THE MANUFACTURE OF THE LINE
Design and Construction--Ships--Testing, Shipment, and
Stowage--Paying-out Machinery--Staff--Preparations for the
Expedition.
The construction of the cable was taken in hand the following February
(1857).
The distance from Valentia, on the western Irish coast, to Trinity Bay,
Newfoundland--the two landing-points selected[14]--being 1,640 nautical
miles, it was estimated that a length of 2,500 N.M.[15] would be
sufficient to meet all requirements. This would provide sufficient
margin for a considerable amount of "slack" cable for accommodating the
irregularities of the bottom. The Gutta-Percha Company of London were
entrusted with the manufacture of the "core," consisting of a strand of
seven No. 22 B.W.G. copper wires (total diameter No. 14 gage) weighing
107 pounds per N.M. insulated, with three coatings of gutta-percha (to
3/8-inch diameter) weighing 261 pounds per N.M., the conductor being, in
fact, covered to No. 00 B.W.G.
This formed a far heavier core than had been previously adopted, and on
this account the difficulties of manufacture were proportionately
increased. The enormous pressure of the ocean at such depths involved
also a much severer test for the core.
On the other hand, as we now know, the conductor--and consequently also
the insulator--should have been still larger, to a material degree. The
engineer of the line strongly urged a conductor weighing 392 pounds per
N.M., with the same weight for the insulator;[16] but his fellow
projectors (the business element of the undertaking) were all for
getting the work done, while the weather permitted, that year; and they
were perhaps overquick to recognize the difference in the capital
required. Moreover, they were here supported technically by the views of
the responsible electrician, as well as by such high authorities as
Michael Faraday and Morse. The latter reported that "large coated wires
used beneath the water or the earth are worse conductors--so far as
velocity of transmission is concerned--than small ones; and, therefore,
are not so well suited as small ones for the purposes of submarine
transmission of telegraphic signals." Faraday had stated: "The larger
the wire, the more electricity was required to charge it; and the
greater was the retardation of that electric impulse which should be
occupied in sending that charge forward."[17]
Thus it will be seen that although Faraday laid the foundations of a
large proportion of the electrical engineering of to-day, his views in
this instance did not prove to be correct. The theoretical resemblance
of a cable to a Leyden jar--in reference to the effect of charging
either--seems to have been prominently in mind, without proper regard to
the _resistance_ offered by the wire to the electric current--a
resistance which becomes less the greater the bulk of the wire. Besides
the engineer being overridden in this matter, the word of the electrical
adviser on the Board (Professor Thomson) regarding the carrying capacity
or working speed that would be obtained with such a core as that decided
on--in view of the length involved--was also unavailing.
While no one can fail to appreciate the businesslike manner in which
this undertaking was pushed through from the moment of inception--comparing
only too favorably with some experiences of to-day--it was, without
doubt, a vast pity that more time was not devoted to a fuller
consideration of some of the problems, such as that involved over the
dimensions of the conductor and insulator. No serious fault could,
however, be detected with its actual manufacture, though the methods of
those days were primitive as compared with present practise, and a
system of efficient electrical testing altogether wanting.
After various experiments had been made with sample lengths of different
iron wires made up into cable, the contract for the outer sheathings
was, in order to get through the work quickly, divided equally between
Messrs. Glass, Elliot & Co., of Greenwich, and Messrs. R. S. Newall &
Co., of Birkenhead--both originally pit-rope makers.
The insulated core was first surrounded with a serving of hemp
saturated with a mixture of tar, pitch, linseed-oil, and wax; and then
sheathed spirally with an armor of eighteen strands, each containing
seven iron wires of No. 22 B.W.G., the completed strand being No. 14
gage in diameter.
[Illustration: FIG. 5.--Manufacture of the Core.]
The cable (Fig. 8) was then finally drawn through another mixture of
tar. Its weight in air was 1 ton per N.M., and in water only 13.4
hundredweight, bearing a strain of 3 tons 5 hundredweight before
breaking--equivalent to nearly five miles of its weight in water.
For each end approaching the shore, the sheathing (see Fig. 9) consisted
of twelve wires of No. 0 gauge, making a total weight of about nine tons
to the mile. This type was adopted for the first ten miles from the
Irish coast, and for fifteen miles from the landing at Newfoundland, at
both of which localities rocks had been found to abound plentifully--so
much so that the armor was insufficient, and present practise provides
double the weight under similar conditions.
[Illustration: FIG. 6.--Serving the Core with Hemp-Yarn.]
