The following extract from an account of the very exciting story of the laying of the, Greenwich made, Atlantic cable, comes from "Wonders of World Engineering" Part 46 1938. The first part of the article is missing (I don't have Part 45!) - but the story picks up when it has been decided to make the cable and to lay it across the Atlantic Ocean ---- read on ------
Bitter experience was to prove the correctness of the
engineer's original estimate. The cable, as it was built, had a central core
made up of seven strands of copper wire, having a combined thickness equal to
No. 14 gauge. Manufacture of the cable began in February 1857. The copper core
with its insulation of gutta-percha was surrounded by hemp saturated with
pitch, tar, wax and linseed oil, and finally armoured on the outside with
eighteen strands of iron wire rope, each strand containing seven wires and
having a diameter equal to No. 14 gauge.
This cable was then drawn, finally, through a fresh mixture
of tar. Thus finished, it weighed 1 ton per sea mile in air, and no more than
134 cwt per sea mile in salt water. The shoreward ends of the cable were much
more heavily armoured than the main
section, the sheathing consisting of
twelve No. 0 gauge wires, giving it a
weight of 9 tons per mile. This heavy sheathing
was adopted for ten miles at the Irish end and for fifteen miles at the
Newfoundland end. Even so, it was found in the light of subsequent practice
that this was barely half the amount of armouring needed over these
sections.
The contract allowed only four months for the spinning and
assembly of the entire cable, which was to be ready by June 1857. About 20,500
miles of copper wire were needed for the 2,500 miles of cable, all but 300 tons
of gutta-percha, and for the sheathing 367,000 miles of wire had to be drawn
from 1,687 tons of charcoal iron, this being laid up into 50,000 miles of
strand. The contract price for the whole cable came to £225,000, the core
costing £40 and the armoured sheathing £50 a mile.
Cable Snaps in Mid-Ocean
Loading of the two cable ships-the Agamemnon in the Thames
and the Niagara in the Mersey took place during the first three weeks of July
1857, and its completion was signalized by great celebrations on the part of
all concerned. The two vessels, with their precious freight, met at Queenstown
(now Cobh) on July 30. The ends of their respective coiled cables were
temporarily joined and messages were flashed through the entire length of the
Atlantic cable.
The story of how the Agamemnon and the Niagara tried, and
tried again, and eventually did lay the cable, is one of the greatest in the
annals of shipping. The European end was
landed on August 5, 1857. Bright wanted the two ships to meet in mid-ocean,
where the two ends of the cable were to be spliced. The vessels were then to
steam away from each other, the Agamemnon towards Ireland and the Niagara
towards Newfoundland. Once again his better judgment was set aside. The directors
decreed that the Niagara should lay the cable from Valentia to a point in the
middle of the Atlantic, whence the Agamemnon should continue the work until she
reached the American side.
After one false start, the ships got away properly,
telegraphing back to the shore messages of their progress. The start was made on
August 6. Day after day, in beautiful weather, the laying went on. By 3.45 p.m.
on August 11, Niagara had laid 380 miles of cable, transmission of signals
through it being perfect all the time. Then, on that fateful afternoon, the
cable, now going down into depths sounded at 2,000 fathoms (12,000 feet), suddenly
snapped. The work of the Niagara, inaugurated with such rejoicings, had
suddenly finished in an anti-climax.
The disconsolate "Wire Squadron” steamed to Plymouth. Later
Bright went to Valentia Harbour with a little paddle steamer, and succeeded in
recovering about fifty miles of the lost cable. New capital had to be
raised, under great difficulties, for
the public was fighting shyer than ever
of this admittedly risky enterprise, and
Bright resolutely set himself to devise
some better means for paying out the
cable. The existing apparatus had been the same as that used for laying short-distance sections, to which the peculiar difficulties entailed by the vast depths and distances of the Atlantic did not apply. Bright fitted a brake in which a lever exercised a constant holding power that remained in perfect proportion to the weight attached to it. He also rigged a dynamometer which controlled and indicated the strain entailed by paying out. Moreover, experiments were conducted by Professor Thomson to test the conductivity of the copper strands, so that all copper wire below a certain standard of conductivity was rejected. This was the first example of organized conductor testing to be carried out in a cable factory.
