Auto rack car with end closure

An auto rack rail road car has a main deck and upper deck. It is provided with a door for controlling access thereto. The door is a radial arm door, and has a ladder mounted thereon by which personnel can ascend the second deck when the door is open. A second ladder is mounted to the first deck so that when the door is open the second ladder is positioned to co-operate with the first ladder. The arcuate path of the door is free from overhanging obstructions. The door also has internal and external weld-free stiffeners member for enhancing the rigidity thereof. A roller mounted to the door permits the door to be moved between open and closed positions. The door may further include a lock. A guide member protruding from the door co-operates with a groove in the main deck which slidingly guides the door as it moves between open and closed positions to control access to the car.

FIELD OF THE INVENTION

This invention relates to the field of auto rack rail road cars for carrying motor vehicles, and more particularly to doors for auto rack rail road cars.

BACKGROUND OF THE INVENTION

Auto rack rail road cars are used to transport automobiles. They may be used to transport finished automobiles from a factory to a distribution center. A long standing concern has been the frequency of damage claims arising from vandalism and theft of the rail car cargo. Unauthorized access to the rail cars may be achieved by prying open the rail car access doors. The access doors of rail cars described in the prior art typically have slots or other openings to accommodate bridge plates, support structures or other obstructions. These openings may weaken the structural integrity of the door, making the door less secure. The slots or openings may also provide an opening in which to insert a pry bar to force the door open. An example of a rail car having a door with slots is described in U.S. Pat. No. 4,944,234 issued to Hesch on Jul. 31, 1990, and entitled Rail Car End Assembly (the “Hesch Patent”). The Hesch Patent shows a rail car door with a number of slots to accommodate bridge plates. In addition to possibly weakening the door, these slots might be used to insert a pry or other object to gain unauthorized access to the rail car. The slots may also permit contaminants such as dirt and other foreign matter to enter the rail car, potentially damaging the rail car lading.

Auto rack rail road cars have ladders to permit rail yard personnel to ascend to or descend from the upper decks of the rail car. Typically, the ladders are located near to the doors. These ladders are preferably secured to the rail car body structure generally and are subject to vibration during operation of the rail car. The lower end of the ladder is typically secured to the first deck of the rail car, and the upper end of the ladder is typically secured to a support or brace member at the other end. The support, or brace, may be anchored to the top chord of one of the wall assemblies. In cars in which the door extends past the height of the top chord to obstruct access to the gable end, the positioning of the brace may tend to present design challenges. Due to mutual proximity, care is taken to avoid having the brace member interfere with the opening and closing of the door. As a result, the door may be configured to accommodate the ladder bracing. In U.S. Pat. No. 4,936,227, issued to Baker et al., on Jun. 26, 1990, and entitled End Door for Rail Car, interference with a brace member for the ladder is avoided by forming a notch in the outer edge of the door so that the door avoids collision with the brace. However this notch may tend to weaken the door and may also tend to permit dirt and other unwanted substances to enter the interior of the rail car. The notch may also provide an access point for vandals or thieves to pry the door away from the rail car.

U.S. Pat. No. 4,924,780, issued to Hart on May 15, 1990, and entitled Sliding End Panels for a Rail Car, shows a multi-panel door with a ladder attached to a panel of the door. The door employs a number of hinged panels, with each panel substantially supported and guided by a wheel on a narrow track. It has been observed that multi-panel, hinged doors may tend to require more maintenance, and more care in operation generally, than rigid panel radial arm doors. Further, each hinge, or opening, or crack may tend to provide a location at which vandals or thieves may seek access to the cars, or a point at which parts can be misaligned.

Single panel, or rigid assembly, doors may tend to be simpler to build and operate than multi-panel doors. An example of a rigid door is the radial arm door. Radial arm doors typically have a cross-section with an arcuate portion and a straight or linear portion tangent to the arcuate portion. The door may typically be supported by a pair of roller assemblies located along the lower edge of the arcuate portion and are constrained by the radial arm to follow a track of constant radius defining part of an arc of a circle. Since both rollers typically lie on the arc, the tangent portion of the door may tend to be cantilevered relative to the nearest roller. As a result, the roller assembly closest to the tangent portion may tend to support not only its share of the arcuate portion, but also most, or all of the weight of the tangent portion. This uneven weight distribution may cause the roller assembly nearest the tangent portion to wear prematurely. For example, in U.S. Pat. No. 3,995,563 of Blunden issued Dec. 7, 1976, two roller assemblies directly support the arcuate portion of the door. The tangent portion, may therefore tend primarily to be supported by the roller closest to the meeting point of the tangent and arcuate portions. It would be advantageous to distribute the loading more evenly between the rollers.

In typical radial arm door installations, for example as shown by Blunden, the rollers are guided by an arcuate track having a flange. The track is mounted to the top surface of a first deck of the rail car. A roller housing connects the roller to the door. The housing has a J- or L-shaped extension in the nature of a finger, or hook, that overlaps the flange to tend to prevent the door from becoming separated radially from the track. Difficulties may arise if forces transverse to the track are applied to the door. For example, in the normal course of operation, the track may sag after years of operation under the weight of the door. If the track sags, the rollers may tend to work their way off the track surface. Alternatively, ice or some other obstruction may form or become lodged between the track and the roller. In either case, the door may be forced out of alignment with the track. If the extension becomes deformed then the door may not open and close properly. Similarly, if the track itself is not adequately supported then the track and door may begin to sag with extended use, causing similar difficulties. Even without obstructions or misuse of the door, the extension and track may wear out sooner than may be desirable if the track is constructed using relatively thin pieces of steel or other metal.

The roller and track arrangement described above may also leave a gap between the bottom edge of the door and the track. As noted above, such gaps may provide an access point for vandals, and may permit foreign matter such as dirt to gain access to the interior of the rail car. The presence of dirt and debris in particular may inhibit the roller from rotating if the dirt becomes lodged between the roller and its axis, or may hasten wear.

Potentially damaging dirt and debris may also enter the rail car via gaps formed along the attachment interface between the rail car roof and the top chord of the wall assemblies. This may tend to occur when a corrugated roof structure is used. While the peaks of the corrugation may abut the top chord along a longitudinal edge thereof, the valleys of the corrugation form passages for dirt and other debris to pass from the exterior to the interior of the rail car. This may occur even if the peaks abut an attachment plate or bracket of the top chord with the peaks abutting a generally flat surface of the plate or bracket instead of the edge of the top chord.