[Illustration: FIG. 7.--Applying the Iron Sheathing.]
[Illustration: FIG. 8.--The Deep Sea Cable.]
[Illustration: FIG. 9.--The Shore-End Cable.]
Only four months was allowed for the manufacture of this 2,500 miles of
cable, which had to be delivered in June of that year (1857). This
involved the preparation and drawing of 20,500 miles of copper wire
(providing for the lay) and stranding into the 2,500 miles of conductor.
For the insulation nearly 300 tons of gutta-percha required to be
prepared, and the three separate layers of gutta-percha required to be
applied to the wire, subsequently followed by the spiral serving of
yarn. Finally--and with a due allowance for lay--367,500 miles of wire
had to be drawn, from 1,687 tons of charcoal iron, and laid up into
50,000 miles of strand for the outer sheathing. The entire length of
copper and iron wire employed was, therefore, 340,500 miles--enough to
engirdle the earth thirteen times, and considerably more than enough to
extend from the earth to the moon. The work was enormously increased, of
course, on account of the sheathing being composed of a number of
strands instead of several single wires. While having certain mechanical
advantages at the outset, this stranded sheathing is not a durable type
of cable--besides being somewhat costly--and is never adopted nowadays.
The contract price for the entire cable was £225,000, the core costing
£40 and the armor £50 per mile.[18]
As fast as the cable was made at the respective factories, it was coiled
into iron tanks ready for shipment.
[Illustration: FIG. 10.--Coiling the Finished Cable into the Factory
Tanks.]
_Ships and Paying-out Machinery._--The race against time--resulting from
an unfortunate arrangement with American interests--was truly appalling;
for, besides the manufacture of the line itself, ships had to be
selected and prepared for receiving the cable, and machinery for paying
out the line had to be designed and made. So far as the manufacture
went, the machinery for that was already in existence, in view of the
cables that had previously been laid--apart from the fact that the
sheathing machinery was practically the same as had already been used
for making ropes with. But this being the first _ocean_ line, special
apparatus had to be worked out for submerging a cable satisfactorily in
deep water. So far as ships were concerned, the British and United
States Governments had already expressed willingness to furnish these.
The former undertaking took shape by the Admiralty placing H.M.S.
Agamemnon (a screw-propelled line-of-battle ship and one of the finest
in the British navy) at the company's disposal for the expedition. She
had been Admiral Lyons's flagship during the bombardment of Sebastopol a
couple of years before; but, in her coming mission, was to do more to
bring about the reign of peace--by drawing together in closer commune
the several nations of the earth--than any man-of-war was ever called to
do, before or after. With a somewhat peculiar construction, she was
admirably adapted for her work. Her engines were quite near the stern,
while amidships she had a magnificent hold, forty-five feet square and
about twenty feet deep. In this capacious receptacle nearly half the
cable was stowed from the works at Greenwich. The American Government
sent over the largest and finest ship of their navy, the U.S. frigate
Niagara (Fig. 11), a screw-corvette of 5,200 tons. As a consort, the
U.S. paddle frigate Susquehanna was also detailed for the expedition,
while H.M.S. Leopard and H.M. sounding-vessel Cyclops were similarly
provided by the British Government. The latter was to precede the
fleet--nicknamed the Wire Squadron--to show the way.
[Illustration: FIG. 11.--U.S.N.S. Niagara.]
The paying-out apparatus for the two laying vessels H.M.S. Agamemnon and
U.S.N.S. Niagara had to be somewhat hurriedly put together; consequently
not as much attention was paid to its design as the novelty of the
undertaking really demanded. The previous, and somewhat primitive, gear
hitherto used had proved to possess too little strength, the cable--when
being laid in anything but quite shallow water--having more than once
obtained the mastery, through meeting insufficient restraining force. In
the new machine (Fig. 12) there was certainly no lack of holding-back
power. It erred, indeed, the other way, being so heavy and powerful that
it was liable to break the cable under any material strain. The degree
of retardation was regulated by a hand-wheel actuating a frame-clutch
surrounding the outside of a brake-wheel. The details of this machine
were worked out by Messrs. C. de Bergue & Co., the manufacturers. The
engineer-in-chief also furnished external guards to the propelling
screws of each laying vessel to prevent a foul with the cable in the
case of going "astern." This cage was nicknamed a "crinoline" (then in
fashion with ladies), which, indeed, it somewhat resembled. The above
screw-guard may be seen in several of the illustrations of either ships
farther on. Were it not for the necessity of sounding operations, it
would be applied to all telegraph-ships to-day.
