Evening star. [volume] (Washington, D.C.) 1854-1972, 1894-11-16
THE LONG BRIDGE
What Maj. Davis Says Of 1t in His
Annual Report.
NECESSITY FOR ITS RECONSTRUCTION
Distinctions That Arise During
Freshets From Its Height.
GREAT DAMAGE LIKELY

Maj. Davis of the engineer corps, in his
annual report to Gen. Casey, chief Of ensi-
neers, in regard to the progress of the pro-
| ject for the improvement of the Potomac
| river at Washington, makes the following
statements in support of his oft repeated
recommendation for the reconstruction of
| the Long bridge:
At the date of the inception of the Poto-
mac river improvement QSSO the Long
| bridge consisted of three parts, namely:
| Commencing at the Washington shore, %
a bridge across the Washington channel of
wooden spans on masonry piers and about
| 100 feet in length; C2) a causeway of earth
| between masonry retaining walls across
the flats between the two channels and
| about 1880 feet in length. and CD a bridge
across the Virginia channel about 1000
| feet in length.
The Long bridge across the Virginia
channel is a wooden Howe truss bridge,
| consisting of thirteen spans of l35 feet
each in the clear and one draw span 49,
| feet in length swinging on a pivot pier,
| giving two openings Of about 30 feet, only
| one of which is arranged for the passage
| of vessels. Each span, except the draw,
| consists of three wooden trusses. The ex-
| treme widths Of the bridge from out to
|
stream, northwest side. is a wagon road
| 1872 feet wide in the clear. but with 10
| sidewalk, while on the downstream side Is
| the single track of the Baltimore and Po-
tomac railroad, with a clear width between
| trusses Of 1872 feet. The bridge spans rest
| upon masonry piers built Of an inferior
quality of sandstone and founded upon pile
| and grillage founda lions, the grilage being
| at the level of low tide. In order to pre-
vent these insecure foundations from being
| undermined by the river currents, large
| quantities of riprap stone have been thrown
| into the river and piled about them until
| there is now a series of immense mounds
| extending across the river channel. So
| great is this obstruction that the natural
| discharge area of the river at the Long
| bridge is reduced no less than 80 per cent
by these pier foundations and the riprap
stone deposited about them.
The Direction of the Bridge.
The direction Of the bridge is not normal
to the direction of the proposed, the pres
ent, nor even the original channel, so that
the piers Cbeing built at right angles to the
line Of the BRIDGE are not parallel to the
direction Of the current, but are oblque to
1t, and so become themselves q serious Oh
| struction during freshets.
A further obstruction arises during Tres n
cts from the height of the existing bridge.
The lower chord is but 1913 feet in the clear
above low tide, while the floor Is but Is feet
| above low tide.
The freshet of 1889 rose to a height of
1871 feet above low tide at the Long
| bridge, and thus the superstructure of the
| bridge diminished the maximum freshet
| cross section by a depth of no less than
"a feet, or about one-tifth of the height
which the water rose above low tide.
| The cross section of the river at the Long
| bridge for freshet discharge has been
| greatly diminished by reason of the clos
| ing of the Washington channel a neces-
| sary part of the plan OF Improvement. This
| diminiShes the available freshet cross sec
at he
| based upon the freshet cross section of
| 1877. The height as well as the discharge
| cross section of the freshet of 1889, how
| ever, were much greater than that of 1877,
and the area required for the discharge of
such a freshet would be much greater
| than was estimated when the plans for the
improvement were originally prepared.
Draw Badly Located.
The draw of the existing bridge is badly
| located, having been placed near the east
| erly edge of the navigation channel. AL
| though this channel has since been widen
| ed by dredging, the draw opening is obliQue
! to the general direc ton of the channel and
| the current, and the opening is therefore
| difficult one for vessels to pass, and so
| interferes with the safe navigation of the
| river.
The project for the improvement of the
| Potomac river provided for rebuilding the
| Long bridge over the Virginia channel,
| with wide spans upon piers Offering the
| least possible resistance to the flow of
| water" AS the improvement progresses
the necessity for this becomes more and
| more urgent.
Long bridge. on account of its faulty
| construction, remains constant menace
| to the interests on the river front above
| 1t, and also TO the work of improvement
| of the flats, upon which the government
| has already spent large sum. In the
event of a freShet occurring while the river
| is full of ice the most serious results are
70 ba finr
| is not at all unlikely. Should an ice gorge
| form at Long bridge, 1t would back up the
| waters of the river and overflow portions
| of the city front, and, through the sewers
above the bridge, such of the lower parts
of the city as are drained by them.
During the freshet of June, 1889, the
water reached (as above stated a height
at Long bridge of about thirteen feet above
low tide. The street surface at 18th and
B streets northwest is about eight feet
above low tide, and during the freshet re-
ferred to the water was about five feet
deep in the street at that locality. Great
damage was done by the freshet of 1889
but greater damage may occur from a
freShet of lesser magnitude if accompanied
by an ice gorge. The bridge should be re-
built as recommended by the board of en-
gineers.
The Duty of the Railroad Company.
The Baltimore and Potomac Railroad
Company was authorized to take posses
sion of the Long bridge by an act of Con-
gress approved June 81, 1870, which In part
provides as follows:
Provided, That the said Baltimore and
Potomac Railroad Company will maintain
in good condition the said bridge for rail-
way and ordinary travel; and the bridge
shall at all times be, and remain, a free
bridge for public use for ordinary travel
That if the said Baltimore and Potomac
Railroad Company shall at any time neg
leCt to keep said bridge in good repair
and free for public use for ordinary travel
the government of the United States may
enter into possession of the said bridge;
and Congress reserves the right to alter
or amend this law.
On April B. 1892 plan submitted
to Congress providing for the separation
of the roadway and the railroad across
the Washington channel and the reclaimed
area, elcvatinS the tracks of the railroad
across the reclaimed area high enough to
give passageway for vehicles under them
and the reconstruction of the Long bridge
over the Virginia channel with long spans
of about 21O feet each, with a pivot draw
in the deep water of the channel The
piers We're to be of frst-class masonry
extending down to the bed of the enlarged
cross section of the river so as to pro-
vide the least possible obstruction to the
flow of water. The bridge was to be ar
Sil all