Patent Publication Number: US-9834230-B2

Title: Hopper car discharge structure

Description:
FIELD OF THE INVENTION 
     This invention relates to the field of railroad freight cars and to discharge apparatus for railroad freight cars. 
     BACKGROUND 
     In the North American railroad industry, bottom dumping gondola cars and open top hopper cars are frequently used. In more recent times standards for contamination of lading have risen, such that it may be desirable to take steps to prevent traces of lading from one car load being transported with the car when it is filled with subsequent lading. 
     Quite separately, where the lading may be corrosive, or may tend to attract or retain moisture, it may be desirable to take steps to discourage accumulation of lading on upward facing surfaces adjacent to the discharge section of the car. 
     It may also be desirable to take such steps without giving rise to unintended consequences in terms of the structural integrity, durability, service life or performance of the car over its operating life. 
     SUMMARY OF THE INVENTION 
     In an aspect of the invention, there is a structure for a bottom dumping railroad hopper car. The hopper car may have at least a first hopper, that first hopper having a downwardly opening discharge section, the discharge section having an opening through which to discharge lading, the opening having a periphery. The structure has a center sill, the center sill having at least one shear web and at least one flange. The shear web stands upwardly of the flange. The flange has a margin extending laterally outboard of the web. The structure includes a wall member that extends upwardly of the margin of the flange. The wall member is located between the flange and the periphery of the discharge opening. At least the majority of the margin of the flange is located in the lee of the wall member. 
     In a feature of that aspect of the invention, the wall member extends from a height below the periphery of the discharge section opening to a height higher than at least a portion of the periphery of the discharge opening. In another feature, the wall member has an upper margin, and the upper margin of the wall member lies at a greater height than an uppermost portion of the periphery of the opening. In still another feature, the wall member extends from a height below at least a portion of the periphery of the discharge section opening to a height that is above all of the periphery of the discharge opening. In a further feature, substantially all of the flange adjacent to the hopper discharge section is sheltered behind the wall member. In a still further feature, the flange has an outermost distal tip most laterally outboard of the web, and the wall member extends outboard of the distal tip. In yet another feature, the wall member is secured in place other than by weldment to the center sill. In an additional feature, the wall member is secured in place without attachment to the center sill. In still another feature, the wall member is secured to the discharge section of the hopper. In again another feature, the wall member has a curved upper margin that seats about a service delivery conduit. In a yet further feature, at least a portion of the wall member is maintained in position by a retainer that extends at least partially underneath the center sill. 
     In another aspect of the invention there is a railroad hopper car. It has at least a first hopper. That first hopper has a downwardly opening discharge section. The discharge section has an opening through which to discharge lading. The opening has a periphery. The car has a center sill. The center sill has at least one shear web and at least one flange. The shear web stands upwardly of the flange. The flange has a margin extending laterally outboard of the web. The car has a wall member that extends upwardly of the margin of the flange. The wall member is located between the flange and the periphery of the discharge opening. At least a majority of the margin of the flange being located in the lee of the wall member. 
     In a feature of that aspect, the wall member extends from a height below the periphery of the discharge section opening to a height higher than at least a portion of the periphery of the discharge opening. In another feature, the wall member has an upper margin, and the upper margin of the wall member lies at a greater height than an uppermost portion of the periphery of the opening. In still another feature, the wall member extends from a height below at least a portion of the periphery of the discharge section opening to a height that is above all of the periphery of the discharge opening. In yet another feature, all of the flange adjacent to the hopper discharge section is sheltered behind the wall member. In a further feature, the wall member is secured in place other than by weldment to the center sill. In still a further feature, the car has is one in which at least one of: (a) the wall member is secured in place without attachment to the center sill; (b) the wall member is secured to the discharge section of the hopper; and (c) the wall member has a curved upper margin that seats about a service delivery conduit. In another feature, at least a portion of the wall member is maintained in position by a retainer that extends at least partially underneath the center sill. 
     In still another feature, the wall member has the form of a plate having an angle formed therein such that the wall member has a first portion and a second portion. The first portion defines a first flange of the wall member for engagement with the flange of the center sill, and the flange of the wall is positioned one of (a) on an upper surface of the flange of the center sill; and (b) to curl around the flange and extend at least partially therebelow. The second portion extends upwardly from the first portion, and the second portion has an upper margin that is one of (a) mounted to a portion of the discharge section at a height above any uppermost portion of the periphery of the discharge opening; (b) secured to the center sill other than by welding; (c) is formed to seat about a services conduit; and (d) is formed into a second flange such that the overall member has a channel form, and said second flange is secured to structure other than the center sill. 
