History of the Atlantic Cable & Undersea Communications
from the first submarine cable of 1850 to the worldwide fiber optic network
the Laying of the New Marseilles - Algiers Cable
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History of the Atlantic Cable & Undersea Communications |
| 1879: An Account of the Operations Connected with the Laying of the New Marseilles - Algiers Cable |
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Journal of the Society of Telegraph Engineers,
Vol. VIII, 1879, page 454. An Account of the Operations Connected with the Laying of the New Marseilles - Algiers Cable. By E. March Webb I must apologise for the roughness of the drawings I have brought, and for the hurried manner in which this paper has been prepared, but in self-defence I must tell you that I did not expect this honour, and that I quite understood the few notes I had time to collect were to serve merely as a rough outline for a more elaborate article, to be prepared by a member of this Society, who is much more likely to do the subject justice.
In June, 1871, the India Rubber, Gutta Percha, and Telegraph Works Company laid a cable for the French Government from Marseilles to Algiers. The late Monsieur Ailhaud, Inspector-General of French Telegraphs, represented the French Government during the laying. Sir S. Canning superintended the laying. He was assisted by Messrs. F.C. Webb, Bell, and Herbert Taylor. Only two types of cable were used—a light shore end, single sheathing of 12, No. 5 galvanised iron wire, weighing 4½ tons per knot; and a deep sea, sheathed with 16, No. 13 homogeneous wire, weighing about 1½ tons per knot. The conductor was of 7, No. 22 copper wire stranded. The total weight of core was 273 lbs. The Caton, French corvette, accompanied the International, and on approaching the African coast, piloted her into Algiers Bay. The cable has worked very satisfactorily, and though the duplex system has been employed the traffic has so greatly increased, often amounting to 800 messages per diem, that the French Government was obliged to consider the advisability of laying a new cable. Tenders were invited, and the India Rubber, Gutta Percha, and Telegraph Works Company secured the contract.
The specification of the new cable is too long to be here repeated at length, but the following clauses in it may prove interesting. The specification was drawn up by the French Government Engineers. The electrical conditions are: That the conductor resistance must not exceed 12 ohms per knot at 75° Fahr.; that the electrostatic capacity per knot must not exceed .4 of a microfarad; that the insulation resistance per knot, reduced to 75° Fahr., after 1 minute charge, must not be less than 200 megohms; the conductor to be composed of 7 copper wires stranded, and to weigh 106 lbs. per knot; that the insulating material is to be 3 coatings of gutta percha, weighing 139 lbs. per knot, the total weight of core being 245 lbs. per knot. The mechanical conditions were: That the deep sea type of cable be composed of 15 homogeneous wires, No. 13 gauge, and the cable have a minimum breaking strain of 5½ tons, and the weight per knot being 1.58 tons; that the intermediate type of cable be composed of 10 galvanised iron wires, No. 6 gauge, and the cable have a minimum breaking strain of 6 tons, and its weight per knot being 3.16 tons; that the heavier type for shore end be composed of 10 galvanised iron wires, No. 0 gauge, and the cable have a minimum breaking strain of 15 tons, and its weight per knot being 10 tons. These weights are wet in air. The shore end and intermediate types were served and coated with compound in the usual manner. The deep type was served with two layers of tape, and coated with compound. The galvanising was tested by 4 successive immersions of the wire, of 1 minute each, in a solution composed of 1 part sulphate of copper to 5 parts water. On the table there are sample cases, shewing the different types. The s.s. Dacia owned by the Company, left the Thames on September 5th, with the cable destined for the new line.
The Dacia is a screw steamer of 1,856 gross tonnage. She is 283 feet long, 34.7 beam, and 17.9 depth of hold. Her engines are compound, of 170 nominal horse-power. She has 4 cable tanks, in which can be carried 1,500 tons of cable, besides 5 smaller tanks, in which are coiled different lengths and sizes of buoy and grappling rope. She has an exceptionally fine between-decks, which is a matter of great importance for carrying on such work as joints, splices, etc., in bad weather. The dynamometers for the picking-up and paying-out gear are of the usual vertical description, and have 4-sided scales attached, showing the various strains calculated to such different weights as may be placed on the dynamometer carriage. To the sliding wheel is affixed a pointer, which, as the wheel rises and falls with the varying strains, indicates the latter on the scale. To the paying-out drums are attached a pair of small horizontal engines, fed from the main boilers. These engines are found very useful in starting the drum and picking-up on it. The drum itself is held by a very powerful friction strap-break. The engines are about 20 horse-power. A little forward of the paying-out drum there is a break or holding-back gear, consisting of two rows of semicircular iron plates placed upon a heavy baulk of timber, thus: One row of plates is movable, and when approached to the other can, if required, completely hold the cable. The plates are moved as seen in the figure.
