MODIFYING RAIL CARS FOR PROPPANT TRANSPORTATION

Abstract

Systems and methods are provided herein for modifying a railcar to transport containerized proppant. Various examples are provided, including: stripping a rotary gondola railcar, stripping a gondola hopper railcar, installing or modifying a floor on a stripped railcar, installing container braces on a floor of a railcar, installing braces between the side walls of the railcar, installing struts between the side walls of the railcar using the beam of the container as a strut, creating a mold for foam reinforcement of a railcar, installing foam reinforcement in a railcar, and transporting a container of proppant using a modified railcar. Although these examples are described in relation to a coal railcar, they can be modified to use other types of railcars as well. These examples can also be combined together to form a method for modifying a railcar.

Claims

1. A method for converting a coal-carrying railcar into a proppant-container-carrying railcar, comprising: removing at least one structural member of the railcar; and installing a structure for supporting at least one proppant container.

2. The method of claim 1, wherein removing at least one structural member comprises removing structural members of the railcar associated with using a rotary-car dumper.

3. The method of claim 1, wherein removing at least one structural member comprises removing structural members of the railcar associated with discharging coal from the railcar via a hopper.

4. The method of claim 1, wherein installing a structure for supporting the at least one proppant container comprises installing a floor in the railcar.

8. The method of claim 1, wherein installing a structure for supporting the at least one proppant container comprises installing a foam block shaped to receive at least a portion of a proppant container.

6. The method of claim 1, wherein installing a structure for supporting the at least one proppant container comprises installing at least one capturing mechanism configured to engage at least one portion of the at least one proppant container.

7. The method of claim 4, wherein installing a floor in the railcar comprises installing a steel plate in the railcar.

8. The method of claim 4, wherein installing a floor in the railcar comprises installing a structural framework for supporting the at least one proppant container.

9. The method of claim 4, wherein installing a floor in the railcar comprises installing structural supports to the floor, the structural supports oriented such that they secure the at least one proppant container in place.

10. A method for forming a foam block shaped to receive at least a portion of a proppant container, comprising: removing at least one structural member of a railcar having four sidewalls; removing at least a portion of each of the four sidewalls; installing a floor in the railcar; pouring an expandable composition into the railcar; and placing a lid on the railcar, such that the expandable composition expands up to the lid in at least one location.

11. The method of claim 10, wherein the lid includes at least one protrusion shaped to form a cavity in the expanded foam for receiving a proppant container.

12. The method of claim 10, wherein the lid includes at least one indentation shaped to form a protrusion from the expanded foam for securing the proppant container in place.

13. The method of claim 10, further comprising embedding a support member in the expandable composition.

14. The method of claim 13, wherein the embedded support member is fastened to a component of the railcar.

15. A method for installing a foam block in a modified railcar, comprising: forming a foam block using a mold; installing a plurality of anchors in the foam block; lifting the foam block from a mold, using the anchors; and placing the foam block into a modified railcar.

16. The method of claim 15, wherein the modified railcar is a railcar with at least one structural member removed.

17. The method of claim 15, wherein the modified railcar is a railcar with structural members forming four compartments, each compartment shaped to receive a single proppant container.

18. The method of claim 15, wherein the modified railcar is a railcar with at least one angular sidewall removed.

19. The method of claim 15, wherein the step of forming a foam block using a mold comprises using a mold formed by: removing at least one structural member of a railcar having four sidewalls; removing at least a portion of each of the four sidewalls; and installing a floor in the railcar.

20. The method of claim 19, further comprising installing a cap on the top of the railcar.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0011] FIG. 1 provides several views of an example container-bracing system for use in conjunction with a rail car modified to transport proppant.

[0012] FIG. 2A is an illustration of an example modified rail car.

[0013] FIG. 2B is an illustration of an example modified rail car for forming a foam mold.

[0014] FIG. 2C is an illustration of an example modified rail car with a completed foam mold.

[0015] FIG. 2D is an illustration of an example modified rail car with an installed foam mold that holds several proppant containers.

[0016] FIG. 3 is a top-down illustration of an example modified rail car having lateral support braces and carrying four proppant containers.

[0017] FIG. 4 is an illustration of a proppant container having flanges that interface with locking mechanisms.

[0018] FIG. 5 is an illustration of a proppant container having a flange that interfaces with locking mechanisms.

