Wheeling register. [volume] (Wheeling, W. Va.) 1878-1935, 1893-12-13
BRIDGING TEE CHANNEL

A Great Link Uniting France and Eng
Iand-Unique Pier FoundatiOns-There
WIN be seventy Three Big Cantiiever
spans-Its Construction win COnsumo
seven Years and Cost S163, 100000.
The Channel Bridge and Railway
Company, which proposes 20 bridge the
English Channel, has just published
pamphlet giving a minute description
OF this mammoth project.
The new bridge will cross the chan
mel In a straight line, landing at either
end near Dover and Calais. 1t will
consist OF 20 spans Of 1913 feet and
l,64O feet alternately, with minimum
clearance OF III feet above high water,
aud will have a length Of 20I miles be-
tween the two shores. The mean
depth OF water below lowest spring
tides is 12O feet, and the maximum
depth is 167 feet.
THE PIER FOUNDATIONS.
The visible part Of the piers will con-
sist of oblOng towers 90 feet wide and
las feet long, faced with cut granite.
These piers support a pair OF braced
metal columns destined to carry the
trusses. The towers will rest on base
OF masonry TO be constructed In depths
of not over los feet by means Of metal
caissons surrounded by metal Golfer
dams. The bottom dimensions of the
caissons are to be 9S feet by It's feet,
and the space between the level Of the
cutting edge and the roof is divided by
partitions into a number Of working
chambers, OF about 500 square feet area
each.
The calssons arc to be held 10 posi-
ton by hawserS from circle of anchor
ed uont00ns. For depths over los feet
it is proposed to prepare foundation Of
concrete on a previously leveled bot
tom. submerged ia layers of eight feet
TO sten feet 10 thickness, deposited in
metallic coferdams OF decreasing d.
mensions, placed one above the other.
The concrete will DO carried up TO
within 100 feet, more or less, from the
surface, aud the foundation completed
by sinking a caissOn liko those ABOVE
described, On this bed OF concrete.
BUILT on ARTIFICIAL BLOCKS.
For few piers, which 20 down 10
greater depths, foundation will be eff
footed 0y the submerSi0a Of artificial
blocks by the aid of movable metal plat
forms. The complete metal platform
will weigh about $500 tons, which
weight viii Do sufficient TO insure sta
blitv under the most violent shocks by
waves and storms.
Into IS slots OF the platform are fitted
square latliced columns, which rest on
the rock bottom and form an ova some
what smaller than the pier. Between
these columns and guided by them are
10 be lowered blocks of artificial stone
of average dimensions OF % fee. by Is
feet, 10 feet high. These blocks arc %
be made 10 tt exactly into each other
when placed side by side, aud 70 cOnsti-
tute the outer wall Of the pier. The
heaviest of the blocks will weigh $50
tons.
PROOF AGAINST DEBAILNENr.
The suDerstructure is 70 be composed
of two lattice trusSes joined sc their
TOD chords, so aS 20 De triangular In
cross section. The trusses will extend
over the whole length of the l,2l3 feet
spans, being prolonged on the cantilever
principle for els feet on each end OF
the latter into thu I, go feet spans. The
bridge will carry two roadway about 80
feet above the base Of the triangle
which is formed by the trusseS. The
rails will run in channels, providing
against derailment and the road way
will be covered throughout with an iron
platform. Each line OF rails will rest
upon a longitudinal lattice girder, sup
ported at intervals by transverse girders
in the shape Of a trapezium, Of which
the large bSse will be connected with
the bottom chords OF the trusses. For
the erection OF the superstructure the
movable metal platforms, which have
been viousiyNdescribsd, will be util
lied.
The location OF the bridge is to be In
dicated by electric incatdsscent light
signals during the night, sound signals
during the fog aud warning signals con-
sistiDg Of rod bOuys as TO approaching
piers.
TUE COST OF THE CHANNEL BRIDGE.
The estimate Of cost is based on the
snpoositi0n that she constr ctiOn will
occupy seven years. 1t alDnntS to
st3. 26O, coo for 4, 70O. 600 cubic Yards Of
masonry; sol. 200. 600 for 900, 90 IONS OF
snperstructurs; $500, 600 for app r,ches.
s., 600, 600 for installation OF gnting