The Indianapolis journal. [volume] (Indianapolis [Ind.]) 1867-1904, 1889-10-28
A sTUpENDoUs PROJECT.
A Steel Bridge Across the Channel from
Euoraud fo Franco

EuGfan0 10
A great steel bridge across the English
channel is projected. The bridge will
stretch over the sballowest apd narrowest
part of the channel. between Cape Girls Nez
and Folkestone. and will be supported by
columns resting on the bottom of the sea.
The amount of metal and machinery to DO
provided would represent an aggregate
weight OF about 1000, 600 tons, the assump-
tion being that each country will nave to
supply one-half of this amount Regard
calculation gives. with reasonable GER
tainty, $780, 00.0 600 francs for ma
sonry supports, and 4S0. 1000. 900 francs
for the metallic superstructure-
in all, sec. coo, 900 francs, or f34, 400. 600. The
time required for the undertaking may be
fixed at about ten years. The whole of the
pillars will occupy a little over one-twelfth
OF the section OF the channel. The dis
lance between the piers. fixed at 800 and 500
metres for the large spans, Will not be less
than 200 and 100 metres, respectively, for
the small ones. and will be sufficient TO pre-
vent their proving an obstacle to the free
navigation OF sailing vessels. AS for the
metallic superstructure, the metal columns
firmly placed upon the platforms of the
supporting piers of masonry are of a dis
tinctly cylindrical shape. and vary in height
bet ween 40 and 1918 metres. and on them
Will be placed the main girders of the
bridge. There will thus be between the
lower part of the beams and the level of
the sea at low water a free space varying in
height between sixty-one and 63.7 metres,
which height at high water Will be reduced
to fifty-four and 56.7S meters, respectively.
This height is amply sufficient for the pas
sage of vessels of whatsoever description or
tonnage. By placing the flooring upon ver-
teal cylindrical columns the minimum
height of fifty-four meters is kept through-
out the whole width of the span, a result
not achieved in the bridge over the Forth.
The girders are to be simple, unlatticed and
trussed, SO as to insure the proper distribu-
tfnra nf oil 0fraccnl Tho laval nf tho mar
manent way is seventy-two meters above
the lOw-water level. There will be a
double set of rails, and the width of the
hOorlng proper Will be eight meters. The
width of the bridge is variable. the great
est distance being between the axes of the
main girders, twenty-five meters, a space
necessary to insure the stability of the
structure under the action OF ylo-
lent egusts of wind. The road-ways
are of the ordinary width of fifteen metres
between the axes and the rails, the latter
set IN groves TO Obviate accident. The floor,
made of ribbed sheet iron. is to cover the
bridge throughout its length so as to make
| every part accessible to the men appointed
for it's supervision. Between and outside
the roadways, pavements are provided for
the men to stand on. and thus keep out of
the way of passing trains. On the flooring
may be set up. refugees, stations for the
guards, slgnal-bOxes. switches, etc. All
, these arrangements can be multiplied ac-
cOrding to the requirements of the traffic,
and scattered over any convenient points
and spans on the piers. Lighthouses may
be erected to Indicate obstacles. TO be
avoided. The various kinds of lights used
in lighthouses may also serve to indicate
TO shippers the distance from the Colbart
and Tarne banks To meet military objec-
tions arrangements could be made for max
ing the span at either end of the bridge I'M
fit for use; the two end spans, notably,
which are In contact with the abutments,
might be removable OF r~evolve.