided
temporarily may vet have to be under
gone.
Cutting a great canal across the top
of Capitol Hill would of course be done
in sections, as they would build sub
way in New York. BL; there is danger
that many of the beautiful trees In the ]
Capitol Plaza might be affected, per- ,
TE -nd I'M h. Eo-, ofr I
sponsibiIity for the cost of the work |
is far from settled
II is believed that 100000 would be
, equired TO do the work, under the most
favorable conditions. The item OF re-
storing street surface, sidewalks, etc, |
would cost about S90 on