This is called Switch Expansion Joint (SEJ) installed at both ends of a Long Welded Rail (LWR). You can search with the terms for knowledge. There is another type of SEJ called 'thick web SEJ' which looks different than the one you clicked ( Thick web SEJ picture attached ; Credits: Asif)
please wait...Translate to EnglishThis thing is called a Switch Expansion Joint (SEJ) and it's put at both ends of a Long Welded Rail (LWR). If you wanna know more, search with those fancy words. There's also another type of SEJ called 'thick web SEJ' that looks different from the one you clicked on (check out the picture of the Thick web SEJ attached; Credits: Asif).