Methods of predicting the effects of a dynamic deployment system on fibre optic cables

The UUV/offboard sensor of the 21st century requires a high bandwidth, real time data link to its host platform. This can take the form of a dynamically deployed optical fibre. (Dynamic deployment is where the fibre is deployed as a result of the deployer's forward motion and fibre/sea drag-essentially a passive system). The benefits of utilising optical fibre in this way would be lost and indeed an entire operation could be in jeopardy if the integrity of the link were compromised by the deployment system. Link failure could even result in the complete loss of the sensor. DRA are currently addressing the issue of reliable fibre deployment. A computer model has been developed to predict the tension build-up in a fibre due to payout path configuration. Additionally, a series of tests conducted in our optical fibre deployment test facility is designed to replicate dynamic fibre deployment through various configurations of payout path components. The test programme serves to validate the computer model and to assess other effects such as failure modes and signal degradation. This paper presents details of both the computer model and the test-rig together with the findings to date from the test programme.