Evening journal., 1916-07-25
SUGGESTS LIGHTER
Loads ON BRIDGE
Trolley Service on Washing
ion Street Bridge Too
Heavy, Engineer Says
SUGGEST SOME
IMPROVEMENTS

In the Levy Court today Benjamin A.
Groves objected TO awarding the con-
tract for building the road in Christiana
hundred leading from Centreville Mr.
Groves pointed out that the work would
cost about $4,000 a mile, and that the
money would have TO be transferred
from some other hundreds fund if the
work was carried out After some dis
cusslon II was agreed TO consider the
subject at the noon recess Meanwhile
report Of both the Brandvwine aud
the Christiana hundred road accounts
will be prepared.
At the meeting Of the Levy Court TO-
day Boiler. Hodges and Baird. engi-
neers, OF New York. presented a report
through Alfred ]. DUPONT regarding the
condition Of Washington street bridge.
Much detail was given showing the con
dition of the bridge
summary of the report follows.
The bridge is a steel and iron strlc-
ture, ISL feet long between abutmcnts
carrying a roadway 20 feet in width and
two sidewalks each Q feet wide. making
total width OF 60 feet and resting on
masonry piers. The trusees are of the
pin connected" type, carving on their
top chords lattice floor girders. which in
turn carry steel and timber floor string.
ers, TO which the plank flooring and
trolley rails are attached
The structure was DESIGNED and
built twenty-four years ago BY the
Edge Moor Bridge Company. and was
intended 10 carry light loads. no troll
ley tracks being provided and motor
trucks not being in use az that time.
Some years later additional stringers
were provided and the necessary rails
laid on them for two trolley tracks.
In addition 10 these loads motor
trucks and other heavily laden We
hicles are constantly passing over the
roadway
The inspection was made on July
6 and Z and the bridge was care
fully examined under trafio and
many of the points were exftnined
as to measurements as a check on
the information obtained from the
working drawings. As the structure
was fabricated by a reputable bridge
building plant. however. II can be re-
lied upon that the sections called for
in the drawings were placed in the
bridge.
At the north abutment additional
masonry has been built on top Of the
| bridge seat and closely encases the
steel shoe and the truss members
connected thereto. No bond between
the steel and the masonry can be re-.
lied on under existing condition and
corrosion is undoubtedly going on
but cannot be seen as the metal Il
concealed. A similar case exists a
the south abutment. In each case thu
metal should be made accessible fol
cleaning and painting
Upon investigation IL was found
that the trolley cars now operated
over the bridge weigh twelve tons
and carry a maximum load Of six
tons, making a total Of eighteen tons
on wheel base Of seven feet. the
cars being thirty feet long. On an
/ alyzing the effect Of such loads the
/ inspector found that the stringers.
floor girder details and certain truss
members are stressed above what
they think safe limits. This is par
] ticularly true with respect to the de-
tails Of the short diagonal rods IN
the short trusses.
Summing up the bridge conditions,
the report says
We, therefore, advise that the
structure is not, in our opinion. ca
pable OF safely carrying increased
trolley loads, and that even the pres
ent trolley loads should be reduced
j 80 per cent.
While the arrangement OF the
floor planking is good, the construc-
ton is not susceptible TO an exact
analysis OF its strength but our COM
putations indicate that taking all
factors into consideration the con-
struction Of the floor system does not
warrant the running Of very heavy
motor trucks over the floor
The maximum load on trucks
should not be allowed to exceed five
tons. A bridge Of the style of the
Washington bridge should be subject
70 a periodic inspection by a competent
| fpcneofOr ou1v In