This break has been found to work very well, owing to its simplicity and the quickness with which break-power can be applied. It was first fitted to the Dacia during the latter part of the first West India Expedition, and was afterwards considerably improved by Mr. F.C. Webb. The engines of the picking-up gear are double cylinder of about 50 horse-power. I have seen them break a double sheathed shore end. When the Dacia’s main engines were compounded a reducing valve was placed in the steam pipe between the boilers and the picking-up gear, so that the pressure on the cylinders of the latter should not exceed 30 lbs. The rest of the machinery is of the usual description, and offers no sufficient novelty to warrant any further account. There is a plan and longitudinal section of the ship for your inspection. The Dacia was first fitted out for cable work by Sir Charles Bright in 1869. The ship proceeded direct to Algiers, and on the afternoon of the 16th September laid the shore end of the new cable. This operation was watched with great interest by the Governor-General of Algeria, who was accompanied by the principal Government officials of the Colony. The operation of landing a shore end, as carried out by this Company’s Engineers, is as follows: The ship being anchored so near the shore as is found convenient, a warp is passed over the stern, is sent ashore, and led through two spider wheels placed so far apart as possible and firmly anchored by mushrooms. The warp is brought back on board and taken to the picking-up gear. The shore end is made fast to the warp, passing over the stern, and slowly paid out. As the cable is paid out, barrels, fitted (according to a plan devised by Mr. F.C. Webb) for the purpose, are attached to it at about 8 fathoms apart. While the cable is paid out the picking-up gear heaves on the warp passed forward, and thus drags the cable, supported by the barrels, ashore. Any deviation from a straight line due to tide or current can be straightened out by stopping the paying-out aft and heaving in forward. On several occasions during the laying of the Peru and Chili cables we took advantage of the proximity of a railway by making fast the warp to a locomotive, instead of bringing back on board to the picking-up gear. This was, as may be imagined, a very comfortable and speedy way of landing a shore end. In the above manner of landing a shore end, no shore labour is required, a matter of great importance, and in fact only four ship’s hands are necessary on shore for the purpose of keeping the lines clear. Another advantage is, that instead of throwing the cable over in bights, as may happen when only boats are employed, the cable lies on the bottom in a perfectly straight line, and not with one turn over another, as sometimes may occur. Again, and it is a very important point, that the engineer on board has the whole operation completely under his eyes, as he can control the paying out of the cable and the heaving in of the warp. A great advantage in using barrels is that a shore end can be landed when boat work is out of the question through heavy surf. I remember a case in point during the same Peru and Chili expedition, when landing a shore end on a very exposed beach. The boat sent ashore with the lines capsized, and the hands were only saved through wearing life belts. The boat was rescued from the breakers by some fishermen on shore, with the lines still in it The crew managed to get on shore, some by clinging to the boat and some by swimming, but all much exhausted. We landed two shore ends that morning. The Dacia, after successfully completing the landing of the shore end, ran, paying out cable, to the position fixed upon, and buoyed the intermediate end in about 600 fathoms. 6.94 n.m. of shore end, and 2.97 n.m. of intermediate were laid. The Dacia then immediately commenced sounding towards Marseilles, along the proposed route of cable. The soundings were taken night and day. At night the operations were greatly facilitated by the use of the electric light, which brilliantly illuminated the after part of the ship. For this purpose the Dacia carries two engines of 5 horse-power each, working two Gramme machines. The Serrin lamp, slightly modified for work on board ship, was used alternately with a lamp called the “Silvertown Hand Regulator.” Sir William Thomson’s sounding apparatus was employed and used successfully in some very rough weather, caused by a “Mistral,” which is the north-west wind sometimes encountered in the Gulf of Lyons. The ordinary manner of balancing the weight of wire paid out is to place the counter weights on a rod attached to one end of the break strap, but we used on this occasion, and very well it answered, a self-adjustable counter-balance.
