We will develop a fiber-optical sensor system that can be applied to monitor pipelines. By recording the response of a fiber-optic transducer to ultrasound that is generated on the wall of a pipeline we can measure the flow velocity of the fluid inside the pipeline. Similar measurements are presently conducted by pipeline operators using piezo-electric transducers, but their sensitivity is not high enough to locate small leaks or pipeline deposits through a change in flow rate. In addition the ultrasound measurements will let us accurately determine the identity of the pipeline content. The fiber-optic transducer implemented by Queen’s researchers and their collaborators already has a 1:300,000 signal to noise ratio and a flat frequency response from DC to 35 kHz. The transducer is inherently immune to electric and magnetic fields, radio-frequency noise, and temperature. It is also non-intrusive and can be retrofitted to existing infrastructure. Since the sensor head is part of a regular single-mode telecommunication fiber it is straightforward to generate a large sensor array that can be monitored in a single location. In this project a scale model of a pipeline will be built and interrogated with both conventional and fiber optic sensors.