Typically, auto rack rail car doors, and in particular, radial arm doors, can be characterized as being thin shell structures. That is, the door has a developed span in the order of 5 ft to 9 ft wide, depending on the arc, a height on the order of 16 or 17 ft, and a skin thickness of perhaps {fraction (3/16)}″. Although the door obtains some stiffness from its arcuate shape, the large door area may be relatively vulnerable to damage, and may be prone to relatively large deflections. It is desirable for the shell to be stiff. Given the area of coverage of the door, even a relatively thin shell of steel sheet may have a considerable weight, particularly when fitted out with locks, rollers and other door hardware. Thus, it is undesirable to increase the general thickness of the door to obtain greater stiffness, since there is an inherent weight penalty.

In the past, attempts have been made to stiffen the door by providing welded angle irons, pipe, tubes and so on. However, it has been observed that welded reinforcements in doors may tend to be initiation sites for fatigue cracks, and even when repaired, may tend to crack again. It would be advantageous to provide reinforcements to give stiffness to the door, without necessarily relying on welds that might be prone to crack formation.

Another feature of auto rack doors relates to the portion of the door lying above the level of the wall top chord to enclose the gable end of the car. In earlier types of auto rack rail road car, such as that shown in Blunden Patent noted above, the radial arm door did not extend above the level of the top chord. However, this did not necessarily prevent determined thieves or vandals from climbing over the top of the door to obtain access to vehicles carried on the highest deck. Consequently, there have been several attempts to enclose the gable end. A disadvantage in many of these cases is the need to notch the door to accommodate the ladder support structure as noted above. Further, since the door tended not to be restrained at the roof line, the gable end portion of the door tended to be relatively weak. Thieves, or vandals, might be able to bend the upper portion of the door outward, and thereby gain access to the upper deck. It would be advantageous to discourage this activity by restraining a significant portion of the door to follow the arc of the roof line, and to lock the door to the roof when the door is in the closed position.

SUMMARY OF THE INVENTION

In an aspect of the present invention there is an auto rack rail road car that has a set of radial arm doors. At least one of the radial arm doors has a deck access ladder mounted to it. Furthermore, in another aspect of the invention the radial arm doors follow an arcuate track relative to the main deck. The space above the main deck, to a height greater than the height of the top chords, is clear of overhanging structural obstructions such as ladder braces.

In another aspect of the invention there is an auto rack rail road car comprising having a rail car body. The rail car body has a first end, a second end, and at least a first deck for carrying automobiles. The first deck extends between the first and second ends. The body has a non-folding door operable to control access to the rail road car. The door has a deck access apparatus mounted thereto by which personnel can ascend the second deck when the door is in an open position.

In another feature of that aspect of the invention, the door has an external surface facing away from the decks, and the deck access apparatus includes footholds mounted to an external surface of the door. In a further feature, the door has an external surface facing away from the decks, and the deck access apparatus includes ladder rungs mounted to the external surface of the door. In another feature the deck access apparatus is a ladder. In still another feature, the door is a radial arm door.

In still another further feature, the door follows an arcuate track between open and closed positions. In a further feature, the door is supported on a first roller and a second roller. The first and second rollers are constrained to follow concentric paths. The first roller has a first path radius, and the second roller has a second path radius. The first path radius is different from the second path radius. In another further feature, the first and second rollers each support a portion of the weight of the door during motion of the door between the open and closed positions.

In another feature of that aspect of the invention, the rail road car has a pair of laterally spaced first and second longitudinally extending walls bounding the first and second decks, and a roof extending transversely between the walls to overspan the decks; the walls each having a top chord distant from the first deck; the roof extending to a greater height than the top chord. The door follows an arcuate path relative to the first deck. The door extends to a height greater than the height of the top chord. The path of the door is free of overhanging structure.

In another further feature, the door has a main sheet and an array of horizontal and vertical stiffeners. The main sheet has a first side and a second side. The horizontal stiffeners are mounted to the first side of the main sheet, and the vertical stiffeners are mounted to the second side of the main sheet. In a further feature, at least one of the stiffeners is mounted to the main sheet with mechanical fasteners. In a still further feature, at least one of the vertical stiffeners is connected to at least one of the horizontal stiffeners by a mechanical fastening through the main sheet.

In yet another feature, the rail road car has a longitudinal centerline lying in a central vertical plane. The door is supported on at least first and second rollers. The first roller bears at least as great a portion of the door as any other roller supporting the door. The door is mounted to move angularly through an arc centered about an axis of rotation, the axis of rotation being offset laterally from the central vertical plane. The door is movable to a closed position, and, in the closed position the first roller is positioned closer to the central vertical plane than the axis of rotation. In a further feature, the first roller has an axis of rotation and the axis of rotation of the first roller intersects the axis of rotation of the door. In still yet another feature, the door is a radial arm door having an arcuate portion and a tangential portion, and the first roller is mounted to the tangential portion of the door.

In another feature of that aspect of the invention, the first deck has a guideway and the door has a guide follower mounted to engage the guideway. In a further feature, the guideway is a slot formed in the first deck, and the guide follower is a member extending downwardly from the door into the slot. In another further feature, the deck is greater than ¾ inches in thickness.

In still another feature of the invention, the deck access apparatus is a first ladder mounted to the door. A second ladder is mounted to the first deck. When the door is in the open position the first ladder is positioned to co-operate with the second ladder. In a further feature, the door is a radial arm door having, when closed, an outboard arcuate portion and an inboard tangential portion. The deck access apparatus is a first ladder mounted to the door; and the ladder is mounted to the tangential portion.

In another aspect of the invention, there is an auto rack rail road car having a first deck upon which to carry wheeled vehicles, and a housing structure extending upwardly of the deck to define a space in which to shelter wheeled vehicles. The housing structure has a top chord distant from the deck, and a roof overspanning the first deck. The roof rises to a greater height than the top chord. The car has at least a first pair of radial arm doors operable to control access to the interior of the sheltered space. At least a first of the radial arm doors is movable on an arcuate path relative to the first deck, and the first door extends to a height greater than the top chord. The path of the first door is free of overhanging obstructions.

DETAILED DESCRIPTION OF THE INVENTION

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 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 are not necessarily to scale and in some instances proportions may have been exaggerated in order more clearly to depict certain features of the invention.

In terms of general orientation and directional nomenclature, for each of the rail road cars described herein, the longitudinal direction is defined as being coincident with the rolling direction of the car, or car unit, when located on tangent (that is, straight) track. In the case of a car having a center sill, whether a through center sill or stub sill, the longitudinal direction is parallel to the center sill, and parallel to the side sills, if any. Unless otherwise noted, vertical, or upward and downward, are terms that use top of rail, TOR, as a datum. The term lateral, or laterally outboard, refers to a distance or orientation relative to the longitudinal centerline of the railroad car, or car unit, indicated as CL—Rail Car. The term “longitudinally inboard”, or “longitudinally outboard” is a distance taken relative to a mid-span lateral section of the car, or car unit.