On the end of the spindle carrying the drum a worm is cut, which works in a worm wheel on the end of a fore-and-aft shaft, acting as a lever. This shaft is threaded, and runs through a weight running in guides. As the drum spindle revolves, the fore-and-aft shaft or lever turns and works the weight outwards, increasing the break power in proportion to the weight of wire paid out, for the break strap, one end of which is secured to the main body, is brought round the drum and made fast to the lever. At the extreme end of the lever there is fixed a weight, intended to regulate the speed at which the sucker descends. In order to facilitate the picking up of the wire, three pulleys are placed in the lower shaft, thus. When picking up, the wire passes round the first pulley and on to the drum. The third pulley is connected by a band to a pulley on the drum spindle, and the second pulley is connected by another band to the after steam winch. Thus the strain comes on the lower shaft when picking up, and the wire is coiled on the drum by means of the band connecting the third pulley to the pulley on the drum spindle. The wire used was steel, gauge No. 20, weighing about 15 lbs. per knot. Breaking strain, when new, a little more than 200 lbs. The solution used for preserving the wire from rusting was composed of three ounces of caustic soda to one gallon of pure water. I may here remark, that in order to expedite the work a spare sounding apparatus was afterwards placed on board the Charente, French telegraph steamer. The French officials were so pleased with it that we left the machine on board their ship. Between the 17th and 23rd September, the time we occupied in running to Marseilles, the Dacia took 93 soundings, in addition to the 40 already existing near the route of the cable—making 143 soundings along our line. An average day’s work (24 hours) would consist of from 10 to 11 soundings at intervals of 7 to 10 miles, in depths varying from 1,400 to 1,500 fathoms. The greatest depth encountered was 1,536 fathoms. The bottom was fairly uniform in character, and consisted of clay and ooze. Mr. W.H. Preece, who was on board during the laying of the cable, examined the soundings under his microscope, and found principally Globigerinae and Orbulina, like the ooze of the Atlantic. I may add that Mr. Preece has kindly promised further information on this subject. The average time occupied in sounding in depths of 1,400 to 1,500 fathoms was from 25 to 30 minutes. On our arrival at Marseilles, we found the Charente French Government Telegraph steamer, commanded by Captain Cavallier, of the French Navy, awaiting our arrival. The Charente is a screw corvette of about 1,000 tons. Her picking up and paying out machinery is of excellent quality and very well arranged, and was designed by the late Monsieur Ailhaud, and by Monsieur Wünschendorff, Inspecteur Ingenieur of French Telegraphs. She is a most handy vessel, and well adapted for cable work in moderate depths. The manner in which she is equipped reflects great credit on the French administration. Her crew is drafted from the French Navy.
The operation of landing the shore end at Marseilles was effected during the afternoon of September the 28th, in the same manner as at Algiers, but the time occupied was considerably longer, owing to the fact that the cable hut is about a quarter of a mile from the beach, on the bank of a small stream along the bed of which the cable had to be laid. The stream was about 3 feet deep, and running very strongly, owing to floods. The cable was carried up the stream in three boats towed from the bank, and we had rather a difficult job to get them under a low bridge at the mouth of the stream. 9.05 n.m. of shore end and 5.02 n.m. of intermediate were laid. A very amusing incident occurred whilst landing the shore end. A gentleman, much decorated, and evidently a great authority, was explaining the operations to an admiring circle of friends, and on being asked why the cable was supported by barrels, informed his hearers that it was for the purpose of keeping the cable dry. The various sections were spliced up in one length before commencing to pay out, in order to avoid any splicing during the paying out. At 4.54 a.m. on September 29th, the ship started paying out cable towards Algiers. At first the speed was 6 knots per hour; it was afterwards increased to 7, which rate was maintained till a few hours before reaching Algiers. The speed was slackened so as not to reach the buoy at intermediate end before daylight. During the laying, the paying out machinery was illuminated by the Electric light. It is impossible to over-rate the value of this mode of lighting for work of such a nature. Every part of the machinery stood out clearly and distinctly as in daylight, and you may imagine what an advantage the being able to dispense with the usual fixed and hand oil-lamps was. When paying out cable we employ Hearson’s “Strophometer,” as made by Elliott Brothers. This instrument was used by the Company on the Peru and Chili expedition, and has been found of great service. It consists of a dial face, numbered, round which a pointer moves. The instrument is connected to the paying out drum, and indicates the least fluctuation in speed. By watching it carefully, those who have been accustomed to its use can tell when the depth changes to any material extent. A detailed description of this instrument is to be found in the Transactions of Naval Architects for 1874. I have brought the instrument used on this expedition. You