New Orleans Republican. [volume] (New Orleans, La) 1867-1878, 1875-10-24
Deepening New York Harbor.

The work OF removing Ways reef and the
reef Oft One Hundred and Twenty fifth
street, Harlem river, having been completed
under the direction of General John New
ton, the drilling scow is now engaged in re-
moving Diamond reef, which obstructs navi-
cation OF the channel between Governors
Island and the Battery. Drilling and blast
ing are continued day and night, and it is
expected that the work of removing the
reef will be completed early next spring
The scow is under the charge of Julius II.
Stinedinger as civil engineer. 1t was taken
to Diamond reef October 9. This reef
is 400 feet long and $50 feet wide.
1t consists OF gneiss rock, horizon
tally stratifed and running in an
easterly depth. The least depth Of water
at present On it is nineteen feet, and it is
intended to remove it to minimum depth
of twentysix feet at mean low water, being
three and half feet more than the
draft OF the bar at Sandy Hook. The work
will take about nine months of steady drill
ing and blasting, and will cost about
500, GOO. The debris is taken up by crap
ping machines and deposited on scows,
which carry it away and dump it at the ex-
pense of private applicants who desire the
material for filling IN dumping lots. The
crew, consisting of the working force, are
the same men who have previously been
engaged in the removal of Ways reef,
Quincy's reef and the reef off One Hundred
and Twenty fifth street, in Harlem river.
They are picked men, each being able
to attend diver and to run the drilling
engine, besides being first class
seaman. They are in charge of Captain
Harrow. There are three divers EN-,
ployed who have to descend at slack water
to make submarine surveys, marking the
depth, plugging the drill-holes and charg-
ing the plug-holes with nitrO-g ycerine. The
divers are all experienced wrecllers. The
size Of boiler employed limits the number
of holes to be drilled at one time to seven.
The total number of drill pipes is twenty
one; the hourly advance OF the drills is
from nine inches to four feet, depending
entirely upon the hardness of the rock and
the swiftness of the tidal currents. The
holes are about seven feet apart and are
drilled about three feet below grade, in
order to secure the required depths by one
drilling process. The drill-h holes are charged
with tin cans containing nitrO-glycerne,
into each of which fuse or exploder
is inserted and connected with the bat
tery on deck. The average number of
blasts per week is about three-and the
average amount of tons of rock removed by
each blast is abont 200 The largest num-
Der of holes simultaneously fired on Da-
mOnd reef has been twenty -one-containing
over 100 pounds Of nitro-gl ycerine, which is
the largest amount ever fired by the scow.
the cartridges used were filed with two
thirds nitro-glycerine to oEe.third water,
throwing the water and rock about l5c feet
high. When the debris is removed by the
dredge thorough survey OF the reef is
made, and the remaining loose stones are
chained by the divers and raised on deck by
derricks. To facilitate these final opera
tions sounding machine has been designed
and is in use. This machine consists of a
horizontal iron bar, lowered to the required
depths and dragged over the reef. Each
time it strikes the diver descends and ascer-
tains the character of the obstruction. The
instrumental observations necessary for 10
eating the position of the drill holes on the
reefs are taken and fatted by the superin-
tendent himself, sextants being used on
board the scow or theOdolites on shore for
this field word. The charts used are the re-
suits of the photographic work of General
Newton's surveyors.