The use of underwater optical cables, considered as a part of terrestrial links, has dramatically increased in recent years and a large variety of application and environmental conditions can be encountered. Different cable designs have been proposed, according to customer requirements and to the various sites of installation.

The main purpose of a marinized terrestrial cable construction is to provide a sufficiently reliable communication link that meets the system performance requirements in an economical manner. Whilst cable designs may vary, they share generic performance capabilities in order to meet this purpose. These normally involve the following considerations.

Prior to any system implementation a survey normally is conducted in order to find the optimum route and to give the cable the optimum protection along this route.

A survey vessel is only normally required for long or complex routes, as highlighted in the desk study and agreed by the parties concerned.

The cable installation should follow approved procedures in order to guarantee the required lifetime performance of the complete system.

A repair method is only needed if this is the maintenance philosophy adopted. In this case, repairs are carried out at convenience either in the factory or in situ. Only in situ repair methods are covered in this chapter, as factory repairs are covered by factory procedures.

On the basis of a desk study, and from the results obtained from any survey investigations (seabed and sub-bottom profiles), it is decided in which areas the cable must be particularly protected against environmental and human activities that could damage the installed cable. The cable length should be manufactured taking into account the type of cable armouring that may be required in the various sections.

This chapter covers tests that may be considered for cables, closures and beach closures for marinized terrestrial cable applications. These applications have some of the characteristics of shallow water submarine applications, but the cables are usually less rugged and the environments are generally more benign.