[0019] FIG. 6 is an illustration of a modified rail car having structural support installed underneath a foam block.

DESCRIPTION OF THE EXAMPLES

[0020] Reference will now be made in detail to the present examples, including examples illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts.

[0021] Systems and methods are provided herein for modifying a railcar to transport containerized proppant. Various examples are provided, including: (1) stripping a rotary gondola railcar, (2) stripping a gondola hopper railcar, (3) installing or modifying a floor on a stripped railcar, (4) installing container braces on a floor of a railcar, (5) installing braces between the side walls of the railcar, (6) installing struts between the side walls of the railcar using the beam of the container as a strut, (7) creating a mold for foam reinforcement of a railcar, (8) installing foam reinforcement in a railcar, and (9) transporting a container of proppant using a modified railcar. Although these examples are described in relation to a coal railcar, they can be modified to use other types of railcars as well. These examples can also be combined together to form a method for modifying a railcar.

Example 1

Stripping a Rotary Gondola Railcar

[0022] In one example, a gondola railcar is stripped for use in transporting proppant. The railcar can be a complete and intact railcar, or a railcar that is substantially complete and intact. In this example, the railcar includes mechanisms for traveling along a track, such as wheels, axles, bearings, coil springs, brakes, and frame components.

[0023] The area of the gondola railcar designed for carrying a material, such as coal, can include a variety of structural members. For example, the interior walls of the railcar can include struts that extend from one interior wall to another, from an interior wall to the floor, from an interior wall to another structural member, or some combination thereof. In this example, at least some of the struts connected to the interior wall are removedfor example, by using a plasma cutter or another suitable cutting tool.

[0024] For rotary gondola railcars, any components related to the rotary unloading mechanism can be removed as well. This includes, for example, structural members or engagement points where the car contacts the rotary unloading mechanism. This can also include structural members provided for the purpose of maintaining structural rigidity while the railcar is being rotated into an unloading position. Any suitable method can be used for removing the structural members or engagement points, such as by removing fasteners, plasma cutting, and so on.

Example 2

Stripping a Gondola Hopper Railcar

[0025] In another example, a hopper railcar is stripped for use in transporting proppant. The railcar can be a complete and intact railcar, or a railcar that is substantially complete and intact. In this example, the railcar includes mechanisms for traveling along a track, such as wheels, axles, bearings, coil springs, brakes, and frame components.

[0026] The area of the hopper railcar designed for carrying materials, such as coal, can include a variety of structural members. For example, the interior walls of the railcar can include struts that extend from one interior wall to another, from an interior wall to the floor, from an interior wall to another structural member, or some combination thereof. In this example, at least some of the struts connected to the interior wall are removedfor example, by using a plasma cutter or another suitable cutting tool.

[0027] The hopper mechanisms can be removed from the railcar, either partially or fully. For example, the valves, doors, or other mechanisms for opening the hopper and allowing material to exit the hopper can be removed. These components can be removed by, for example, removing fasteners, plasma cutting, and so on. The railcar can be stripped down to the point where the railcar would not hold materialfor example, because the floor is partially missing as a new floor can be constructed at a later stage. For gondola hopper railcars that include doors or gates other unloading mechanisms, these mechanisms can be removed as well.

Example 3

Installing a Floor on a Stripped Railcar

[0028] In some examples, after a railcar has been stripped, a floor can be installed in the railcar, or the existing floor can be modified. This example can include, for instance, installing lateral support braces that extend from one side of the car to the other that can support the floor and the weight that will be placed on it. A solid floor can be installed on top of those supports, or on top of existing supports, such that the floor is solidly supported. The floor, and any associated supports, can be secured via fasteners, welding, interference fitting, or compression fitting.

[0029] The floor can be made from a metal, such as one or more steel plates bolted or welded to the frame of the car or to other support structures. In some cases, the floor can be made from other materials, such as epoxy, urethane, or any material that can support the weight of proppant containers.

Example 4

Container Braces on the Floor of a Railcar

[0030] Once the floor of the railcar has been stripped, reinforced, and/or otherwise modified, container braces can be installed on the floor. FIG. 1 shows an example embodiment of a container bracing system. In this example, the container 110 is a cylinder with a top and bottom plate. Each of the top and bottom plates include a plurality of structural flanges 112 that can welded to the plate. In this example of FIG. 1, the top and bottom plates include eight flanges 112. However, more or fewer flanges can be used. In some examples, the container 110 can include an input port 114 that, when actuated, allows granular material to flow in or out of the container 110 based on the orientation of the container 110.