will see it on the Table. For the purpose of facilitating communication between ships engaged in cable work, the Company’s Engineers have drawn up and had printed a code of signals. You will see on the table a few copies of the work. This code is gathered from various sources, and has taken some time to compile. The system adopted is a three flag hoist for each signal, which represents one or more words or a whole sentence. The flags used are those employed in the usual commercial code. The arrangement is such that not only the letters representing the flags, but also the words or sentences themselves are arranged in alphabetical order. As this paper treats of cable work generally, I would call the attention of the meeting, that principally through the exertions of Her Majesty’s Post Office the Board of Trade has issued a circular, dated 14th August of this year, in which appears a clause (Article No. 5) referring to cable ships. With the permission of the meeting I will read this article. “A ship, whether a steamship or a sailing vessel, when employed either in laying or in picking up a Telegraph Cable, or which from any accident is not under command, shall at night carry, in the same position as the white light which steamships are required to carry, and, if a steamship, in place of that light, three red lights in globular lanterns, each not less than 10 inches in diameter, in a vertical line one over the other, not less than 3 feet apart; and shall by day carry, in a vertical line one over the other, not less than 3 feet apart, in front of but not lower than her foremast head, three black balls or shapes, each 2 feet in diameter. “These shapes and lights are to be taken by approaching ships as signals that the ship using them is not under command, and cannot therefore get out of the way. “The above ships, when not making any way through the water, shall not carry the side lights, but when making way shall carry them.” These regulations apply on and after the 1st September, 1880. The continuity signals between the ship and the cable hut at Marseilles were carried on by means of a clockwork discharger at the hut. You will see one of the instruments on the table. This clockwork is similar in many respects to the one used by Mr. Herbert Taylor, who was chief electrician during the laying of the 1871 Marseilles-Algiers cable, and I believe that Mr. Henley, during the laying of one of the Red Sea cables, used a pendulum to make the contacts. I think also that Mr. F.C. Webb, during the repair of the Hague cables, used a clockwork apparatus, but I am uncertain as to its principle of working.
The apparatus consists of a clockwork arrangement moving a lever, which every fifth minute makes contact between the cable end and one pole of a condenser, the other pole of which is connected to earth through the galvanometer. A current is applied on board through the marine galvanometer, and when the lever of the clockwork makes contact between the cable-end and the condenser, a signal is observed simultaneously by ship and shore. Between these fifth minute contacts the cable-end is insulated, the lever moving on to the opposite contact point, thus discharging the condenser. The current is reversed after every 12 continuity signals, that is every hour, and should ship desire to communicate with shore the current is either reversed before the 12 signals have been completed, or the same current is continued beyond the 12 signals, instead of being reversed after the twelfth. In order that shore may be able to call ship, two hand levers are attached, by means of one of which the clockwork is switched out, and with the other the signals may be given as rapidly as may be desired by hand. The condenser power on shore is adjusted according to the length of cable in circuit and the deflection required on board ship. The advantages of this system are: immunity from any trouble caused by a bad watch at hut and perfect regularity of signal. In order to avoid any touching of the cable end, a closed commutator is used, to the centre pillar of which the cable is permanently attached. The cable at will can be transferred from the clockwork to either the instrument, testing apparatus, or earth. The only stoppages made during the laying were on the occasions of changing tanks, always a critical operation in deep water. The weather had been perfect, the cable had run out smoothly, the test room reports were satisfactory, and all on board expected a speedy conclusion of the work, when at 6.30 a.m., October 2nd, the buoy on Algiers intermediate was picked up. I have brought a chart showing the lines of old and new cables. But when heaving up the buoy moorings attached to cable, it was found that the latter had fouled some rocks, and while manoeuvring in order to free the cable, a defective link in the chain parted. The defective link is on the table. There may be a dismal sort of satisfaction derived from seeing the object which retarded what otherwise would have been a speedy piece of work. After several attempts to grapple, it was found that the ship—a strong breeze then blowing—was, owing to her lightness, quite unmanageable, and it was decided to run into Algiers Harbour and ballast. The Charente meanwhile had been grappling, but also unsuccessfully. The bottom was found to be ooze between patches of rock and lines of reefs, and at the point where the cable had been buoyed there was a rapid descent seawards. On entering the harbour of Algiers for the purpose of ballasting, the unwelcome news was