_Preparations for Starting._--By the third week in July (within the
course of as many weeks) the great ships had absorbed all their precious
cargo--the Agamemnon in the Thames and the Niagara in the Mersey. The
process of coiling the cable on board the Agamemnon is illustrated in
Fig. 13.
[Illustration: FIG. 12.--The Paying-out Machine, 1857.]
_Staff._--For such an undertaking the staff had, of course, to be
considerable. Besides the engineer-in-chief (Mr. Bright), the
engineering department was composed as follows: Mr. (afterward Sir
Samuel) Canning, formerly a railway engineer, who had laid the Gulf of
St. Lawrence and other cables; Mr. William Henry Woodhouse, who had laid
some of the cables in the Mediterranean; Mr. F. C. Webb, with much
experience in early cable work; and, finally, Mr. Henry Clifford, a
mechanical engineer, destined to be responsibly associated with a large
proportion of the cables since laid.
Besides Mr. Whitehouse (whose health, however, did not permit him to
accompany the expedition) there were on the electrical staff Mr. C. V.
de Sauty, Mr. J. C. Laws, Mr. F. Lambert, Mr. H. A. C. Saunders, Mr.
Benjamin Smith, Mr. Richard Collett, and Mr. Charles Gerhardi, all of
whom were afterward prominently connected with subsequent submarine
cable undertakings. Their respective energies were divided up between
the two laying ships.[19] The expedition was to be further strengthened
by a representative of The Times, as well as of the Daily News and New
York Herald.
[Illustration: FIG. 13.--Coiling the Cable on Board.]
On the vessels being fully loaded ready for the start, "send-off"
festivities occurred, in which all classes of those engaged on the work
took part. The Times recounted the function on board the Agamemnon as
follows:
The three central tables were occupied by the crew of the
Agamemnon, a fine, active body of men, who paid the greatest
attention to the speeches, and drank all the toasts with an
admirable punctuality--at least, so long as their three pints of
beer per man lasted. But we regret to add that with the heat of the
day and the enthusiasm of Jack in the cause of science, the mugs
were all empty long before the chairman's list of toasts had been
gone through. Next in interest to the sailors were the workmen and
their wives and babies, all being permitted to assist. The latter,
it is true, sometimes squalled at an affecting peroration, but that
rather improved the effect than otherwise, and the presence of
their little ones only marked the genuine good feeling of the
employers, who had thus invited not only their workmen, but their
workmen's families to the feast. It was a momentary return to the
old patriarchal times.
This function having come to an end, the Agamemnon set out for
Sheerness. When leaving her moorings, opposite Glass & Elliot's works,
the scene was one of considerable interest. It is recorded that many
thousands of persons thronged the riverside as far as Greenwich
Hospital. In the immediate neighborhood of the factory a salute was
fired as the proud vessel moved away, and a deafening cheer was raised
by the assembled crowds. The crew of H.M.S. Agamemnon manned the
gunwales, and returned the cheer with lusty lungs, while from the stern
gallery, ladies waved their handkerchiefs, and _savants_ forgot for a
while the mysteries of electricity and submarine-cable work, as they
returned the hearty cheers which reached them from the shore.
Similar proceedings took place on board the Niagara, and the two ships
met at Queenstown, County Cork, on July 30, 1857. They were moored about
three-quarters of a mile apart, and a piece of cable run between the two
to enable the entire length of line (2,500 N.M.) to be tested and worked
through. The result was all that could be desired, and the Wire Squadron
set sail for the rendezvous at Valentia Bay on Monday, August 3d.
Besides the vessels already named, there were H.M. tender Advice and the
steam-tug Willing Mind to assist in landing the cable at Valentia, as
well as the U.S. screw-steamer Arctic and the paddle-steamer Victoria
(Newfoundland Telegraph Company) on duty in Trinity Bay, Newfoundland,
to await the arrival of the fleet and assist in landing the cable at
that end.
On arrival in harbor the following day, the ships were hospitably
welcomed by his Excellency the Lord-Lieutenant of Ireland (the Earl of
Carlisle), who had journeyed from Dublin Castle for the purpose. A
_déjeuner_ banquet was given by the Knight of Kerry (Sir Peter
Fitzgerald), the lord of the manor for many miles round, and this little
corner of Ireland--"the next parish to America"--was quite _en fête_ for
the occasion.