Method and apparatus for prestressing rails by electrical heating and method of laying rails

摘要

In a method for heating rails by means of electric current, a current source (1) is connected to two rails (B, C), in such a manner that the rails are connected in series. Then a current is led through the rails and the rails are heated to a desired temperature. The heating of the rails (B, C) by means of a series connection is followed by heating of the rails by means of a parallel connection thereof. This method is used for prestressing rails when laying rails in a track, in such a manner that the rails will be at least substantially stressless at a neutral temperature. The invention also comprises an apparatus for heating rails (B, C) by means of electric current, which apparatus includes a current source (1), conductors (2 - 4, 6) as well as connecting elements (5) for connecting said conductors to the rails. Said conductors (2 - 4, 6) and said connecting elements (5) are arranged for successively connecting the current source (1) in series and in parallel to the rails (B, C).