     It may be understood that the various aspects and features may be mixed and matched as may be appropriate. It may also be understood that the foregoing is not intended to be an exhaustive listing of aspects and features of the invention. These and other aspects and features of the invention may be understood with reference to the description which follows, and with the aid of the illustrations of a number of examples. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
       The description is accompanied by a set of illustrative Figures in which: 
         FIG. 1 a    is an isometric view of a railroad hopper car body shown from below, to one corner and to one side, with most hopper sheets and gate mechanisms removed to expose structure; 
         FIG. 1 b    is a side view of the railroad hopper car of  FIG. 1   a;    
         FIG. 1 c    is a cross-sectional view of the hopper car body of  FIG. 1 a    taken on section ‘ 1   c - 1   c ’ of  FIG. 1 b    with a hopper door in the closed position; 
         FIG. 2 a    is an enlarged detail of the side view of  FIG. 1 b    with a hopper door in the closed position; 
         FIG. 2 b    is an enlarged detail of the hopper car body of  FIG. 2 a    with a hopper door in the open position; 
         FIG. 3 a    is an enlarged detail of the sectional view of  FIG. 1   c;    
         FIG. 3 b    is an enlarged detail of the isometric view of  FIG. 1   a;    
         FIG. 4 a    is a side view of a shed plate for the railroad hopper car of  FIG. 1   a;    
         FIG. 4 b    is an end view of the shed plate of  FIG. 4   a;    
         FIG. 5 a    is an alternate, and simplified, end view section to that of  FIG. 3   a;    
         FIG. 5 b    shows an alternate section to that of  FIG. 5   a;    
         FIG. 5 c    shows a further alternate section to that of  FIG. 5   a;    
         FIG. 5 d    shows another alternate section to that of  FIG. 5   a;    
         FIG. 5 e    shows another alternate section to that of  FIG. 5   a;    
         FIG. 5 f    shows another alternate section to that of  FIG. 5   a;    
         FIG. 5 g    shows another alternate section to that of  FIG. 5 a   ; and 
         FIG. 5 h    shows another alternate section to that of  FIG. 5   a.    
     
    
    
     DETAILED DESCRIPTION 
     The description that follows, and the embodiments described therein, are provided by way of illustration of an example, or examples, of particular embodiments of the principles, aspects or features of the present invention. These examples are provided for the purposes of explanation, and not of limitation, of those principles and of the invention. In the description, like parts are marked throughout the specification and the drawings with the same respective reference numerals. The drawings may be taken as being to scale unless noted otherwise. 
     The terminology used in this specification is thought to be consistent with the customary and ordinary meanings of those terms as they would be understood by a person of ordinary skill in the railroad industry in North America. The Applicant expressly excludes all interpretations that are inconsistent with this specification, and, in particular, expressly excludes any interpretation of the claims or the language used in this specification such as may be made in the USPTO, or in any other Patent Office, other than those interpretations for which express support can be demonstrated in this specification or in objective evidence of record, (for example, earlier publications by persons not employed by the USPTO or any other Patent Office), demonstrating how the terms are used and understood by persons of ordinary skill in the art, or by way of expert evidence of a person or persons of at least 10 years&#39; experience in the railroad industry in North America or in other former territories of the British Empire and Commonwealth. 
