ASI Group

ROV Highlight: Trash Rack Recovery

Seabotix on a rocky shore

At a power generation plant in Canada, facility personnel discovered that a dislodged trash rack had fallen from the structure and was preventing the stop log gate from fully closing. Trash racks are designed to prevent debris from entering a water conveyance system. ASI was hired to immediately provide underwater remote inspection and intervention services to relocate and recover the fallen trash rack. Our technicians rushed to prepare a remotely operated vehicle (ROV) and ancillary tools, then arrived on site within 24 hours to begin operations for the trash rack recovery.

underwater images of trash racks
Sample still images from a trash rack inspection

The recovery procedure consisted of feeding a rope through the fallen rack with the use of ASI’s Seabotix ROV equipped with a manipulator arm, camera and sonar. The ROV was deployed by hand through the stop log sill of the intake structure. Once the rack was located and the rope attached, ASI technicians were able to hoist it up with the help of a portable gantry, pulleys and a chain fall. With the rack clear of the gate slot, the plant was able to lower the stop log gate and seal the intake, allowing for safe isolation of the turbine so that a full inspection could take place.

image of Seabotix ROV

The post recovery inspection of the intake revealed that the pressure caused from the clogged trash rack was enough to dislodge two support beams from the concrete walls, resulting in the fallen rack that was lodged under the gate structure. ASI provided raw video and screen captures of the inspection and recovery as deliverables to the client.

ROVs are an amazing example of technology and are an instrumental tool when it comes to inspections. Not only can they be used to mount cameras and sonar equipment, but they can be outfitted with additional gear and tools to perform tasks that help with repairs and maintenance

Want to learn more about what ASI’s ROVs can do? Contact us today