Dropped deck center beam rail road car with shallow center sill
A center beam rail road car has a center sill that runs along the car from end to end. The center sill is dog-legged, having end portions mounted over rail car trucks, and a downwardly stepped central portion between the trucks. A central beam assembly stands upwardly of the center sill. A lading supporting deck structure extends laterally to either side of the center sill. The deck structure has a depressed medial portion between the trucks, and raised end portions over the trucks. The deck portions have lading bearing interfaces. The medial portion of the center sill has a top flange that is carried at a height that lies flush with, or below, the level of the lading bearing interface of the medial portion of the center sill. In one embodiment, a column member for carrying buff and draft loads is spaced upwardly from the medial portion of the center sill. The car may be constructed in a version having a top truss, or having a top chord member that lies within the profile of vertical posts of the central beam assembly. In embodiments having a narrow top chord, the car may be provided with a top chord cover.
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This invention relates generally to center beam rail road cars, and, in particular, to center beam cars having a depressed deck portion between a pair of rail car trucks.
BACKGROUND OF THE INVENTIONCenter beam rail road cars generally have a rack-like body, in which there is a longitudinally extending deck and an upstanding center beam assembly running down the center of the car. The center beam structure is carried on a pair of rail car trucks. The cars have a pair of end bulkheads that extend transversely to the rolling direction of the car. The lading supporting structure of the beam includes laterally extending decking mounted above, and spanning the space between, the trucks. A center beam web structure, typically in the nature of an open frame truss for carrying vertical shear loads, stands upright from the deck and runs along the longitudinal centerline of the car between the end bulkheads. This kind of webwork structure can be constructed from an array of parallel uprights and appropriate diagonal bracing. Most often, a top truss assembly is mounted on top of the vertical web and extends laterally to either side of the centerline of the car. The top truss is part of an upper beam assembly, (that is, the upper or top flange end of the center beam) and is usually manufactured as a wide flange, or wide flange-simulating, truss, both to co-operate with the center sill to resist vertical bending, and also to resist bending due to horizontal loading of the car while travelling on a curve. Typically, a center sill extends the length of the car. The center beam thus formed is conceptually a deep girder beam whose bottom flange is the center sill, and whose top flange is the top truss (or analogous structure) of the car.
Center beam cars are commonly used to transport packaged bundles of lumber, although other loads such as pipe, steel, engineered wood products, or other goods can also be carried. The space above the decking and below the lateral wings of the top truss on each side of the vertical web of the center beam forms left and right bunks upon which bundles of wood can be loaded. The base of the bunk may include risers that are mounted to slant inward, and the vertical web of the center beam is generally tapered from bottom to top, such that when the bundles are stacked, the overall stack leans inward toward the longitudinal centerline of the car.
Lading is most typically secured in place using straps or cables. Generally, the straps extend from a winch device mounted at deck level, upward outside the bundles, to a top fitting. The top fitting can be located at one of several intermediate heights for partially loaded cars. Most typically, the cars are fully loaded and the strap terminates at a fitting mounted to the outboard wing of the upper beam assembly. Inasmuch as the upper beam assembly is narrower than the bundles, when the strap is drawn taut by tightening the winch, it binds on the upper outer corner of the topmost bundle and exerts a force inwardly and downwardly, tending thereby to hold the stack in place tight against the center beam web.
Each bundle typically contains a number of pieces of lumber, commonly the nominal 2″×4″, 2″×6″, 2″×8″ or other standard size. The lengths of the bundles vary, typically ranging from 8′ to 24′, in 2′ increments. The most common bundle size is nominally 32 inches deep by 49 inches wide, although 24 inch deep bundles are also used, and 16 inch deep bundles can be used, although these latter are generally less common. A 32 inch nominal bundle may contain stacks of 21 boards, each 1½ inch thick, making 31½ inches, and may include a further 1½ inches of dunnage for a total of 33 inches. The bundles are loaded such that the longitudinal axes of the boards are parallel to the longitudinal, or rolling, axis of the car generally. The bundles are often wrapped in a plastic sheeting to provide some protection from rain and snow, and also to discourage embedment of abrasive materials such as sand, in the boards. The bundles are stacked on the car bunks with the dunnage located between the bundles such that a fork-lift can be used for loading and unloading. For bundles of kiln dried softwood lumber the loading density is taken as 1600 to 2000 Lbs. per 1000 board-feet.
It has been observed that when the straps are tightened, the innermost, uppermost boards of the topmost bundle bear the greatest portion of the lateral reaction force against the center beam due to the tension in the straps or cables. It has also been observed that when these bundles bear against the vertical posts of the center beam, the force is borne over only a small area. As the car travels, it is subject to vibration and longitudinal inertia loads. Consequently the plastic sheeting may tend to be torn or damaged in the vicinity of the vertical posts, and the innermost, uppermost boards can be damaged. The physical damage to these boards may tend to make them less readily saleable. Further, whether or not the boards are damaged, if the plastic is ripped, moisture can collect inside the sheeting. This may lead to the growth of molds, and may cause discolouration of the boards. In some markets the aesthetic appearance of the wood is critical to its saleability, and it would be advantageous to avoid this discolouration.
