Railroad freight car structure

Abstract

A railroad freight car has an underframe that includes a center sill and lateral cross-members such as bolsters, cross-bearers and cross-ties. Side sills run along the edges of the car. A floor sheet is welded to the center sill and side sills and above the cross-members. Floor stringers are welded to the top side of the floor sheet. A surface covering is mounted on top of the stringers. Thermal insulation may be installed between the surface covering and the floor sheets.

We claim: 
     
         1 . A railroad freight car comprising:
 an array of spaced-apart cross-members;   a floor sheet surmounting the cross-members;   an array of stringers surmounting said floor sheet; and   a lading bearing surface mounted above said stringers.   
     
     
         2 . The railroad freight car of  claim 1  wherein said array of cross-members includes at least a first cross-member having a flange and a web; said flange is spaced away from said floor sheet; and said web extends between said flange and said floor sheet. 
     
     
         3 . The railroad freight car of  claim 2  wherein said web of said first cross-member has an uppermost margin welded to said floor sheet. 
     
     
         4 . The railroad freight car of  claim 1  wherein said array of stringers includes at least a first stringer and a second stringer; said first stringer has a web that stands upwardly away from said floor sheet; and said stringer has a flange surmounting said web of said stringer. 
     
     
         5 . The railroad freight car of  claim 1  wherein thermal insulation is mounted above said floor sheet between said stringers and below said lading bearing surface. 
     
     
         6 . The railroad freight car of  claim 1  wherein said floor sheet is imperforate. 
     
     
         7 . The railroad freight car of  claim 1  wherein said floor sheet defines an upper flange relative to said cross-members. 
     
     
         8 . The railroad freight car of  claim 7  wherein said cross-members have upstanding webs, and said upstanding webs have upper margins welded to said floor sheet. 
     
     
         9 . The railroad freight car of  claim 1  wherein said floor sheet has an array of apertures formed therethough. 
     
     
         10 . The railroad freight car of  claim 1  wherein said freight car has a straight-through center sill; said array of cross-members includes cross-members that extend laterally to either side of said center sill; and said floor sheet co-operates with said center sill to provide flange continuity across-said center sill. 
     
     
         11 . The railroad freight car of  claim 10  wherein one of:
 (a) said straight through center sill has a top cover plate, and said floor sheet is mounted to co-operate with said top cover plate to provide flange continuity across said straight-through center sill; and 
 (b) said floor sheet extends across said straight-through center sill. 
 
     
     
         12 . The railroad freight car of  claim 1  wherein said floor sheet forms an upper flange to said cross-members, and forms a lower flange of stringers of said array of stringers. 
     
     
         13 . The railroad freight car of  claim 12  wherein said cross-members have webs, and said webs of said cross-members have respective upper margins welded to said floor sheet. 
     
     
         14 . The railroad freight car of  claim 12  wherein said stringers have respective webs standing upwardly from said floor sheet, and said webs have lowermost margins welded to said floor sheet. 
     
     
         15 . The railroad freight car of  claim 13  wherein said stringers have respective webs standing upwardly from said floor sheet, and said webs have lowermost margins welded to said floor sheet. 
     
     
         16 . The railroad freight car of  claim 1  wherein said freight car is a box car having upstanding walls and a roof located upwardly of said floor sheet. 
     
     
         17 . The railroad freight car of  claim 1  wherein said railroad freight car is an insulated box car. 
     
     
         18 . The railroad freight car of  claim 1  wherein said stringers, in cross-section, have a form that is one of:
 (a) an angle having a web standing away from said floor sheet and a flange mounted to said web, said flange being spaced away from said floor sheet; 
 (b) a tube having at least one web standing away from said floor sheet and a flange mounted to said web, said flange being spaced away from said floor sheet; 
 (c) a channel having a web standing away from said floor sheet and a flange mounted to said web, said flange being spaced away from said floor sheet; 
 (d) an I-beam having a web standing away from said floor sheet and a flange mounted to said web, said flange being spaced away from said floor sheet; and 
 (e) a T-bar having a web defining a stem standing away from said floor sheet and a flange mounted to said stem distantly from said floor sheet. 
 
     
     
         19 . The railroad freight car of  claim 18  wherein said stringers, in cross-section, have a form that is a channel having a web standing away standing away from said floor sheet and a flange mounted to said web, said flange being spaced away from said floor sheet, and said channel is a top-hat section in which said channel has a back, two webs standing away from said back; and said webs having respective toes distant from said back, said toes having out-turned flanges. 
     
     
         20 . The railroad freight car of  claim 12  wherein said stringer has a web and said web of said stringer is perforated. 
     
     
         21 . The railroad freight car of  claim 1  wherein said lading bearing surface is one of (a) a nailable floor; (b) an aluminum extrusion; (c) aluminum decking; and (d) wood decking. 
     
     
         22 . A railroad freight car that has a matrix member that defines the upper flange of at least one of (a) a cross-tie; and (b) a cross-bearer of said freight car, while also forming a bottom flange of longitudinal stringers that support a floor covering of said railroad freight car. 
     
     
         23 . A method of constructing a railroad freight car wherein said method includes the steps of (a) welding a floor matrix sheet to underframe cross-members of said freight car; and (b) welding longitudinally extending stringers to said floor matrix sheet. 
     
     
         24 . The method of  claim 23  wherein said cross-members have webs, and said method includes welding upper margins of said webs directly to said floor matrix sheet. 
     
     
         25 . The method of  claim 23  wherein said longitudinally extending stringers have webs, and said method includes welding lowermost margins of said webs of said stringers to said floor matrix sheet. 
     
     
         26 . The method of  claim 23  wherein said method includes the step of installing insulation between said stringers above said floor matrix sheet. 
     
     
         27 . The method of  claim 23  wherein said method includes using automated welding apparatus to make continuous fillets along at least one of (a) said cross-members to attach them to said floor matrix sheet; and (b) cross-ties to attach them to said floor matrix sheet; and (c) a bolster to attach it to said floor matrix sheet. 
     
     
         28 . The method of  claim 23  wherein said method includes inverting said floor matrix sheet between welding said cross-members thereto and welding said stringers thereto.