The Sun.
London, England, 1864-11-29 00:00:00

Proposed Iron Girder Bridge.

A great railway undertaking, resembling in ohs
racier the Britannia, Saltash, and Victoria bridges,
and surpassing even these in point of dimensions,
is to be submitted for the sanction of Parliament in
the ensuing Session. The North British and Edia.
burgh and Glasgow Railway Companies have given
notice of a bill empowering them to construct a
great iron girder bridge across the Firth of Forth,
from near Blackness Castle, three miles above
Queensferry, on the West Lothian coast, to
Charleston, in Fifeshire. The plans of the bridge
have been prepared by Mr Thomas Botch, C.E.
The scheme was before Parliament last year in
connexion with a rival line to Glasgow which it
was proposed to construct, but the North British
and Edinburgh and Glasgow Companies having
compromised their differences the opposition line
was withdrawn, and the Forth-bridge project was
not entertained. This year it is brought forward in
connection with a proposed branch of the Edin•
burgh and Glasgow Railway, and with the through
line to Perth, and also to Dundee, via Taybridge,
which the North British ask power to construct in
Fifeshire. The length of the proposed bridge is
3,867 yards, or 2 miles 367 yards. It will be about
17 miles from Edinburgh and 34 from Glasgow,
and it is intended to accommodate an express
route from these cities to the north of Scotland,
in connection especially with what is known as
the " east coast" route. Instead of a single span
of 600ft.,with two side spans of 300 ft., which was
the scheme of last year, it is proposed to make four
spans of 500 ft. each over the navigable channel, the
spans diminishing to 200 ft. and 100 ft. on either
side. The clear height of the bridge in the channel
will be 125 ft. at high water of spring tides, thus
giving ample height for the tallest vessels frequent-
ing the ports of Grangemouth and Alloa. The
frame of the girders over the widest spans will be
about 70ft., giving a total visible elevation of 195 ft.
for the distance of nearly half a mile, the height
diminishing at the ends of the bridge a
the spans become reduced in width. Taking the
submerged part of the work the height will be 25ft.
of foundation below the silt bottom, 50ft. of depth of
water at ebb spring tides, and 18ft. of fluctuation
of tides, making in all 285 ft. in height of work to
be executed. The middle piers will be of stone to
the height of 10ft. above high water at spring
tides, and the rest of the structure will .be of mat.
leable iron. The bridge will be built for a single
line of rails, with a gradient in the south end of 1
in 134, and in the north end of 1 in 100, so as to
give the necessary elevation in the middle. The
dimensions of the Britannia-bridge may be stated
by way of contrast :—Span, 460 ft. ; height, 104 ft. ;
depth of tube, 301 t. Two years ago the North British
and Edinburgh and Glasgow Companies obtained
powers to construct a through line via Queensferry
to Dunfermline and Perth. Tbe latter are forming
their part of the line, consisting of a branch from
Ratho to Queensferry, for local service and marine
outlet, and the former will take up a portion of the
lino on the north side in connexion with the Forth-
bridge scheme. But leave will be asked to abandon
the great ferry works and.a portion of the north
line should the bridge be sanctioned. The cost of
the bridge is estimated at between £500,000 and
£600,000, but, on the other hand, the companies;
would save the capital cost of piers, breakwaters,
steamboats, and cost of working the ferries.

The Countess of Beetive, who has been serious:y
ill for some time past, is now in such a weak cmditi on tha
no hopes are entertained of her recovery,