Autorack railroad car and underframe therefor

An autorack railroad car body unit underframe, said underframe comprising:

• a lengthwise-running straight-through center sill running continuously from end to end of the car body unit;
• said center sill having a first end and a second end;
• said center sill having a mid-span location mid-way between said first end and said second end;
• said center sill having a draft sill at said first end thereof;
• said center sill having an end location at said draft sill;
• said center sill having a top flange, a bottom flange, and at least one shear web member extending therebetween;
• and
• decking over which to conduct lading length-wise along said car body unit, said decking extending laterally to either side of said center sill;
• said center sill having a depth of section, hm, at said mid-span location;
• said center sill having a depth of section, hd, at said draft sill;
• and
• hmis less than 20% greater than hd.

A center sill for an autorack railroad car, said center sill comprising:

• a first end, a second end, and a medial portion between said first and second ends;
• said center sill having a top cover plate, a bottom cover plate, and a pair of first and second laterally spaced apart webs extending between said top cover plate and said bottom cover plate, said top cover plate and said bottom cover plate defining respective top and bottom flanges of said center sill;
• at least one of said first and second ends including a draft sill, said draft sill having a maximum depth of section, hd, at a first longitudinal station of said center sill;
• said medial portion having a minimum depth of section, hm, at a second longitudinal station of said center sill distant from said first longitudinal station;
• at said first longitudinal station said top cover plate being carried at a first height, h1 relative to TOR;
• at said second longitudinal station said top cover plate being carried at a second height, h2, relative to TOR;
• h1 being at least as great as h2;
• and
• hd being at least as great as hm.

An autorack railroad car body, said car body having first and second ends, said car body comprising:

• an underframe and a housing structure overspanning said underframe;
• said housing structure including a longitudinally running array of posts mounted along lateral margins of said underframe, longitudinally running first and second top chords surmounting said posts, a roof structure extending upwardly of, and between, said first and second top chords, side wall panels mounted between pairs of said posts, said housing having at least a first end through which to permit lengthwise loading of vehicles;
• said underframe including a center sill, and a pair of first and second side sills, said center sill and said side sills running lengthwise along said car body, said first side sill being spaced laterally to a first side of said center sill, said second side sill being spaced laterally to a second side of said center sill, said center sill being between said first and second side sills;
• said underframe having decking upon which vehicles can be conducted lengthwise along said car body;
• said decking extending between said center sill and said first side sill, and extending between said center sill and said second side sill;
• said center sill including at least one draft sill portion adjacent one end of said car body, and a central portion, said central portion being located in a medial portion of said car away from said first end of said car body and away from said second end of said car body;
• adjacent to said draft sill said decking being carried at a first height relative to TOR;
• adjacent to said central portion of said center sill said decking being carried at a second height relative to TOR;
• said first height being greater than said second height;
• said center sill having a first depth of section at said draft sill;
• said center sill having a second depth of section at said central portion thereof;
• and
• said second depth of section is less than said first depth of section.