Depressed Center Beam Flat Car

1. Field of the Invention

This invention relates in general to railway cars and, more particularly, to a depressed center beam flat car.

2. Description of the Prior Art

At present lumber and other construction material is conventionally transported by railroads in center beam/center partition railcars, generally having a 100 ton nominal capacity built to conform to the Association of American Railroads (AAR) Plate "C" clearance. The distance between end bulkheads of these cars is generally sixty or seventy three feet, and the tare or empty weights range from 63,000 to 69,000 pounds. Cars with tare weight in the foregoing range respectively have lading carrying capacities ranging from 200,000 to 194,000 pounds. The center beam/center partition design permits the construction of lightweight cars with long spans between bulkheads, such as in the previously described car having a length of seventy three feet.

The lumber and the like that is transported in center beam/center partition cars is commonly made up of equal length pieces banded together in modules. The lengths of the modules range from eight to thirty two feet in increments of two foot lengths and nominal four foot widths. The actual width of lumber modules varies according to nominal dimensions of 2".times.4", 2".times.6", 2".times.8", 2".times.10", and 2".times.12". The height of each module is a constant twenty four inches. The transported lumber is normally air dried having an average density of approximately 31.5 pounds per cubic feet.

The lumber modules can be stacked up to five high on both sides of the center beam/center partition cars. Due to its length between bulkheads, the center beam/center partition car having a seventy-three foot length is preferred over other sizes, because it accomodates a large combination of lengths of lumber and the like. The weight of typical loads of lumber in known center beam/center partition cars in a fully loaded condition is approximately 170,000 pounds. Inasmuch as a standard 100 ton center beam/center partition cars possesses a carrying capacity of 194,000 to 200,000 pounds as stated previously, such existing cars only achieve a payload efficency in the range of 85% to 87.6%.

Center beam/center partition cars of the foregoing design have a center of gravity of approximately ninety-six inches loaded and fifty-six inches empty. The center structure of those cars requires that during loading and unloading, materials must be placed and removed to even weight levels on each side of the center structure to avoid unbalanced loads which can cause the cars to tip-over with the result that lumber modules could be hurled to the ground in various directions like projectiles. Written warnings are clearly stencilled on these existing cars stating that uneven loading and unloading at the sides of the cars can cause tipping of cars sideways. Thus, such standard cars present the potential of damage to the lumber and equipment, and possible safety hazards for personnel during the loading and unloading of materials. Further, the high center of gravity of the loaded car in the prior art produces relativily poor track worthiness and ride stability. Therefore, it is desirable to provide center beam/center partition cars that not only provide greater efficency, but also demonstrate greater stability during loading/unloading and when being transported.

It is therefore an objective of the present invention to provide an improved center beam flat car of depressed center design demonstrating enhanced operating efficiency and greater stability in use. The depressed center beam flat car of the invention is designed to be comparable in spans between bulkheads and in tare weight to the current designs of such cars. The car herein disclosed employs a depressed load carrying section between the truck assemblies on both sides of the center sill and center beams not contemplated in existing center beam/center partition cars. The depressed floor of the invention is attained by the use of unique means provided at the interface between the depressed feature and the standard floor area near the ends of the car for the adequate tranfer of live and dead loads, and dynamic loads to the longitudinal and transverse structural underframe members. The depressed loading area of the depressed center beam car herein disclosed also significantly increases the available volumetric capacity for loading modules and also substantially lowers the center of gravity of empty and fully loaded cars. The car of the invention is designed within the AAR Plate C clearance diagram.

The depressed center flat car herein disclosed, when, for example, built with a seventy-three foot length between bulkheads, has an additional loading capacity on each side of the center beam of about fifty-six feet in length between the truck assemblies, an additional height of approximately two feet as compared to normal floor level, and an increase of width of four feet from car sides to center beam in comparsion to standard center beam/center partition cars. The depressed section for carrying loads thus results in an additional carrying capacity over known cars of approximately 26,460 pounds for lumber having a density of 31.5 pounds per cubic feet. Thus, the payload carrying efficiency is 196,560/200,00 or 98.3% which achieves an efficiency of over 15% over current center beam/center partition cars. It is also estimated that incorporation of the depressed floor section of the invention will decrease the loaded car center of gravity in the range of ten to fourteen inches. The reduced center of gravity decreases the probability of the car tipping over during the loading/unloading cycles and significantly improves the track worthiness and ride stability of the car.

