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History of the Atlantic Cable & Undersea Communications
from the first submarine cable of 1850 to the worldwide fiber optic network

1889 Obock-Perim Cable

Introduction: In 1889 Obock was a French territory, while Perim was under control of the British. This is the text of the agreement between the French Government and the Eastern Telegraph Company to lay a cable to connect Obock to Perim, and thence on to the rest of the British network. [British and Foreign State Papers, 1888-1889, Vol. LXXXI, pages 1034-1042].

Of particular interest in this document are the detailed technical conditions for the specification and laying of the cable, and the list of supplies to be provided by the company for the Oblock cable station.

The cable was completed on 14 July 1889 [Bulletin de la Société de Géographie de Marseilles, 1890, page 390].

—Bill Burns

CONVENTION between the French Government and the Eastern Telegraph Company, for the Construction of a Submarine Cable between Obock and Perim. Signed at Paris, May 17, 1889.
[Approved by French law of July 9, 1889 ("Journal Officiel," July 10, 1889)]


Convention between the Minister of Commerce, Industry, and the Colonies, in the name of the State, of the one part, and M. Jules Despécher, living in Paris, Rue Caumartin No. 12, representing the Company (Eastern Telegraph Company, Limited) of No. 50, Old Broad Street, London, acting in the name and for account of the said Company, in virtue of a Power of Attorney executed in the presence of William Webb Venn, Public Notary in London, the 16th May, 1889, of the other part.

It has been agreed and concluded as follows:—

Art. I. The Eastern Telegraph Company will establish between Obock and Perim a telegraph cable, according to the specifications contained in the annexed conditions of contract.

One end of this cable shall be landed at Perim, where it shall be connected with the Company’s telegraph station, and the other end upon the shore at Obock, whence it shall be prolonged by a subterranean line to the telegraph office which shall be there established by the French Government.

II. The Company undertakes, at its own charge, risk, and peril, the maintenance of the said cable for a period of 20 years, during which it undertakes to maintain communications in good working order, and, with this object, to repair the cable and to renew it, if that should become necessary, from any cause whatever, throughout the duration of the present Convention.

The maintenance of the connection between the landing place at Obock and the telegraph office of the Administration is at the charge of the French Government.

III. The landing place of the cable at Obock shall be determined by the engineers of the French telegraph service, the engineers of the Company advising.

The French Government may designate one or more of its engineers to verify, on board the ship charged with the laying, the specification of the cable, to assist in the electrical tests, and. generally to follow the operations relative to the laying and the subsequent repairs, if any take place.

IV. The Company shall be bound to install the buoys and. beacons which the French Government shall deem necessary for the protection of the cables.

The Company shall submit itself to all the obligations which follow from the International Convention concluded at Paris the 11th [? 14th] March, 1884,* for the protection of submarine cables. In any case, the Government shall not incur any responsibility on account of difficulties which may arise between the Company and the concessionaires of other submarine telegraph lines, owing to the crossing of the cables, or generally, whatever they may be, or from whatever cause.

V. The establishment of this cable conveys no privilege or monopoly in favour of the Company, all rights being reserved.

All Customs dues upon the cable and the telegraph instruments, as also all port charges for the ship carrying the cable, shall be remitted in favour of the Company.

VI. The cable shall be established and in working order within two months from the date when tho present Convention shall come into execution.

If this condition shall not be fulfilled, and except in the case of force majeure duly authenticated, or of accident during the laying, necessitating the lifting or repair of the cable, the Company shall be liable to a fine of 100 francs (4/.) for each day of delay, and, if the delay is prolonged beyond six months, the present Convention may be declared null and void without the necessity for any preliminary demand in due form of law, and the caution money specified in Article XVII shall revert to the Treasury.

The cable, established and ready to be worked, shall be handed over to the French Administration during the five days which follow the completion of the work of installation, with all the transmitting instruments in use at submarine telegraph stations.

VII. The telegraph service by the cable shall be assured at Obock by and at the cost of the French Administration; at Perim by and at the expense of the Company.

