The Washington weekly post. (Washington, D.C.) 1878-1916, 1900-03-06
RISKS IN TUNNELlNG.
Mysterious Dangers to BE Encountered
While Under Ground.

From the New York Mail and Express.
| That there will soon be tunnels under
the East River TO Brooklyn and to South
| Brooklyn seems 10 be assured. 1t is posi-
| Bile. strange enough, to forecast more
closely what the engineers will encounter
under the bed of the river than what they
| will encounter under the surface of Man
haitian Island. No complete map exists Of
| the underworld of the city, with its net
work of sewers, conduits, gas, steam, and
water mains, while some experience all
| ready gained in work under the river has
! placed in the possession of contractors 4
pretty accurate idea of its bed.
! They have gained this despite the heavy
tides that make core borings difficult or
impossible. In the neishborhood of Black
wells Island the current at spring tide
| sweeps up and down the channel some
times at the rate of nine knots an hour.
The tide runs with scarcely abated flow
almost to the turn. For only about fif-
teen minutes is there anything like still
water, and this is merely on top. The I'M
dercurrent runs later than the surface.
and While it may be still above, the tide
will be running strong at the bottom.
The geological formation of the riverbed
is accounted 10 be the work of a double
glacier that flowed from the Hudson Val
ley by way of the Harlem, and divided On
the north end or BlackWelis Island form
ing the channel on either side Under the
channel Is an almost solid bed of meta
InOrphic rock. On the New York side in
the neighborhoOd of Blackwelrs Island
this is comparatively soft gneiss Midway
II becomes hard and straight-grained
with considerable mica. On the BROOKLYN
side Ii Is massive and f1inty as granite
DecOmpOsed feldspothic rock soft az
cheese il fQIlOH TnOpflpP with st.li
pyrites and sections of carbonized wood
Near the Brooklyn side strata of rock
have been encountered under such pres
sure that at intervals they gave forth
sharp reports like the explosion of a pistol
Experience has shown that perhaps the
greatest difficulties TO be met will be those
connected with the health of the work
men. TOlling under the unnatural air
pressure which would be needed whenever
decompoSed rock or pothOleS of mud are
discovered, the men who will push the
tunnels from shore to shore must face
certain physical discomforts and some
slight risks OF strange and fatal maladies.
NO person having any disease OF the
Dronchia! tubes, lungs, or heart has any
right TO enter pressure. Sudden death has
stricken down even the healthy in work.
ing uncer the bed of the river
The first injurious effect OF working I'M
Ger pressure IS an itching caused by air
EloDuleS IN the capillaries. This NAV be
cured quickly by inducing prOfuse per
spiratiOn. The next stage is bends an
intense rheumatic pain in the joints caus-
ed by air glObuleS in the sockets. This
may be benefited by subjecting the pa
uent to profuse perspira ton and remoy-
ing him TO a heated pressure chamber !
The last stage Is paralysis, frequently re-
sulting in death. OF four men who died
while digging in the gas tunnel under the
East River. the first expired half an hour
after succumbing to pressure, and the |
second before he could be removed from,
the tunnel The third and fourth became !
paralyZed from the shoulders down and
lived only a short time
II was found that hot black coffee. pro- |
Vided IN large quantities, was helpful to |
the men. When the air-preSsure did NOT
exceed thirty pounds above that of the |
a atmosphere, men We're able to work for /
nine hours, laying off one hour in the |
middle OF the day. Working under the |
highest presSures, they Were unable To re /
main IN the unnatural atmosphere with
safety longer than one and a half hours |
which, with an hours rest between. made
an actual days work of less than five
hours.
The following rules have been formulat-
ed for working under pressure;
Never enter the air lock with an emptv
Use as far as possible a meat diet. and
take warm coffee freely.
Always put on extra clothing on coming
out, and avoid exposure 10 cold
Exercise as little as may be during the
hrst hour after coming out, and lie down |
If possible
Use intoxicating liquors sparingIy. Bet
ter not at all
Take at least eight hours sIee, a,,o-,,
night
Never enter the air lock If at all sick
In exit from the air lock, the time occI1-
pied is 10 be five minutes for each afnoc-
phere above the normal