     In terms of general orientation and directional nomenclature, for railroad cars described herein the longitudinal or lengthwise direction is defined as being coincident with the rolling direction of the railroad car, or railroad car unit, when located on tangent (that is, straight) track. In the case of a railroad car having a center sill, be it a stub sill or a straight-through center sill, the longitudinal direction is parallel to the center sill, and parallel to the top chords and side sills, as may be. Unless otherwise noted, vertical, or upward and downward, are terms that use top of rail, TOR, as a datum. In the context of the car as a whole, the terms cross-wise, lateral, or laterally outboard, or transverse, or transversely outboard refer to a distance or orientation relative to the longitudinal centerline of the railroad car, or car unit, or of the centerline of a centerplate at a truck center. The term “longitudinally inboard”, or “longitudinally outboard” is a distance taken relative to a mid-span lateral section of the car, or car unit. The commonly used engineering terms “proud”, “flush” and “shy” may be used herein to denote items that, respectively, protrude beyond an adjacent element, are level with an adjacent element, or do not extend as far as an adjacent element, the terms corresponding conceptually to the conditions of “greater than”, “equal to” and “less than”. The directions correspond generally to a Cartesian frame of reference in which the x-direction is longitudinal or lengthwise, the y-direction is lateral or cross-wise, and the z-direction is vertical. Pitching motion is angular motion of a railcar unit about a horizontal axis perpendicular to the longitudinal direction. Yawing is angular motion about a vertical axis. Roll is angular motion about the longitudinal axis. Given that the railroad car described herein may tend to have both longitudinal and transverse axes of symmetry, a description of one half of the car may generally also be intended to describe the other half as well, allowing for differences between right hand and left hand parts. In this description, if used, the abbreviation ksi stands for thousands of pounds per square inch. Also, it may be taken as a default that the structure of the car is of all-welded mild steel fabrication except as otherwise shown in the illustrations or indicated in the text. This need not necessarily be the case. Other materials, such as aluminum or stainless steel might be used. 
     In this discussion it may by understood that persons of ordinary skill in the art are familiar with the Rules and Standards of the Association of American Railroads (the AAR), which govern interchange service in North America. This specification or the accompanying illustrations may refer to standards of the AAR, such as to AAR plate sizes. To the extent necessary or appropriate, those references are to be interpreted in a manner consistent with the Rules and Standards as extant on the earliest of the date of filing of this application or the date of priority of the earliest application from which this application claims priority, as if they formed part of this specification on that date. 
     By way of a general overview, as shown and described herein, open top hopper cars may have box type center sill construction, the box being formed of two spaced apart vertical webs that join upper and lower flanges. The edges of the flanges may extend outboard beyond the vertical shear webs to form a shelf or ledge. In one embodiment, the bottom flange shelf or ledge may extend about 4″ past the shear webs. For pneumatic operation of the doors, pipes may run along the outside faces of the center sill webs on both sides of the car. Various pipe arrangements are possible on either side of the car. Near the hopper door areas, the ledge or shelf of the protruding flange may provide an upwardly facing surface upon which product may hang up when the car is unloaded. This event creates a potential contamination problem with the next loading. 
     As shown and described herein, an inclined plate, which may be termed a “shed plate”, may be positioned to hang from pipes running along the center sill web, with the object of sheltering the ledge or shelf and discouraging, or eliminating hang up of product. In one embodiment, the plate may have a bent short face that lies on top of the bottom flange. The shed plate fastening arrangement may vary depending on the number of pipes that are mounted to the center sill behind each plate. Where spacing between the pipes allows, the shed plate may be positioned behind the uppermost pipe. Otherwise, the plate may be attached to the front of the pipe i.e., laterally outboard of the pipe. By adding an inclined shed plate, lading material may tend not to have the opportunity to hang up on the bottom flange. This may aid in preventing product contamination, and may also tend to reduce the amount of time used in cleaning off the material, and the car, after each unloading. By hanging an inclined plate from pipes running along the center sill web, the commodity is guided and material hang up on the bottom flange may be reduced or eliminated when unloading the car and the potential contamination problem with the next loading may be avoided. The shed plate may be a robust and permanent application tending to improve overall car performance for the user. 
     Material hang up may sometimes otherwise tend to be ignored. Alternatively, it may be removed from the ledge by an operator using a water hose, or possibly an air hose. It may generally not be desirable to ignore the possibility of product contamination, and it may not be desirable to use water—either because the commodity itself needs to be kept dry, or because the presence of water may tend to cause other problems such as may occur due to freezing or due to corrosion. Air may also be problematic where it is undesirable to raise dust, or to spread the hung up material indiscriminately; or, where the lading is dense particulate material, air may not be satisfactorily effective, or may entrain particles undesirably. 
