New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1890-02-16
THROUGH THE AQUEDUCT.
FEATURES OF THE GREAT SIPHON UNDER
HARLEM RIVER
THE TUNNELS SAFETY VALVE - THE GATE
HOUSE AT 135TH-ST. AND THE PIPE LINE
"A DANGEROUS DESCENT OF SHAFT NO


II any one thinks the Aqueduct dry subject
let him wait till June. 1t will be wet enough
then The reporter who made the first genuine
and original trip through it found it rather too
wet. Especially was it in that condition in
Gouids Swamp siphon and in the
great siphOn under the Harlem River
Only didapper could have made subterranean
and subaqueous passage Of those sections. AS
Deputy Chief Engineer Rice and the reporter
lodged the former so they passed over the latter,
high and dry, each promising the other TO OK
plore both siphons when they are pumped out in
the course of the next two months. The second
instalment Of the reporters account of his tour,
published in last Sundays Tribune, left the eX-
plorers at the mouth of Shaft No. 3D. out OF which
they had had long and laborious climb, after
o longer and more aborious wade down TO Shalt
No "a. the beginning of the great siphon and
back again.
1t would have been less expensive to build
stone or steel viaduct TO bring the water over
the river than to bore great hole through SOLID
rock. 3O7 feet below the tide, but certain adj
vantages were gained by the latter method which,
it is believed will cOunterbalance its greater cost
Not the least of these is immunity from the danger
of foreign attack. Should any foul invader at any
time presume to invade this part Of the country
and succeed in planting his cruel guns on Wash
ingtOn Heights, or at Spuyten Duyvil, or on
Wards Island, or if he should fire them from the
starboard bow of men-of-war anchored at Harlem
Bridge, what would be easier than TO punch out
the piers of High Bridge with a few big shells,
turn the old aQueduct into the river and bring us
TO terms with a water famine ? For that matter.
the old aqueduct is helpless, defenceless sort of
structure from beginning to end Being surface
conduit the enemy might destroy it IN hundred
places with picks and shovels, 10 say nothing Of
shells from gunboats in the Hudson. New-lork
cannot realize what narrow escape 1t has had.
Just think of leaving our water-supply exposed
in that reckless way all these years. II Iayu
had only known.
The new Aqueduct, armored with the hills, is
practically out of reach Of the foe. In case OF
hostilities there would be only four places to
Guard: the Croton gate-house and the waste weirs
and blow-ofis at PocanticO, Ardsley and South
Yonkers
Tie first design of the engineers contemplated
a crossing of Harlem River at distance OF only
1877 feet below the water, but tests with the
diamond drill exposed a crevice in the bedrock
which extended many feet lower and 1t was 10
avoid that that the siphon was carried down 3O7
feet.
I'm our experiments" said Mr.. Rice TO the
renorter. 1--WE came across an extraordinary geo
logical formation One of our drills, passing from
rneiss rock into limestone, brought up core
which showed the two strata TO be firmly welded
togetbcr. | had never seen or heard OF such
thing before"
The siphon is a circular tube Of brick. 10 feer
6 inches in diameter, and the water In IT Is under
oroot rressnre At Shaft No 20, where the
horseshoe section ends. the flowing capacity oil
the Aqueduct is reduced from 3ls,OOO'ooO gal
Ions a day 70 100000. 900, leaving 6S,OOO,Ooo
pallons TO be turned into jerome Park when
the historic home of the defunct American Jockey
Club shall have been converted into reservoir
for supplying the Annexed District with water
The siphon having smaller area than any other
portion of the tunnel. the stream must 10"
,brouqh II much more rapidly than it flows
elsewhere in order to keep the larger section
south Of the river up to its full capacity Of
o5o 600 900 gallons. Plunging down Shaft No.
"a the water sweeps under the Harlem to Shaft
No o.. where il lifts itself into great vertical
column over 400 feet in height. Then, breaking
of abruptly to the horizontal, it climbs gentle
alone 70 the gatehouse at One-hundrd-and-
thirty
FOR CLEANING OUT THE GREAT sIPHoN.
No 25. one of the greatest shafts in the world,
is in reality double shaft. The sphon being
the lowest part Of the Aqueduct. whatever sedl-
ment the water may contain will be deposited
there and it became necessary 70 PROVIDE q
means OF cleaning it out from time to time
Chief Engineer Fteley has designed an ingenious
vet remarkably simple apparatus for the puI-
nose The two shafts are side by side. divided
only by a stout wall OF masonry. in which. al
the extreme bottom. there is a gate. which belhg
opened permits the water TO pass from one 70 inc
other. The first shaft. a section of the Aqueduct
Ill. 4ha
its auxiliary. is empty, long as the
gate is kept closed To clean out the siphon it is
necessary TO empty all that portion of the AQue-
duct between South Yonkers and One-hundred-
and-thirty-ffth-st The first proceeding is TO
dam the water at South Yonkers. The next IS
10 omen the gate at the bottom Of No. % and let
the water pour into the auxiliary shaft In
this there are enormous buckets which slide up
and down with the speed Of the WIND, Delhg
held in position by bronze guides. They have
valves in the bottom. which open as they plunge
into the water and close when they are pulled
up. filed TO the brim They travel 80 faSt tiat
the water las no chance 20 rise in the smart,
and the Aqueduct is emptied in an lncredloV
short time Pipes convey the waste 10 Harlem
River. The apparatus is operated by splehdlo
engines, designed for that especial purpose.
The foresight shown by Mr.. Fteley and the care
with which he has worked out the minutest de-
tails of the construction are forcibly brought TO
mind in the arrangement OF the gate. To the
casual observer the rod by which it is raised and
lowered is unnecessarily large and heavy. 1t
is four inches square and weighs about eleven
tons. while the gate itself weighs but one ton.
Both are bronze so that they will never rust.
Suppose" said the Chief Engineer "a block
of wood were to float down the Aqueduct and be-
fastened in the opening between the two
shafts With weak. pliable rod we should be
helpless. 1t would be necessary 10 pump out all
the water and send man down to remove the
obstruction With the large rod that we are using
we are prepared for just such emergency. 1t