We don't have synonyms for railway tie yet — it may be a rare, specialized, newly coined, or misspelled word. The closest thesaurus entries we have are railway line.
(n) :
Alternative form of railroad tie. [(rail transport, US) A heavy, preserved piece of hewn timber laid crossways to and supporting the rails of a railroad or a member of similar shape and function of another material such as concrete.]
(n) :
Alternative form of railroad tie. [(rail transport, US) A heavy, preserved piece of hewn timber laid crossways to and supporting the rails of a railroad or a member of similar shape and function of another material such as concrete.]