FIG. 1shows a single unit auto rack rail road car, indicated generally as20. It has a rail car body22supported for rolling motion in the longitudinal direction (i.e., along the rails) upon a pair of rail car trucks23and24mounted at main bolsters at either of the first and second ends26,28of rail car body22. Body22has a housing structure30(shown inFIGS. 2aand2b), including a pair of left and right hand sidewall structures32,34and a canopy, or roof structure36that co-operate to define an enclosed lading space. Body22has staging in the nature of a main deck38running the length of the car between first and second ends26,28upon which wheeled vehicles, such as automobiles can be conducted. Body22may have staging in either a bi-level configuration (shown inFIGS. 2aand2b) in which a second, or upper deck40is mounted above main deck38to permit two layers of vehicles to be carried; or a tri-level configuration in which a top deck is mounted above the upper deck40, and above main deck38to permit three layers of vehicles to be carried. The staging, whether bi-level or tri-level, is mounted to the sidewall structures32,34. Each of the decks defines a roadway, trackway, or pathway, by which wheeled vehicles such as automobiles can be conducted between the ends of rail road car20.

In the example shown inFIG. 1, a through center sill50extends between ends26,28. A set of cross-bearers52extend to either side of center sill50, terminating at side sills56,58. Main deck38is supported above cross-bearers52and between side sills56,58. Sidewall structures32,34each include an array of vertical support members, in the nature of posts60, that extend between side sills56,58, and top chords62,64. Roof structure36includes a central corrugated roof sheet structure66and mating, formed roof side sheet portions65and67. Roof structure36extends between top chords62and64above deck38and such other decks as may be employed. Roof structure36also includes uncorrugated formed sheet gable end portions61,63that extend longitudinally outboard of corrugated roof sheet structure66from the “number 2 post”80to meet doors68and70. The use of a non-corrugated end sheet portion may tend to simplify the fit-up geometry of the door-to-gable end interface, facilitating a better fit to roof to door seals as described below.

Doors

Referring toFIGS. 3,4,5and6a, doors68and70are a co-operating pair of radial arm doors that are operable to enclose the openings at the ends26,28of car20and thereby to control access to the internal space defined within housing structure30. Doors68and70are movable to a closed position as shown inFIGS. 3 and 5to inhibit access to the interior of car20, and to an open position as shown inFIG. 4to permit access to the interior. Alternatively, one of the ends26or28may be closed or sealed using some other means such as an end wall structure (not shown) and doors68,70provide access to the remaining end26or28. Except as otherwise noted, doors68and70are mirror (that is, left and right hand) configurations of one another and the description of one applies to the other except to the extent of being to the opposite hand. Similarly, rail car20is substantially symmetrical about its longitudinal and mid-span transverse centerlines, unless otherwise indicated.

Referring toFIGS. 3,5, and6a, doors68and70are shown in the closed position, and inFIG. 4doors68,70are shown in the open position, both doors being movable along the arcuate paths between respective open and closed positions, thereby controlling access to the internal space of the rail road car

Door68(or door70, opposite hand, as may be) has a generally rigid body (i.e., non-folding) that, preferably, employs a monolithic main sheet82, formed to have the desired arcuate and tangential portions81and83. Notably, door68does not have (i.e., is free of) slots, or recesses formed in the door to correspond to the location of the wheelways of the mid-level deck (or, in a tri-level, the mid and upper levels), and does not have a notch at the level of the sidewall top chord. As such, door68may tend to present less opportunity for undesirable foreign matter, such as rain, sand, gravel and such like, to enter into the car and mar the finish of automobile products carried in transit. The reduction in the number of slots or recesses in the door may also tend to enhance its structural integrity and overall stiffness and may tend to provide a measure of discouragement for thieves and vandals.

Door68has a first, arcuate, outboard portion72and a second inboard, or tangent portion74. Each portion72,74is rigidly connected to the other. The major axis of rotation ‘X’ of door68runs substantially in the vertical direction. Outboard portion72has a generally arcuate horizontal cross-section of constant radius of curvature centered on axis ‘X’. Second portion74has a substantially linear (i.e., flat) cross-section. Arcuate portion72is preferably formed integrally with second portion74so that it lies tangent to arcuate portion72. Alternatively, portions72and74could be formed separately, and then be rigidly connected to each other.

Referring toFIG. 8, door68is constrained to follow a generally circular arc by a radial guidance member, such as radial arm84, attached thereto. A first end86of the radial arm84is attached to a side of door68, and a second end88of the radial arm84is configured for pivotal attachment to a structure inboard of the door68, preferably a pivot mount on the underside of mid level deck40. At its first end86radial arm84may also be pivotally attached to the concave side90of door68at a location proximate to a free vertical edge92of the tangent portion74. The structure to which radial arm84is attached may be the underside of the upper deck40(of a bi-level car), the top deck (of a tri-level car, not shown), or the roof36. To avoid obstructions when door68is opened and closed, radial arm84has a dog-leg or elbow96in a horizontal plane. As best shown inFIGS. 3 and 4, door70differs from door68in that it has a radially inwardly stepped shell98defining an accommodation, recess or cavity to accommodate a hand brake (not shown). Door68is preferably constructed from sheet metal, such as formed steel sheet. It could also be made of aluminum sheet.

Referring toFIGS. 8,16,17and18, when door68(or70, as may be) is in the open position, the most longitudinally inboard edge100of the arcuate portion72abuts a shear bay panel77which is mounted between a vertical support referred to as the “number one post” indicated as79and a longitudinally inboard vertical support referred to as the “number two post”81. The number one post79stands laterally inboard relative to the number two post81, and, in the open position, door68moves to the outside of the shear bay panel77. When door68is in the closed position, the most longitudinally inboard edge100of the arcuate portion72abuts a panel identified as shear bay panel extension102, that extends longitudinally outboard of number one post79.

When door68(or70) is in the closed position a gap may tend to exist between edge100and an adjacent structure such as shear bay panel extension102. Were such a gap to exist, it might tend to permit contaminants including dirt and other matter to enter the interior of the rail car20. To discourage such a result, doors68and70have a wing member in the nature of a vertically running, inwardly extending flange103mounted to edge100. A sealing member in the nature of a vertically running p-seal104(seeFIGS. 7aand17) is attached to flange103and may tend to reduce or eliminate the gap, thereby tending to inhibit entry of debris into the interior of rail car20.

