ANZCAN (Australia-New Zealand-Canada) Cable is a 1,380 channel (23 supergroup) analogue cable system manufactured by STC and was laid in 1982-1983. Third-level support is provided by International Networks and Technology.

Two manufacturers produced cable for the ANZCAN project with the major contract for the high capacity segments totalling 7437 nautical miles between Australia and Canada going to a British Company, Standard Telephones and Cables (STC). The shorter segment of 736 nautical miles between New Zealand and Norfolk Island was manufactured in Japan by a consortium of manufacturers led by the Nippon Electric Company (NEC).

The 1,380 circuit cable has an outer conductor diameter of 37.34 mm (1.47 inches). When the cable comes close to shore, soft iron tape is used to prevent electrical interference and the cable is sheathed in one or two layers of armour wire.

The New Zealand-Norfolk Island cable has an outer conductor diameter of 25.4mm (1.0 inches) and carries 480 circuits. Its construction is similar to the main cable except that copper tape is used instead of aluminium for the outer conductor.

There are 89 repeaters in the New Zealand-Norfolk Island segment of ANZCAN and 1034 repeaters crossing the Pacific from Australia to Canada. A typical analogue cable repeater is up to 2.7 m long and 230 mm in diameter, can weigh up to 533 kg and contains more than 300 components - all of them thoroughly tested to ensure a 25 year working life. The repeater case must be strong enough to withstand the great pressure of water at the ocean bottom at depths of up to 6 km. The water pressure is more than 80 tonnes per sq. metre.

TERMINAL EQUIPMENT

The Australian terminal station for ANZCAN is in the same building at Paddington, Sydney, that was used for COMPAC. The main function of the equipment at the terminal station is to apply power to the cable and also to connect the complex translation equipment (MUX) that enables the speech on the 1,380 circuits to be combined into a complex electrical wave, transmitted along the cable and then restored back to 1,380 separate conversations. The terminal equipment also, however, includes apparatus which continually watches over the performance of the complete ANZCAN cable system and which can detect faults in the cable or the repeaters. Additional equipment enables maintenance staff to locate any such fault.

Cable coming ashore at Takapuna, Auckland New Zealand

ANZCAN ROUTE SURVEY

HMNZS Monowai, the Royal New Zealand Navy's hydrographic survey ship, left Auckland on November 12, 1980 for a journey that would take five months and cover 8000 nautical miles.

One of the most modern survey ships afloat, Monowai had been chosen to carry out the entire route survey for the ANZCAN cable. The task involved gathering information on depths, sea-bed composition, temperature and current strength to allow selection of the best route for the subsequent cable laying operation.

Monowai was built in 1960 and commissioned as a survey ship in 1977, following an extensive refit and conversion from her previous role as a merchant vessel. The conversion included total refurbishing and extended the accommodation, adding extra surveying office space, a helicopter deck and hangar, fitting a bow thruster unit and controllable pitch propellers for greater manoeuvrability.

For the cable survey the normal ships gear was supplemented by additional specialised equipment. This included echo sounders that could measure the thickness of the ooze on the sea bottom at depths of 6 km, side scan sonar, deep ocean cameras, underwater television, additional navigation devices, a gravimeter to measure the earth's gravitational pull, sea-bed samplers, current meters and tide gauges.

All the survey information is fed into a Marconi hydroplot system. An Elliot 905 computer was used to assimilate the survey data, store information on magnetic tape and draw a plot of the ship's track on a plotter on the survey bridge. The computer is controlled using terminals on the bridge.

For the ANZCAN route survey, naval and scientific personnel worked closely with staff from Cable and Wireless Ltd, the company whose ships would undertake the actual cable lay and who have been associated with many earlier telegraph and telephone cables in the Pacific.

THE CABLE SHIPS

Two of the world's most advanced cable ships, C.S. Cable Venture and C.S. Mercury, were used for the main ANZCAN cable lays, with smaller vessels used for laying the shore ends at Port Alberni (Canada), Fiji, Keawaula (Hawaii) and Norfolk Island.

Cable Venture, the main cable laying ship operated by Cable and Wireless PLC, began the first cable lay (part of the Canada-Hawaii segment) in late November, 1982 following completion of the shore end at Port Alberni. Specially equipped to lay high capacity telephone cables, Cable Venture also has storage capacity for the large number of repeaters and equalisers required by modern cable systems.

Even so more than one load of cable was required for most of the segments. The Canada to Sydney segments required seven cable lays. Cable was brought from Southhampton to Noumea in a specially converted freighter and transferred directly to the cable ship. This new development saved time normally needed for the cableship to make the round trip itself.

Cable laying is controlled by a linear cable engine which enables cable and repeaters to be laid continuously at speeds of up to five knots although the ships speed is normally reduced to about two knots when a repeater or equaliser is due to go over the stern.

The second cable lay, using Mercury, commenced with the shore end landing at Bondi Beach, Sydney in January, 1983. Mercury is a dual purpose ship, mainly used for cable maintenance but also capable of laying major cable systems. Mercury went on to complete three of the ANZCAN cable lays, including the segment between New Zealand and Norfolk Island which commenced with the landing of cable at Takapuna Beach, Auckland in March, 1983. The cable laying did not always occur in calm seas and especially during the first lay gale conditions with winds of up to force 13 were at times experienced. At one stage conditions were so bad that the cable had to be cut and buoyed while the cable ship steamed to Vancouver to shelter and repair damage.

With ANZCAN complete another cable ship took over responsibility for maintaining the cable system from the end of 1984. Constructed primarily for the maintenance of ANZCAN, C.S. Pacific Guardian was launched from the yards of Swan Hunter Shipbuilders Ltd, Newcastle upon Tyne, in June, 1984. She took up her duties at the end of 1984, and was originally based in Fiji. She now rotates between Auckland and Sydney.

	Technical Details
Laid	1982-83
Capacity	14MHz Cable System
Transmission Capacity	1380 x 4kHz channels
Total cable length	8,175nm (15,140km)
Number of Repeaters	1125
System Design Life	25 years
Maximum Depth	5,600 m
Landing Points	Bondi Beach, Sydney, NSW Anson Bay, Norfolk Island Takapuna, Auckland, New Zealand Suva, Fiji Keawaula, Hawaii Port Alberni, Vancouver, Canada

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