High-Speed Ocean Cable Telegraphy

The invention of permalloy and its application to submarine cables have led to the installation of transoceanic cables of many times the traffic-carrying capacity of the former non-loaded cables. This paper relates briefly the history of the development of permalloy-loaded cables and discusses certain outstanding problems concerned with their design, construction and operation. In a concluding general survey the field of usefulness of loaded submarine telegraph cables is considered. To a considerable extent the paper is a critical summary of material previously published by members of the staff of the Bell Telephone Laboratories. Its scope is indicated by the sub-titles as follows: Loaded Cables Now in Service Historical Remarks Permalloy and Its Application to Cables Principles of Design of Loaded Cables Principles Involved in Operation Apparatus for Restoration of Signals Apparatus for Automatic Operation Electrical Measurements of Loaded Cables A General Survey