The times. [volume] (Washington [D.C.]) 1897-1901, 1900-05-19
MEMORIAL BRIDGE PLANS
Report Of the Beard of Engineers
Transmitted TO the Senate.
Design Submitted by w. X. Burr
Recommended for AIop;fon-ip-
proved by the Secretary of War
It's Cost Estimated nj St,SGo,Go0
Description OF Proposed structure.


The Secretary of War yesterday trans
mitted to the Senate the report of the
Board OF Engineers appointed to choose
a design for the Memorial Bridge to be
constructed across the Potomac from
Washington TO Arlington. The report &C
cepts the design of William H. Burr. and
recommends that it be adopted. In a let
ter accompanying the report, the Secre-
tary of War states that he concurs in the
decision of the board, ard favors the de-
sign OF Mr.. Burr. The estimated cost of
this structure is given at Si,S6o.00e.
The report states that there were sub
mitted for the consideration of the board
two designs each by Messrs. L. l.. Buck.
William R. Hutton. and George S. MORT
son, and three designs by MIR. William II.
Burr After careful study the board
places the comparative merits of the de-
signs as follows:
NO l. Design No . of Mr.. William II.
Burr.
NO 3 Design No. of Mr.. William R.
Hutton.
NO g. Design No. of Mr.. L. L. Buck.
Morrison.
THE board expresses the opinion that
the general design of MIR. Burr, desig-
mated as the first in the order OF merit,
meets the conditions of the problem and
should be adopted. subject to certain rec
concentrations and notifications set forth
in the report. as to width, slope OF road
way. curve of under side of draw, towers,
provision for tramcars, elevation OF initial
,,,,o,- Era-
tions as experience may suggest upon the
undertaking of the work or during its
progress
After history Of the attempts made in
the past to obtain a great bridge TO span
the space between the Naval Observatory
and Arlington. the report tells of the ef-
forts to organize the board and to get
the best bridge architects to compete.
The accepted design is described as fol-
lows. The best features of Mr.. Burr's
three designs are to be combined in the
structure:
This is a design for double-deck
bridge 60 feet in width between ratings
Two sidewalks, each ten feet wide. and q
roadway forty feet wide are carried upon
the upper deck. while a double-track street
railway is provided for upon the lower
deck The total length of the open work
of the bridge proper and aprroa ches is
about 3.440 feet.
The bridge proper consists of two esq
foot span steel arches, one steel draw span
having a clear span of 213 feet, and two
more 2S3-foot steel arches.
1.-The 2S3-foot steel arches are circular
(eegmentep. the springing line being
"a feet above mean low water. the rise &c
feet above the spring. and the radius OF
the intrados about AGO feet. The clear
headroom under the crown of the arches Is
SO feet. A clear headroom OF about rs feet
9 inches is provided under these arches for
a width of so feet at the centre and about
&c feet inches for width of 100 feet.
There are ME 2-hinged. solid web steel
arch ribs. 10 feet in depth. with epandrels
of open steel construction in each span.
These ribs and spandrel posts carry the
floor beams and stringers, which in turn
support the buckle-plate foundation for the
asphalt roadway and granolfthic sidewalk
of the upper deck and the ties of the street
railroad of the lower deck.
THE drawspan is composed of 2 bascu'e
arms supported on trunnions, balanced by
rear extensions and CONFERENCE.-The. The
clear opening is about 167 feet, the clear
span at low-water level 2l3 feet, and the
span from centre to centre of trunnions
225 feet IL 1-2 inches The bascue arms
are composed of steel ribs or trusses of
the lattice girder type, with parallel chords.
Is feet deep over all. The clear beadroom
is about 80 feet when the draw is closed
The floor is to be of asphalt cork blocks
nodded to fit the buckle plates, which are
supported as above. or alternatively Of pre-
pared wood. 1t is proposed TO operate the
draw by four 5o-horsepower electric mo-
tors.
'The Washington approach consists OF
Is 46-foot masonry arches, back of which
is an earthen embankment about 800 feet
long.
THE 45-foot span masonry arches are
full semi-circular. the springing line being
"a feet above low water. the rise above
the spring 90 feet and the radius OF the
intrados rs feet. The face of the arch
ring is of granite but the main par. OF
the ring is constructed on the Melan sys
TEN of combined concrete and steel, there
being main concrete steel ribs. The
granite arch ring is 8 feet deep through
out. while the concrete and steel ribs are
20 1-2 inches deep at the crown and 49>t
inches deep al the spring. masonry
spandrel wall. partly OF granite and part
ly of concrete. provided with circular
openings to admit light and air to the
lower deck rests upon the granite arch
rings. The asphalt roadway and grano-
Ethic sidewalks are supported by concrete
floor arches between 1-beams. The weight
OF this floor system, together with that for
the street railway on the lower deck, is
carried down TO the arch ring by framed
steel posts between the above masonry
spandrel walls.
"The Arlington approach consists of 81
ls-foot masonry arches. identical with
those composing the Washington approach.
back of which is about 1900 linear feet
OF earth embankment.
1.-THE two bascule piers and the adjacent
piers between the 2S3-foot steel spans are
yxeI 49, Of 10 T.
process the caissons TO be filled with con-
crete The other piers are also TO be found
ed upon bed rock and built up within cof-
feIdams. The facing of all piers is to be
granite and the interior concrete. The
shore piers OF the river spans and all the
piers OF the approaches and of the abut-
ments are pierced with arches whose axes
are parallel to the axis of the structure.
These arches have spans of "a or rs feet,
and their springing lines are at the eleva-
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