The Dorset County Express and Agricultural Gazette.
Dorchester, Dorset, England, 1859-05-10 00:00:00

oPENING or Till ROYAL ALBERT BRIDGE
AT SALTASH ay Till PRINCE CONSORT.

The Albert Bridge year by year has been approaching
oolupletion, unnoticed and unknown, till its opening by
the Prince Consort has suddenly announced that the
most difficult engineering work which has ever been
attempted in this or any other country is completed.
On seeing the working drawings of the bridge some time
since the Prince Consort was so impressed with the Inge-
ty of the design that we believe he deten ll i ;; ed to
have a small copy of it erected at Balmoral, and at the
same time signified his intention of opening the bridge
at Saltash himself. The occasion was quite worthy of
this honour, and it is only to be regretted that the
great engineer who designed and carried out the
work (Mr. Brunel) was prevented by ill health from
being present at such • ceremony. It is not often that
Plymouth has an opportunity of paying its respects to
Royalty, so this occasion was made the must of. The
great gathering was of course around Balks'', where the
fields and hedgerows were thronged with spectators, and
where enterpriaing agriculturists reaped an unexpected
harvest by charging for adiuksion to the meadows which
were near the bridge. Altogether at this point, what
with the crowd, the flags, SUMO evergreens, a battery t,f
artillery, and • few commune* of the taith, the scone
was animated enough, and the only anxiety MPS on
account of the weather, which was dull and lowering,
and which the delicate attentions of a south-west wind
hourly threatened to make worse. Fortunately, how-
ever, the rain held off, and the day passed off smoothly
and pleasantly enough. .tt the temporary station on
the eastern side of the bridge the niost distinguished
of those who were to receive his Royal Highness awaited
his arrival. The Tamar was covered in every part with
slope of war, with boats and steamers ; and high above
all, in two hugh arches, the Albert bridge bestrid like
another Colossus this arm of the sea, stretching across
into the hills of Contwall, amid which the line was
hidden till it emerged again on a bridge of the frailest-
looking woodwork over the Cioinbe Lake. The line for
which this magnificent work has been constructed is
the Cornwall Railway, and which, crawling the valleys
and hills of that uneven country, of course presents a
continued series of engineering difficulties. In a distance
of 60 miles there are no leas than seven tunnels and
upwards of five miles uf viaducts, besides cuttings,
curves, and gradients almost innumerable. The viaduct
of all others is of course the Albert bridge at Saltash,
which is unsurpassed by any in the world. The whole
structure consist. of 19 spans or arches. Seventeen of
these spans are wider than the wideat arches of West-
minder bridge, while two, resting on a single cast iron
pier of four columns, cross the whole 'dream of the
Tamar at one gigantic leap of upwards of !CO feet, or a
greater distance than the breadth of the Thames at
Westminster. The total length of the structure from
end to end is 2.24.4.1 feet, very nearly half a mile, and 300
feet longer than the entire stretch of the Britannia ,
bridge. Its greatest width, as fonueil only for a single
pair of rails, is 30 feet at basement, but its height Irmo
foundation to summit is no less than 260 feet, or noire
than 50 feet higher than the 51onunient. The Bri-
tannia bridge, both in size, purpose, and engineering im-
lortance, seems to offer the best comparison with that
in Cornwall, but the similarity is far from being as
great as might be at first supposed. Each is built on a
different principle, and the engineers of each had most
peculiar difficulties to overcome. Each bridge, in fact,
surpasses in its way, and is best adapted to the duty it has
to perform and the obstacles it was necessary to surmount.