The normal hours of the working service of the cable from Obock to Perim shall be those of Limited Day-service Offices.

The Company undertakes, nevertheless, to make the necessary arrangements so that, even beyond the hours when the Obock Office is open for the service of private telegrams, the transmission of the official despatches of the French Government may always and at any hour be assured upon the cable from Perim to Obock.

VIJI. The taxes to be collected are fixed as follows:— 1st. The terminal proportion, or, should the case arise, the transit accruing to France for the Obock Colonial service, 15 centimes per word.

This proportion shall be added to any other tax to be collected or established for the correspondence exchanged with any telegraph office whatever.

2nd. The proportion of transit for the cable, 20 centimes per word, belonging exclusively to the Company.

This proportion shall be collected for the local correspondence between Obock and Perim, and shall be added to the total of the normal rates applicable to the correspondence from and to Obock when it shall be sent between Perim and all places of origin, or of destination, by the lines which, landing at Perim, shall not belong to the Company.

This transit tax shall not be added to the rates applicable to the correspondence from and to Obock passing in transit to Perim by the Company’s lines. Consequently the taxes to be collected for all correspondence from and to Obock, which shall pass to Perim by the lines of the Company, whatever may be the place of origin or destination, shall be the normal rates applied by the Company for Perim and Aden without any other increase beyond that of the 15 centimes per word for the French terminal proportion.

The tax for local correspondence exchanged between Obock and Aden is fixed at 75 centimes per word, of which 60 centimes 6hall belong to the Company.

These different taxes shall only be modified by agreement between the Minister and the Company, or in virtue of arrangements resulting from International Conventions.

IX. The official correspondence of the French Government, destined for or originating at Obock, shall be transmitted on the Eastern Company’s lines at a reduction of half the normal tariff applied to private correspondence for the same section.

The exercise and the limits of this right to a reduced tariff for the agents of the Government shall be determined by special Ministerial decrees.

The French Administration shall be credited in the monthly accounts with the amount of this reduction.

X. The accounts relative to the taxes belonging to the cable

shall be agreed monthly between the French Administration at Obock and the Company’s office at Perim, and the settlement shall take place in Paris at the end of each quarter.

The balance of account resulting from the application of the clauses of the present Convention shall be payable in Paris and in French money.

XI. The provisions of the Telegraphic Convention of St. Petersburg, and of the Regulations annexed, revised at Berlin, or of any other International Acts by which this Convention or its regulations may be at some future time replaced, shall be applied to the correspondence which shall be transmitted by the Obock-Perim cable.

XII. In consideration of supplying the said cable, the transmitting instruments, and of the expenses and engagements of the Company, the Minister of Commerce, Industry, and the Colonies undertakes to pay it, during 20 years to date from the opening of the service of the cable, a total annual sum of 37,500 francs (£1,500).

The amount of the subsidy shall be payable in Paris half-yearly, per completed six months, it being understood that the payment in respect of the first half-year shall be proportionate to the time which shall have elapsed since the inauguration of the cable service.

XIII. In case of interruption of the communication by the cable, repairs shall be effected as soon as possible; if not made within three months, the French Government shall have, under reserve of the power possessed by the State in virtue of Article XVIII, of pronouncing the forfeiture, the light itself to proceed to make repairs on account of the guarantee funds established under Article XVII below.

For every interruption of the communication between Obock and Perim exceeding 90 days in one year, there shall be made a reduction of the subvention proportionate to the length of the interruption.

The subsidy shall, nevertheless, continue to accrue to the Company if the interruption result from a requisition by the French Government.

XIV. No interruption of service shall be admitted apart from the case of rupture of the cable or authenticated derangement in the communications, except requisition of the French Government, according to the provisions of Article VIII of the St. Petersburg Convention.

XV. The French Government shall not incur any responsibility on account of difficulties arising in the working and maintenance of the cable from any cause whatever.

XVI. The Company shall not cede any of its rights under the present concession, nor lease the cables, without the written consent of the French Government.