FIG. 1 is a side elevational view, with parts removed, of the depressed center beam flat car of the invention;

FIG. 2 is a top plan view of the depressed center beam flat car of FIG. 1;

FIG. 3 is a partial side elevational view, with parts removed, of the depressed center beam flat car of FIG. 1 showing among many features the center sill and draft sill;

FIG. 4 is a partial plan view taken along lines 4--4 of FIG. 3;

FIG. 5 is a partial end elevational view taken along lines 5--5 of FIG. 1;

FIG. 6 is a partial end elevational view, with parts in section, taken along lines 6--6 of FIG. 2;

FIG. 7 is an end elevational view, with parts cut away and parts in section, taken along lines 7--7 of FIG. 2;

FIG. 8 is a partial side elevational view, with parts in section, taken along lines 8--8 of FIG. 7;

FIG. 9 is partial side elevational view, with parts in section, taken along lines 9--9 of FIG. 7.

FIG. 10 is a partial plan view, with parts removed, of the depressed center beam flat car of FIG. 1, and

FIG. 11 is a partial side elevational view, with parts removed, of the depressed center beam flat car of FIG. 1.

Referring now to FIGS. 1 and 2, there is illustrated the depressed center beam flat car of the invention, generally designated by reference numeral 2. The depressed center beam flat car 2 includes a center beam assembly 4 extending along its longitudinal centerline above a longitudinally extending center sill 6 having an upper surface 8. As best seen in FIG. 7, center sill 6 has a box beam cross section. A plurality of hollow truss vertical column assemblies 10 are spaced along the length of the longitudinal center line of the depressed center beam flat car 2 on upper surface 8 of center sill 6 and the pair of draft sills to be described. In FIG. 7 a longitudinally oriented upper center beam assembly 4 is carried by the top ends of the truss vertical column assemblies 10, as illustrated in FIG. 7. The upper beam assembly 4 includes a horizontal extending continuous center beam 12, having a U-shaped cross-section, which includes a lower portion formed by a lower horizontal section 12a and a portion of spaced vertical sections 12b. The lower section 12a and a lower portion of vertical sections 12b are affixed within the upper end of each of the truss vertical column assemblies 10. A pair of opposed center beam cross ties 16 are welded to center beam 12 at each of the top ends of the truss vertical column assemblies 10 and respectively project outwardly to support a center beam side sill 18 on each side of the center beam assembly 4 (FIG. 3). A center beam cover plate 20 is attached to the center beam 12, side sills 18, and plurality of cross ties 16 to form an continuous upper surface over the upper center beam assembly 4.

A pair of draft sills 22 are suitably supported on opposite ends of the center beam flat car 2, and each carry a conventional coupler 23 at their outboard ends as seen in FIGS. 1, 2, and 11 and some of the truss column assemblies 10 on their upper surface. The draft sills 22 merge with the longitudinally extending center sill 6 at a center sill transition section 24 as best seen in FIGS. 3, 7, and 10. The center sill transition section 24 includes a slanted center sill transition member 24a. A web plate transition tie 24b having a upward opening U-shaped configuration is affixed to the bottom portion of center sill 6. A center sill/web plate transition tie support 24c in the form of an angle member carries the web plate tie 24b, and is attached to a web plate 24d that extends outward to the side sills to be described. As seen in FIG. 10, the horizontal width of center sill 6 is reduced as compared to the draft sills 22 at each end for reasons to be described.

Referring to FIGS. 7, 10, and 11, a pair of side sill assemblies 26 extend the length of the depressed center beam flat car 2 on both sides. The side sill assemblies 26 include an upper side sill section 28 at each end and a depressed intermediate side sill section 30 as illustrated in FIGS. 1, 7 and 11. As seen in FIG. 7, the end side sill sections 28 are formed in a modified U-shaped cross-sectional configuration opening outward and are reinforced by side sill stiffeners 28a. The depressed side sill intermediate section 30 is formed with a modified cross-sectional Z-shape as shown in FIG. 7. As best seen in FIG. 7, the depressed side sill section 30 is unified with the adjacent upper side sill sections 28 at each end by a side sill transition assembly 32. The side sill transition assembly 32 comprises a welded vertical side sill tie plate 34 having an affixed triangular shaped transition tie plate gusset 36 disposed under the upper side sill sections 28. A transition bottom tie plate 38 is affixed to the bottom of the depressed side sill section 30 and is further attached at its outer edge to the side sill tie plate 34. A lateral vertical lower transition tie plate 40 is disposed above the transition tie plate 38 in welded relationship to depressed side sill section 30 and side sill transition tie plate 34. The side sill transition assembly 32 maintains the structural integrity between upper side sill end sections 28 and the depressed side sill sections 30. From the foregoing, it should be apparent that end sections 28 of each side sill assembly 26 are oriented along an axis vertically above the longitudinal axis of intermediate side sill section 30. The longitudinal axis of the intermediate side sill section 30 is also laterally spaced inward toward center sill 6 by a distance less than the axis of end side sill sections 28.

