The sun. [volume] (New York [N.Y.]) 1833-1916, 1897-01-22
ENGINEERS DAM
TWO HUNDRED VISITORS IysPEor
the OPERATIONS.
Greatly Interested IN tho Vast Reservoirs.
witch VIII Hold $4,000. 900 600 Gallons
Of Wnter-Itow the Work Goes On-A
Lofty Ride That n Cable Man Deciined.

Greatly Interested IN tn. Vast Reservoirs.
witch VIII Hold $4,000. o 900 Gaiion.
of wnter-Itow the Work Goes On-A
Lofty Ride That n Cable Man Deciined.
As a part OF the programme Of their forty
fourth annual meeting. q delegation Of over
200 OF the American Society OF Civil Engi-
necrs. Mt the invitation of Mr.. A. Fteley, Chief
Engineer OF the Croton Aoueduct Commission.
visited and inspected tho new Croton dam
now being built at Cornell's. yesterday. The
journey was made by special train from the
Grand Central Station 10 Cioton, and thence
by carriages. over an hour was spent in
looking over the great hole where work is nov
being prosecuted. Half a dozen employees Of
the contractors abandoned their work, and
simply answered Questions.
Tho excavation nee essary 10 secure o solid
foundation for tho dam has been found to be
a much greater undertaking than was at first
supposed. About the lowest point has been
reached. however. and masonry Is now being
placed at q depth OF II feet below sca level.
From this point the completed structure will
have a total height Of $50 feet, of which only
the top on feet will be the true reservoir form
Ing part OF the dam. The dam will be zoo
feet wide at the bass and "a at the crest. Its
length. with the embankmont at tho south
end, will DO 1,4o0 feet. 1t will form q reser-
volr having q capacity Of 3e. 00o.o ZOO, 900 gal
lois, which Is lbout equal to the combined
capacity Of the nine dams now erected. About
$4,000 cubic yards Of the masonry of the main
structure are laid. and the work seems SCARCE
~ started. Over ,0o0, 900 cubic yardssof ex-
c~avation 10 now completed. and IL In estimated,
that 5000 cubic Yards more will finish this
portion Of tho work. In keeping the eIcava-
tion dry. about $500. 900 gallons OF water .
day is pumped into the Temporary channel
which has bren blasted OuI and walled In on
the north side OF the valley. Above this cham
mel. the splllway. the length OF which will be
1000 feet, is partly completed.
Yesterdays visitors were more interested In
details OF the operations unGer way than IN
into groups about the various points OF inter-
est; The, system OF trolleys by which all ma
and praise. Three wire cables. two inches in
diameter. are stretc bed across the valley at .
height OF about l75 feet above the river.
From a carrier that runs on ea"h OF these ca
blea, a block and tackle 10 operated. by means
OF which. not only all materials. put also
and transported. Tie cables are the longest
In use In this manner. measuring 1.4O0 feet
q srS week sn saeh ssSle 70 !. f inspected. 4 a BIT iso Of plank RnSs
is laid across two, brackets at the side of the
carrier. upon which q man stands while the
Journey OF more than q quarter OF a mile. and
ut an average distance, from the ground OF
nearly 200 feet. Some time AGO ono OF the CO.
bles was condemned. and a representative Of
the manufacturers was sent TO find out why;
but when IL was suggested That ho examine
the cable himself, he promptly declined. The
laying bricks near the top OF "skyscrapers."
Many were interested In the method OF ex-
cavation. The formation Is a decoinposed
limestone. too soft TO drill. and too hard 70
A hole about three feet square Is run horizon
tally into the bank for.about thirty feet, and
tw" lateral drifts are made at It's in"er end.
In these. after renliing the original hole. are
,xplod "a from thirty 20 fifty twenty-nve-pound
kegs Of powder ..anu the loosoned rock rs trans
ferred by a steam shovel 10 cars which are
drawn by q cable up an incline TO the TOD OF
the dumps.
" praised. The rock used Is q very hard
gneise. containing considerable iron. and Is
quarried about two miles above the dam. Zach
stone 10 steamed and washed carefully before
being. put In place, and no work Is done when
tie thermometer Is lower than 20 degrees.
On the return trip. after luncheon. the SOC
cial train passed over the new raised tracks
between l45th and Tooth streets. This was
the nrst train over this line which will not DO
regularly opened before the first OF Lext month
A stop was made for the inspection Of the new
Harlem River Bridge at Park avenue. The
structure is OF steel. heavier than ordinary.
and has a total length Of 730 feet The draw.
900 feet long and 81 feet wide. carrie: foSr
n direct-acting steam toRgle. The rail-lock-
ing device Is n new one. and was carefully ex-
nmlned. The bridge was Ibuiit by the King
Bridge Company. Of Cleveland. O.. for the
the other roads entering the Grand Central
Station will lease trackage. Throughout the
bridge and elevated track a new. form of-ex-
ira heavy rail Is used. electrically connected,
and insulated from all contiguous iron by
laminated cotton fibre.
The.exoursionisis pronounced the whole trip
a success. Last night thoy held a reception,
followed by dancing and supper at the Waldorf.