ESBR STOP-LOG

A stop-log is a metal block weighing around 20 tons each made from steel, 2 m high and hollow in the inside. The problem with inserting the stop logs is, that since the river carries so much soil (15-80% soil in the water), it accumulates in the rails and on the floor, so the stop-logs cannot be placed there in a fashion that it seals of the water. The second problem is, that in order to remove the stop-logs after the maintenance, they have to be cleaned as well - soil accumulates inside of them, and makes them too heavy to lift (up to 70 t together with the soil material).

The inspection of the stop-log rails is done by a rail based electro-mechanical scanner, the conceptual design can be seen on the picture "conceptual design rail scanner". The system scans along the rail region detecting the debris by fusing the data of a sonar and a potentiometer. The sonar measures the distance to the region directly ahead of the system and the potentiometer the inclination of the mechanical shield as it passes over debris. The system also posses a water pump to clean small debris and mud. To validate the proposed solution a scaled version of the system is being constructed for testing within DFKI underwater facilities.

A scaled version of the stop-logs are also being constructed at DFKI for testing of different methodologies of cleaning accumulated silt within the stop-log, the picture "conceptual design of cleaning the stop-log" represents one of the proposed methodologies.