Mold assembly for pre-stressed concrete railroad ties

A mold assembly for the manufacture of prestressed concrete railroad ties comprising:

• prestressed concrete molds supported by existing track near the area where the ties are to be installed;
• each mold having a plurality of components to form a number of ties including transverse end portions of each mold having means to locate reinforcing strands within each tie at a single level at a position sufficiently close to a neutral axis to minimize stress fluctuations;
• wherein each mold has a bottom that is contoured with inclined portions to provide a desired tie cross section which varies in a manner designed to carry the compressive and tensile loads applied to the tie by the wheels of rail cars and at the same time minimize the amount of concrete required;
• means for pouring concrete into the mold;
• extractor means for removing a group of ties simulatenously from a given mold;
• said extractor means having means for simultaneously clamping the reinforcing strands extending outwardly from a given mold and means for lifting the strands as a group from the mold.