The present invention relates to the railroad transportation industry, and more particularly to a cambered frame system for supporting and distributing loads in an intermodal rail car.
Approximately 65,000 intermodal rail car cars are used in the United States. Intermodal rail cars are specifically designed to transport both domestic and International Standards Organization (ISO) containers. ISO containers are eight feet wide, and either eight feet six inches tall or nine feet six inches tall, and are typically either 20 or 40 feet long, although larger sizes are available. 20-foot long ISO containers have a gross weight (lading and tare) load limit of 67,200 pounds. Intermodal rail cars may be loaded with two tiers of containers. With ISO containers, the lower tier generally consists of either two 20-foot ISO containers positioned end-to-end in the rail car or one 40-foot container, and the upper tier generally consists of one 40-foot ISO container stacked on top of either the two 20-foot ISO containers or the single 40-foot container.
The average intermodal rail car is between 10-12 years old and, as a result of overstress created by fully loaded 20-foot containers, many of the intermodal rail cars have become structurally compromised. In particular, the central portion of the intermodal rail car potentially becomes stressed to the point of failure of the supporting horizontal steel structure. As a result of this stress caused by the fully loaded 20-foot containers, the Association of American Railroads (AAR) reduced the maximum allowable weight limit for 20-foot ISO containers from 67,200 pounds to 52,900 pounds effective January 2012, thereby decreasing transportation efficiency of the US intermodal rail industry. This invention will restore the ability of the current intermodal rail fleet to again carry fully loaded 20-foot containers without damaging the rail cars.
A method of transporting containers on a rail car is described. The method includes the steps of, first, providing a frame having at least two longitudinal beams and at least two cross beams. The at least two cross beams extend perpendicular to, and interconnect, the at least two longitudinal beams. The two longitudinal beams may be cambered along the length of the beams. Next, the method includes the step of attaching a first container to a first end of the frame. Then, the first container and the frame are loaded into the rail car. Finally, the method includes the step of loading a second container into the rail car and onto a second end of the frame.
A method of transporting a plurality of frames on a rail car is also described. The method includes the steps of, first, assembling a plurality of frames, each of the plurality of frames having at least two longitudinal beams and at least two cross beams. The at least two cross beams extend perpendicular to, and interconnect, the at least two longitudinal beams. The at least two longitudinal beams are cambered along the length of the beams. Next, the method includes the step of stacking the plurality of frames on top of another to create a frame stack unit. Then, the neighboring frames of the plurality of frames of the frame stack unit are secured together. Finally, the method includes the step of loading the frame stack unit into the rail car.
A method of designing an apparatus for reinforcing a flat bed rail car is also described. The method includes the step of, first, providing a frame having at least two longitudinal beams and at least two cross beams. The at least two cross beams extend parallel to, and interconnect, the at least two longitudinal beams. The at least two longitudinal beams are cambered along the length of the beams. Next, the method includes the step of determining a minimum and maximum combined weight of a load to be carried by the rail car. Then, a combination of beam size and camber for the at least two longitudinal beams is selected based on the minimum and maximum combined weight.
Now referring to
The frame system 1 includes a first longitudinal beam 8 and a second longitudinal beam 10. The longitudinal beams 8, 10 extend between the first end 2 and second end 4 of the frame system 1. A plurality of cross beams 12, 14, 16, 18, 20 extend between, and interconnect, the longitudinal beams 8, 10. In the illustrated example embodiment the frame system 1 includes five cross beams 12, 14, 16, 18, 20 that are evenly spaced along the longitudinal beams 8, 10 between the first end 2 and the second end 4. However, the frame system 1 may be provided with fewer or more cross beams to customize the frame system 1 for a particular application.
As can be seen in
As can be seen in
The frame system 1 further includes a plurality of corner castings 28, 30, 32, 34, 36, 38. The corner castings 28, 30, 32, 34, 36, 38 are of the type known in the ISO-container shipping industry. The first end 2 of the frame system 1 is provided with two first end upper corner castings 28 and two first end lower corner castings 30. The first end upper corner castings 28 and lower corner castings 30 are respectively provided on the upper and lower surface 5, 6 of the frame system 1, and are positioned adjacent the first cross beam 12 on the first and second longitudinal beams 8, 10. The second end 4 of the frame system 1 is provided with two second end upper corner castings 36 and two second end lower corner castings 38. The second end upper corner castings 36 and lower corner castings 38 are respectively provided on the upper and lower surface 5, 6 of the frame system 1, and are positioned adjacent the fifth cross beam 20 on the first and second longitudinal beams 8, 10. The upper corner castings 28, 36 and the lower corner castings 30, 38 are respectively specific to the upper and lower surfaces 5, 6 of the frame 1. That is, the upper corner castings 28, 36 and the lower corner castings 30, 38 are not identical components and cannot be interchanged with one another. Four central corner castings 32, 34 are provided on the upper surface 5 of the frame system 1. The central corner castings 32, 34 are positioned adjacent the third cross beam 16 on the first and second longitudinal beams 8, 10, and are the same type of casting as the type used for the upper corner castings 28, 36. In the illustrated embodiment the upper surface 5 of the frame system 1 is provided with four auxiliary corner castings 42, 44. Two of the auxiliary corner castings 42 are provided adjacent the second cross beam 14, and two of the auxiliary corner castings 44 are provided adjacent the fourth cross beam 18. The frame system 1 may be provided with fewer or more corner castings to customize the frame system 1 for a particular application.
