The Sun.
London, England, 1850-03-06 00:00:00

TUBULAR BRIDGE.

THE FIRST TRAIN THROUGH.

MENAI STRAIT F, TUESDAY AFTEIINOON..--The
opening of this magnificent structure, looked forward
to with so much interest, came off this day at dewy,
with the grandest success. At half-past six o'clock
A.M., three powerful en ices (the Cambria, the St.
David, and the Pega-us), of from 50 to 60 horse
power each, decorated with flags of all nations and
union jacks, steamed up, and harnessed together,
started from the Bangor-station, carrying Mr. Ste-
phenson, who drove the first engine through the tube,
and the o.l3wing gentlemen :—Mr. Bidder, engineer,
Mr. Trevethick, locomotive manager of the London
and North-Western Railway ; Mr. Edwin Clark,
Mr. Latimer Clark, Mr. Appold, and Mr. Lee. At
precisely seven o'clock the adventurous convoy, pro-
gressing at a speed of seven miles an hour, were lost
sight of in the recess of the vast iron corridor. Instead
of being driven through with a dispatch indicative of
a desire on the part of those who manned it to get in
and out with the utmost expedition, the locomotives
were propelled at a slow and stately pace, with
the view of boldly proving by means of a
dead weight the calibre of the bridge at
every hazard. The total weight of the locomotives
was 90 tons. The appearance of the interior of the
tube during the interesting experiment was of a
novel and remarkable character. The pauses that oc-
curred during the progress of the transit furnished
an imposing view of the interior of the gigantic
structure, which, as contrasted with that of a tun-
nel of similar length, was rendered comparatively
cheerful by the recurrence at intervals of loopholes
of which serve the three useful purpose of ven-
tilating, and lighting, and divesting the tube of steam
from the passing engines. The locomotives were
brought to a standstill in the centre cf each of the
great spans, without causing the slightest strain or
deflection. The first process—that of going through
the tube and returning—occupied altogether ten
minutes. The second experimental envoy that went
through consisted of twenty-four heavily-laden wag-
gons, filled with huge blocks of Brymbo coal, in all,
engines included, an aggregate weight of 300 tons.
Tnis was drawn deliberately through, at the rate ( f
feom eight to ten miles an hour, the steam working
at quarter power, and on the engines of this train,
besides the gentlemen already enumerated, there
were Mr. lledworth Lee, the resident en-
gineer, Mr. Charles Rolfe, Mr. J. Maclaren,
Mr. Borthwick, Mr. 'l'. L. Gooch, Mr. Frank
Forster, engineer, Mr. Binger, manager of the
line, Mr. C. Mare, maker of the tubes, and a large
number of scientific gentlemen. During the passage
of this experimental train through the tube, a breath-
less silence prevailed that was almost solemn, until
the train rushed out exultingly and with colours
flying on the other side cf the tub:, when loud accla-
mations arose, followed at intervals by the rattle of
artillery down the straits. Upon the return, which
occupied about seven minutes, similar demonstrations
ensued, and during the progress of the train, those
who stood upon its top to ascertain any possible
vibration reported they could not detect any sensible
deflection. After this, Mr. Stephenson and his staff
steamed up to Plas Llanrair, Mr. Foster's seat, and
partook of a handsome repast. Meantime the loco-
motives were passing up and down the interior of
the tube without eliciting the slightest manifes-
tation of strain. An ordeal stronger still was
then resorted to ; a train of 200 tons of coals was
allowed to rest, with all its weight, for two hours in
the centre of the Carmarthenshire tube, and at the
end of the time, on the load being removed, it was
found to have caused a deflection of only four-
tenths of an inch. It ,is remarkable that
this amount of deflection ip not so much as one
half-hour of sunshine would produce upon the struc-
ture, it being morever calculated with confidence that
the whole bridge might with safety and without in-
jury to itself be deflected to the extent of 13 inches.
These loads it is most material to remember are im-
mensely more than the bridge will ever be called on to
bear in the ordinary run of traffic, though the engi-
neers are of opinion that it would support with ease,
and without much show of deflection, a dead weight
on its centre of 1,000 tons. Twelve miles an hour is
the limit of speed at which Mr. Stephenson intends
that trains shall at first go through, more particularly
as there are sharp curves at the termini of the tube.
During the trial of the dead weights a very in-
teresting episodical proceeding took place in the inte-
rior of the Carnarvonshire land tube—that of putting
the last rivet into the plates, making exactly the
2,000,000 th that have been used. The rivet having
been put in by Mr. Mere, was driven home and fas-
tened by Mr. Stephenson with successive strokes with
a huge hammer. This ceremony was followed by the
waving of hats and the deafening acclamations of the
wor k people.
Mr. STEPHENSON, in a brief address, eulogized the
industry of these men and their devotion to their
work. lie could never forget the ingenuity and the
humbler sphere
manner
rre
inofwtihlieohgrtehaet
labour exhibited in the
operation, nor the
k had been carried out under th.e superintendence
owfor
r.
T.
Fleet, who had distinguished himself as a
masterlyh um
sterling and honest workman.
It being now nearly twelve o'clock, another testing
train was prepared to be taken through the tube. It
consisted of the three engines, the 200 tons of coal,
and from thirty to forty railway carriages, containing
between 600 and 700 passengers packed together as
closely as figs in a basket, all so clamourous and
eager to " ge through the tube," that it became im-
possible to accommodate them. At length, obediently
to a long wild whistle, the train, which was almost
long enough to cover the extent of tube, glided slowly
into the interior, saluted by a loud burst of "Rule,
Britannia," from an array of Liverpool seamen up
aloft in the towers at the entrance, on the front of
which, cut deeply in the atone, were the words

