m*- w - Clpdigital.org

•SM
i w
WWW
J,i.
4
0
•
'A^Hk.
TUBING THE ENGLISH CHANNEL 185
rj|
3| mt/JL. % '
. . . . s • •».
•wirntf r ' i - r ^ ^
V
4
/
V
xU M
L ^B • . -to.
THIS PNEUMATIC BATTERY TUNNELING MACHINE. GIVEN ITS INITIAL TRY-OUT ON
THE NEW YORK SUBWAY LATELY, WILL DOUBTLESS BE USED IN THE NEW TUBE
had been so clamorous that in 1882 the that this seepage at no time would ex­
idea had bee.n to all intents and purposes ceed 26,500 gallons a minute for a double
abandoned. The fear of the English had tunnel. Each tunnel would be about
seemed to be that the French could eighteen feet in diameter. Drainage tun­
quickly rush an army through the tube, nels would be connected with these two
seize London, and, in short, make a traffic tunnels. According to an authori­
speedy conquest of Britain. As a guartative engineering publication, the diffiantee
that they had no such motives, the culties of boring these tubes would in
French proposed to elevate a section of all likelihood not be so great as that of
the approach along their coast line, so as completing the Astoria gas tunnel under
to offer a fair target to the British fleet. the East River in New York City. It
International, as well as internal poli­ is expected that the tunneling machines
tics, make rapid changes as the years fly can each dig 3.7 miles per year. As it is
by, and today the British would be the intended to work from several points at
last to seek a bombardment of the French once by making use of the drainage gal­
coast.
leries to drive cross drifts, whence new
Meantime the French have been busily bores may be started on the main tunnel,
at work bringing the plans up to date. it is believed the entire job could be
The total distance from the Paris-Calais finished in five years.
railway to the London-Dover line is 37 The cost of such a task would be not
miles. Of this distance 32 would be less than $2,000,000 a mile. The French
underground. In mid-channel the floor engineer, Albert Sartiaux, says it would
of the tunnel would rise from each side be wise to estimate an expenditure of
to a hump, so as to permit the drawing $77,000,000 in all. Five to seven per
off of such seepage water as would be cent would be realized annually on this
certain to find its way in. It is estimated investment.
•v