     Commencing with  FIG. 1 a   , a railroad freight car body is shown generally as  20 . In the embodiment shown the railroad car body is the body of an open topped hopper car. Generally there is an upstanding wall structure indicated as  22 , and an underframe structure  24 . The upstanding wall structure includes lengthwise or longitudinally running first and second side walls  26 ,  28 , which may have left and right hand side sills  30 ,  32  and top chords  34 ,  36 , and side sheets  38 ,  40  extending as shear panels therebetween, with upstanding side wall stiffeners spaced along the side sheets to run between the side sills and top chords. Each set of a side sill, shear web side sheet and top chord may function as a deep beam. Car body  20  may include respective near and far end sections  42 ,  44  which may include end walls  46  supported by laterally extending end stub walls  48 . As may be understood, the side walls  26 ,  28  and end walls  46  may co-operate to define a lading carrying or lading holding receptacle, or vessel, or container, nominally designated as  50 , in which lading may be transported. That holding receptacle may be open at the top, and bounded peripherally by the respective top chords of side walls  26 ,  28  and end walls  46  that, together, define the opening  52  to the car through which lading may be introduced. Lading may exit car body  20  through bottom outlets, or discharge openings,  100 . 
     Underframe structure  24  may include a straight-through center sill  60  having near and far end draft sills  62  and truck centers  64 . Center sill  60  may run the full length of the car from end to end. Main bolsters  66  extend laterally from center sill  60  at the locations of the truck centers underlying stub wall  48 . Main bolster  66  may be stub bolsters, with the bending moment carried from (or to) side sills  30 ,  32  by the laterally extending top flange  68  of bolster  66 . 
     Car body  20  may also include at least one hopper. In the illustration shown, hopper car  20  may have three hoppers  70 ,  72 ,  74  that share the volume of container  50 . Each hopper is bounded laterally by side walls  26 ,  28 , and longitudinally by respective first and second (or fore-and-aft) slope sheets. These slope sheets may also be designated as end slope sheets  76  that run upwardly and longitudinally outwardly to meet the angled-in upper ends of stub walls  48  and end walls  46  of end section  42 ; and intermediate or internal, or interior slope sheets  78  that angle upward and longitudinally inboard to toward the next adjacent hopper. As is typically the case, the hoppers may have a downwardly convergent V-shape or inverted pyramid shape. In a car of this nature, the laterally extending slope sheets function not only as a funnel that supports and then directs lading to the outlet, but also as shear webs extending across the car between the side sheets of the side walls, giving the car body stability between the side walls, acting as shear transfer members when the car is being conducted around a curve, for example. 
     In this description, hoppers  70 ,  72 ,  74  are downwardly opening, or bottom opening hoppers, which is to say that they are unloaded by permitting egress of the lading downwardly out of container  50  under the influence of gravity. In that sense the cars are “flow through” hopper cars. To that end, each hopper, be it  70 ,  72 , or  74  has a discharge section  80 , which is located at the bottom of the V-shape. The discharge section may include slope sheet lower margins or extensions  82 ,  84 , such as may extend from the intermediate or end slope sheets, respectively, as may be; and inboard and outboard side sheet extensions  86 ,  88 , all of which may co-operate to form a four-sided convergent throat of discharge section  80 . Discharge section  80  further includes a gate or door  90 . Egress of lading through the throat is governed by door  90 . Door  90  is movable between a first position and a second position. In the first position, which may be a closed position, door  90  obstructs, or prevents discharge of lading from its respective hopper. In the second position door  90  is deflected to a less obstructive position permitting the discharge of lading through the opening. 
     Each hopper may have a door, or a pair of mutually acting doors that co-operate to close the bottom opening. In the embodiment shown, each hopper  70 ,  72 ,  74  may have a single acting door, those doors being indicated respectively as  92 ,  94 , and  96 . Each may be hinged at its upper extremity as at hinge fitting, or fittings  98 . The door transmission linkages are not shown. 
     The co-operating lower margins of slope sheet extensions  82 ,  84 ,  86 ,  88  define a rim, or lip, or mouth, or periphery of the discharge opening  100  against which, or with which, door panel  102  mates in the closed position so as to prevent discharge. It may be noted from  FIGS. 1 a  and 1 b    that opening  100  is not necessarily level and horizontal, but may be angled to the horizontal as indicated. That is, the top edge of opening  100  (at the hinge), and the bottom edge of opening  100  may be horizontal, and may run perpendicular to the centerline of car  20  more generally. The side edges of opening  100  may run in a plane parallel to the centerline of the car, but may be oriented on a descending angle from hinge  98  to the distal lip  104  at the lowest part of opening  100 . 