" Erected Anno Domini, 1850: Robert Stephenson,
Engineer." A the huge train trailed slowly through
the tube successive salvos of artillery were fired at
each end. This accomplished, the steam was got up,
and the company assembled proceeded at the rate of
thirty -five miles an hour, amid the magnificent
scenery and snow-capped hills of Wales, to Holyhead,
where they were received by all the principal towns-
poeple, and with salutes from the steam-ships in the
harbour.
The effect of the recent hurricane on the calibre of
the tube has proved that its lateral surface strength is
sufficient, and far more than sufficient, to resist the
strongest wind. It is calculated that, taking the force
of the mind at 501 b. on the square foot—an excessive
supposition—the resistance offered by the bridge
would be 300.
tons, which multiplied by 2, is equal to
GOO tons, which is not two-thirds of its own weight.
The wind going at 80 miles an hour, the rash of a
hurricane would only press in the ratio of 128 tons on
the side. It is intended, when both tubes are up, to
brace them together with stays so as to counteract any
possible oscillation.
The great work has now been four years in hand,
and is nearly complete, while Telford's suspension-
bridge took eight years. The floating and actual
transference of the tubes has occupied since June
last—a short period when the bulk of the fabric is
taken into consideration. Great fears were enter-
tained for its safety during the late gales, from the re-
collection in this part of the country of the damage
done to Telford's suspension-bridge.
The express train at two o'clock P.m. from Holy-
head, and which started ten minutes after the expe-
rimental train arrived there, would have been sent
through the tube, and thus have saved an hour, but
this could not be done without the consent of the
Railway Commissioners, unless under heavy penalties.
It is understood that Captain Symonds, the Govern-
ment Inspector, will inspect on the 9th inst., and re-
port to Government; and the public inauguration for
every -day traffic may be expected on the 15th inst.
The inauguration was to have taken place on the 17th,
St. Patrick's-day, out of compliment to the natives of
the sister isle, but that day happening to fall on a
Sunday, this could not be accomplished. It may be
interesting to know that the general opinion of the
numerous engineers present yesterday, appears to be
that the Britannia tube-bridge is as trustworthy as
any tunnel on terra firma.