communicated to the ships of the sudden breaking down of the old cable, and it was assumed that the cable had been broken during one of the dredges. This at first appeared impossible, as the line of the old cable as laid down in the charts had certainly not been crossed by either ships, but afterwards it was ascertained that the actual position of the old cable was more to the eastward than as laid down in the charts. After ballasting, and transferring to the Charente some cable for the repair of the old Marseilles-Algiers line, the Dacia put down buoys in such positions as were deemed necessary. Further attempts to grapple the cable near the end were then made, but were unsuccessful owing to the rapid slope of the ground, and the rocky nature of the bottom. The cable was then grappled nearer shore, the shorewards end buoyed, and the part seawards picked up until near the end originally buoyed when the cable parted, being firmly held by rocks. The cable was again grappled nearer the seawards end, and the piece originally buoyed (that is the intermediate end) picked up. With the cable we picked up the part of the mooring chain which had been carried away, and on the chain the defective link. Altogether a little more than a third of a mile of intermediate type was lost, this portion being firmly held by rocks. The Charente meanwhile was engaged in grappling and in picking up the old cable, not so easy a task as would at first appear, owing to the foul ground in which the cable was constantly held, necessitating frequent breakage. On this smaller chart you can see the various drags made by the Dacia and Charente. On October the 11th the Dacia joined up the intermediate recovered to the shore end lately cut and buoyed, and splicing up a piece of fresh cable to replace that lost, ran out to buoy on the Marseilles end (I have forgotten to mention that when the chain parted we cut and buoyed the deep-sea cable), and completed the new cable. The delay in finishing the work was due to the necessity of allowing the Charente to conclude her operations on the old cable, as the two lines ran so close together. The old cable was found, wherever examined, to be in as good condition as when first laid, the galvanising being perfectly bright and sound throughout, although the cable had been submerged for eight years. I have brought some pieces of the old cable with me in order to shew the preservative nature of the bottom. For the instruments, plans, &c., I have brought to-night, I need hardly tell you that I am indebted to the India Rubber, Gutta Percha, and Telegraph Works Company. I only wish more time had been at my disposal for availing myself of their kindness. I may add that the rates on the old cable were twopence per word from Algiers to any part of France. Since the new cable has been laid the tax has been decreased to one penny per word, a very low rate considering the length of cable. And now, gentlemen, I must thank you for the kind attention you have given me during the reading of this paper, which, as you are now able to judge, shews only too well how hurriedly it has been prepared. The Dacia has only been back three weeks, and I have had a great deal of work to attend to connected with this expedition, and the repairs of the Lizard-Bilbao cable. Discussion on E. March Webb's Paper Col. Crossman: I had, sir, the pleasure and great privilege of being on board the Dacia when the operation of paying out the cable of which Mr. Webb has given us so interesting an account was being carried on. I do not profess to be an electrician. My duty as connected with submarine work is rather blowing off communication with people in the outer world than it is in connecting people with other people, as in the case of the operations referred to. I must say this, that I never felt greater pleasure than I did in being on board that ship. The Members of this Society have great reason to congratulate themselves upon having amongst their body men who can do their work as I saw them do it on board that ship. Mr. Frederick Webb: I have no particular remark to make, except that I think the paper one that does great credit to Mr. March Webb. It is some time since we have had any full description of the laying of a cable, and in our present state of knowledge as regards laying cables, it is rather a reproach to the Members of this Society that there has not been something of the sort before. We have many companies and firms that have laid cables, but this is the first systematic description that we have had of the laying of a cable. It was stated that it was written hurriedly but I think it is fuller than any description given yet, particularly with the full longitudinal section of the Dacia, which was originally designed and fitted by Sir Charles Bright. I think this is the first time that a full longitudinal section of a telegraphic ship has been exhibited before either the Institution of Civil Engineers or this Society since I exhibited a longitudinal section of the s.s. Monarch, before the Institution of Civil Engineers, in February, 1858. I think the improvement in the sounding machines, as far as I have seen from the drawings, is very ingenious, and is likely to be used again. The idea of having the weight to screw itself along the break lever, so as to compensate for the weight of the wire as it goes out, is very ingenious, and, I think, should lead to further improvements in the same direction. With regard to the holding-back gear, I think that was first designed by Mr. Matthew Gray when laying