| 摘要 |
Prestressed concrete railroad ties are formed in molds which are supported by existing track near the area where they are to be installed. Each mold will form a number of ties. Reinforcing strands are located within a plurality of longitudinally spaced molds. Concrete is then poured into the molds and the ties are formed bottoms up in the molds. A group of ties are simultaneously removed from a given mold by a special extractor which first simultaneously clamps the reinforcing strands extending outwardly from a given mold, and then lifts the strands as a group from the mold by a suitable crane. Preferably the center of gravity of ties is spaced from a pivot point which will cause 180 DEG rotation locating the ties in upright position to be loaded on a railway car or other vehicle to take them to the site where they are to be installed.
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