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VANCOUVER (PORT SAN JUAN)-FANNING ISLAND CABLE.
THE SPECIFICATION HEREINBEFORE REFERRED TO.
SPECIFICATION
FOR THE MANUFACTURE OF THE LENGTHS AND TYPES OF CABLE TO BE FURNISHED BY THE CONTRACTORS UNDER THE CONTRACT.
Length in Nautical Miles to be
Manufactured.
Description.
Type.
Sheathing.
Core
G00 lbs. Copper.
340 Gutta Percha
Core Brass Sheathed.
"1
Core not Bra40 Sheathed.
PUBLIC RECORD OFFICE
Heavy Shore End
A.A.
Type B. 12 No. 6 reclosed with 14 No. 1 (300) galvanized, compounded and yarn served.
1.25
Heavy Intermediate...
E.
10 No. 2 (-280) galvanized, compounded
and yarn served.
3.25
Light Intermediate ...
B.
12 No. 6 (200) galvanized, compounded
and yarn served.
60.00
Main Cable
D.
18 No. 14 (083) galvanized, each wire
taped and compounded.
3589.00
64.50
3589.00
Total Contract Length of Cable
3653-50
Reference :-
C.O.885
7
ALLY WITHOUT PËRMISSION OF THE. BE REPRODUCED PHOTOGRAPHIC- |COPYRIGHT PHOTOGRAPH-NOT TO
PUBLIC RECORD OFFICE, LONDON
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VANCOUVER (PORT SAN JUAN).—FANNING ISLAND CABLE.
Core
600 lbs. Copper.
2340 Gutta Percha.
(A.) The Conductor to consist of a central copper wire 144 mils. in diameter, Conductor. closely surrounded by copper wires each of approximately 22 mils. in diameter, the completed Conductor to weigh 600 lbs. per nautical mile or within 24 per cent. thereof, but the average weight per nautical mile shall not be less than that specified.
The resistance per nautical mile of the Conductor at a temperature of 75° Fahren- heit shall not be more than 2.03 B.A. ohms.
The central wire to be drawn through compound before the surrounding wires are laid round it.
In place of the surrounding wires specified above, copper strips may be em- ployed, the strips to be laid in a close spiral, in an approved manner, round the central wirc.
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The weight of the copper strips, if employed, to be such that the average weight of the Conductor per nautical mile is not less than 600 lbs. or within 24 per cent thereof, nor shall the resistance of the completed Conductor exceed 2·03 B.A. ohms. at a temperature of 75° Fahrenheit.
(B.) The Conductor to be insulated with three or more coatings of gutta-parcha Insulator. of uniform radial thickness, and of the best description and manufacture, and may be applied with or without the use of compound between the successive coatings of gutta-percha.
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295
PUBLIC RECORD OFFICE
Reference:
C.O.885
7
PUBLIC RECORD OFFICE, LONDON |
ALLY WITHOUT PERMISSION OF THE BE REPRODUCED PHOTOGRAPHIC- COPYRIGHT PHOTOGRAPH-NOT TO
Core.
Brase sheathing of Cores.
Core
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The average weight of the Dielectric shall not be less than 340 lbs, per nautical mile, and no coil of core shall have a less weight of dielectric than 332 lbs per nautical mile.
The Core seven days after manufacture, and not before this period has elapsed, shall be submitted for testing to the Engineer or his representative.
For the purpose of these tests the Core shall be immersed for at least twenty-four hours in water having as nearly as practicable a temperature of 756 Fahrenheit, and when tested at this temperature the resistance of the dielectric after one minute's electrification shall not be less than 500 nor more than 1,500 megohms per nautical mile, and its average inductive capacity shall not exceed 0·440 microfarads per nau- tical mile, and the maximum variation in the capacity of any coil is not to be higher -than 5 per cent. above the average value specified.
The total weight of the Core when completed to be 940 lbs. per nautical mile, or within 24 per cent. thereof, but the mean weight of the whole must be at least equal to the specified weight.
(c.) The Cores of Types AA, E and B, specified as to be brass sheathed, are to be covered with a sheathing of brass tape, four mils. thick, laid on spirally with a sufficient overlap, and further covered with an ozokerited woven tape, the whole to be done in an approved manner.
(D.) Each coil of Core shall, if required, be submitted to an alternate E.M.F. of at least 5,000 volts, this electrical pressure test to last fifteen minutes on each coil.
The coils of Core to be delivered in lengths of not less than 1.0 nautical mile without joint, and the length and weight of Conductor and Dielectric of each coil shall be given in writing to the Engineer.
No coil can be accepted that does not comply with the electrical conditions before mentioned.
(E.) The completed Core to be covered with an ample and sufficient serving of serving. jute yarn, steeped in cutch or other approved preservative mixture of such strength as to have the best preservative effect, and applied wet. The yarn to be of good quality, of even size, free from lumps so as to give a uniform gauge to the served Core, and of sufficient strength to avoid breakages when being laid up. This serving is to be suffi cient to prevent the sheathing wires being laid up so close as to render the Cable too springy.