[0031] The bracing system can include a floor brace 120, an A-frame 130, and one or more stabilizer struts 140. In some examples, the bracing system is made entirely from steel or a similarly strong metal. Other materials can be used if they exhibit high strength and durability, and low susceptibility to fatigue. The floor brace 120, for example, can be a flat steel plate that is bolted or welded to the floor of the railcar. The A-frame 130 support members can be mounted to either end or sides of the floor brace 120 and attached to the ends or sides of the railcar. For example, the A-frame support members can be mounted via a pivoting or rotating hinge attached to the floor brace 120, such that the A-frame member 130 can be adjusted to various positions.

[0032] For example, when a container 110 is not present, the A-frame members 130 can be rotated such that they lay flat on top of the floor brace 120. To accomplish this, at least one of the A-frame members 130 can include a swing joint 150 that allows the member 130 to pivotably rotate at the location of the swing joint 150. As a result, the A-frame members 130 can be folded toward each other and laid on top of the floor brace 120. This design allows for a container 110 to be placed and the A-frame members 130 to be swung upward from their resting positions to attach to the container 110 at location 135.

[0033] A brace plate 140 can be fixed to one A-frame member 130 and removably attached to a corresponding A-frame member 130 when the A-frame 130 is in position and coupled to the flange 112 at location 135. The brace plate 140 can be attached to the A-frame member 130 using any suitable fastening method. In some examples, the A-frame members 130 can be coupled to a flange 112 of the container 110 by a fastener that extends through an aperture in the flange at location 135, or by a fastener fixedly attached to the flange at the same location.

[0034] To prevent the bottom of the container 110 from shifting, the base plates 120 can include mechanisms for coupling to one or more flanges 112 of the container 110. For example, a base lock 125 can be provided for coupling the base plate 120 to a central flange 112, as shown in FIG. 1. The base lock 125 can include guide portions that spread apart, in a V shape, to guide the flange 112 into the base lock 125. The flange 112 can then be coupled to the base lock 125 using any suitable fastening method. With the central flange 112 in place, additional flanges 112 can optionally be fastened to the base plate 120. For example, flanges 112 can be coupled to the base plate 120 at apertures 122, 128, using any suitable fastening method.

Example 5

Installing Struts between the Side Walls of the Railcar

[0035] In one example, struts are installed spanning the side walls of the railcar in an orientation that provides adequate room for a plurality of sealed proppant containers. The standard last leg of frac sand transportation to the well is by truck. The sand is sealed in containers or tanks that typically contain about 45,000 to 50,000 pounds of proppant each. To integrate rail transportation in the sand delivery system it is most economical to transport three or four proppant containers in equally divided spaces in the railcar.

[0036] FIG. 3 shows an example rail car 330, from a top-down view, where three struts 330 are positioned between the side walls 310 after the railcar has been stripped. Those three struts 330 divide the railcar into four equal spaces sized, each sized to accept a proppant container 320. The struts 330 can be removably fastened to the side walls 310, or they can be welded to the walls 310. The struts 330 can include fastening modules 340 designed to couple to a flange of a container 320. For example, the fastening modules 340 can include hardware similar to the base lock 125 of FIG. 1. The modules 340 can fasten to the flanges in any way, however, such as by using a pin lock that fastens by extending a pin through an aperture of the flange. The fastening modules 340 can also be mounted direct to the side walls 310 such that they can fasten additional sides of the containers 320, as shown in FIG. 3.

Example 6

Installing Struts between the Side Walls of the Railcar using a Structural Member of the Proppant Container

[0037] FIG. 4 shows an example proppant container 410 having several flanges 430, 440, with the lateral flange 440 being extended on either end such that it interfaces with another surface or member. For example, the lateral flange 440 can extend to a side wall 420 of the railcar at one or both ends of the lateral flange 440. The lateral flange 440 in this example, locks into a capturing mechanism 450 on the side wall. Releasing the capturing mechanism 450 allows for insertion and removal of the container 410 from the railcar. When the container 410 is locked in place, the lateral flange 440 can serve as a transverse strut. The capturing mechanisms 450 can be any mechanism for locking a flange 440 in place, such as a pin lock, cam lock, or any other type of fastening device.