Time Prince Consort was expected at Salim!' at 12,20,
and precisely as that time arrived the heavy boom of
guns from the flagship and citadel announced that he
had reached the junction of the Cornwall line, about two
miles from Saltash. His Royal Highness was ammo-
pained by General Grey and Colonel Ponsonby. The
chief personages on the platform lianr.g been duly pre-
sented, the Mayor of &Bull, attended by the other
members of the corporation, presented an address, which
was listened to by the Prince. without alighting, at the
door of the Royal carriage. To this the Prince, bowing
LP he received the address, gracefully replied. A second
address was also presented by the Chairman and Direc-
tors of the Cornwall Railway, though the majority of
the directors were unfortunately prevented attending on
this twist interesting occasion, inasmuch as their engine
broke down half-way between Saltash and Truro, and
the train only arrived exactly as the proceeding's tentii•
nated. Immediately after the delivery of the addresses '
and His Royal Highness's reply, the Royal train moved
forward, and entered the Albert Bridge. The pace was
very slow in order to give hia Royal Highness an oppor-
tunity of surveying the extraordinary work. As the
engine passed unSer the standard of the centre pier, a
Royal mink was firtsl front • battery of artillery on the
hill. The tram then continued its course through the I
Saltash station, where moue thousen& were assembled,
who gave ham Royal Highness a most enthusiastic web
come, and passed on to the Coombe Lake viaduct. This
viaduct ix of wood, though in its way quite as curious as
the colossal iron span of Saltash. Its height from the ,
water is about 120 feet, and Ito slight looks, the web of
neatly •rratiged beams, which, fixing one upon another, ,
carry the nadway high over all, that it fates the pas- ;
senger's confidence in Mr. Brunel to the very utmost to
venture on it in a heavy tram. It has, of course, been
PruPerly tested, and, before proof, was known to he
rannig enough for what it was required to bear. Vet
this bridge, we are told, in nothing to one higher up the
line, at St. Auden, where the same kind of structure
spans a tremendous ravine at a height of 156 feet from
the ground. Returning over the Coombe via-
duct, the train stopped at Saltash station, and
Ids Royal Highness alighting, proceeded on foot
to examine the wonderful proportions of the
Albert Bridge ill detail. For this purpose lie
was attended by Mr. Brereton, Mr. Brunel's
maperititendent engineer, and Mr. Woolcomb, one
of the director* of the railway. The whole struc-
ture, as we liars said, containa 19 spans. The 17
smallerspaus, or arches, if see may so term them, were
made with comparatively little difficulty. Theme lead
from the hills at either side to the edge of the Tamar,
and consist of 1111411111V0 double columns of solid 1111111011rYo
11 feet square, with wrought-iron longitudinal beams of
boiler plate, to carry the roadway on either side. The
main atruie piers are at the water's tslge, and sumiort
the ends of the great spans crowing the river. These
two of course are of the moat solid kind, and more
resemble the massive columns of Egypt than the works
of modern entrineen. Each ia of granite, ?d feet wide
by 17 feet thick, and no less then 190 feet from the
foundation to aummit. It is, however, on the main
pier, in the centre of the river, on which both the great
spans rest, that all the pressure and vibration comes,
and for this was required • loser of such proportion*
that nothing short of the solid reek itself would suffice
for its foundation. But to reach this was a matter of no
ordinary difficulty, inammuch as some 70 feet of sea
water, with 2) feet of mud and concrete gravel, lay
between Mr. Brunel and the stone on which lie wiahed
to build. An it 1111 l ense wrought-iron cylinder of boiler
plate, 100 feet high and 37 feet in diameter, and weigh-
lug upwards of 300 tons, was made and sunk exactly
on the spot wheuce the masonry wu to rise. Irmo thus
the water was pumped out and air forced in ; the meet
descended, and working as in a gigantic diving bell at
the very bottom of the river, cleanst out the until and
gravel till the nick MLA reached and hewn into him to
support the cylinder evenly all round. Powerful steam
atepumpe were necessary to keep the labourers sup-
plied below, and, as a matter of course, they worked at
an atmospherical ',mowre of umvards of 3.51b5. to the
inch. At first this affected them severely ; but after a
time 40 labourer, could remain at once in the large
diving apparatus with appanmtly little inconvenience.