XVII. The Company shall deposit within one month, under penalty of the cancelling of the present concession, a caution money of 50,000 francs (£2,000) in cash or in government bonds, upon which it shall receive the interest. This caution money, which must at all times be maintained by the Concessionaire at the amount of 50,000 francs (£2,000), shall remain in the Suitors’ Fund during the entire duration of the concession on account of the guarantee funds, applicable both to the working and maintenance of the cable.

This caution money shall be repaid, together with the last annuity.

XVIII. The Company may forfeit the benefits of the present concession to the profit of the State, which alone shall benefit by such forfeiture:—

(1.) If, after the opening of the communication under the conditions stipulated in Article VI above, there occur, in the service of correspondence between Obock and Perim, an interruption of more than six months without the Company, after demand in due form of law, being justified by adequate efforts having been made to terminate the interruption.

(2.) If an interruption arising under these conditions be prolonged from any cause whatever during a lapse of time equal to or greater than one year, saving, nevertheless, the case of force majeure, duly authenticated and admitted by the Minister.

(3.) In case of violation of any one of the clauses imposed on the Company by the present agreement.

In case of forfeiture, the 50,000 francs (£2,000) caution money shall revert to the State, and the Company shall lose the landing rights granted by the present Convention.

XIX. The duration of the present Convention shall be 20 years, at the expiration of which the cable shall remain the property of the Company, but if the Convention has not been renewed the Company shall lose the landing rights of the cable granted to it by the present Convention.

XX. The French Government shall have at any time, on giving six months' notice in advance, the right of terminating the present Convention and of purchasing the cable which is the object of it. the purchase being made in this case under conditions to be discussed, if necessary, on the report of experts.

At the expiration of the 20 years, the Government may also purchase the cable, but, in order to determine the purchase price, account shall only be taken, if necessary, on the report of experts, of the commercial value of the said cable.

XXI. All differences between the Administration and the Company concerning the clauses of the present Agreement shall be decided administratively at Paris.

XXII. The provisions contained in the present Agreement shall only come into force after approval by the French Chambers.

XXIII. The present Convention shall be registered at the fixed charge of 3 francs. The expense of stamp and registration of the present contract shall be borne by the Company.

Done at Paris in duplicate, the 17th May, 1889.

Approved, Despécher.

Approved, Tirard.

Tender for the Establishment of a Submarine Telegraph Line between Obock and Perim.

Art. 1. The cable will be laid between Perim and a point on the coast as close as possible to Obock.

At Perim, it will connect to the telegraph station served by the Eastern Telegraph Company.

On the shore at Obock, the cable will terminate in a cable hut which will be constructed by the Company and at its expense; all necessary connections will be made in the usual manner to a section of underground line which will be established under the care and expense of the Company until the telegraph station of the French Government is established at Obock. The trench for the underground cable will have a depth recognized as sufficient by the delegated engineers of the French Government.

2. The French Government will give in due course to the Company all licenses or permits and all facilities for the landing of the cable on the coast of Obock, for the construction of the cable hut, and for the establishment of the underground section to connect the submarine cable to the telegraph station at Obock.

3. The cable will be new, and constructed in accordance with the rules of the art and to the following specification:

Electrical conditions.

The cable core will consist of a conductor having seven copper wires of a total weight of 59 kilograms per nautical mile of 1,852 meters, whose electric resistance at a temperature of 24 degrees centigrade shall not exceed 9.65 B.A. units (ohms).

The insulation will be composed of three layers of gutta-percha according to the system of inductive capacity perfected by Willoughby Smith, alternating with the same number of layers of resin composition (Chatterton’s compound), the first layer of this composition being placed directly on the strand of copper. It will have a minimum weight of 59 kilograms per nautical mile.

The weight of copper and gutta-percha will be within 5 per cent.

In the tests to be made before the core is covered with its outer coating, after 24 hours immersion in water at 24 degrees centigrade the dielectric must have a minimum isolation of 150 million B.A. units (ohms ) per nautical mile after two minutes of charge, with both positive and negative currents. The same isolation will be required for the armoured cable after loading, but in this case temperature corrections will be applied according to the formulas of Messrs. Clark and Sabine.

