The Sun.
London, England, 1857-09-03 00:00:00

THE ROYAL ALBERT BRIDGE AT
SALT ASH.

The first tube of this stupendous structure was
laid on the piers on Wednesday, and will in a few
months be raised to the required height. In the
meantime a second tube will be got ready for plac-
ing, and the bridge be made complete. Its progress
has already altered the appearance of Saltash more
than anything that has occurred for many years.
Saltash, situate on the Cornwall side of the Tsmar,
about 3 miles north of Devonport, .has in la,ps'e of
time suffered the fate of many a more populous
place, and had a decline and fall. Before Devon-
port was, Saltash was a considerable town noted
for its fisheries, its market., and its members
of Parliament, but of late years the rising towns
nearer the mou h of the river have supplanted
its trade and its fishing, and reforms have taken
away its privilege of affording places to M.P.'s; but
it still continued somewhat famous as the ruler
of the liberties of the Tamar and as the recipient of
tolls from all vessels coming within its bounds ;
and it was still famous, too, for its rowing amazons,
who. in contests with men, carried off prizes at
many of the rowing regattas of Britain and the
Continent. This fame, however, is fast passing
away, as the introduction of steam-vessels to con-
vey passengers from the "ancient borough" to
Devonport has rendered the plying of boa's a very
uncertain and precarious livelihood, so that not
only the women but the men hive had to seek other
employments. It was remarkabl,, to-,, for its
cockles and shell-fish ; but that is no longer the
case, for these bivalves are not to be found in the
same locations as formerly, and those found are now
collected mostly by Irish denizens of Plymouth, and
by them sold to the Saltash women, who now, in-
stead of catching, simply prepare and vend the
fish. But the determination to m ace a rail-
way from Plymouth to Truro, and the selection
of Saltash Passage as the point for crossing tie
Tamar, has caused,the sun of prosperity again to
shine on the old town, and new hous •st are now
being built, the shops and streets improved, and a
bustle and activity given to it the like of .which have ,
not been witnessed for many years. But never was
Saltash so full of people as on Tuesday, Sept. 1,
1857. The crossing the Tamar was the difficulty of
the Cornish railway, which it was necessary should
commence from the terminus of the South Devon
line, and hence across the Tamar, at as short a dis-
tance as possible. Saltash Passage was considered
a very eligible spot for the undertakiug, where, from
the height of the hills on both sides, it was believed
a bridge could be advantageously thrown actors at
a great elevation ; but the Government authorities
offered a sturdy opposition to allowing the waters of
the Tamar to be cumbered with many piers for the
benefit of a private company, and that company also
wanted to do the work cheap. Here then st ppe lin
the genius of engineering resources, Mr. Brunel, and
it was announced that he could give a perfect solu-
tion of the difficulty to the satisfaction of all parties.
An entirely new kind of iron bridge was to be tried,
one that should combine in one structure the merits
both of the tubular and suspension bridges previ-
ously erected, and possess the strength of the for-
mer with a saving of 25 per cent. in the weight of
iron. It would require but one pier in the centre
of the river, and be carried across at a clear eleva-
tion from shore to shore, ample enough to give the
fullest satisfaction. The Royal Albert Bridge now
erecting at Saltash is the result of Mr. Brunet's de-
sign. There is only one other bridge of the kind yet
erected, viz., that one built at Chepstsw, in the
year 1854, for the South Wales Railway line, and
also constructed by Mr. Brunel. In 1853 the
bridge was commenced by Mr. C. J. Mare,of Black-
wall, as contractor. Subsequent to Mr. Mare's
bankruptcy the entire management of the erection
of the bridge has been undertaken by Mr. Brunel,
who has let the several branches of the work in
small contracts.

This bridge is altogether 2,200 feet in length,
the span of each main opening being from the cen-
tre of one pier to the centre of the other, 455 feat;
height of centre pier from foundation in the bed of
the river, 240 feet ; height of roadway, above high
water mark, 100 feet ; of ditto above low water
mark, 118 feet. The main openings are each span-
ned by an oval tube, whose diameters are 17 feet
and 12 feet, the ends of which are connected by
chains, which together form a parabolic curve, and
from those chains are suspended the roadway. To
prevent the sacking down of the tube, at intervals
of 40 feet occur vertical strutts above the points of
suspension, diagonal braces connecting the strutts
for the purpose of distributing the load, the height
of the section over each opening being 1,100 tons,
these sections when fixed in their permanent posi-
tions will stand with their shore ends ou brick pil-
lars surmounting granite and lime-stone piers, and
their other ends on standards supported by four
hollow octagonal cast iron columns, ten feet in di-
ameter, built in the centre of the xiver and stand-
ing
,12 feet above high water mark—two of the
iron colums supporting each section. From the bot-
tom of the roadway to the top of the tube at the
centre is about 75 feet and the whole is constructed
of malleable iron plates. The section of the bridge
has been constructed on a temporary quay by the
water's edge, and docks cut under a stage erected
for the admission of two pontoons at each
end. These pontoons draw about eight feet six
inches of water, one foot of immersion beyond
their natural draft being equal to 250 tons, or
thereabouts. By means of valves the pontoons
admit water into their interiors, and were thus
passed beneath the ends of the tuba ; and on closing
those valves, rose with the tide, an i raised their
ponderous weight the necessary height required.
At the ends of the tubes, bed-plates and rollers
allow of their free extension and ooutraction under
varying temperatures—a very necessary provision.
The important and interesting part of the work
that was carried out on Tuesday was the raising
and floating off of the first or weste-n section from
the yard where it was built, and landing it on the
piers. During the past week extensive preparations
were made, under the superintendence of Mr. Bru-
nel and his engineering staff, for the carrying out
of this work. Five vessels, borrowed from the Go-
vernment authorities, were moored in a semicircle
above the bridge, on board of which were two
powerful crabs for the purpose of warping the tube
round its position. A large portion of the gear
employed and appliances used were bor-
rowed from the Dockyard, but Mr. Canning,
of Teat's-bill, supplied the rope used in controlling
R.N., who had
chargepontoons.
the
bridges, was present to superintend everything afloat,
Mr. Brunel taking entire control of the pontoons,
o f
the
floating Capt.
ofClacton,
t m
e and Conway
nai
and directing the operations by means of signals