When door68is in the closed position a gap may tend also to exist between a top edge106of door68and an adjacent structure such as roof36. An angled flange108protruding from top edge106spans the gap and overlaps with roof36. Flange108preferably overlaps above roof36and runs along the top edge of door68(or70), following the arcuate, descending profile of the door edge in a manner corresponding to the arcuate, descending edge of the gable end of roof36. Alternatively, or additionally, an obstruction such as a seal or a p-seal110for inhibiting the passage of matter between top edge106and roof36may be provided along the top edge106of door68. P-seal110is mounted to run along the arcuate descending profile of the door edge, and thereby, when the door is closed, to engage the corresponding roof profile and thereby to tend to form a sealed door to roof interface. Seals104and110may be alternatively attached to the adjacent structure of shear bay panel extension102as shown in FIG.17and roof36as shown inFIG. 18. Afurther, main vertical door seal111is shown in FIG.16. Door seal111is an ‘O’-seal mounted to the transversely inboard (when closed) edge of door68. Seal111is compressed when the two doors are brought together, seal111then bearing against a mating land on door70.

Ladder

Referring toFIG. 4, an upper door traversing apparatus or deck access apparatus, in the nature of a ladder114, having an array of footholds in the nature of, for example, ladder rungs116, is mounted to extend outwardly from an upper region of tangent portion74of door68along the external or outboard surface118. Ladder114permits personnel to ascend upper deck40(or third deck, if applicable) when door68is in an open position. Six rungs116are preferably arranged vertically and equidistant from one another along external surface118.

When door68(or70) is in its open position, rungs116lie generally above and are generally in line with and accessible from, a second ladder, or ladder portion such as a deck level access ladder120, such that a person may climb from track level up access ladder120and onto rungs116and thereby to obtain access to the upper deck, or decks of car20. Deck level access ladder120is mounted laterally outboard of door68to permit movement of door68between closed and open positions.

Access ladder120is mounted rigidly to main deck38, and extends substantially vertically upwardly therefrom. Rungs122of access ladder120are preferably oriented parallel to the plane of main deck38and parallel to the longitudinal center line of the rail car20. Rungs122are mounted to a support structure124of access ladder120. Support structure124has a wedge-shaped horizontal cross-section and longitudinal flanges125and127. Each rung122is mounted at one end to flange125and at the other end to flange127. The wedge-shaped cross-section of support structure124is wider adjacent the longitudinal outboard end of rail car20to increase the effective depth of section and thereby to tend to enhance structural support for access ladder120while permitting passage of door68between ladder120shear bay panel102. Ladder120is free of a longitudinal brace to either the “Number 2 post”80, or to the top chord62,64.

The absence of a longitudinally extending ladder brace at, for example, the level of the top chord may tend to obviate the need for a brace accommodating notch or cut-out in the upper portion of doors68,70. Since a ladder is provided on door68(or70) itself, and since ladder120is free-standingly mounted to main deck38, the arcuate path of the door is not then overhung by an overhead brace or other ladder support structure that might otherwise tend to obstruct the motion of the door. As such, this may tend to reduce, or eliminate another opening through which foreign objects may enter car20, and may tend also to improve the sectional stiffness of doors68,70more generally and of the upper gable extension portions of doors68,70that lie at a height greater than the height of the top chord in particular. While it is preferable that each door68,70have a ladder114mounted thereon along with an associated adjacent access ladder120, access to upper deck40may be achieved by including a ladder114on just one of doors68and70.

The inside face128of the tangent portion74may be provided with a hand hold rung129, or rungs (shown inFIG. 5) suitable for a person standing on main deck38, upper deck40, or on a top deck (if applicable) to permit a person to move between deck38or40and ladder114. Hand holds130may also be provided on the outboard side118of door68adjacent to rungs116. The lower hand holds130may also be grasped to open and close doors68and70.

Stiffening Members

As noted above, door68(or70, as may be) has a generally rigid body that may be a monolith or that may be formed of at least two single panels laminated to one another. An array of stiffening members in the nature of a transverse or horizontal stiffeners132is attached to door68and may tend to enhance the rigidity of door68. Transverse stiffener132is a pressing in the form of a hat section having arcuate and tangential portions conforming to the profile of door sheet82. It is mounted to extend along the profile of the outboard surface118of door68and is preferably horizontally oriented. Four horizontal stiffeners132are spaced equidistantly from one another, with each rung116of ladder114located between adjacent stiffeners132.

Stiffeners in the nature of vertical stiffeners,131,133,134,135, and137are mounted to door68. Vertical stiffeners133and135are attached to the inboard surface136of door68adjacent to the free edge of arcuate portion74. External stiffener131is Huck™ bolted through panel82to bridge the gap left between stiffeners133and135to accommodate the end of deck40. The free edges of the tangent portions of doors68and70are similarly reinforced by vertical hat section channel members, identified as vertical stiffeners134. A vertical stiffener137is mounted along the upper region of the free edge of the arcuate portion of door70, but differs from stiffener134in being truncated to accommodate the inwardly extending portion of stepped shell98.

Stiffener134is a formed channel having a back, a pair of legs extending from the back to form a channel, and a pair of feet bent outwardly from the legs, the feet providing flanges that lie against the inside the main sheet of door68. The feet are then secured in place using mechanical fasteners, such as Huck™ bolts. Stiffeners131,133, and135are of similar construction and assembly but is somewhat narrower in width than stiffener134.

Referring toFIG. 7b, to increase further the rigidity of door68(or70), the vertical stiffeners are connected to horizontal stiffeners132through door68at those locations where the vertical and horizontal stiffeners overlap. Door sheet82is thus sandwiched between horizontal stiffeners on one side and vertical stiffeners on the other.

As noted above, in the preferred embodiment, the vertical and horizontal stiffeners131,132,133,134,135, and137are generally hat shaped in section, each having a flattened U-shaped lateral cross-section and outwardly extending flanges144and146, running along their respective longitudinal edges. The longitudinal flanges144,146each have apertures, or bores formed therethrough to admit a mechanical fastener. These bores, or holes, of the vertical stiffener, such as may be are located to correspond to, (that is, align with) the corresponding bores or holes of the horizontal stiffeners132at the attachment intersection such as point142. Door68(or70, as the case may be) has corresponding holes or bores formed therethrough. It is preferred that the mechanical fasteners used to secure stiffeners131,132,133,134,135and137in place be driven through the flanges of the respective horizontal stiffener from the outside, through main sheet82of door68(or70, as may be), and through aligned holes in the flanges of the vertical stiffener on the inside of the door. As such, each connection location of a vertical stiffener with a horizontal stiffener will be a four point connection, the four points forming a rectangle such as may tend to provide resistance against rotational deformation of the joint or connection so formed. The fastener148may be a bolt and nut, a formed rivet, or, preferably, a Huck™ bolt. The Huck™ bolt has a collar portion which receives a Huck™ bolt rivet having non-pitched threads. This may tend to form a relatively secure connection tending to have a reduced tendency for fatigue crack formation as compared to a welded connection. A welded connection may nevertheless be used. Additional fasteners may be used to attach the vertical and horizontal stiffeners132,134to the door panels.

