Mariana Trench Romance

By combining our expertise in special cable development with the world's leading Optcal Fiber technology, we are attempting to meet highly challenging development requirements. We are beginning to take on the challenge of unchartered territory.

While marine development cables require the same tensile strength as undersea cables, the big difference is that they are always connected to equipment and are used while moving freely in all directions under the sea. Fujikura is a pioneer in Japan in undersea cables, boasting an extensive delivery record, and also possesses cable technology used in special cab-tyre cables used in large cranes on land, elevator cables and other moving equipment, so the company had ample groundwork to advance into this field. The marine development cable developed this time was developed by combining these foundations with some of the world's leading Optcal Fiber technology.

The required requirement was to develop a primary and secondary cable that would supply power and transmit information from the mother ship to the launcher and child vehicle for the unmanned exploration vehicle "KAIKO" capable of diving to a depth of 10,000m. At the time, the "Magellan 750" made by the US company Eastport (now Oceaneering International, Inc.) was the deepest that could dive, but its nominal maximum depth was 7,000m.

After receiving the order, in April 1988, a new Marine Technology Development Office was established within the Covered Wire business (currently the Metal Cable business). A full-scale development system was established, but initially, it started with only four people. The system is composed of cables (primary and secondary) and accessories (dead-end hardware and underwater connectors), and due to the tight development period, all of the development was carried out simultaneously. The primary cable is an ultra-long cable of 12,000m, with a mechanical strength of 50 tons. The secondary cable is also designed to be highly flexible and lighter than seawater so as not to affect the maneuverability of the child vehicle. Both the primary and secondary cables have a composite cable structure with a power line core and an Optcal Fiber core. Thus began the challenge to enter an uncharted territory.