Scour Tracker^TM Products…….

Streambed scouring, the eroding away of streambed material that supports bridges, has been the cause of disasters and near-disasters throughout the nation. Scouring occurs as fast-moving stream water flows around bridge support structures and abutments. The states' Department of Transportation bridge inspectors need accurate, cost-effective, and easy-to-use measurement systems that can identify potential scour and alert proper authorities as the event is occurring.

ETI offers a variety of scour measurement techniques because each bridge can have its own unique potential scour environment with its own set of requirements. Regardless of the technique used, if scour is detected each system can use its onboard telecommunications to alert responsible bridge safety personnel. Both digitized voice and digital data describe the present conditions.

Sonar-type systems are the choice for coastal and bay bridges where the channel bottom may be sandy or contain riprap and there is little debris. At rivers and creek beds where debris may accumulate, buried sensors such as a sliding magnetic collar and transmitting float-out devices may be better suited.

Every 30 minutes the sonar determines the elevation of the streambed using a rapid series of soundings. If scour has caused the elevation of the streambed to decrease significantly, an alert condition is initiated.

• SMC-3 Sliding Magnetic Collar

A cylindrical collar with built-in magnets is free to slide down a stainless steel support mast as the streambed erodes. Magnetic reed switches inside the mast are activated as the collar comes in proximity, providing the elevation of the streambed within the scour area.

• FLT-3 Float-out Transmitter

Float-out devices are buried at scour-prone locations near the bridge. Should scour occur sufficiently to release the device, the buoyant float-out rises to the water surface, activating an internal transmitter. A unique digitized signal identifying the alarming device is sent to a receiver mounted on the bridge.

ETI's Smart Remote Sensor Control Unit (SRSCU) collects data every 30 minutes from:

1. sonar scour sensors

2. sliding magnetic collar scour sensors

3. ETI's stage sensor (water surface elevation)

The SRSCU is mounted on a pier in the vicinity of the measured streambed. A few simple wiring connections that connect the sensors to the SRSCU and it is ready to start collecting data. It combines the data from sensors connected to it into a single record and transmits that record to the nearby Master Unit.

Scour System Master Unit

The Master Unit can communicate with several SRSCUs. It analyzes their data and determines if a condition exists that requires notification of bridge maintenance personnel. If so, the Master Unit places a data (or synthesized voice) call to a designated office.   

ETI's Scour Tracker^TM scour monitoring instrumentation is installed on more than 70 bridges in 16 states