Norwich bulletin., 1917-01-04
RAscULE SPAN FOR
THAMES RIVER BRIDGE

BASCULE SPAN FOR
THAMES RIVER BRIDGE
is Recommendation of Highway Com
missioner in Report to Legislature.
Two methods of changing the
Thames River railroad bridge into a
highway bridge are explained by State
Highway Commissioners Charles ].
Bennett IN q report which he sent to
OF the two plans he recommends the
seccpd which consists in replacing the
present draw span with a new span of
the bascule type; that is. bridge
which opens vertically.
The report is as follows:
Chapter 220 of the Special Laws of
Connecticut. Session of January, 1915,
provides. among other things. that the
further investigation of the railroad
bridge over the Thames river between
New London and Groton for the pur-
pose of determining a satisfactory
method of changing the structure into
a highway bridge.
In accordance with this particular
provision of this act, the highway
commissioner makes the following re-
port regarding the reconstruction of
the said bridge:
Any plan for this bridge must rec
ognize first. the fact that this is an
old structure discarded by the rail-
for present day traffic. Hence, what
ever is done must be done carefully
and with no absolutely certain knowl-
edge of results. Changes in plan will
be necessary as the work develops
and an accurate estimate of the cost
is impossible. Nevertheless, as a re-
suit of the Investigations of several
consulting engineers. as wall as Of
this department, it seems that the re-
suits of the proposed RECONSTRUCTION
will be good and the problem success
fully solved.
An exhaustive study of the condi-
provided for by the abor& Require
rnent, together with two general ptars
for the transforming of the structure
into a highway bridE and flle recon
suitable floor system to carry hf-h-
way travel, including changes in ths
draw span SO as to permit Of the p.rc-
per opening of the bridge for naviga-
ton.
The new bridge, at present under
construction by the New York. Kew
Haven and Hartford HafIroad com-
pany has been located 50 clsss to the
present structure as to prevent the
without interfering with 6he hew
structure. Consequently. there must
be some revision of the present draw
factory opening of both bridges sim
ultaneously without interruption to
navigation.
There are two plans which have
been Outlined for this purpose: First.
the ends of the present draw span
should be cut off to such a length as
to permit of its opening without irtwr-
fering with the new bridge. After this
cut off should be huns froA towers to
be erected on the top of the present
rest piers. This plan is open to many
objections structuraily. and is merely
presented as being possible solution
of the difficulty.
The better plan to be followed, how
ever, is the second which consists in
replacing the present draw span with
a new span of the basruic type; that
is, a bridge which Opus vertically.
Under this plan. the ea-ta1y half Of
the present draw span viii be re-
placed by a fixed steel bridge, and the
oascule, or moving bridge. will be ia
troduced in the westerly half. of the
present bridge so as to trin= the
channel span OF the old bridge and
new bridge into exact alignment This
plan is recommended since 1t presents
less difficulties from a structural point
of view; is more definite in result,
and provides a new bridge for at least
a portion of the structure in such a
manner as to be without serious doubt
as to its ultimate strength. The bas-
cplar pier and open in an opposite
direction to the bascule span of the
new railroad bridge.
The estimated cost of transforming
the bridge under the second scheme,
including the cost of converting the
floor system of the railroad bridge in
to a highway structure and providing
the new bascule Hft.Span and the fxed
span over the eastdrly portion of the
present channel, is 100000. In addi-
ton to this. the cost of approaches.
including the necessary bridges over
the Central Vermont railpoad and over
approaches to the new State dock on
the west side of the river. with the
construction of the necessary highway
and pavement approaches to the
bridge, both east and west, win APP
proximate $4,000 more, making the
total cost of the Improvement $4,000.
In connection with the above mat
ter. the first question which must be
asked is: Shall the improvement be
undertaken; that is. Is there need of a
bridge across the Thames river at
gument, this question may be answer
ed in the affirmative. There Is no
question that in order to complete the
highway system of the state and
don and Groton, there should be- a
quick means Of crossing the Thames
river at New London for trolley cars,
automobiles and other vehicular traf-
fc.
Furthermore the state has alpeady
committed itself by previous 1egisIa-
tive acts to the taking of this railroad
bridge over from the New York, New
Haven and Hartford railroad.
Having established the necessity for
the reconstruction of = this bridge. it
to be seen whether the i'm
either in full Or in part,
should be financed by the state. In
discussion of this question, it is inter-
estirg to note that the act (namefy
ch. 900. Special Acts 1879. practically
pledging the state to the taking of
this bridge, reserved to. the grantor the
right to construct. maintain and OPP
crate street railway upon this bridge
and approaches. The legislature hay
ing passed this provision makes it
seem fair, at least, that the state
should assume the share of the ex-
pense which ordinarily wouId be paid
by the trolley company.
Furthermore, Chapter $50 of the
Public Acts Of 1915 provides for the
Of such trunk line bridges
as are located between towns, either
Of which has lass than ten thousand
This particular bridge
Games within the scope of this law,
ri1@~ t1na fArwn af Grafton contains ao-