New-York tribune., 1874-06-11
ANCHORAGE OF THE EAST RIVER BRIDGE.

BY FRANCIS COLLINGwOOD OF NEW-YORK.
The front face of the Brooklyn anchorage of
the East River Bridge $50 feet back from the center OF
the tower The base at the 'front.' and for IS feet and
inches back, has width Of 100 feet inches At this
point the width s increased 10 feet for additional
length of AB feet total length being 1872 feet and
extreme width 1l9 feet and Inches The base is q tim
ber platform Of three feet thickness thoroughly boted
Tho lower is laid transversely with one-inch
spaces, the second longitudinally with tw0-inch
spaces the third transversely with fOurnch spaces.
All spaces thoroughly filed with cement mortar.
concrete and the platform is entirely surrounded by
concrete Below this platform bearers placed long
tudnally with about ninefeet spaces. the bottom OF
these being at the level of high tide the East RIVER
The surface Of the ground at the front edge had
age elevation Of % feet above tide at the rear an aver
age % feet increasing however, to IS feet at one
corner where it quite near to large brick build
2s feet feet with buildings within 10 feet changing
suddenly down to IA feet h3wever the rear OF another
ing to vary quite rregularly from loan and gravel TO
sand of all kinds Water stood in the soil at about eet
sand which when saturated would run like water. but
was very hard and compact until disturbed ana very
difficult 10 penetrate.
The excavation was made OF such size TO give at
the bottom clear space all around between the timber
platform and the sheetng OF Is inches, or inches be-
tween the platform aud strngpieces supporting the
lower OF sheetnS The extreme SIZE OF the exea
walton at the I22 feet inches width at the
rear 2 feet and the front, and l35 feet long
This space had to be excavated entirely to uniform
level refore the foundation could be started and the
problem to support the banks as to enectvely
prevent damage to surrounding property, and at the
time not have the bracng interfere with the free
movements OF wOrkmen, or with lowering or placing
the timber and stone IN position The designing and
carrying the work intrusted TO the writer,
and hoped that 1t has sufficient novelty to make 1t
worthy OF record.
The design was affected somewhat by the fact that all
materials the anchorage had to be brought 1000 feet
streets from the dock the river and
desirable to transport the same from the ex'
cayation to the yard at the pier for storage.
double track tramway OF standard gauge was there
laid down. connecting with the street railroads for
block Two lines OF rails also provided for over
anchorage site connecting by switches with either
track) 10 be put down as the work would allow
Of IT, The general level Of the top Of the bracing
nxed at ISL feet above tide to accommodate the grade Of
these tracks
FORM OF THE MASONRY.
The form OF the masonry throughout Is In plan the
same that OF the foundation the stone work being
back IS inches all around from the edge OF the platform
There series of Offsets at the bottom. but Its gen.
eral form in elevation Is that OF truncated pyramid
with sides batterng above ground half inch per foot
rise The top OF the also the grade line OF the
bridge aud has elevation OF 80 feet Mt front and IS
feet inches In The extreme grade line
is lOI feet inches by lit feet, the difference OF
10 feet between front aud rear being pre-
q inches long, Is divided into three parts.
iucncs aud Will support aad contain the Two central