Tie exchange method

Abstract

A method for sequentially exchanging selected consecutive groups of old ties for groups of new ties while retaining groups of old ties between the selected old ties in a railroad track consisting of two rails fastened to the ties supported on ballast, which method comprises advancing at least one elongated bridge-like work vehicle along the track, sequentially operating a succession of different individual devices mounted on the advancing work vehicle to remove rail fastening elements whereby the selected ties are detached from the rails, to remove tie plates positioned between the detached ties and the rails, to withdraw the detached ties laterally from the track, to scarify the ballast where the detached ties have been withdrawn whereby shaped recesses are formed in the ballast under the rails, to insert new ties in the shaped recesses, to place new tie plates between the new ties and the rails, to tamp ballast under the new ties, and to fasten the rails to the new ties. The different individual operating devices are intermittently displaced along the elongated work vehicle for effectuating the sequential operation thereof while the work vehicle advances.