[0038] FIG. 5 shows a view of the container with its lateral flange 440 interfacing with two capturing mechanism 450 on the side wall of the railcar and functioning as a transverse strut. As shown, the location of the lateral flange 440, when fastened to corresponding capturing mechanisms 450, provides a lateral brace between opposing side walls 420 of a rail car 610. The rail car 610 includes additional capturing mechanisms 450 to fit two more containers 410 in this example. In other examples, capturing mechanisms 450 can be deployed to accommodate any number of containers 410. These mechanisms 450 can be used in conjunction with any of the other mechanisms and methods described herein.

Example 7

Creating a Mold and Foam Reinforcement of a Railcar

[0039] In one example, a high-density foam can be used to reinforce a railcar and prepare it for safely transporting multiple proppant containers. Any type of high-density foam can be used for this purpose. However, an ideal foam will have high strength and resilience values. An example of a suitable foam product is 16 LB Density Urethane Foam provided by U.S. Composites, Inc. The 16 LB Density Urethane Foam has a parallel compressive strength of about 580 psi, tensile strength of about 450 psi, shear strength of about 230 psi, and flexural strength of about 750 psi. The 16 LB Density Urethane Foam is merely one type of material suitable for this purpose. Any other foam, resin, epoxy, polyester, or fiberglass material having suitable strength made be used instead of, or in addition to, the urethane foam. In some examples, the selected material should have a parallel compressive strength of at least about 400 psi, tensile strength of at least about 300 psi, sheer strength of at least about 100 psi, and flexural strength of at least about 500 psi.

[0040] FIGS. 2A-2D depict varying stages of a method for creating foam reinforcement for a rail car 200. In FIG. 2A, a rail car 200 is shown with the rolling gear 230 still intact, although the mold can also be created using a rail car 200 without such rolling gear 230. In this example, the rail car 200 has been stripped in the manner described above, removing all unnecessary parts, including structural supports. As shown in FIG. 2A, the side walls 220 of the rail car 200 have been cut at locations marked as 222for example, the walls can be cut down to within 1 or 2 feet of the floor.

[0041] For the mold railcar, a wood floor 240 can be installed to act as a base for the foam mold. In one example, 2-foot by 8-foot wood beams are installed as flooring of the railcar. The wood flooring 240 can be covered with a sheet of plastic or similar impermeable material that can prevent uncured urethane foam from seeping through the wood beams. Other types of material, such as metal or composite, can be used for the floor 240 as well. However, wood is likely the cheapest and easiest option.

[0042] In the next stage of the method, shown in FIG. 2B, a cap 250, or lid 250, can be constructed out of a lightweight material to be installed a distance above the wood floor 240 and limit the expansion of the urethane foam 260 as it cures. For example, the lid 250 can be made from fiberglass, epoxy, carbon fiber, or metal. In examples where the sides 220 of the railcar have been cut down, the lid 250 can be shaped to wrap around the top edges of the cut sides, as shown.

[0043] The shape of the lid 250 can dictate the final shape of the expanded foam 260. In examples where the proppant containers are designed to nest, at least partially, within the expanded foam block 260, the lid 250 can be shaped to form nesting cavities for the proppant containers to fit within. For example, a cavity can be shaped to match the contours of the bottom plate of the proppant container, including the associated flanges, shown as part of the container in FIG. 1. The lid 250 can therefore include a shape that includes multiple nesting cavities for a plurality of proppant containers. In one example, cavities are molded for each of four individual proppant containers.

[0044] To create the mold, the urethane mixture can be poured onto the plastic-covered flooring. Then, the lid 250 can be installed on top of the cut-down sides 220 of the railcar 200 and secured in place. The lid 250 can be secured by one or more latching mechanisms, or by placing a load on top of the lid 250. The securing mechanism can be designed to withstand the force of the expanding urethane foam 260, such that the lid 250 causes the foam 260 to form around the shape of the lid 250 and form nesting cavities for the proppant containers.

[0045] After the foam 260 has cured, the lid 250 can be removed as shown in FIG. 2C. To remove the foam block 260 itself, anchors 262 can be installed in the foam 260 by drilling and mounting. In some examples, four anchors 262 are installed with one near each corner of the foam block 260. A crane or other lifting mechanism can be used to lift the foam block 260 from the molding railcar 200 and install it in a stripped railcar or store it at a storage location. The lifting can be done by attaching cables 264 to the available anchor 262 and lifting via the cables 264.

