Year: 1872

The New York Commercial Bulletin
says Our readers will remember that
we alluded in recent issue to a novel
method which had been adopted to sink
heavy iron columns into the sand at the
bottom OF the great we'll in the Brooklyn
rafk. 1t was certainly plan which no
one but vigorous thinker would have
conceived. There is an expedient almost
rs unique Tor driving piles now in use by
me government in the construction of q
large wharf on League Island, in the Del.
aware.


On large scow is placed small steam
engine 10 hoist the piles into position !;
aud the driver itself, fastened to the end
OF The scow. does not, at first sight or at .
distance, differ very much in appearance
tiom the ordinary pile-driver. There is,
however. introduced between the upright
guides and beneath the heavy weight, or
pile hammer, IA short cannon, which does
a chiet share of the effective work. This
(Which in this instance weighs 1890
pounds. and has 6l-2 inch bore, two feet
deep) Is set, inuZzle up. with its head ar
ranged to rest firmly on the top of the
pile, when the latter has been drawn into
IT'S upright position ready to be driven
That the head OF the gun may rest the
more firmly on the pile, a large bore is
cut into ii II little distance, SO as toreceive
he top of The pile. The heavy weight or
hammer is provided on its lower side with
IL pi>ton--or ramrod-whicll Just fits into
The bore of the gun when the hammer
tails. On the upper side of the hammer
Is deep bore. little larger thai. the
bore OF The gun. into which piston fixed
at The top OF The frame just fits, to break
us force when the hamrper flies up.
There Is also an arrangement for holding
'he hammer at the top of the frame (not
unlike that IN some OF the common pile.
driNer',) and oi letting it fall whenever
The man who operates the machine NAV
desire. -


In driving, the pile having been drawn
to its position, its point resting in The
mud and the cannon adjusted to its top,
the hammer is drawn to the guides or top
oi the frame. A cartridge is then dropped
INTO The gun, when a spring is touched
ana the heavy hammer falls; as it de.
scends the piston or rammer on its lower
side enters the gun, and by the compress
SION OF the air before it generates heat
enough to fire the cartridge, the explosion
OF which sends the hammer up, while the
recoil OF the gun, very greatly increased
by the method Of firing, sends the pile
down. The piston at the top of the frame
entering the bore in the upper side of the
hammer, by the compression of airwithin
it, gradually stops its rise, and so prevents
it from ever being shot too high. Being
caught at the right point on the guides or
frame, it is held there till another car.
fridge has been dropped into the gun and
the spring is again touched. when it falls
and discharges the gun, and is itself shot
up, while The recoil OF the gun sends the
pile Yet farther down.


1t is said that tLis is far more effec.
tive arrangement! than any hitherto used,
with the additional advantage that no in
Jury is done to the top of the pile as in orr
binary pile-driving. At League Island
eight hundred heavy piles have been driv-
en 10y This apparatus through mud and
clay TO Il very hard bottom twenty-one
feet below mean low water. AS many as
twelve such piles have thus been driven
in Il single hour.