       FIGS. 1 c , 3 a  and 5 a -5 h   , show a cross-section of an intermediate portion  110  of center sill  60  at a mid-car location between the trucks. In a full, straight-through center sill car, the center sill  60  may typically have a top flange or top cover plate  112 ; a bottom flange or bottom cover plate  114 , and at least one, typically two, vertically extending spaced apart left and right hand shear webs  116 ,  118 . In general, shear webs  116 ,  118  are spaced symmetrically to either side of the longitudinal centerline plane of car body  20 . The flanges and webs may typically co-operate to define a closed box section. In some locations bottom flange  114  may be a solid monolith extending fully across the space between webs  116 ,  118  to form a closed section, as at  106 , and at other locations the bottom flange may be bifurcated, i.e., split, where the flange legs  108  form angles commencing at the bottom margins of webs  116 ,  118 , and extend laterally outwardly therefrom to form left hand and right hand toes, such that the center sill section is not closed, and access is provided to the interior. The solid and bifurcated lower flange regions may have smoothly tapering transitions into each other. The top cover-plate may have laterally outboard extending distal margins  120  that extend laterally proud of webs  116 ,  118 . The bottom cover plate may also have flange extensions or legs, or toes, or projections  122  that extend laterally proud of webs  116 ,  118 . In each case the projecting portion is such that a ledge or shelf  124  is defined between the laterally outermost extremity of the projection, as at  126  and the junction of web  116  or  118  with flange  114 . It may be that in a car of this nature bottom flange  114  may be both thicker and wider than the top flange or top cover plate  112 . 
     In a car of this nature, the straight-through center sill may tend to penetrate the various slope sheets that it encounters, the penetrations tending to be oblique. At some locations the slope sheets pass above the center sill; at other locations the center sill extends up into, and across, the bottom of the lading containing zone. In the regions where the center sill passes below the slope sheets, slope sheet stiffeners, sometimes called “elephant ears”, namely generally triangular or trapezoidal shear webs  130 , extend from a first margin or vertex running longitudinally along, and welded to the top cover plate parallel to the longitudinal centerline, to second and third margins or vertices welded to the underside of the mating intermediate slope sheets  78 . The shear webs may have lightening apertures formed therein, as at  132 . The space below the slope sheets may define a machinery space (or spaces) in which a door actuator, or actuators, and actuator reservoirs may be mounted. Such actuators may be pneumatic actuators connected to drive the door or doors to open and closed positions, as may be. 
     In the alcove formed between the upper flange overhang and the lower flange shelf, it may be that services may be run along the center sill. Those services may include mechanical drive transmission members, such as drive shafts or pneumatic or electrical conduit for carrying pressurized air or electrical cables, as may be. The pneumatic lines for transmitting power to the doors may be indicated as  134 ,  135 ,  136 ,  137 , for example. An electrical conduit, such as to permit an externally connected electrical power source to activate the doors, is indicated as  138 . Alternatively, the train line (i.e., the pipe or conduit connected through all cars to the source of compressed air at the locomotive that provides the supply of compressed air for filling the brake reservoirs and operating the brakes)  140  may run along one or other of the center sill webs. 
     It may not be desirable for stray lading to collect on ledge or shelf  124 . Lading that collects on the shelf may contaminate subsequent discharged lading of another type. Alternatively, collected lading may also tend to encourage retention of moisture, and the consequent increase in tendency for commencement of corrosion. 
     It may be that the uppermost portion of the periphery of opening  100 , e.g., such as along or adjacent to hinge fitting  98 , lies at a height that is higher than shelf  124 . In the unloading of the hopper car, the discharged lading may not necessarily flow immediately away from the discharge, but may form a tapering or slope-sided pile that builds up underneath the car before being conveyed away. As more lading tries to flow out of the hopper, the uppermost portions of that pile may back up, and may tend to flow over, and collect upon, shelf  124 . To prevent this from occurring, hopper car body may have a shield, or shroud, or protector, or deflector, or plate, or wall member, or shed plate, however termed, is indicated as  150  in  FIGS. 3 b    and  5   c.    