Rollers

Referring toFIGS. 4,5,6b,6cand7a, to facilitate opening and closing of door68(or70), a rolling contact member, such as a wheel or roller150, is mounted along the lower margin of tangent portion74of door68(or70as the case may be). Roller150has a sealed bearing152with a shaft155extending therethrough. Shaft155is carried in a bracket156mounted to door68. Shaft154and sealed bearing152permit rolling motion of the roller150on an adjacent horizontal surface, which is preferably perpendicular to longitudinal axis ‘X’ of door68. Sealed bearing152may also tend to prevent the interface between shaft155and bearing152from becoming contaminated with water, dirt or other debris that might otherwise tend to inhibit movement of roller150about shaft155. Roller150is mounted adjacent to a lower edge158of door68for rolling motion on main deck38so that roller150carries a substantial portion of the weight of door68when the door68is opened and closed.

Door68has a second roller160mounted to the lower margin of door68(or70) near the free edge of arcuate portion72. In this description the first roller150is a leading roller and the second roller160is a following roller (this nomenclature being arbitrarily chosen on the basis of motion as the door is being closed). Both rollers are in rolling contact with, and in operation between open and closed positions of door68(or70) roll along, main deck38. In the preferred embodiment, rollers150and160roll along a main deck plate, such as guide plate222, of main deck38(described in greater detail below) throughout the full range of travel between the open and closed positions of door68(or70as may be). Except as described below, following roller160has substantially the same general configuration as lead roller150. As described below, in the preferred embodiment, roller160is located adjacent vertical edge100(that is, the free edge of arcuate portion72) and roller150is angularly spaced from roller160by about 70 degrees.

Referring toFIGS. 6band6c, the lower margin of main sheet82of door68(or70) is reinforced by inner and outer cuffs, or skirt plates identified respectively as151and153. Shaft167of roller160has a first stub end155for engaging a mating aperture,157in door68(or70, as may be).

A second, slotted end159for seating in, and extending through an aperture161in bracket169and an eccentric medial barrel163. Barrel163is sized to mate with bearing152. Rotation at shaft155relative to apertures157and161will cause barrel163to move as a cam, thereby permitting height adjustment of roller160relative to door68(or70). On fit-up door68(or70) is mounted on the car, and supported in its desired closed position. Shaft167of roller160is rotated to the desired position, and then a square bar, or key165inserted in slotted end159is welded to bracket169. Although roller160has been described as having an adjustable cam, both rollers150and160could be so provided. In the preferred embodiment, roller150has an adjustable cam, and roller160has a fixed shaft, such that angular adjustment on fit-up is at roller150.

Leading roller150is positioned to trace a first arc of constant radius R150when door68is moved from an open position to a closed position. Following roller160is positioned to trace a second arc of constant radius R160, having the same center (i.e., axis ‘X’) as the first arc, when door68(or70) is moved between open and closed positions. The radius R160of the second arc is less than the radius R150of the first arc and is concentric with the first arc so that door68opens and closes following a radial arc, as it is constrained to do by its radial arm84. The radius of arcuate portion72of door68is preferably greater than, and is concentric with, the first arc traced by leading roller150. Both rollers150,160are located on the inboard side136of door68.

Following roller160is mounted adjacent to the free vertical edge100of arcuate portion72. The axis of rotation of roller160is substantially normal to arcuate portion72, orienting roller160to trace an arc of constant radius concentric with the arc of arcuate portion72. That is to say, the intersection of the axis of rotation of roller160with the skin of the main panel of the door, is perpendicular to the skin at the point of intersection. Lead roller150is mounted to tangent portion74of door68(or70). The axes of rotation of rollers150and160preferably lie in the same plane. Bracket156holding roller150is mounted to tangent portion74, such that the point of contact of roller150with deck38is inwardly offset from the inner face of the main panel of tangent portion74a distance δ, and holds roller150at an angle φ relative to a perpendicular drawn from tangent portion74such that the axis of rotation of roller150intersects the axis of rotation ‘X’ of door68more generally.

A radial line from the center of rotation of door68(or70), indicated as point X, to free vertical edge100is designated as an angular datum. The radial line from X to roller160, namely the axis of rotation of roller160, lies at an angle β from the datum. The juncture of the bent portion of door68, namely arcuate portion72, with the other portion, namely the distaff or tangent portion74occurs at the point of tangency, indicated inFIG. 7aas ‘P’. A further line XP is constructed from X through P, this line being parallel to the longitudinal centerline CL of car20when door68is closed, and being perpendicular to tangent portion74. The included minor angle between the datum and XP is indicated as α. The included minor angle between XP and the axis of rotation of roller150is indicated as Ψ. The included minor angle between the axes of rotation of rollers150and160is indicated as θ. The total included angle between the datum and the axis of rotation of roller150is the sum of β+θ, and is indicated as angle ρ.

By mounting roller150to tangent portion74at a skewed angle (actually=Ψ) relative to tangent portion74, the axis of rotation of roller150lies outside the angular arc defined by the extremities (namely edge100and point P) of the bent, or arcuate portion72of door68(or70). Put another way, angle ρ lies outside the range of angles falling between the datum and line XP, ρ being greater than α. Roller150is thereby placed closer to the free edge of tangent portion74than it would be if roller150were mounted to arcuate portion72of door68. As such, a relatively greater portion of the mass of door68may tend to be supported in the span between the points of contact of rollers150and160than would be the case if roller150were mounted between the datum and point ‘P’. The portion of door68(or70) cantilevered beyond the point of contact of roller150, namely that portion between roller150and free edge92of tangent portion74, is correspondingly reduced. As such the distribution of the static weight of door68between rollers150and160may tend to be more evenly allocated than might be the case if roller150lay within the range of angle α instead.

