Third-party contact to pipelines (typically caused by contact with a digging or drilling device) can result in mechanical damage to the pipe. Because this type of damage often goes unreported and can lead to eventual catastrophic failure of the pipe. A reliable, cost-effective method is needed for monitoring and reporting third-party contact events. Since over half of subsurface damage results from third-party infringement, the capability for detecting contact and locating encroachment would be greatly beneficial.

Several methods exist, or are being investigated, for monitoring and reporting third-party contact or activity near the pipeline. These include continuous fiber-optic sensors buried alongside the pipe, satellite surveillance, cathodic protection monitoring, and methods that rely on telephone calls prior to digging. Because all of these methods have inherent limitations or are undesirable under certain conditions, the current project was initiated to investigate an alternate monitoring method.

This method, acceleration or vibration sensing and locating the event by analyzing the produced sound signal due to third party interference, is capable of directly and continuously monitoring pipelines for third-party contact. Implementation of this method is relatively straightforward, and it can be retrofitted to existing pipelines without the need for excavating the pipeline.