Evening star. [volume] (Washington, D.C.) 1854-1972, 1872-01-12

AS there seems to be disposition on the part
OF the railroad company to deny the accuracy
dition OF the railroad bridge. We give the follow
ing report Of the engineer who examined the
bridge under the instructions of the Legislature,
Trough the Board of Public Works. It will be
see,r that Lis report fully substantiates all we
WASHINGTON, December u, 1871.
SIR: As instructed by Won, i have made q
thorough anu careful examination OF the rail-
road bridge, am beg leave to present the fol-
lowing report:
The bridge is composed of arehed trusses.
the bridge built Of arched trusses is supported
upon double-timber tres:les, built upon piles,
driven into the bed of the river, and sawed at
pile, which have been driven during the past
two years. The piles were all found to be in q
coed state Of preservation. The timber trestles
found in some parts to be very defective, partc-
ularly at the tops Of the posts under the ca ps
the feet Of the braces where they are notched
into the posts, and the upper sides OF the
holsters.
In some OF the spans the end of the cap had
entirely rOtted away. In span No. III. counting
from the Washington side, the bolster had
teeo;S:.a 50 soft and Punky that the hridxS-ehord
braces were loose and working in the Joints. In
span No. 10 the outside brace was actually
tumbling to pieces. These old trestles are so
much lecayed that they can contribute but very
little toward the support of the bridge.
In the middle Of most of the spans, which were
originally forty eight feet, new pile Dents have
been driven. These new bents consist of only
two 14-inch piles, one under each chord. LIN
some of the spans they are kept in place by an
outside pile which is bfaced against them. They
are also tied together near the water line by two
planks, and are braced diagonaliy. A cap, II
by Il, is simply laid on the top, not framed in.
ON the cap is a bolster about six feet long, and
on the top of this, and beneath the chord,
wedges are driven from time to time, as the
bridge settles.
These bents must, in some cases, bear nearly
the whole weight OF the bridge aud its load, and
in others do not strengthen it all in consequence
! OF the wedges over the bolster becoming loose
and dropping out
9xl3, bent into an elliptical form, lower chord,
| 10x12, and diagonal suspension rods and braces.
The upper or arched chords, except 10 spans
! newly timbered, are, most OF them, in bad con-
dition. They were made Of a very poor quality
Knots and shakes, and@pioSaby owing ' to the 3.
| strain exerted on them by the suspension rods,
| or else owing to the timber not being properly
direction. Every rain has filled these cracks
with water, with no chance Of its drying out; In
consequence Of which, decay commenced, and
as in some cases At present. the wIoe insi de- y
the chord has rotted, leaving but q mere shell
of sound timber. Of an inch or an inch and q
condition Of the upper chords of spans Nos. 2, 8
| 7,S, Q, IL and II, counting from the Washington
end, the first six spans succeeding the trestie
work, and the first two spans east OF the Pratt
truss.
The lower chords of these trusses are in equally
bad condition, although the timber has not split
and cracked as badly as in the upper chords; ye,
water has soaked in around the suspension rods
beneath the rods OF the fioor-beams and at the
feet Of the braces, and in consequence the wood
has decayed very much. Holes were bored In dit.
ferent parts of the chords to ascertain the amount
Of decay, which was found in some cases to ex-
tend. through the whole stick in others to q
depth vary ing from two to four inches. die
not lind single chord that was sound. The
chords Of span No are rotted nearly through
beneath the end OF the door beams and around
the nobs Of the rods. Tho chords Of span No. 2:
are in . similar condition. Some Of the floor.
beams and track etringcrs In these spans are
also much decayed, In some places halfway
through. In spans Ave, six, and seven the lower
chords are very much decayed, In some places
entirely through; 4 BY ~ and By ~ timber,
have been boiled on 70 the sides to keep them In
place.
The chords Of the SIX remaining spans are In nc
better condition. Most at them have been re-
paired by bolting timber to the sides. The hool
beams and track stringers In some Of these SPAN
ere also much decayed.