A passage, called by the Dutch settlers of New York Helle Gat, being that
part of the East River between Long Island and Manhattan Island, also
between Long Island and Ward's Island, and between Ward's Island and
Manhattan Island. The reefs of rock in the main passage, some of which were
islands at low tide, caused with rising and falling of the tide numerous
whirlpools and eddies, which rendered navigation at times dangerous, always
difficult, and for large ships impossible, although the depth in the
tortuous channel might be sufficient. The East River receives the Sound tide
from the east and the Sandy Hook tide from the south. The times as well as
heights of these tides being different, additional force is imparted to
these treacherous currents. It was claimed that one out of every fifty
sailing vessels attempting to go through Hell Gate was more or less damaged
by the rocks.
	A survey was made in 1848 by Lieutenants Charles H. Davis and David
Porter, of the United States Navy, and in their report they recommended the
destruction by blasting of Pot Rock, Frying Pan, and Ways Reef, which lie
between Long Island and Ward's Island.
	The first attempts at removing the obstructions in Hell Gate were made by
M. Maillefert, with whom a contract was made by citizens of New York. He
commenced work in August, 1851, and by surface blasting operated  upon the
most prominent surface of the rocks and reduced them to an average depth of
about sixteen feet. Congress in 1851, appropriated for the work $20,000 and
placed it under the direction of Major Fraser. The method was by surface
blasting, as had been practiced by M. Maillefert. The reefs in this channel
are largely composed of a stratified gneiss, and the layers, being tipped up
nearly perpendicular, were unevenly affected by the action of the water, the
softer parts being worn away and the harder parts left in vertical sheets or
points. In 1866 Gen. John Newton, of the United States Engineer Corps, was
ordered to make a survey, and proposed the construction of a drilling scow
which should be securely moored at the site of operations. The machine was
constructed, and put into operation on Diamond Reef, near the mouth of the
East River, in May, 1871. Coenties Reef was also operated on with this scow
in alternation with the work on Diamond Reef. These operations proving
satisfactory, the machine was taken to Hell Gate, where it was in operation
nearly three years, and effected a great improvement in the channel.
	The first really important engineering accomplishment was the removal by
tunneling and blasting of Hallet's Point Reef, which extended from the
Astoria shore into the East River. By means of diverging tunnels and
transverse galleries the reef was thoroughly undermined and nitroglycerin in
cans was introduced into a large number of holes drilled in the pillars
supporting the roof and in the roof itself. After water was let into the
mine the nitrogen was exploded and the reef was destroyed, the debris being
removed by grappling and dredging, so that there was a depth of 26 feet at
low water over the site of the reef. The explosion at Hallet's Point took
place September 24th, 1876, and was followed by energetic prosectuion of
work on Flood Rock or Middle Reef, where similar tunnels were constructed.
After over 21,000 feet of tunneling had been constructed and holes
aggregating 113,192 feet had been drilled, 300,000 pounds of explosives were
put into the holes, and water was let into the tunnel. The result of the
explosion that took place October 10, 1885, and subsequent dredging, was to
provide a channel of uniform depth of 26 feet through Hell Gate.

 Source:  The New International Encyclopaedia
Publisher:  Dodd, Mead and Company--New York
Copyright:  1902-1905


Transcribed by Miriam Medina