Butte semi-weekly miner. [volume] (Butte, Mont.) 1886-1890, 1889-10-05
II GREAT
The Largest Swing Span Draw-Bridge in
the World.

h World.
New London (Ct.) Corr. Boston Herald
The largest swing span draw-bridge in tn,
world, that on the New York, Providenc,
u Boston railroad, over the Thames
river, was swung into place at $50 on tn,
afternoon of September 8. It's 2,4OO, OO(
pounds OF solid steel shot into the morticeG
OF the bridge proper, and the double-rai
tracks locked together as naturally al
though they had been doing that sort of q
thing for the past twenty years. The feat
was performed in the presence of crowds o.
interested people, and it is regarded as an
other of the many triumphs of engineering
which have been scored in the erection Of
this bridge. Passengers over the shore line
ferry for months past have noticed that
the work on the swing span was rapidly
progressing. It was built along the fen.
der pier, up and down the stream,
and consequently offered no obstruc-
ton to navigation, but grew in size
~riveters have been engaged upon it.
Engineers speak q structure OF this kind
as swung when it is lifted clear of it's false
works and it's weight is carried by the
pivot pier. The trial was made, as indi-
Gated, on Saturday afternoon, and the
engineers of the bridge were in great sus-
pense until it was satisfactorily completed,
for it has required no end OF skillful fgur-
ing and engineering to accomplish
this feat with a double-tracked draw to
the unprecedented length of 500 feet. 1t
must be adjusted g. nicely as to admit of
it's turning in either direction over the
226 feet OF clear water on either side OF
the pivot pier, and also to make a com.
plete revolution. This was done on Satur-
day. Then the fine calculations of the en-. |
gineers were apparent, for with the thou
sands of tons of construction in the pivot |
pier and the steel superstructure, when the
great draw swung into place, the elevations
Of the ends and the length were
as near the thousands of an
inch as the most exacting
the engineers d. sired. The
draw will sustain a live weight of 1000 per
loot OF track. Trains will SOC begin run
ming over the great bridge, and from
twenty to forty-fve minutes Of vexatious
delay by the system of ferry transfer be.
tween Boston and New York at New Lon.
ION will be gone forever. The matter OF
building the bridge, which is the largest
in the world, has been dis. |
;ussed for over thirty years. A. P. Boil '
ar OF New York was finally engaged to
make the necessary surveys, and his plans Z
we're approved by q commission OF engi.
leers in 1883. Work was not begun on 6
he structure by the New York, Providence
Boston railroad, it's owner, until early I
n 1888. 1t runs across the river grom the
erminus OF the Yale Harvard regatta .
curse at Winthrop and is 1,422f feet long. /
draw is fanked on either side by spans q
80 feet, and there are two other spans ;
It either side OF the river of $50 feet each. '
he unusual length of draw was required a
y the United States government 90 that v
here should be no obstruction to the pas.
age OF the naval feet to the Thames naval f.
tation farther up the river. The piers q
he bridge are still more unique and ex. q
'ensive than the superstructure. There 4
7ere great depths of mud and water to be +
ontended with. In sore places ffty.seven n
let OF water and eighty feet OF mud were +
ound where the piers must be set. At q
hese places the way to build foundations S
as to construct immense timber curbs, q
were then driven full of piles, which q
ere cut off at a level midway in the curbs. n
he spaces about the heads oil the piles i,
ere afteward filled with concrete, which
the whole together and made a SUBJ a
tantiai basin upon which to erect the il
lasonary. The center pier is an immense !,
seventy-one feet square. 6