The end portions of the depressed center beam flat car 2 above the upper side sill sections 28 include symetrically oriented upper floor sheets 40 carried by the end side sill sections 28 and the draft sills 22, as shown in FIGS. 7 and 11. A floor section 42 is positioned above the intermediate side sill sections 30 and are in a depressed planar orientation below floor sheets 40 by a suitable distance, such as, for example, by approximately fourteen to eighteen inches. The longitudinal extent of the depressed sections 42 may be approximately 75% of the between bulkhead length of depressed center beam flat car 2. As seen in FIGS. 7,8,10 and 11, the depressed floor section 42 comprises a plurality of floor sheets 44 supported by a plurality of spaced cross bearer assemblies 46. The floor sheets carry a plurality of upper tapered pieces 48 on which the commodity to be transported may be arranged. The cross bearer assemblies 46 in the form of I-beams and are arranged in spaced relationship to each other between the side assemblies 26 with their outer end portions 50 being affixed respectively to the opposed intermediate side sill sections 30. (FIG. 7).

As shown in FIG. 8, the intermediate portions of the cross bearing assemblies 46 are respectively supported by a laterally aligned pair of cross bearer supports 52 in the form of plates, through which the upper flanges 53 of cross bearing assemblies 46 extend in suitable slots 54. The pairs of cross bearer supports 52 are suitably attached on opposite sides of center sill 6 and project downward. The upper surface 56 of the tapered pieces 48 are tapered downward from the side sill assemblies 26 toward the center of the depressed center beam flat car 2. As is well known, the tapered top surfaces 56 orient the carried load toward the center of the depressed center beam flat car 2 for better stability. Further, the depressed floor section 42 lowers the center of gravity of the depressed center beam flat car 2 for a significant increase in stability. As seen in FIG. 10, the depressed floor section 42 has a reduced overall width as compared to the width of upper floor sheets 40 at each end. Such reduced floor width allows commodities of standard width, i.e. 48 inches, to be carried on the depressed floor section 42 and comply with existing regulations mandating clearance. The reduced width of depressed section 42 is provided by the reduced horizontal width of center sill 6 as compared to draft sills 22. The union of the center sill 6 and draft sills 22 is effected by means of the center sill transition section 24. Further, the inward orientation of intermediate side sill section 30 relative to end side sill sections 28 provides outward support of the reduced width of depressed floor section 42.

A bulkhead assembly 58 of conventional design is mounted on each end of the depressed center beam flat car 2 at a position above draft sill assembly 22. The depressed center beam flat car 2 is carried by a pair of conventional truck assemblies (not shown) having wheels 60 (FIG. 3). Although trucks of any suitable capacity can be used in the invention, the truck assemblies may be, for example, of a 100 ton design. A bolster assembly 62 is mounted at each end of depressed center beam flat car 2 above the truck assemblies. As seen in FIGS. 5 and 6, the body bolster assembly 62 includes a bottom cover plate 64, which is welded to side sill sections 28, the draft sill assembly 22, and a body bolster cover plate 66. A body side bearing 68 is arranged below bottom cover plate 64 and reinforced by body bearing reinforcement 67. The body bolster assembly 62 is further reinforced by three body bolster web stiffeners 70 and bolster webs 72. A plurality of winch assemblies 74 are carried on the side sill assembly 26 at plurality of locations to secure cables for retaining the load in a known manner.

As seen in FIG. 6, the outboard ends of the upper center sill assembly 12 is affixed to the upper portions of each bulkhead assembly 58 by means of a modified Z-shaped plate 76. A lower vertical section 78 of plate 76 is affixed to the inboard panel 80 of bulkhead assembly 58. The intermediate horizontal section 82 of plate 76 forms a lower support for the ends of upper center sill 12, which are open at end portion 83. The upper vertical section 84 of plate 76 also retains the ends of center sill 12. A stiffener plate 86 is welded to the outboard wall of bulkhead assembly 58 and the upper section 84 of the plate 76. Both ends of the upper side sills 18 are retained on the bulkhead assemblies by a plate (not shown) of similar configuration as plate 76, but having smaller dimensions to conform to the reduced size of side beams 18.