Another Set-Back
By the end of May 1858, 3,000 miles of cable were coiled- in
the two ships. This time Bright's'
original plan for splicing the two ends
and allowing the two ships to steam away
from each other was adopted, and
successful trials of this arrangement
took place in the Bay of Biscay on May
31, 1858. On June 3 the ships set sail
for a mid- ocean rendezvous. There followed an appalling storm, in which the
Agamemnon nearly capsized. As it was, part of her precious cargo shifted, as
did a large proportion of her coal. Many
of her crew were injured, and timbers were started all over the vessel, so that
her cabins were swimming in water for days on end. It was only by a series of
fortunate events that the battered Agamemnon, on June 25, was able to rejoin
the Niagara and the assistant vessels, which were this time the Gorgon and the Valourous.
Each vessel carried a considerable spare mileage of cable,
against accidents of this kind. The arrangement was that they should continue
operations until 250 miles of cable had been lost, after which both were to
return to Ireland. Once again the Agamemnon
and the Niagara returned to the rendezvous, and once again the wearisome and by now quite unceremonial business of splicing the two ends was gone through. That was on June 28. There
had been no fault on either vessel. The cable had parted mysteriously and
completely somewhere down in the pitch darkness of the miles-deep Atlantic disheartening
to think of Nature being the enemy. There was something beyond soft and
harmless ooze down there in the black Atlantic deeps.
The two ships headed away from each other, and, as before,
everything went as smoothly as possible. Yet nobody yet dared to dream of
success. Sure enough, when the Agamemnon had laid 146 miles of cable, another
break took place. She returned to the rendezvous, but the master of the Niagara
had decided that the limit had been reached.
The Niagara reached Ireland on July 5, and on July 12 the disconsolate company
of the Agamemnon also reached port.
The fate of the Atlantic cable now hung in the balance. The
chairman of the company advised abandonment of the whole enterprise. Only the
original projectors still kept faith. On July 17, 1858, the squadron once again
left Valentia Harbour. Their move was described as “a mad freak of stubborn
ignorance,” among other epithets, and was" regarded with mixed feelings of
derision and pity." Yet this time
they succeeded. On July 29, the splice
was made, and for the last time the cable sank into the depths, weighted with a
32 lb shot. This significant act was watched without enthusiasm by the dejected
company. Cautiously the two ships steamed away, one eastward and the other westwards, with their companion
vessels in attendance. In the afternoon, a large whale, making straight for the
cable, passed the Agamemnon. Every one held his breath, while the huge animal
swam under the stern, just grazing the cable, but doing no damage. There was one bad scare - through a sudden
cessation of electrical continuity, but this was later found to have been due
to a defect in the apparatus on the Niagara.
Ireland and Newfoundland United
ON July 31 a gale blew up, and for three days it was
expected that the cable would part as the stern of the labouring vessel
pitched upwards. On August 2, the
Agamemnon narrowly missed collision with
an American schooner, the Chieftain,
which bore right down on her with no
other object than to see what she was
doing., One other accident was narrowly
avoided through similar ignorance on the
part of another vessel. On the morning
of August 5, the mountains of Kerry rose high before the Agamemnon, and at 3
p.m. on the afternoon of that day, Bright himself brought the cable
ashore.
At the other end, the Niagara met with no storms, whales or
mismanaged schooners, but a certain amount of anxiety was caused by large
icebergs on the Grand Banks. She dropped anchor in Trinity Bay, Newfoundland, on
August 5, and the cable was carried ashore.
Great enthusiasm greeted the long- last completion of the
arduous and doubtful task. Engineers and navigators alike were feted on both
sides of the Atlantic, though what they all felt they needed was a complete
rest over an indefinitely long period. A few days later, Bright was knighted by
the Lord Lieutenant of Ireland, in the absence of Queen Victoria. Bright was
just twenty- six years of age at the time.
Now came the second tragedy. Wildman Whitehouse used
currents at a high tension and the simple insulation was insufficient to bear
the strain. Signals grew weaker, and to strengthen them the voltage was
increased, thereby hastening the end of the cable which had cost so much pain
and time to lie. For a brief period,
the cable showed the world how man's communications could make nothing of
distance. Then the signals began to fade. They grew fainter and fainter. They
became so weak as to be unintelligible. The great Atlantic cable was dead.