The axis of rotation of roller160lies relatively close to the datum, angle β being less than ⅓ of angle α. In the embodiment illustrated the included minor angle θ between rollers150and160is greater than the included minor angle α of arcuate portion72. As such, the wheelbase, or span, between the points of contact of rollers150and160and deck38is also longer than it might be if roller150fell within the range of angle α. Use of a relatively long wheelbase in this way may tend to encourage smoother and more stable operation of door68.

Given that both are referenced to lines drawn perpendicular to tangent portion74, angle Ø and angle Ψ are equal. Further, when door68is in the closed position, tangent portion74lies perpendicular to the car centerline, such that angle Ø (or angle Ψ), also defines the angle of intersection of the axis or rotation of roller150with the centerline of car20. The point of intersection of the axis of rotation of roller150and the centerline of car20will lie longitudinally well outboard of door68, and of car20more generally.

As mounted to tangent portion74, leading roller150is located such that the arc traced by it terminates at a point that lies a distance λ laterally inboard relative to the center of the axis of rotation of door68. As noted, the angular distance between rollers150and160may be about 70 degrees. The length of an arc, being of generally constant radius as measured from point X, and bisecting the axes of rotation of rollers150and160adjacent rollers150and160, may be approximately 34 inches.

It is advantageous for the static load on roller160to be at least ¼ as great as the static load on roller150. It is preferred that the static load on roller160be at least ⅓ as great as the static load on roller150.

InFIG. 7a, the overall chord length of door70(or door68) is indicated as L0/A, measured from the outboard edge100to the inboard edge92. The parallel projected distance from inboard edge92to the center of roller150is indicated as L2. The parallel projected space distance between roller150and roller160is indicated as L1and the remainder between roller160outboard edge100is indicated as L3such that L1+L2+L3=L0/A. It is advantageous for (L2/L0/A) to be less than 0.4. It is preferable that (L2/L0/A) be in the range of 0.15 to 0.35, at which 0.25 to 0.30 is a possible range, and 0.27 (+/−) is one possible value in preferred embodiment. It is also advantageous for (L1/L0/A) to be at least as great as 0.5 and preferably in the range of 0.55 to 0.70 with a value in a preferred embodiment of 0.58 to 0.60.

Referring toFIGS. 5,6a,9and10, a door securing apparatus in the nature of a locking assembly140is attached to door68(and door70, opposite hand, as may be) to inhibit movement of door68(or door70) when locking assembly140is in an engaged (i.e., locked) condition. Locking assembly140has an actuator assembly141, and engaging apparatus identified as latch assemblies204and216.

Actuator assembly141has an actuator arm member in the nature of a lever192mounted on a stub shaft162. Stub shaft162protrudes through a rectangular mounting plate175, and is held in place by a cotter pin177. The inner end of stub shaft162has flats that mate with an aperture in lever192in a torque transmitting relationship. The far end of stub shaft162(which faces toward the outside of the car and extends through an aperture in door sheet82) has a four sided socket218for receiving a torque transmitting door opening key. Shaft162is surrounded by a bushing202mounted to plate175. Bushing202is preferably sintered and permanently lubricated, such as an oilite bushing, to tend to reduce the maintenance required for the lock assembly140. An external housing181is mounted by fasteners (such as rivets) to main sheet82of door68(or70). Mounting plate175is mounted on the inside face of main sheet82. The fasteners of housing181are carried through mounting plate175as well, forming a sandwich. When a key of appropriate shape and dimensions is passed by rail yard personnel into housing181to engage socket218, torque can be transmitted to turn lever192and thereby release locking assembly140.

Lever192has a first wing173cut in a profile having a knee198and a foot183. Foot183can be actuated from inside doors68and70when those doors are closed, typically by a person stepping on it to release locking assembly140. A linking member, in the nature of a pivotally mounted hard-eye210attached to a cable assembly208are connected to transmit the motion of knee185to latches216(at roof level) and204(at the mid height deck level). Lever192has a second wing179extending in the opposite direction from wing173. Another linking member, in the nature of a clevis212, is mounted pivotally to the distal end of wing179to transmit motion to pin168of engaging apparatus (latch assembly)164.

Latch assembly164(best shown inFIG. 9) is attached to door68(or70) and includes a receptacle166located in the first deck of rail car20, as illustrated in FIG.4. Receptacle166is configured for close fitting mating engagement with a first pin168of latch assembly164. The socket of receptacle166and pin168are substantially co-axial when in an engaged position. Pin168is mechanically linked to shaft162, and is movable between an engaged position and a disengaged position when shaft162rotates about its longitudinal axis to move link212, as described below. When in an engaged position, pin168inhibits horizontal movement of door68along its arcuate path. Pin168has a tapered engagement end170to facilitate entry of pin168into receptacle166. Engaging apparatus164is located on an inboard side136of door68.

Engaging apparatus164includes a bracket172, which is attached to door68using a fastener secured through bracket mounting holes174. Bracket172has a guide176for guiding pin168when pin168is moved between engaged and disengaged positions. The guide176encourages substantially vertical movement of pin168along a longitudinal axis of pin168. Guide176includes a bushing178. Bushing178is held in place by upper and lower retaining flanges180of bracket172. Bushing178is preferably sintered and may be lubricated to facilitate movement of pin168. Bushing178may also be made of bronze to resist corrosion. Bushing178may, for example, be an oilite bushing. Water or other contaminants that enter bushing178, are encouraged by gravity to exit bushing178via a drain182at the lower end thereof.

A biasing member such as a spring184, is mounted coaxially about pin168. Spring184is captured, or retained, at one end against a flange186of bracket172and at the other against a stop attached to pin168, in the nature of a washer188surrounding pin168. Washer188acts against protruding stubs of a shear pin190passing laterally through pin168. Washer188is thus sandwiched between cotter pin190and spring184. Spring184is disposed to encourage pin168to enter receptacle166when pin168is aligned with receptacle166and so also to return lever192to its undeflected position. Spring184is compressed when pin168is in a disengaged position.

Door68has a second engaging apparatus namely latch assembly204having a similar configuration to engaging apparatus164. Latch assembly264includes a second pin206for engagement in a second receptacle in upper deck40. Second pin206is oriented to act from below the second receptacle, unlike first pin168, which is located to act from above receptacle166. Second pin206is pivotally connected to wing173of lever192. A downward movement in knee198of lever192causes a downward displacement and disengagement of second pin206from the second receptacle. At the same time, first pin168also moves to a disengaging position because first end196of lever192is moved upwards causing first pin168to also be disengaged from receptacle166. This configuration permits either rotation of shaft162or application of a force to foot183of lever192to cause pins168and206to together become either engaged or disengaged at the same time. The springs of the respective engaging apparatuses164and204encourages pins168and206to return to their engaged positions.

