The through-pin rail anchor is composed of through-pins of rail clips with baffles. During installation, one side of the rail clamp clamps the rail bottom, and the other side wedges into the through pin, so that the entire rail anchor is firmly clamped to the rail bottom. In this way, when the rail is subjected to longitudinal resistance, because the baffle plate of the rail clamp is close to the sleeper, the sleeper and the track will prevent the rail from crawling. In order to give full play to the role of rail anchors, anti-climbing braces are usually installed between sleepers to connect 3 to 5 sleepers to jointly resist rail crawling.
Under normal circumstances, when a train is running, a longitudinal force acting on the rail is often generated, causing the rail to move longitudinally, and sometimes even driving the sleepers to move together. This longitudinal movement is called crawling. Crawling generally occurs in the main line of the double-track railway, the heavy vehicle direction of the single-track railway, the braking range on the long downhill and when entering the station. Track crawling often causes uneven rail seams, skewed sleepers and other phenomena, which is very destructive to the line, and even causes a small track runway, which endangers driving safety. Therefore, effective measures must be taken to prevent crawling, usually rail anchors and anti-climbing braces are used to prevent line crawling.