some cables on the West India Panama Line. I simply improved it by putting the screw arrangement, so as to make the two parts of more easy adjustment by hand. The simplicity of that plan, and the fact that it does not carry any inertia with it, or drag any machinery into motion, is of vary great advantage, and when you see the drawings of the machinery in the Great Eastern, with some five wheels, each with a jockey-pulley on it, one is astonished to find that so many have been used. The machine shown has held the cable in the same depth of water as the machine used on the Great Eastern. I have seen myself, when paying out a cable in deep water and the ship has been pitching, the holding-back gear with only two wheels and break straps used, move after the break stopped and thus slack the turns on the drum, thus causing the cable to slip on the drum, which is the most dangerous thing that can occur. When you are paying out a cable and it begins to slip, it is likely to run away altogether, as it did in some of the early Mediterranean cables. I consider that the holding-back gear is a great improvement on the old one with wheels. Of course, there are many things with regard to the complete fitting of the ship which do not bear on the subject of this paper; but with regard to the clock arrangements Mr. March Webb has mentioned that I used on the Hague cables, it was a clock sending for five minutes a current, then insulating for five minutes, and then putting to earth for five minutes. Mr. Latimer Clark suggested it. The same thing was used on the Red Sea cable by Messrs. Siemens when acting as electricians for Messrs. Newell. In the Persian Gulf we used an arrangement—from which I believe the one described in the paper was partially taken—designed by Messrs. Latimer Clark and Co. and Mr. Laws, in which the condenser was first used; but I believe this was further improved by Mr. Herbert Taylor for the first Algiers cable, and has since been improved by Mr. Robert Gray, to whom great credit is due for the completeness of the work, including soundings, the adoption of the electric light, and, indeed, all the careful steps taken in the work of the Algiers cable, so ably described by Mr. March Webb. Sir Charles Bright: The holding-back gear which Mr. March Webb has described as being on board the Dacia, and which Mr. F. Webb has just referred to, I had made in the West Indian Cable Work, in 1871. I had fitted on board the Dacia the same system of V sheaves and jockey-pulleys for holding-back gear as was used for the Atlantic cable and some other cables, but I found a good deal of inconvenience in a warm climate from the compound sticking in the sheaves, and so I therefore devised this arrangement. The Dacia, which Mr. March Webb has referred to, was originally built by Laing, of Sunderland. I had her fitted up for the object of making her, as far as I could from my experience, a thoroughly complete cable-laying and repairing ship, and I think that the character which she has had since in every expedition, proves that she is a success. The tanks I had put in at Sunderland where the ship was strengthened in various parts. The machinery was made from my designs at Messrs. Easton and Anderson’s, and I think I may say that the paying-out and picking-up gear are not excelled by any machinery of the same kind on any other vessel. She has shown her capability of doing good work on many occasions, and I remember hearing that in the repairs of the direct Atlantic cable immediately after the laying, when the machinery of another ship broke down, the end of the cable was passed over to the Dacia, and she brought up the cable easily. Mr. Webb’s paper is so clearly written, and touches on so many points, and is withal so modest a description of a work excellently carried out, that I have very little to say in comment upon it. There seems to have been no hitch in the work, and everything seems to have been a success. I congratulate Mr. Robert Gray, and all the other gentlemen who took part in the operation, upon the successful way in which so important a work in deep water has been carried out, without any of those vicissitudes which those who go to sea to lay cables are unfortunately sometimes likely to meet with. Mr. Phillips: Is there not some risk of the barrels being carried down with the shore end in landing? They have to be removed, of course, and as they are removed there must arrive a point when the barrels are no longer able to support the bight. I should think it would be a dangerous thing to have them carried down while they hold fast to the cable. Possibly they have some method of taking them off simultaneously all along. Mr. R. Gray: Perhaps I can answer that. We laid a cable once with barrels at Dieppe when the tide was running strongly, but by anchoring the ship firmly, and heaving strongly, we could draw the line always straight. It is a little off the line, but very little. Mr. F. Webb: Sir Charles Bright has mentioned the holding-back gear was designed by him. I have always understood (of course I may be misinformed) that Mr. Matthew Gray designed it at the time of laying the West India cable, but I may have made a mistake. Perhaps it was when he was there with Mr. Matthew Gray. The screw gearing referred to by Mr. March Webb was put on by me, and was not in the ship when it came back from the West Indies. I mention this because Sir C. Bright’s remarks would appear to imply that the whole machine as there shown was made to his instructions in the West Indies, and that thus