     Wall member  150  may have a lower or bottom margin  152  and an upper or top margin  154  spaced upwardly and away from lower margin  152 . As may be noted, lower margin  152  is positioned to shield shelf  124 , or a majority of shelf  124 . In the embodiment shown in Figures la,  2   b , and  3   b , for example, lower margin  152  is positioned against, and outboard of, the outermost outboard margin extremity  126  of shelf  124 . Upper margin  154  is located at a height that is level with, or higher than, the uppermost part of the periphery of opening  100 , and may be located at a height that is as high as, or higher than, the centerline CL 156  of hinge fitting  98 , at hinge pins  156 , and further still, in some embodiments may extend to a height as high as, or higher than, top cover plate  112 . In this location, the nearest adjacent hopper discharge section structure is inboard hopper discharge side sheet extension  86 . At its upper margin, extension  86  may have a flange  148  that is welded or bolted to, and that may act as a local doubler of the laterally projecting portion of top cover plate  112  lying outboard of the shear web  116  or  118 . Flange  148  may be mounted on the underside of cover plate  112 . Similarly, outboard side sheet extension  88  may have a flange mounted to side sill  30  or  32 , as may be. 
     In each of these embodiments, for lading to flow over the top edge of wall member  150  would imply that the lading is flowing uphill. Generally, particulate matter such as grain, plastic pellets, potash, ores, aggregate, and so on, may tend not to flow uphill. It may be said that wall member  150  is located between the outlet opening  100  of discharge section  80 . This may be expressed alternately as shelf  124  (or in other embodiments described below, the predominant portion or majority of shelf  124 ) being located in the lee of wall member  150 ; or in the further alternative it may be said that shelf  124  is protected by, or is in the shadow of, wall member  150  relative to discharge opening  100 . In this example, wall member  150  is longitudinally local. That is, wall member  150  does not run continuously along center sill  60 , but rather runs only locally in the region of the respective hopper discharges, covering the longitudinal extent of the fully opened door opening of the hopper, and, in the embodiments illustrated, has a greater length to overlap the opening both fore and aft in the x-direction. 
     In some embodiments, upper margin  154  may be held in place by being welded to center sill  60 , as, for example, to the outboard edge of cover plate  112 . Similarly, lower margin  152  may be welded to the outboard edge of bottom cover plate  114 , as at extremity  126 . However, it may not be desirable to weld items to center sill  60 . That is, it may not be desirable to weld items to the bottom flange defined by bottom cover plate  114 , as a weldment may be considered to be a defect or irregularity in the structure in terms of stress analysis. The weldment or adjacent heat affected zone may be a fatigue crack initiation site, for example. Upper margin  154  may be secured to flange  148  of side sheet extension  86 , whether by mechanical fasteners or by welding. In this way, installation of wall member  150  need not require additional weldments or stress field singularities (such as fastener through-holes) in the bottom flange of center sill  60 , and may not require additional weldments or stress-field singularities in the top flange of center sill  60 . 
     Additionally, or alternately, lower margins  152  may be secured in place by a laterally extending strap, or ligature, or bar, or link, or spring, or retainer  160  as shown in  FIG. 1 a   . Retainer  160  has a first end  162  secured to the lower margin of a first wall member  150  on one side of center sill  60 , and a second end  164  secured to the lower margin of a second wall member  150  secured to the opposite side of center sill  60 . Retainer  160  may have a dog-legged or kinked form, with an intermediate bend in the middle, as at  166 , and may have a spring pre-load tending to urge ends  162  and  164  to pull toward each other, thereby urging lower margins  152  of wall members  150  to seat tightly against extremities  126  of the bottom flange  114 . 
     In the view of  FIGS. 1 a , 3 b , and 5 c   , wall members  150  are secured not to inboard side sheet flange  148 , but to the uppermost of the longitudinally running pipes or conduits, by a mechanical fastener as at clamps or fittings  168 . 
     In the alternate embodiment of  FIGS. 4 a , 4 b , and 5 a   , wall member  170  has the form of a bent plate having a short leg  172  for seating on shelf  124 , and a long, upwardly extending leg  174  such as may have an uppermost margin  176  at a height higher than the opening of the door, and such as may terminate above the height of the uppermost service conduit  178 . The upper edge may be a free edge, or it may be secured to conduit  178  by fittings such as fittings  168 , as may be. In this embodiment, upwardly extending leg  174  may be angled inward on a diagonal angle, as suggested by angle alpha. In profile view, upwardly extending leg  174  may have a rectangular shape, as does wall member  150  as shown in  FIG. 1 a  and 3 b   , or it may have a trapezoidal, or somewhat triangular, shape, as shown in  FIG. 4 a   , in which vertical edge  180  corresponds to the free edge next to door  90 , and oblique or diagonal edge  182  corresponds to the sloped edge of opening  100 . As before, shelf  124  is located in the lee of wall member  170 . 
