1. A COVERED HOPPER RAILWAY CAR HAVING A CROSSSECTIONAL AREA WITH AAR CLEARANCE LIMITS COMPRISING, A SEPARATE STUB CENTER SILL STRUCTURE ADJACENT EACH END OF THE CAR, AN ARCUATE SIDE SHEET ON EACH SIDE OF THE CAR STRUCK FROM A CONSTANT RADIUS HAVING ITS CENTER AT A SUBSTANTIAL DISTANCE OUTSIDE THE CONFINES OF THE CAR AND BEING WITHOUT ANY SEPARATE EXTERNAL VERTICAL REINFORCING MEMBERS, THE OUTER SURFACE OF EACH SHEET AT ITS MAXIMUM LATERAL EXTENT BEING SUBSTANTIALLY AT THE AAR CLEARANCE LIMIT WITH THE SHEETS BEING SPACED FROM EACH OTHER A DISTANCE AT SAID LATERAL MAXIMUM EXTENT OF AROUND TEN AND ONE-HALF FEET, A SIDE SILL SECURED ALONG THE OUTER SURFACE OF THE LOWER MARGINAL PORTION OF EACH SIDE SHEET, A TOP CHORD MEMBER SECURED ALONG THE UPPER MARGINAL PORTION OF EACH SIDE SHEET AND EXTENDING IN A DIRECTION LONGITUDINALLY OF THE CAR, EACH TOP CHORD MEMBER HAVING A GENERALLY LATERALLY EXTENDING UPPER PORTION, A ROOF SECURED BETWEEN THE UPPER PORTIONS OF THE TOP CHORD MEMBERS, AN END SILL AT EACH END OF THE CAR EXTENDING TRANSVERSELY OF THE CAR BETWEEN THE SIDE SILLS AND OVER THE ADJACENT STUB CENTER SILL STRUCTURE, A PLURALITY OF HOPPERS SPACED AT INTERVALS ALONG THE LENGTH OF THE CAR, A BOTTOM HOPPER OUTLET STRUCTURE FOR EACH HOPPER POSITIONED CENTRALLY OF THE WIDTH OF THE CAR BETWEEN THE STUB CENTER SILL STRUCTURES, A BOLSTER ASSEMBLY AT EACH END OF THE CAR SECURED TO THE ADJACENT STUB CENTER SILL STRUCTURE AND INCLUDING A GENERALLY HORIZONTALLY EXTENDING SHEAR PLATE OVER THE ADJACENT CENTER SILL STRUCTURE EXTENDING BETWEEN AND SECURED TO THE SIDE SILLS, AN END HOPPER SLOPE SHEET FOR EACH END HOPPER INCLUDING AN INCLINED SHEET PORTION AND AN UPPER VERTICAL SHEET PORTION, SAID INCLINED SHEET PORTION EXTENDING FROM ITS ASSOCIATED BOTTOM OUTLET STRUCTURE UPWARDLY ADJACENT AND INWARDLY OF THE INNER END OF THE ADJACENT STUB CENTER SILL STRUCTURE TO A POSITION OVER THE SUBJECT SHEAR PLATE TO PROVIDE EACH END HOPPER WITH A HOPPER PORTION OVERHANGING THE SHEAR PLATE, SAID UPPER VERTICAL SHEET PORTION BEING AT THE END OF THE CAR GENERALLY IN VERTICAL ALIGNMENT WITH THE ASSOCIATED END SILL AND EXTENDING UPWARDLY TO THE ROOF, AND EXTERNAL LOAD CARRYING MEANS AT EACH END OF THE CAR EXTENDING FROM THE ASSOCIATED END SLOPE SHEET IN THE AREA OF CORNER JUNCTURES OF THE INCLINED SHEET PORTION WITH THE VERTICAL SHEET PORTION AND SECURED BETWEEN THE ASSOCIATED END SLOPE SHEET AND SHEAR PLATE FOR TRANSMITTING LOADS THEREBETWEEN.