I had claimed what I had no right to claim. I feel sure Sir Charles intended only to allude to the machine without the screw gearing, although he did not make this clear. Mr. W.H. Preece: Mr. President, the first fact that strikes one on hearing this paper read is, that if this Society has done no other good, it has at least done this, that it has brought the contractors out of their shells; for instead of having all the operations of cable-laying kept a secret in the archives of their head offices, we have here a Member of one of the largest contracting firms in this country coming up and telling us all the secrets of the prison-house. We must be indebted not alone to Mr. March Webb for the very clear and able paper he has read, but also to Mr. Robert Gray and to the India Rubber and Gutta Percha Company for allowing Mr. Webb to do so. I had, with Col. Grossman, the very great pleasure of being a guest on board the Dacia, and having been often in more unfortunate circumstances on board ship in carrying out cable operations, I experienced very great pleasure in having a change once in my life and being on board an idle witness. Now, there were some things on board the Dacia that I liked very much. There were one or two things, perhaps, that I didn’t like. I am bound to confess that I didn’t fall desperately in love with the mode of laying shore ends by means of barrels. There may be circumstances when such an operation is absolutely necessary. There have been circumstances when it would be impossible to lay the shore end of a cable by boats and when barrels would come into use; but from what I have seen I have not yet come to the conclusion that you can more rapidly and conveniently lay cables by barrels than by the ordinary method of forming a raft either by boats or steam launch. Mr. Phillips asked a question which I do not think was answered to his satisfaction, because I do not think that Mr. Robert Gray grasped the question in the same light as I did. I understood Mr. Phillips to ask whether there was not some probability of the weight of the cable sinking the barrels, and whether in consequence some inconvenience might not arise. But I do not think that at all likely to occur from the mode in which the operation is carried out, because the number of barrels, or the distance at which these barrels are placed apart, is simply dependent on the weight of the cable, and the buoyant power being known it is simply matter of calculation to say how many barrels should be required for any given length. When all the lines are pulled straight in the way described by Mr. R. Gray there is no more easy operation than simply to run along, cut away with a hatchet the lashes that fix the barrels to the cable, and so release them all one after the other. No barrel sinks, nor do I suppose it is at all possible in ordinary depths or with ordinary care that one should sink. Mr. Webb referred to one curious and anomalous operation connected with laying a shore end that probably did not strike the meeting, because he rather hurried over that part. He mentioned the fact that in laying one of the shore ends of the Chili and Peru cable a railway locomotive was employed for the purpose. We have heard of some very curious things in connection with submarine cables. I have heard of a submarine cable being broken by a bull! I have heard of another destroyed by fire! but I have not yet heard of a submarine cable being landed by a locomotive. The operation was, however, very simple. The locomotive was employed as power to pull ashore the hawser to which the barrels were attached. Another fact which struck me very forcibly during this expedition was the extreme value of the electric light. The electric light has been blazing away and trying to force itself into use in some of our large halls, and public places, and it has been successful certainly in the British Museum, whilst in other places it has only been partially so; but certainly of all places where the electric light has been employed I know nowhere where it has shown itself so eminently useful and practical as on board a steam ship while laying a cable. In the operations connected with the sounding across the Mediterranean this was used all night long for several nights, and not one single sounding was lost. This light shone forth and was handled, thanks to Mr. Page’s practical knowledge, with great skill, and it threw a flood of light from the quarter-deck that not only enabled the engineers to conduct their work, but the guests who were indulging in cards and cigars and a few of the luxuries on board the Dacia, deep into the small hours. During the paying-out it certainly was of enormous advantage, for, in the whole time, never once from the time the ship left Marseilles till it arrived off Algiers did we lose the benefit of what may be called “daylight.” In the five or six days occupied I do not think one single minute was lost through the absence of a lamp or through the absence of light. It happened in the year 1860 that I read a paper in this very hall before the Institution of Civil Engineers on “The Maintenance and Durability of Submarine Cables,” and one of the results of my experience, which at that time was not great, in maintaining cables was to advocate the absolute necessity of obtaining a clear and definite survey of the bottom of the ocean upon which the cable was about to be laid. I urged that with great force at the time, and the then President of the Institution asked me from his chair in rather a gruff tone whether