Discovered a crack, 20 centimeters long, about 60 centimeters from the bottom of the riverbed. Underwater, the diver reported the information with rapid breathing. Okay, received. Please check 50 centimeters to the left. "On the riverbank, the companions stared closely at the screen, observing the real-time transmitted images while responding to their underwater homework companions. Recently, at the Beijing Hangzhou Grand Canal Bridge on the Xinyan Railway in Jining, Shandong Province (hereinafter referred to as the "Beijing Hangzhou Grand Canal Bridge"), the only "bridge doctor" team in China that operates underwater - the Bridge Underwater Inspection Team of Jinan Railway Bureau's Railway Preparedness Boat Bridge Department (hereinafter referred to as the "Bridge Underwater Inspection Team") - innovatively introduced underwater inspection robot technology based on manual diving exploration, and "human-machine collaboration" conducted comprehensive "physical examinations" of the bridge's underwater piers. In the past, this bridge underwater inspection team, known as the "underwater frogmen", had to carry "armor" and dive deep into the water, using the touch of their fingertips to "pulse and diagnose" the piers of the railway bridge. This year, there is a new chapter in the power of protection - a reliable "new partner" has been added to the team of divers, namely underwater detection robots. Wang Yunze, the chief engineer of the bridge underwater inspection team project, told Science and Technology Daily reporters that this robot has extraordinary skills. It has the ability to "float" and "adsorb and crawl", and can swim like a fish or adsorb on the bridge pier like a gecko. With high-definition cameras and sonar, it can quickly scan and accurately mark abnormal points, and provide real-time feedback of detection data, greatly improving detection efficiency. During the conversation, Wang Yunze controlled the underwater robot to dive into the water and attach it to the bridge pier. On the monitoring screen beside him, the water grass at the bridge pier is clearly visible. As the robot moves rapidly, the track drives the roller brush to remove the water grass in one go. During the inspection, some abnormal situations discovered by the robot require manual review. 28 year old bridge underwater inspection team diver Gao Jiawang put on diving equipment weighing over 20 kilograms and, accompanied by muffled breathing, flipped over and went into the water. The river is fast and muddy, with low visibility underwater. Gao Jiawang relies entirely on experience and touch, touching the surface of the cable-stayed bridge pier inch by inch to determine any abnormal conditions in the concrete. When his fingers sensed subtle abnormal changes in the underwater structure, Gao Jiawang immediately contacted the shore team to record the video data of the discovered problem. At the same time, the underwater robot was beside him, using high-definition video recording and sonar systems to accurately survey again - a "human-machine collaborative" detection loop quietly completed in this invisible depth. Unlike regular diving, bridge underwater inspection faces unique "multidimensional battlefields". Tens of thousands of highway and railway bridges across the country are distributed in different river basins, and the hydrological environment, visibility, flow velocity, and water temperature of each river vary greatly. Divers may encounter entanglements, sharp structures, deep water pressure, and unpredictable changes in water flow every time they dive. This requires divers to have knowledge of bridge structures, be able to understand engineering design drawings, and be able to operate professional equipment such as underwater cameras, RTK measuring instruments, and crack width gauges. They also need to have preliminary emergency skills such as underwater welding and cutting. In order to meet the requirements of such homework, members of the bridge underwater inspection team use their free time to independently obtain certificates such as welder certificate, crew certificate, diving supervision certificate, etc., to ensure that they can independently respond to various emergencies in complex underwater environments. In the murky and icy depths of the water, divers face not only physical challenges, but also psychological extreme tests. The diving suits and helmets they wear often collide with exposed steel bars or stacked rocks at the bottom of the riverbed, and the scratches left on their diving masks are a direct witness to working in difficult environments. Thick diving suits cannot provide warmth, and divers immerse themselves in the bone chilling river water, requiring a change of team members to dive in and continue testing every 20 minutes of operation. Gao Jiawang, who had just finished his homework, had just landed and his hands were frozen unconscious. He sat on the shore with a towel on his head to keep warm and rest. He heard the steady rumble of the train passing over the bridge and said, "At this moment, I think our work is very worthwhile." The inspection of the Beijing Hangzhou Grand Canal Bridge took two days to complete, and the cracks found after comprehensive inspection were within normal range. But the members of the underwater bridge inspection team cannot stop because the next underwater bridge maintenance task is already waiting under the distant railway line. (New Society)