OUTER COVERINGS.
Heavy
(F.) Type AA. (Heavy Shore End.) Type B light intermediate cable to be Shore End. further served with tarred jute yarn, and again closed with 14 galvanized low carbon basic iron wires, No. 1, B.W.G., equal to 300 of an inch when galvanized, or within 24 per cent thereof.
Heavy Inter- mediate.
Light Inter- mediate.
Main
Cable.
Average breaking strain of No. 1, B.W.G., wires to be not less than 25 tons per square inch, nor more than 30 tons per square inch, and to bear 12 twists in lengths of 6 inches.
4
(G.) Type E. (Heavy Intermediate.) The served Core to be covered with 10 galvanized low carbon basic iron wires, No. 2, B.W.G., equal to 280 of an inch when galvanized, or within 24 per cent. thereof.
Average breaking strain to be not less than 27 tons to the square inch, nor more than 32 tons per square inch, with an elongation of 10 per cent., in lengths of 10 inches, and to hear 10 twists in lengths of 6 inches.
(H.) Type B. (Light Intermediate.) The served Core to be covered with 12 galvanized low carbon basic iron wires, No. 6, B.W.G., equal to 200 of an inch when galvanized, or within 24 per cent. thereof.
Average breaking strain to be not less than 28 tons to the square inch, nor more than 35 tons to the square inch, with an elongation of not less than 12 per cent., and to stand not less than 15 twists in lengths of 6 inches.
(1) Type D. (Main Cable.) The served Core to be covered with 18 galvanized steel wires, each wire being well covered with a bituminous compound and taped to a diameter of 100 of an inch.
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The galvanized steel wires to be No. 14 B.W.G., equal to 083 of an inch when galvanized, or within 24 per cent. thereof, and to bear a breaking strain of not less than 84 tons to the square inch, with an elongation of not less than 4 per cent.
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The wire to be capable of being bent round its own diameter three times and unbent three times without breaking.
The wire to be in bundles of not less than 2 cwt., and to have no more than one weld in each bundle.
(J.) The wire to be free from splinters and irregularities, no brittle wire to be put Irregu- in the Cable, nor weld made within 12 feet of any other weld. All joints in the sheath- larities and wires to be welded, either electrically or by efficient workmen, no brazed or soldered welds. joints to be made.
(K.) The galvanized wire to withstand four immersions of one minute each in a Galva- solution of sulphate of copper (1 sulphate to 5 water by weight) without showing a nizing. trace of copper coating.
(L.) Before being used for the sheathing of the Cables, the galvanized wire for the Com- types AA., E., and B. is to be heated in a kilu or oven just sufficiently to drive off all pounding moisture, and, whilst warm, i to be dipped into a hot compound not containing any. of wires, thing deleterious to the Core, and so prepared as to adhere to the wire and form, when set, a perfectly fixed preservative coating that will not come off in passing through the closing machine.
OUTER SERVING.
(M.) Types AA., E. and B., manufactured as above, to be covered with two servings of jute yarn steeped in "freed " coal tar, and laid on spirally in opposite direc- tions, alternating with three coatings of Clark's compound applied hot.
(N.) Type D., manufactured as above, to be covered with two Hessian canvas tapes soaked in an approved preservative compound and laid on spirally in opposite direc- Į tions, alternating with three coatings of Clark's compound.
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GENERAL CONDITIONS.
The manufacture of the Cable shall not be carried on at night without the consent of the Engineer.
No coils of Core shall be sheathed before they have been tested and approved by the Engineer or his representative appointed for that duty..
All coils shall be labelled, numbered, and registered, and as the manufacture of the Cable proceeds, the Engineer or his representative shall be supplied with a com- plete list showing the order in which they are placed in the Cable.
The joints in the core are to be made by experienced workmen. In every case one joint maker is to be employed to join the conducting wire, and another to apply the insulating covering. Each joint shall, if required, be inspected, tested, and passed by the Engineer or his assistant before it is allowed to pass into the Cable.
Reasonable notice shall be given to the Engineer or his assistant when each joint is to be made to enable him to be present at its making, if he so desires, and ample time shall be allowed for a satisfactory test, six hours after it has been immersed in water.
The manufacture of the Cable in every stage, as well as the materials and com- pounds used therein, shall be of the best, and be satisfactory to the Engineer.
The sections of the Cable under manufacture shall be handed over for daily test- ing to the Engineer, with a memorandum for each, showing the numbers, weights, and lengths of the coils jointed on during the previous twenty-four hours, the total length in circuit, and the length completed, and sufficient time shall be given for proper and satisfactory tests to be made.
Every nautical mile of Cable shall be carefully marked with a lead tally, on which the number is stamped, and securely fixed at the end of each mile.
The Cable, when manufactured, shall be coiled in suitable water-tight tanks, re- ceiving at the same time a good coating of whitewash, and shall be kept as far as prac- ticable constantly under water.
A separate and convenient room for testing the Core and Cable, with instruments and batteries, is to be provided by the Contractors at their works for the Engineer's
5006-3
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