     In the alternate embodiment of  FIG. 5 b   , wall member  190  may be substantially the same as wall member  170  (or wall member  150 ), except insofar as the upper distal margin  192  is formed on a radius to curl about uppermost service conduit  178 . As may be understood, although members  170  and  190  are shown only on the left hand side of center sill  60  in  FIGS. 5 a  and 5 b   , it is understood that they may be applied on both sides. 
     In the view of  FIG. 5 c   , a shroud assembly or shed plate assembly  200  has first and second wall members  150  and a retainer  160  as described above. In the view of  FIG. 5 d   , a shroud assembly  210  has first and second, left hand and right hand wall members  202 ,  204  that are substantially similar to wall members  150 , but that have respective upper margins  206  and  208  that are formed on a radius to conform to the outer radius of, and to curl about, the respective uppermost service conduits  178  and  210 . In this example, conduit  178  may be an air pipe, and conduit  210  may be an electrical services conduit. In this embodiment a retainer  160  attaches to the lower margins of wall members  202  and  204 , as above. 
     In the alternate embodiment of  FIG. 5 e   , retainer  220  is secured to wall members  212 ,  214  by mechanical fasteners  216 , such as bolts, rivets, or Huck™ bolts as shown. The fastener could alternatively be located below bottom cover plate  114 . Retainer  220  is otherwise similar to retainer  160 . The upper portions of wall members  212 ,  214  may correspond to one or another of wall members  150 ,  202  and  204 . 
     In the alternate embodiment of  FIG. 5 f   , left hand and right hand wall members  222 ,  224  may have the form of formed channels having a first or short leg or toe  226  that seats upon shelf  124 , a substantially vertical web or sheet  228  that extends upwardly from the outboard margin of toe  226 , and a second, or long leg  230  that seats against, and may be affixed to, the underside of inboard side sheet flange  148  that overlaps top cover plate  112 . In this embodiment, in side view members  222 ,  224  may have either a rectangular shape, as shown in  FIG. 3 b   , or a trapezoidal shape as shown in  FIG. 4   a.    
     The embodiment of  FIG. 5 g    is substantially similar to that of  FIG. 5 f   . However, it differs in that sheets  228  stand vertically, and while members  222 ,  224  shelter the predominant portion of shelf  124 , the sheltered portion being more than a majority of the shelf, and in the embodiment illustrated nearly all of shelf  124 , nonetheless, a small lip  132  of shelf  124  protrudes laterally outboard of the shed plate, leaving a small upwardly facing lip. By contrast, in the embodiment of  FIG. 5 g   , members  232 ,  234 , while otherwise similar to members  222 ,  224 , have a main sheet portion  236  that is inclined such that the lowermost and outermost corner of members  232 ,  234  is flush with, or slightly proud of, extremity  126  of margin  120  of bottom flange or cover plate  114 . As such, there is no upwardly facing edge, or lip on which downwardly flowing material may catch. The embodiment of  FIG. 5 h    is substantially the same as the embodiment of  FIG. 5 g   , but differs therefrom to the extent that members  242 ,  244  have lower corners, or fingers  246 , that extend about, and curl around, the outside of extremity  126 , and reach under the projection  122  to engage the underside of flange  114 . 
     Noting that welding to the web or to the flanges may not be the best choice, there are alternative embodiments, as explained above. In further alternative embodiments, it may be that in an analogous assembly, items  160 , and two items  150  may be manufactured as a single-piece, such as a spring, that may clip into place, and that may also be held at its upper margins or held along its face by fasteners such as fittings  168 . Alternatively, an asymmetrical two-piece assembly may be used. In one embodiment, item  160  and one item  150  may be manufactured as a single, generally L-shaped piece. The L-shaped piece may then be joined to a single piece item to make the full three-sided assembly. In another example, a substantially symmetrical two piece assembly may be made by joining one half of  160  and one plate  150  may be formed as a single spring, in the form of an angle. It may be mated at the centerline of the car with a similar part for the opposite side. Tightening may spring load the parts, such that they may tend to stay in place. It is not necessary that the same arrangement of securement of the shed plate be used on both sides of center sill  60 . For example, the upper margin of one plate may be secured to a hopper discharge flange, while the plate on the other side of the car is secured to a service conduit. To that extent, the features of the various embodiments shown and described herein may be mixed as may be appropriate. 
