Daily Kennebec journal. [microfilm reel] (Augusta, Me.) 1870-1975, 1915-01-06
SOME PEOPLE WORRY
ABOUT VIBRATION
on KENNEBEC BRIDGE
But Statements Of Engineers
Tend to Show That The Bridge
Is as Safe as When New

A matter which seems to be the
cause of certain amount OF uneasi-
ness on the part Of some people is the
vibration of the superstructure of the
Kennebec bridge and the consequent
rafting Of some of the diagonals of the
truss work against the verticalS, which
has given rise in some minds to feel
ing that the bridge is in some way
lacking in strength. Other people seem
to harbor the opinion that the bridge is
overloaded as the result of covering
the structure, during the recent repairs
with the wood block paving. In the
opinion however Of people familiar
with bridge construction, and of Supt.
Hutchins of the Hassam Paving Co.,
who had charge of the work of repair
on the bridge and of laying the wood
block paving, and by whom a thorough
inspection of the bridge was made at
the time the work was done, the struc-
ture is just as safe as it was at the
time that it was erected in 1890.
So far as the overlooking of the
bridge is concerned on account of the
wood block paving, the report made by
Mr.. Hutchins after the completion of
the work shows that the increased
weight is very slight as compared with
that when the bridge used to be re-
planked with three inch plank, being
% pounds to the square foot distribut-
ed over the entire surface of the bridge.
The different parts of the bridge were
given thorough looking over, includ-
ing the rollers on which the bridge
rests and which allow for the expan-
ein ;olo
carefully cleaned. Every part of the
bridge SO far as the structural iron
work is concerned was found to be in
good condition and in the opinion of
Supt. Hutchins will last for many
years.
Regarding the matter of vibration,
which seems to be confined to one YER
teal on the long span, that is a matter
which can easily be disposed of. That
it is nothing new and that it need be no
cause for apprehension, is shown by
the following extracts from the annual
reports of the late Moses r. Leighton,
bridge inspector for Augusta, which
reports cover a period of five years:
Mr.. Leighton says in his report for
the year ending March 1, 1895: y
II have inspected our city bridge care
fully enough to warrant it in my judg-
ment, just as perfect and secure as the
day it was completed. 1t would
be we'll to look from time to time after
the wiring of the diagonals to the
members they come in contact with Gas
they sometimes break Off in order to
avoid the rafting caused by vibration,
so as to avoid remarks by the inexpe-
rienced"
Again, in his report for the year end
ing March 1, 1896, he refers to the rat
thing: = : 81 have carefully inspected
our city bridge. In a structural sense
l find it in excellent condition--as good
as new. In protective sense would
recommend a coat of paint in the near
future. also the stopping up of the
holes under the guard rails over the
piers and abutments to obviate in time
CT rains, the mud from running down
on the bridge bearings, particularly
the roller end of each span, where the
expansion and contraction takes place.
The diagonals in the long span
are wired at the intersection of other
members to stop the rafting caused by
vibration. / notice some of them brol<-
en- off. 1t would be well to keep them
properly wired. +"
His report for the year ending March
|, 1898 says: Il have by request care
fully inspected our city bridge, and in
so doing I commenced at the founda-
ton or bridge seats, and had them
properly cared for. Then | examined
every panel point where the transmits
sion Of strains takes place in the diff
fGrcnt members of the structure. All
these l find intact, perfect as new. In
my Judgment the bridge is as safe and
secure as the material of iron can make
it. 1t is a structure we all should be
proud of, and spare no pains to keep it
so. find but one thing to recommend,
that is, the replacing of some of the
wires holding the diagonals to the YER
ticals, which will necessiate very little
expense"
Concerning the condition Of the
bridge the following year Mr.. Leighton
says: st have never found it at