I wished the bottom of the sea to be surveyed like the land for a railway. I said, “Certainly. I do not think that any cable should be laid on the bottom of the ocean until we know what the bottom of that ocean is”—and from that day to this year I have in more ways than one been striving to urge that principle. I do not think that a single deep sea cable has been laid yet where a proper survey of the ocean has been made. The Atlantic has been sounded but at distances of twenty miles. Plans have been drawn: sections have been shown of the Atlantic, and it has been generally assumed that we know a good deal of its bottom: but, supposing we were to take a line from John o’ Groat’s House to Land’s End and drop a lead at every 30 miles, what should we know of the contour of the country? So with the reading and mere sounding at every 20 or 30 miles we get a very faint notion of what the bottom of the Atlantic or any ocean is. It, therefore, afforded me great satisfaction to find that, before Mr. R. Gray undertook to lay this Cable between Marseilles and Algiers, he was determined to devote the whole of the time at his disposal to finding out all he could of the bottom of the Mediterranean, and the ship was fitted with the apparatus that has been described to you. (The speaker here referred to a map, without which his remarks would not well be understood.) The result was, that for this line no less than 143 soundings were obtained, 93 of which were obtained by the Dacia. The apparatus worked perfectly. Nobody but those who have seen the operation of Sir William Thomson’s sounding apparatus can conceive how easy it is to sound in the greatest depths. The ridiculous little wire that you fancy you could tear with your teeth runs out with the greatest regularity and the most wonderful speed. In fact, as the Paper said, it had taken soundings in 1,500 fathoms in only 25 to 30 minutes’ time. The wire ran out at the rate of about 12 or 13 feet per second, and was brought up as quick. The wire, in fact, came up to the surface just as quickly as it fell, and more than that, it brought up the bottom with it. Mr. Webb did not refer to the fact that here are the identical sounding weights themselves. (Exhibited.) It is rather different to the sounding apparatus generally used. It is so constructed that it offers the same resistance to falling as it does to rising. Having described the manufacture of this apparatus, Mr. Preece went on to say—The result of these soundings was that we obtained 93 samples of the bottom. These have been very carefully placed in bottles, and I am hoping very shortly, with the aid of one of the most distinguished physicists and microphists, to be able to thoroughly examine the contents, and perhaps be able to bring them before the Society. From what I have been able to find out myself, I think that the bottom of the Mediterranean differs but very little from the bottom of the Atlantic, but there is this great peculiarity in the Mediterranean, that the temperature of the water at the bottom is very high. The Mediterranean appears to be a hot-water bath. The temperature of the water all over is uniform—about 55 degrees Fahr. The cable tests show it to be 54 degrees. The tests taken by Carpenter and others show that the temperature is uniformly over the Mediterranean 54, while in the Atlantic it is about 34 degrees, and sometimes as low as 32 degrees, and thus you will see the great difference between the water in the Mediterranean and that in the Atlantic. A more perfect preservative for a cable could not be found than this stuff that comes up from the bottom of the Mediterranean, and when once a cable lies there, there is no reason why it should decay. In fact, the specimens upon that table which have been laid in this soft ooze show very little signs of decay indeed. The galvanisation is as perfect almost as when first laid down. When once a perfect cable has been laid in safety in this soft ooze, there is no reason why it should decay. With regard to testing operations, I can only say that I watched them with a good deal of interest, and found that everything worked perfectly and nicely; and although I have not had the pleasure of seeing other testing operations (of which we have heard a good deal) in actual operation, I have no doubt that in practice the operation described by Mr. Webb will be as effective in giving constant communication on the state of the cable between the shore and the ship as more celebrated ones that have emanated from a gentleman not very far from my left hand side (Mr. Willoughby Smith). I have no other remarks to make, but simply to say that if I find from the examination of the bottom of the Mediterranean which has been brought to London anything of any interest it will certainly be brought before the Society. Before sitting down I have only to express my deep obligations to Mr. Webb for his valuable paper, and to propose that a hearty vote of thanks be accorded to him for it. Mr. Smith: I have much pleasure in seconding it. Mr. March Webb said he had no observations to make, and he simply returned thanks. The Chairman: It is a very interesting paper, and by it he has gone far to remove the reproach said to attach to us by Mr. F.C. Webb, though I am bound to say I think he deserves it as much as anybody, for he has had a great deal of experience, and it was for him to give a paper on the subject. |
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Last revised: 25 August, 2015 |
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