Evening star. [volume] (Washington, D.C.) 1854-1972, 1906-10-21
MODERN BUILDING METHODS.
Two Novelties in One Excavation That
Halt the Passer-by.
From the New York Sun.

From the New York Sun.
Steel piles and an electric pile driver
make a combination of novelties sufficient
ly attractive to keep line of people all
the time looking over the railing in front
of the excavation for the foundation of the
new addition to the Hoffman House.
/ There piles are channel beams of a uni
form length of about thirty feet; stacked
up in the excavation the piles waiting to
be driven look like a pile of structural
steel. For driving they are not sharpened
pointed in any way. as wooden piles are.
but a beam is hoisted up between the leads
or guides Of the pile driver, set precisely
in its proper place and position. and then
simply driven down through the yielding
earth to the desired depth
AS these channel steel piles are not to be
used as supporting piles, they are not
driven in clusters. They driven
sheet piling, though not in long continuous
lines, but here in assemblages in different
parts of the excavation, each assemblage
outlining a square enclosing an area six
feet or more in diameter. They are faced
alternately in and out so that their fanges
clasp, and down the joints thus formed are
driven what are called Il irons. with pro-
jections overlapping the edges OF the
fanges on the piles to make the joints
tighter and help In keeping out moisture
|. when these squares of sheet piling, practi-
cally so many square steel-sided boxes
driven deep into the earth, are brought to
their final use, which is a substitute for
caissons in foundation building.
The earth within these squares o fsheet
ptling will be excavated, and in these ex-
cayations will be built up the concrete
founda ton piers upon which the weight of
the building will rest.
The electric pile driver has an upright
frame just like that of any other pile driver
and its hammer plays up and down In the
leads Just the same, with the wire rope
from 1t running up to and over a shieve
in the top of the frame and on down, all
quite in the usual manner, to drum at the
back, on the pile drivers base. But here
you notice a new feature in the form of
low iron shield, shaped somewhat like the
top shell of an elongated turtle. This shield
covers the electric motor, which is geared
to the drum.
There Is no steam boiler set up here.
flaming fire. no pile OF coal to feed the
boilers furnace. no steam engine attached
to the driver; the power comes from
street main through flexible cable at
tached to the motor and made long enough
SO that the pile driver can be moved about
anywhere within the excavation.
The pile driver operator turns the power
on or off by means of a controller much
like that used by the motorman on an cleo
tric street car, and for further control of
the machine he uses a lever brake And
80 without any flame or smoke or steam
anywhere around, he keeps the hammer
going driving down those channel steel
piles.
The steel frame of the new United States
Express building was set UP without the
aid of steam, electricity being employed
on the derricks and in running the air COM
pressor for the pneumatic riveting tools.