Pins168and206are connected to lever192via wires or cables208. Cables208are attached to lever192with clevis210. Cables208are protected by a cover plate214such as a vertical stiffener134having a cable conduit therethrough. WhileFIG. 5shows cables208exposed, they are covered in the preferred embodiment of the invention. Cover plate214protects the cables from damage during loading and unloading of rail car20. When doors68and70are in a closed position, cover plate214may tend to discourage unauthorized opening of the lock by insertion of a hook or like device into rail car20to engage and pull cables208so that one of doors68or70may be opened.

Lock assembly140may also have a third engaging apparatus namely latch assembly216for securing door68to the underside of roof36. Latch assembly216includes third pin217and is configured in a similar manner as described above for second engaging apparatus204and is connected to knee198by another branch of cable208.

As noted above, pins168,216and217of lock assembly140may be moved between engaged positions and disengaged positions by applying a force to foot183of lever192. This may only be done from the interior of rail car20because lever192and the engaging apparatus164,204and216are located on the inboard side136of door68. To activate lock assembly140from the outboard side118of door68, shaft162is provided with a non-round axial cavity, namely socket218, at an outboard end thereof for receiving a similarly shaped key (not shown). Insertion and turning of the key rotates shaft162causing lever192to move, and thereby causing the connected first, second and third pins168,206,217to each move between engaging and disengaging positions. The non-round axial cavity218may be rectangular, or a unique shape to discourage unauthorized operation of lock140.

First Guide

Referring toFIGS. 3,4and5, door68has a first guide member such as a skirt or plate220protruding downwardly from a bottom edge158thereof. As noted above, main deck38includes guide plate222. Guide plate222has a groove224for receiving the downwardly protruding portion of plate220to slidingly guide door68as it moves between open and closed positions. Guide plate222is generally planar and oriented in a plane substantially perpendicular to a longitudinal axis of door68.

Plate220may be formed integrally with or attached to door68. Unauthorized access using pries or other implements between door68and main deck38may tend to be impeded by the presence of plate220. Plate220may alternatively be in the form of a finger (not shown) for engaging groove224.

Groove224is arcuate, having an arc that corresponds to (a) the angular displacement of door68(or70) between open and closed positions; plus (b) the arc of plate220itself. An end226of groove224is located near to the intersection of an axis tangent to the arcuate groove224and an axis parallel to the longitudinal centerline of main deck38, wherein the tangent axis is normal to the longitudinal centerline of rail car20. The arcuate groove224is preferably of a uniform radius that is concentric with the arcs traversed by rollers150and160. This may tend to encourage alignment of door68as it moves from open to closed positions. Groove224may preferably extend through the thickness T of guide plate222, to permit drainage of groove224.

Guide plate222also has at least one receptacle166for mating engagement with an engaging member168of lock assembly140. Receptacle166is preferably located along an arc parallel to arcuate groove224, and inboard of groove224. Additional receptacles, such as receptacle228may be employed to secure door68in an open position, and receptacle166may be used to secure door68in a closed position.

At least one strengthening member, such as tie plate230(shown in phantom in FIG.4), is mounted to the underside of guide plate222. Tie plate230traverses groove224to add rigidity to guide plate222adjacent groove224.

Referring toFIGS. 2a,2b,3and12, central corrugated roof66preferably has a generally uniform lateral cross-section having a general U-shape. The U-shaped roof66has terminal legs232and234, which may be parallel to each other. Legs232and234terminate at free ends236and238. Free ends236and238are square-cut relative to top chords62and64. That is, free ends236and238each have a profile defining a surface240. Surface240has an undulating shape that corresponds to the corrugations of roof66, as is shown in FIG.13. Free ends236and238are positioned adjacent to, and are preferably in abutting relationship with, top chords62and64. In operative position, roof66is supported atop chords62and64. Because the profile of the corrugations of roof66abut top chords62and64, gaps or passages between roof66and top chords62and64are limited. A sealant, such as a silicone rubber caulking can be used to further obstruct gaps which may remain.

In the preferred embodiment, surface240is generally planar and lies generally normal to a longitudinal axis of associated leg232(or234). To reduce gaps between roof66and top chords62and64, a top chord surface242of each top chord is configured to conform to roof profile surface240. In the embodiment described, top chord surfaces242are generally planar and are oriented to be generally level when in operative position. Accordingly, top chord surfaces242abut roof profile surfaces240when roof66is placed thereon. If roof profile surfaces240are oriented at a different angle, then corresponding top chord surfaces242are preferably configured to be oriented at a corresponding angle so that the surfaces240and242abut each other, and are preferably flush, to reduce the size of any gaps or passages therebetween (not shown).

Top chords62and64are roll formed to give the profile244shown in FIG.12. When viewed in profile, as shown for example inFIG. 12, each top chord62,64has a first leg246and a second leg248extending from either side of medial portion245. First leg246is oriented for attachment to the vertical side wall posts60. Second leg248is oriented for attachment to roof66. First leg246is preferably generally oriented normal to medial portion245, so that it lies in a plane corresponding to the exterior of rail car20. Second leg248is also generally oriented normal to medial portion245but it extends in a direction opposite to first leg246for location adjacent a surface of roof66corresponding to the interior of rail car20. Legs246and248may be attached using fasteners, such as bolts, rivets or by welding, or in some other manner that secures bracket244to top chord62(or64) and roof66.

The above arrangement may encourage drainage of, for example, rainwater passing over roof66, to be directed (i.e., to drain) to the exterior of rail car20. Passage of contaminants to the interior of rail car20may be further inhibited by applying a seal along the interface between roof leg free end236(and238) and bracket244. A water resistant inhibitor such as a silicone caulking249or a weld (not shown) may be used to form such a seal. As shown inFIG. 12, caulking249may be located adjacent leg246.

Top chord62,64may additionally include a guidance member in the nature of a longitudinal flange250running along second leg248. Flange250is preferably angled upwardly and inwardly away from the plane of second leg248to facilitate installation of roof66by acting as a tapered, or chamfered lead-in. As shown inFIG. 12, medial portion245is wider than the width of adjacent posts60so that radiused bend area254, located between medial portion245and second leg248, is less likely to interfere with the positioning of leg end236(or238) onto medial portion245. That is, if the bend radius of the upwardly extending leg were formed without the re-entrant loop, identified as re-entrant bulge256, the radiused bend area254might tend to stand proud of the plane of the outboard surface of leg248. In that instance, the radius would tend to prevent a square fit-up of the square cut ends of roof66with the flat portion of the top chord. Interference with the bend radius could be avoided by termination of roof66at a height above the bend radius, leaving an unsealed gap above the top chord and under the corrugated edge. However, by moving the radius inboard of the plane of the outboard surface of leg248, a square abutting fit may tend more easily to be obtained as shown.