The electrostatic capacity per nautical mile will not exceed 35 hundredths of a microfarad.

The electrical condition of the submerged cable should be such that, according to the above conditions, and taking into account the current average temperature of the water, the results of the resistance of the conductor do not give reason to assume that there are defects in the insulation or conductor.

Mechanical conditions.

The core of the cable will be protected against marine borers by a spiral metallic ribbon according to Clifford’s patent.

The core with this metallic ribbon will be surrounded by a good covering of tanned jute or caoutchouc, applied wet, and of a thickness sufficient to protect against the armouring.

This will consist of contiguous metal wires of varying diameters in conformance with the following:—

1. Type-B—Main cable, length approximately 61 nautical miles: 10 wires of galvanized iron (No. 6 BWG), of a diameter more than 5 mm. (5.10).

2. Type-E—Intermediate cable of 4 nautical miles: 10 wires of BB galvanized iron (No. 2 BWG), of a diameter more than 7 mm. (7.10).

The armouring will be covered with two ribbons of canvas impregnated according to the patent of Johnson and Philips, spiralled in opposite direction and alternated with two layers of Clark’s composition.

Two samples of the core and each type of cable will be deposited with the Administration of Telegraphs.

The cable once made will be coiled in watertight tanks, both in the manufacturer’s factory and on board ship, and kept, as much as possible, constantly in water.

4. Following the specifications above, the cable has been manufactured in the works of the Telegraph Construction and Maintenance Company of London, and loaded on board the steamer Chiltern of the Eastern Telegraph Company with destination Perim, to be submerged as soon as this Convention becomes definitive.

The lengths of each type of cable will be divided into the following positions:—

  Nautical miles.
Perim: Type E 2
Main Cable: Type B 61
Obock: Type E 2

It will not be held against the Company if the amounts expended are greater than the expected length.

The Company will furnish batteries and transmission equipment necessary to operate the line from Perim to Obock.

The Company will make the technical installation at the telegraph station at Obock in conformance with the indications of the engineers delegated by the French Administration.

5. The Administration may appoint one or more of its engineers to verify the specification on board the ship responsible for the laying, to monitor the immersion, to assist with electrical tests, or to proceed themselves, and in a general manner, to monitor all operations relating to the laying of the cable. All the facilities will be given to the engineers so designated for the accomplishment of their mission, especially during their stay aboard the cable-laying ship. These functionaries will, at the expense of the Company, be treated on board, in all respects, on the same footing as the engineer-in-chief of the Company.

6. The Company will communicate to the engineers of the Administration all information taken during the operation of the laying, route, speed, astronomical observations, and diverse bearings, and present them with a detailed chart showing the track of the cable, to which will be attached a sketch of the alluvium.

7. Equipment and supplies to be delivered to the Obock station for cable service will be as follows:—

2 Siemens lightning rods;
2 Saunders tubes for lightning rods;
40 Elements for Leclanché batteries, No. 2;
40 replacement zincs;
10 kilograms salt of ammonia;
100 meters of copper wire No. 18, with one layer of GP;
100 meters of copper wire No. 18, has two layers of GP;
100 meters of copper wire No. 18, wearing the ribbon;
2 single current Morse keys;
2 cable relays;
2 Morse appliances;
2 paper wheels;
500 rolls of Morse paper;
25 bottles of Morse ink;
10 brushes for ink;
20 bottles of oil for appliances;
2 bells;
2 speakers (to telegraph the sound);
2 galvanometers;
2 short circuit switches;
1 double direction switch;
Assorted screws, clamps, terminals, &c.;
1 box of tools;
6 dusting brushes;
2 chamois skins.

8. Delivery of cable, equipment and supplies to the French Government to be confirmed by a report signed by the engineers of the French Government and of the Company.

To be annexed to the Convention of this date.

Paris, 17 May 1889.


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Obock to Perim cable route

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