But it was always dangerous and unpleasant labour, and
all were glad when the first great difficulty was over,
and the noble column of granite, built inside the
cylinder, row above the waters edge at last. Olt this
massive pile the iron columns for the centre pier are
raised. There are four octagon columns. 10 feet in
diameter, and Bad feet high. Each stands 10 feet apart
from the other in the centre of the granite, fonuing a
square of about Ai feet, and all hound together with •
handsome massive lattice-work of wrought iron, which
cheeks vibration, and prevents any latoral thrust. TllO
weight of each column is 150 tons, each being cast in 6-
feet joints, two inches thick, and supported inside with
Powerful ribs and angle irons. As fast as they were
finished, planed down, and fitted together with the
neatness of joiner's work, they were sent off piecemeal
to the centre pier, but not erected, as they could only
be built up under the centre spans as the latter, in one
MIMS, weighing 1,200 tons, were gradually lifted to
their pliers by hydraulic pressure. The great spans,

each end of which rests on two of them columns, may
be heist described as being made on the principle of •
double bow. The lower bow iii of chains, carrying the
roadway; the upper is • tube of wrought iron, to
which the lower is attached by powerful supports.
Eaeli arched tube is elliptical in form, being 12 feet by
17 feet, and both are made of inch boiler plate. At inter-
vals of 21) feet the nodded are wrought iron diaphragms.
, with tie-rods and angle irons throughout their entire
! length. The curve of the arched tube is 28 feet, and the
' temion chains of the lower bow are of course the same.
The double chains are exactly similar in principle to those
of an ordinary muspension-bridge, and are of 14 and 15
earli bar being one inch thick and six hroad,
and each link haying been tested with a strain of four
tons to the inch. Both the chains and tubes are bound
, together by wrought iron trusses to each other. The
' spans before being lifted were tested with a strain (in•
eluding their own weight), of 2,3ut0 tons. The test of
the (los-eminent inspector was only a load of 400 tons,
I under which the bridge deflected one and a quarter
inch. The total quantity of wrought iron used has
Ibeen 2,700 tons; of cast iron, 1,300 tons; of masonry
, and brickwork, 17.0110 cubic yards; and about 14,000
; cubic feet of timber. The inspection of his Royal
I Highness occupied half an hour or so, and
on returning to the eastern eud his Royal
Incline*s declared the Royal Albert-bridge opened
aiind loud and continued cheers. The Prince then des-
cended the embankment to the engineer's office, to look
at the working drawings; and, after partaking of lunch
in a pavilion erected for the purpose, embarked on board
the Vivid and creamed to Tor Point, whes-e horsea were
in readiness, mounting which his Royal Highness and
suite rode ACI,IPM the country for about seven miles, to • ,
place called Tregantle. This place forms the neck of a
little peninsula of land fronting Plymouth and Devon-
port, and one side of which is so well known to the
lovers of picturewme scenery as Mount Edgecumbe. '
The western aide of the isthmus, however, near Tregantle,
fornis a line and epacioui bay, admirably suited for
landing troops and whence, by • short march on Tor
Point, an enemy, by taking the whole line of fortifica-
tions in the rear. might destroy Devonpurt and Ply-
mouth. Across the neck of laud at Tregantle, there-
fore it has just been decided to ‘ut a fosse and throw up
a rampart, to be armed at proper intervals with heavy
guns. It was to inspect this intended fortification, the
works of which have only been ordered within a very
brief period, that his Royal Highness visited this little
spot on Monday. When the lines are finished half the
garrison always in Plymouth will suffice to man them
and keep an enemy confined to the place on which they
land till ample time is given for reinforcements. His
Royal Highness remained here • considerable time, after
which he re-embarked on board the Vivid, and landed
at Plymouth in the evening. The Royal train left Ply-
mouth at 7 o'clock, and returned to Windsor at 1 Tues-
day morning.