In an alternative embodiment, top chords62,64could be in another form, such as a rectangular steel tube, and a bracket having the shape of horizontal leg242, vertical leg248and a re-entrant bulge, such as bulge256could be employed to permit a square cut abutment, and a continuous member for discouraging water drainage into the car.

Second Guide

Referring toFIGS. 14 and 15, rail car20may additionally be provided with a second guide structure258. Structure258may alternatively serve as a guide and retainer to encourage door68(or70) to follow a pre-determined path when door68(or70) is moved between open and closed positions. In the present description, structure258is described in the context of door68. While not expressly described herein, a similar structure of opposite hand may also be used in conjunction with door70.

Structure258co-operates with a corresponding feature260of door68to inhibit displacement of door68in a direction generally normal to a plane of door68. Structure258is preferably configured to engage feature260so that feature260is permitted to move in a direction generally concentric to structure258(i.e., as door68is moved between open and closed positions), but structure258inhibits movement of feature260in a direction generally perpendicular to structure258.FIG. 15is a section taken through the “Number 1 post”78, looking longitudinally inboard, with door70(or68, opposite hand) in a partially open condition in which the guide follower, feature260, of the upper, outer portion of the door is seen engaged with the guide, structure258, near the laterally outboard extremity of its arc.

In the preferred embodiment, structure258includes a web member268and a band, or flange member259. Web member268has an inner edge cut to conform to the sectional profile of the “number one post”,78, and the adjoining shear bay panel76and shear bay panel extension102. The outboard edge of web member268is cut on a circular arc that is centered on axis ‘X’. Flange member259is formed on the profile of the outboard edge of web member268, and is welded to it such that flange259extends downwardly from the plane of web268. The ends of flange member259are bent into weldable tabs for welding (a) to the inside outboard corner of the number one post78and (b) to the shear bay panel76.

In the preferred embodiment, feature260is a protrusion in the nature of bracket262having an upwardly extending finger261. Bracket262is mounted to the outboard vertical door stiffener133(or137as may be). Finger261is spaced radially inwardly relative to the back of stiffener133or137of door68forming a gap therebetween. The gap is configured to receive the downwardly extending flange259of structure258. The gap266is comfortably wider than the thickness of flange259to permit movement of door68(including attached finger261) between open and closed positions when flange259is located therebetween. This arrangement permits door68to be oriented generally perpendicular to main deck38as it is moved between open and closed positions. Radial arm84co-operates with guide structure258, plate220and associated features to direct door68when it is moved between open and closed positions.

Flange259may also be approximately six inches wide so that it may overlap finger261. Web member268may be located or set at an angle from level, and may have a drain hole at the low point (lying outboard of the shear bay panel, preferably, so that liquid, such as rainwater, is directed to a desired location outside the enclosed space of car20more generally. For example, rain water may be directed away from sidewall32and toward number two post80.

In operation, flange259is located between finger261and door68. Finger261or door68(or both) come into sliding contact with flange259, and flange259encourages door68to follow the arc defined by flange259. Flange259can be provided with a high density polymer material coating to encourage sliding. All inside and outside contact surfaces of the track can likewise be coated (including finger and band).

A {fraction (3/16)}″ steel sheet plate bent to conform to shape of the roof extends from just longitudinally inboard of the #2 post80past the #1 post78to stiffen the end portion of roof.

Ballasted Deck Plate

Rail car20has a weight carried by its rail car trucks23and24. Referring toFIGS. 11aand11b, two or more rail car units may be joined, for example to form a three unit auto rack rail road car, indicated generally as340and320, respectively. Cars340and320each have a weight which is carried by their respective rail car trucks350,352, and354, and332and334. If the rail road car is configured as an articulated rail car, as shown inFIGS. 11aand11b, there is a number of rail car units joined at a number of articulated connectors, and carried for rolling motion along railcar tracks by a number of rail car trucks. In each case the number of articulated car units is one more than the number of articulations, and one less than the number of trucks. In the event that some of the cars units are joined by draw bars, the number of articulated connections will be reduced by one for each draw bar added, and the number of trucks will increase by one for each draw bar added. Typically, articulated rail road cars have only articulated connections between the car units. All cars described have releasable couplers mounted at their opposite ends.

Where at least two car units are joined by an articulated connector, there are end trucks (e.g.,350,332) inset from the coupler ends of the end car units, and intermediate trucks (e.g.352,354,334) that are mounted closer to, or directly under, one or other of the articulated connectors (e.g.356,330). In a car having cantilevered articulations, the articulated connector is mounted at a longitudinal offset distance (the cantilever ann CA) from the truck center. In each case, each of the car units has an empty weight, and a design full weight. The full weight is usually limited by the truck capacity, for example, 70 ton, 100 ton, 110 ton (286,000 lbs.) or 125 ton. In some instances, with low density lading, the volume of the lading is such that the truck loading capacity may not tend to be reached without exceeding the volumetric capacity of the car body.

Inasmuch as the car weight would generally be more or less evenly distributed on a lineal foot basis, and as such the interior trucks would otherwise tend to carry more weight than the coupler end trucks, a measure of weight equalization is achieved in the embodiments ofFIGS. 11aand11bdescribed above by adding ballast to the end car units in the region of the end trucks. That is, the dead sprung weight distribution of the end car units is biased toward the coupler end, and hence toward the coupler end truck (e.g.350,332).

For example, in the embodiments shown, a first ballast member is provided in the nature of main deck plate222(described above) of unusual thickness T that forms part of main deck38of the rail car unit. Plate222preferably extends across the width of the end car unit, and from the longitudinally outboard end of the deck a distance LB. In the embodiments ofFIGS. 11aand11b, plate222additionally serves as a rolling surface for rollers150and160, and is the deck plate through which the arcuate guide channel224is made to guide the bottom edges of doors68and70as described above. In this case, thickness T may be 1½ inches, the width may be 112 inches, and the length LB may be 312 inches, giving a weight of roughly 15,220 lbs., centered on the truck center of the end truck332. Alternatively, thickness T may be a thickness greater than ¾ inches, such as 1 inch, 1¼ inches, or 1½ inches, or greater. T may, for example, be a thickness in the range of ¾ inches to 2 inches.

Various embodiments of the invention have now been described in detail. Since changes in and or additions to the above-described best mode may be made without departing from the nature, spirit or scope of the invention, the invention is not to be limited to those details.