Example 8

Installing Foam Reinforcement in a Railcar

[0046] FIG. 2D shows the foam block 260 installed in a different stripped rail car 202. In this example, the rail car 202 has side walls 220 that extent upward beyond the height of the foam block 260. However, the foam block 260 can also be installed in a rail car 202 with side walls 220 that have been cut lower, such as the rail car 200 of FIGS. 2A-2C. The rail car 202 of FIG. 2D also includes a subfloor 240 installed above the floor 210 of the rail car. The subfloor 240 can provide a flat surface such that the force of the foam block 260 is evenly distributed.

[0047] After the foam block 260 has been placed in the rail car 202, one or more containers 270 can be lowered into the corresponding locations of the block 260. Depending on the depth of the receiving locations of the foam block 260, additional restraints for the containers 270 may not be necessary. However, in some examples, further support can be provided by using cables or tie-downs of some sort. For example, FIG. 2D shows several cables 280 that each attach to a container 270 at one end. In this example, some of those cables 280 are attached to anchors 282 placed in the foam block 260. Some of the cables 280, on the other hand, are attached to a sidewall 220 of the rail car 202. In other examples, at least some of the cables 280 can connect between adjacent containers 270.

[0048] FIG. 6 shows an illustration of an example rail car 600 having internal reinforcements for strengthening the side walls 610. These reinforcements can be used to strengthen a side wall 610 such that a foam block 630 can be used with full-sized side walls 610. In the example of FIG. 6, a foam block 630 is provided that fits around a structural member 620 that is coupled to the side walls 610. As the figure shows a cross sectional view of a rail car 600, the structural member 620 can be placed along the floor of the rail car 600 and can include vertical portions that extend upward, along at least a portion of the side walls 610. The structural member 620 can be fastened to the side walls 610 using fastening devices 640.

[0049] In some examples, the structural member 620 is installed before the foam block 630 is placed within the rail car 610. In those examples, the foam block 630 can be molded to accommodate the structural member 620 and any associated fastening members 640, such as by being molded around a similar structural support. In some examples, the foam block 630 can be molded such that it includes holes for installing or uninstalling fasteners 640. In some examples, the foam block 630 itself can be fastened to the side wall 610, such as by being molded to include apertures and then placing fasteners through those apertures and through the side walls 610.

Example 9

Transporting a Container of Proppant using a Modified Railcar

[0050] Once a foam block has been installed in a modified railcar, the railcar can be used for transporting proppant containers. In some examples, a single railcar can carry up to four containers. As explained above, the foam block can include nesting cavities for receiving and holding the proppant containers. A lifting mechanism, such as a crane or other construction equipment, can lift each proppant container and place it in a corresponding nesting cavity. In some examples, the containers are loaded empty and then filled once loaded in the railcar. In other examples, the containers are filled and then loaded. Both methods are contemplated by this disclosure.

[0051] After the containers are loaded and filled, they can be further secured via tie-downs or other support mechanisms. For example, the inner walls of the railcar can be outfitted with various chains having hooks shaped to engage one or more flanges of a proppant container. In that example, after the containers are loaded, the chain and hook can be extended out and secured to proppant container. Similarly, chains with hooks on either end can be extended between containers, such that hooks engage with a flange of a different container at either end. Other types of support mechanisms can be used as well, such as structural members that pivotably extend from the wall of the railcar to a flange or other mounting point on the container.

[0052] After the containers have been secured, they are transported to the unloading area. At the unloading area, any mechanisms securing the proppant containers to the railcar, foam, or each other are removed. The containers can be lifted out of the railcar by a crane or other lifting mechanism that can lift the container straight up before moving it to an unloading area.

[0053] Other examples of the disclosure will be apparent to those skilled in the art from consideration of the specification and practice of the examples disclosed herein. Though some of the described methods have been presented as a series of steps, it should be appreciated that one or more steps can occur simultaneously, in an overlapping fashion, or in a different order. The order of steps presented are only illustrative of the possibilities and those steps can be executed or performed in any suitable fashion. Moreover, the various features of the examples described here are not mutually exclusive. Rather any feature of any example described here can be incorporated into any other suitable example. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the disclosure being indicated by the following claims.