Railcar nailable floor

1. A plank for use in a nailable metal floor structure, the plank comprising:

a web portion having a first end, a second end disposed opposite from the first end, a top surface and a bottom surface;

a first side flange extending from the first end of the web portion and wherein the first side flange is convex;

a second side flange extending from the second end of the web portion and wherein the second side flange is concave;

a first bottom flange connected to the first side flange and extending substantially parallel to the web portion;

a second bottom flange connected to the second side flange and extending substantially parallel to the web portion;

a first central portion having an end extending from the first bottom flange to the bottom surface of the web portion such that the end contacts the bottom surface of the web and is welded to the bottom surface of the web;

a second central portion having an end extending from the second bottom flange to the bottom surface of the web portion such that the end contacts the bottom surface of the web and is welded to the bottom surface of the web; and

wherein the plank is formed from a one-piece construction.

2. The plank of claim 1 , wherein the convex first side flange is formed from a plurality of arcuate sections.

3. The plank of claim 1 , wherein the first side flange is formed from a first arc, a second arc, and a third arc, the first and second arcs having a first radius and the third arc having a second radius, the second radius being longer than the first radius.

4. The plank of claim 1 , wherein the first side flange and the second side flange have complementary curved shapes such that adjacent planks are capable of nesting together and further wherein a nailing groove is defined between adjacent planks.

5. The plank of claim 4 further comprising a cement that is introduced into the nailing groove.

6. A nailable metal floor structure for mounting on the underframe of a freight vehicle, the structure comprising:

a plurality of planks forming a planar floor surface inside the freight vehicle, the planks having a web portion with a planar top surface and a bottom surface, the web portion extending between a pair of side flanges, the side flanges having complementary curved shapes so that adjacent planks are capable of nesting, the side flanges extending to bottom flanges, the bottom flanges extending substantially parallel to the web portion and being separated by a central opening, the central opening formed between first and second angled central portions extending from the bottom flanges to the bottom surface of the web portion and wherein each of the first and second angled central portions has an end that contacts and is welded to the bottom surface of the web;

wherein the planks are disposed in side by side generally parallel relation, each plank having the web portion forming the surface of the floor and having the side flanges depending from the opposite ends of the web portion so that adjacent flanges of contiguous planks are complemental to each other thereby providing nailing grooves between each adjacent pair of planks; and

wherein the plurality of planks are each formed from a one-piece construction.

7. The plank of claim 6 , wherein the first side flange is convex.

8. The plank of claim 7 , wherein the second side flange is concave.

9. The plank of claim 6 , wherein the first side flange is formed from a plurality of arcuate sections.

10. The plank of claim 6 , wherein the first side flange is formed from a first arc, a second arc, and a third arc, the first and second arcs having a first radius and the third arc having a second radius, the second radius being longer than the first radius.

11. The plank of claim 6 , wherein the first side flange and the second side flange have complementary curved shapes such that adjacent planks are capable of nesting together and further wherein a nailing groove is defined between adjacent planks and a cement is introduced into the nailing groove.

12. A plank for use in a nailable metal floor structure, the plank comprising:

a web portion with a top surface, a bottom surface, a first end and a second end opposite the first end;

a pair of side flanges extending from the first and second ends of the web portion respectively, the side flanges having complementary curved shapes;

a pair of bottom flanges extending substantially parallel to the web portion and separated by a central opening;

first and second central portions extending from the bottom flanges to the bottom surface of the web portion and wherein the first central portion has an end and the second central portion has an end and wherein the ends contact the bottom surface of the web portion and are each welded to the web portion; and

wherein the plank is formed from a one-piece construction.

13. The plank of claim 12 , wherein the first side flange is convex.

14. The plank of claim 13 , wherein the second side flange is concave.

15. The plank of claim 12 , wherein the first side flange is formed from a plurality of arcuate sections.

16. The plank of claim 12 , wherein the first side flange is formed from a first arc, a second arc, and a third arc, the first and second arcs having a first radius and the third arc having a second radius, the second radius being longer than the first radius.

17. The plank of claim 12 , wherein the first side flange and the second side flange have complementary curved shapes such that adjacent planks are capable of nesting together and further wherein a nailing groove is defined between adjacent planks.

18. The plank of claim 17 further comprising a cement that is introduced into the nailing groove.