Tests suggested that the main leak in the cable was situated
about 300 miles west of Ireland at a depth of about two miles. There appeared
to be no fracture of the cable, as it was still possible to pass weak currents
through it. Whitehouse's huge 5-feet induction coils had wrecked the cable. Sir
Charles Bright compared the usage it had received to getting up high-pressure
steam in a low-pressure boiler.
It was the year 1865 that saw the laying of the first
successful Atlantic cable. The type of cable adopted, on the recommendation of Sir Charles Bright and others who were called into consultation, consisted of an armoured copper core, the armour consisting of iron wire, each separate strand being encased in hemp. The weight of conductor and insulator came to
300 lb and 400 lb. per mile respectively.
As for the laying of this cable, it was decided that one
vessel should accomplish it throughout. In all the world there was only one
ship large enough to carry the whole cable. That ship was Brunei’s premature
giant, the Great Eastern, of 27,384 tons displacement. Cable-laying activities came
to provide the one bright chapter in her undeservedly sad history. She was the
perfect cable ship, at least by contemporary standards. The cable was shipped
on board the Great Eastern at Greenwich, and on July 23, 1865, she left for the
south of Ireland. At the point where the shore cable had already been laid by
the steamer Caroline, the Great Eastern effected a connexion. Then, accompanied by H.M.S. Terrible and
H.M.S. Sphinx, she turned her head towards the open sea. A fault in the cable
was discovered when the great ship
had paid out about eighty-four miles. After about ten and a half miles had been
hauled in again the faulty section was cut out. The cable was spliced again
and paying out was resumed. The defect consisted of an iron wire perforating
the cable through from one side to the other.
When 716 miles had been laid, the same thing occurred again, and the
fault was the same also. This happened a third time when the ship was
two-thirds of the way across, having laid 1,186 miles of cable.
Average Depth of 1,400 Fathoms
A FAR more serious mishap occurred one day. There was a
heavy swell and, to add to, existing troubles, a breakdown took place on
board. The cable was damaged by the movement of the steamer and, before this additional
trouble could be remedied, the cable had parted and disappeared into the
depths.
Repeated efforts were made to fish for it with grapnels, but
without avail. The grapnels had
succeeded in hooking the cable, however; it was the rope that broke. All was
not lost, however. The Atlantic Telegraph Company, which had sponsored this
first attempt, was absorbed into a new concern, the Anglo- American Telegraph
Company.
For the purpose of grappling the lost cable, twenty miles of
rope, composed of forty-nine hemp-covered iron wires, were provided. The Great
Eastern had her single screw covered by a "crinoline" (she had both
paddle and screw, propulsion), and the hauling-in machinery consisted of two drums driven by a
pair of 70 horse-power steam engines. On June 30, 1866, the Great Eastern,
followed by the auxiliaries Medway and Albany, arrived at Valentia Harbour,
where the ships were met by H.M.S. Terrible and by H.M.S. Racoon. The Great Eastern
took the shore cable on board on July 13 and headed for the open sea. Fourteen days later, the great steamer
arrived off Trinity Bay, Newfoundland, having laid 1,852 sea miles of cable, at
an average depth of 1,400 fathoms.
On August 13 the, Great Eastern, once more in mid-Atlantic,
began dragging operations for the lost 1865 cable. Several times it was hooked, only to be lost
before it could be shipped. Yet on August 31 the cable was successfully brought
on board, when the grapnel had been lowered for the thirtieth time. The cable
had been hooked at a depth of two miles. This message was shortly after flashed
through the previously lost cable to the listening operators in Ireland, who
had almost given up hope “ship to shore. I have much pleasure, in speaking to
you through the 1865 cable. Just going to make splice.”
Such was the beginning 'of the history of inter-continental
communications. The Atlantic cable
pioneers, in the face of so much that was discouraging, even heart-breaking,
persevered to bring about one of the most revolutionary innovations of modern
times. It is a story in which all concerned acquitted themselves
brilliantly.