The corner castings 28, 30, 32, 34, 36, 38 adjacent the first, third, and fifth cross beam 12, 16, 20 are provided with a brace assembly 33, 35, 37, 39. Each brace assembly 33, 35, 37, 39 extends substantially between, and perpendicular to, the upper and lower surfaces 5, 6 of the frame system 1. In the case of the corner castings 28, 30, 36, 38 located at the first and second ends 2, 4 of the frame system, the brace assembly 33, 39 interconnects the upper corner castings 28, 36 with the lower corner castings 30, 38. The other brace assemblies 35, 37 interconnect the respective corner casting 32, 34 with the second surface 6 of the frame system 1.
As can be clearly seen in
With attention directed to
Deployment of the frame system 1 begins with the frame system 1 sitting on a substantially flat surface outside of, but near, the rail car 102. Next, the first 20-foot long ISO container 104 is placed on the frame system 1 such that the first end upper corner castings 28 and two of the central corner castings 32 engage with corner castings provided on the bottom of the first ISO container 104. This placement locates the first ISO container 104 on the frame system 1 such that the first ISO container 104 spans substantially between the first cross beam 12 and the third cross beam 16. Standard interbox connector devices of the type known in the ISO-container shipping industry are installed in the first end upper corner castings 28 and two of the central corner castings 32, and are used to join the corner castings 28, 32 of the frame system 1 to the corner castings on the bottom of the first ISO container 104. An exemplary interbox connector device 98 is shown in
When the frame system 1 is deployed as described above, a substantial proportion of the total load (i.e. the combined weigh of the two ISO-containers 104, 106 and cargo) carried by the frame system 1 is transferred to the first and second ends 2, 4 of the frame system 1. Thus, the frame system 1 removes a substantial percentage of the total load carried by a central portion of the rail car 102 and transfers that percentage toward the ends of the rail car 102 where the rail car trucks are located. Accordingly, the central portion of the rail car 12 is not overly stressed, thereby avoiding structural failure of the rail car 102. The difference between an unburdened and burdened frame system 1 is clearly illustrated in
The ISO containers 104, 106 and frame system 1 must be unloaded once the rail car 102 reaches a desired destination. The unloading process is substantially the reverse of the above described deployment process. First, the second ISO container 106 is lifted from the frame system 1 and removed from the rail car 102. Next, if interbox connector devices were used as indicators on the first ISO container 104, the interbox connector devices affixed to the corner castings on the top of the first ISO container 104 are removed. Then, a wheeled top loader, crane, or other lifting mechanism couples to the top of the first ISO container 104 and lifts the first ISO container 104, with the frame system 1 attached, out of the intermodal rail car 102. Next, the interbox connector devices used to attach the first ISO container 104 to the frame system are unlocked. Finally, the first ISO container 104 is removed from the frame system 1.
In order to maximize cargo transportation efficiency, it may by sometimes necessary to transport a plurality of frame systems 1 between different shipping yards. The plurality of frame systems 1 may be shipped in a frame system stack unit 300, shown in
As can be clearly seen in
Design criteria for the frame system 1 will now be described. As indicated above, the frame system 1 may utilize longitudinal beams 8, 10 of various design specifications (e.g. beam size and beam camber). Different combinations of longitudinal beam 8, 10 design specifications will result in different downward deflection of the longitudinal beams 8, 10, and, thus, result in a frame system 1 that will transfer different percentages of the total load toward the first and second ends 2, 4 of the frame system 1.
The maximum and the minimum combined weight of the load carried by the frame system 1 must be taken into consideration when designing the frame system 1. With the maximum and minimum combined weight in mind, the selection of the longitudinal beam 8, 10 size and camber must satisfy two key operating principles of the frame system 1. First, the degree of load transfer sought from the frame system 1 toward the first and second ends 2, 4 should be such that the central portion of the rail car 102 does not carry more than an allowable load rating when the frame system 1 is burdened with the maximum combined weight. Allowing more than the allowable load rating to be transferred to the central portion of the rail car 102 could further contribute to the failure of the rail car 102 structure. Second, the frame system 1 should be in continuous contact with the rail car along the length of the longitudinal beams 8, 10 when the frame system 1 is burdened with the minimum combined weight. A frame system 1 that does not adhere to this second operating principle may create a situation in which a gap exists between the lower surface 6 of the frame system 1 and the rail car 102. The rail car 102 may encounter relatively bumpy conditions during transportation. The bumpy conditions may result in the longitudinal beams 8, 10 flexing through the space in the gap and coming into repeated violent contact with the rail car 102, thereby possibly severely damaging the rail car 102.
The above described frame system 1 restores the transportation efficiency of structurally compromised rail cars by allowing the structurally compromised rail cars to carry two fully loaded 20-foot long ISO containers. The foregoing detailed description and examples have been given for clarity of understanding only. No necessary limitations are to be understood therefrom. The cambered frame system is not limited to the exact details shown and described. Variations obvious to one skilled in the art are included within the cambered frame system defined by the claims. For example, it is obvious that numerous omissions can be made without departing from the spirit of the several claims.
The present application claims priority to U.S. Provisional Patent Application Ser. No. 61/825,268 filed May 20, 2013 entitled “Cambered Frame System for Intermodal Rail Cars”, the entire contents of which are incorporated herein by reference in its entirety for all purposes.
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