EdgeTech was recently involved in a demonstration of the effective use of high-resolution side scan sonar imaging for canal inspection and mapping.

The Welland Canal connects Lake Erie to Lake Ontario and is key to the St. Lawrence and Great Lakes Waterway System. The 27-mi. waterway allows ocean-going ships access to the Midwest, which would not be possible without the Welland Canal.

The St. Lawrence Seaway Management Corp. manages and maintains the canal and invited EdgeTech to demonstrate a method to quickly survey canal crib wall structures and map the canal bottom for obstructions. A survey was performed with an EdgeTech 4125 system operating at
600 and 1,600 kHz.

The 1,600-kHz frequency was used to image the crib walls, and the resulting images were of extremely high resolution, allowing full viewing of timbers, including missing or damaged timbers, concrete capping deterioration and other features.

The second requirement was general imaging of the canal bottom to look for obstructions and debris that could be a hazard to transiting ships. In one area over a highway tunnel crossing, several abandoned vehicles were located. The EdgeTech system not only showed its value at mapping
the canal bottom but was very effective at producing near photo quality of vertical cribbing surfaces.