Multiple-axle rail car with span bolsters

Abstract

A multiple-axle railcar having a load supported by an upper span bolster attached to a plurality of lower span bolsters is disclosed. A group of axles are attached to each lower span bolster using truck assemblies. The method of manufacturing the span bolsters involves fabricating and joining the components of the span bolsters in a manner that forms a camber in the unloaded span bolster.

What is claimed is: 
     
         1 . A multiple-axle railcar comprising:
 a railcar body have a first end and a second end;   a first upper span bolster pivotally attached to the first end and a second upper span bolster pivotally attached to the second end,
 wherein each of the first and second upper span bolster have a camber with a peak coinciding with an attachment point to the railcar body; 
   a pair of lower span bolsters attached to each of the first upper span bolster and the second upper span bolster,
 wherein each lower span bolster has a camber with a peak coinciding with an attachment point to the upper span bolster; and 
   a plurality of truck assemblies carrying axles, wherein the truck assemblies are mounted to the span bolsters.   
     
     
         2 . The multiple-axle railcar of  claim 1 , wherein the railcar body comprises a pair of Schnabel frames. 
     
     
         3 . The multiple-axle railcar of  claim 1 , wherein three truck assemblies are mounted to each span bolster and have a slot to permit lateral movement of the plurality of axles. 
     
     
         4 . The multiple-axle railcar of  claim 1 , wherein the multiple-axle railcar has 24 axles. 
     
     
         5 . The multiple-axle railcar of  claim 1 , wherein the railcar body comprises a depressed center load carrying member, wherein a center of the depressed center load carrying member is below a mounting point of the load carrying member to the first upper span bolster and the second upper span bolster. 
     
     
         6 . The multiple-axle railcar of  claim 1 , wherein the peak of the camber of each lower span bolster is located at a center of each lower span bolster. 
     
     
         7 . The multiple-axle railcar of  claim 1 , wherein the peak of the camber of each upper span bolster is located at a center of each upper span bolster.