     As has been described, in at least one embodiment there is a structure for a bottom dumping railroad hopper car. The hopper car may have at least a first hopper, that first hopper having a downwardly opening discharge section, the discharge section having an opening through which to discharge lading, the opening having a periphery. The structure has a center sill, the center sill having at least a first shear web and at least a first flange. The shear web stands upwardly of the flange. The flange has a margin extending laterally outboard of the web. The structure includes a wall member that extends upwardly of the margin of the flange. The wall member is located between the flange and the periphery of the discharge opening. At least the majority of the margin of the flange is located in the lee of the wall member. 
     In a feature of that embodiment, the wall member extends from a height below the periphery of the discharge section opening to a height higher than at least a portion of the periphery of the discharge opening. In another feature, the wall member has an upper margin, and the upper margin of the wall member lies at a greater height than an uppermost portion of the periphery of the opening. In still another feature, the wall member extends from a height below at least a portion of the periphery of the discharge section opening to a height that is above all of the periphery of the discharge opening. In a further feature, substantially all of the flange adjacent to the hopper discharge section is sheltered behind the wall member. In a still further feature, the flange has an outermost distal tip most laterally outboard of the web, and the wall member extends outboard of the distal tip. In yet another feature, the wall member is secured in place other than by weldment to the center sill. In an additional feature, the wall member is secured in place without attachment to the center sill. In still another feature, the wall member is secured to the discharge section of the hopper. In again another feature, the wall member has a curved upper margin that seats about a service delivery conduit. In a yet further feature, at least a portion of the wall member is maintained in position by a retainer that extends at least partially underneath the center sill. 
     Alternatively, a railroad hopper car has been described herein. In one embodiment it has at least a first hopper. That first hopper has a downwardly opening discharge section. The discharge section has an opening through which to discharge lading. The opening has a periphery. The car has a center sill. The center sill has at least a first shear web and at least a first flange. The shear web stands upwardly of the flange. The flange has a margin extending laterally outboard of the web. The car has a wall member that extends upwardly of the margin of the flange. The wall member is located between the flange and the periphery of the discharge opening. At least a majority of the margin of the flange being located in the lee of the wall member. 
     That railroad hopper car may be such that the wall member extends from a height below the periphery of the discharge section opening to a height higher than at least a portion of the periphery of the discharge opening. The wall member has an upper margin that lies at a greater height than an uppermost portion of the periphery of the opening. The wall member extends from a height below at least a portion of the periphery of the discharge section opening to a height that is above all of the periphery of the discharge opening. In some embodiments, all of the flange adjacent to the hopper discharge section is sheltered behind the wall member. The wall member may be secured in place other than by weldment to the center sill. That is, the car may be one in which at least one of: (a) the wall member is secured in place without attachment to the center sill; (b) the wall member is secured to the discharge section of the hopper; and (c) the wall member has a curved upper margin that seats about a service delivery conduit. In another feature, at least a portion of the wall member is maintained in position by a retainer that extends at least partially underneath the center sill. 
     In one or another of the various embodiments described, the wall member has the form of a plate having an angle formed therein such that the wall member has a first portion and a second portion. The first portion defines a first flange of the wall member for engagement with the flange of the center sill, and the flange of the wall is positioned one of (a) on an upper surface of the flange of the center sill; and (b) to curl around the flange and extend at least partially therebelow. The second portion extends upwardly from the first portion, and the second portion has an upper margin that is one of (a) mounted to a portion of the discharge section at a height above any uppermost portion of the periphery of the discharge opening; (b) secured to the center sill other than by welding; (c) is formed to seat about a services conduit; and (d) is formed into a second flange such that the overall member has a channel form, and said second flange is secured to structure other than the center sill. 
     Various embodiments have been described in detail. Since changes in and or additions to the above-described examples may be made without departing from the nature, spirit or scope of the invention, the invention is not to be limited to those details.