In part, the difficulty arises because the bearing area may be too small. Further, the join between the upstanding web portion of the center beam and the upper beam assembly can coincide with the height of the topmost boards. This join is not always smooth. Further still, when the posts are fabricated the flanges may not stand perfectly perpendicular to the web, such that one edge of the flange may bear harder against the bundles than another.
It is also desirable that the bundles stack squarely one upon another. Although it is possible to use wooden battens at the top end of the center beam web, this will tend to cause the top bundle to sit outwardly of its neighbours. It has been observed that a thin wooden batten, of ¾ ″ thickness may tend to bow inwardly between adjacent posts, and may not spread the wear load as much as may be desired. A 1½ inch thick wooden batten may have a greater ability to resist this bowing effect. However, the space available for employing a batten may tend to be limited by the design envelope of the car. Inasmuch as it is advantageous to load the car as fully as possible, and given that the design of the car may usually reflect a desire to maximize loading within the permissible operational envelope according to the applicable AAR standard, the use of a relatively thick wooden batten may tend to push the outside edge of the top bundle outside the permissible operational envelope. Wooden battens may also be prone to rotting if subject to excessive exposure to moisture, or may be consumable wear items that may require relatively frequent periodic replacement.
It would be desirable to have an upper beam assembly that is integrated into the structure, that is formed to spread the bearing load across a larger area, that would tend to resist the bowing phenomenon, that would tend not to require frequent replacement, and that would tend not to be prone to rotting.
Existing center beam cars tend to have been made to fall within the car design envelope, or outline, of the American Association of Railroads standard AAR Plate C, and tend to have a flat main deck that runs at the level of the top of the main bolsters at either end of the car. In U.S. Pat. No. 4,951,575, of Dominguez et al., issued Aug. 28, 1990, a center beam car is shown that falls within the design envelope of plate C, and also has a depressed center deck between the car trucks. It would be advantageous to be able to operate center beam cars that exceed Plate C and fall within AAR Plate F, with a full load of lumber in bundles stacked 5 bundles high. A five bundle high load of 33 inch bundles requires a vertical clearance in the left and right hand bunks of at least 165 inches. This significantly exceeds the vertical loading envelope of a plate C car.
In known center beam cars, such as those shown in U.S. Pat. No. 4,951,575 and in U.S. Pat. No. 4,802,420 of Butcher et al., issued Feb. 7, 1989, the deck structure of the cars has included inwardly tapering risers mounted above the cross bearers, with longitudinally extending side sills running along the ends of the cross-bearers. The side sills have been angle or channel sections. In U.S. Pat. No. 4,951,575 the side sills are z-sections with the upper leg of the Z extending outward, the lower leg extending inward, and the web between the two legs running vertically. In U.S. Pat. No. 4,802,420 of Butcher et al., the side sill is a channel section, with the legs extending laterally outward and the web, being the back of the channel, extending vertically between the two legs. In both cases the winch is mounted outward of the vertical web.
In center beam cars it is desirable that the center sill be aligned with the couplers to reduce or avoid eccentric draft or buff loads from being transmitted. In dealing with lateral loads, the side sills act as opposed flanges of a beam. The loads in the side sills, whether in tension, compression, vertical shear or lateral bending, tend to be transferred to the main sill through a main bolster assembly at each end of the car. In general the bolster is located at a level corresponding to the height of the main sill, and the shear plate, if one is used, is typically at a level corresponding to the level of the upper flange of the main sill.
It is desirable to have a well deck, also called a depressed center deck or dropped deck, between the trucks, to increase the load that can be carried, and so to increase the overall ratio of loaded weight to empty weight of the car, and also to reduce the height of the center of gravity of the car when loaded, as compared to a car having a flat, straight through deck from end to end carrying the same load. In the case of a well deck, longitudinal compression and tension loads in the side sills must be carried from the level of the side sills in the well, to a second, higher level of the side sills to clear the trucks, and then through the bolster structure and into the main sill. The transmission of forces through the vertical distance of the eccentricity of the rise from the side sills height in the well to the side sill height of the end deck adjoining the bolster results in the generation of a moment. When the side sill has a knee at the transition from the well to the end structure of the car, the height of the knee defines the arm of the moment.
The centerline height of a coupler of a rail road car, when new, may be 34½″ above top of rail (TOR). This is a standard height to permit interchangeable use of various types of rail cars. The main sill, or stub sill if used, tends to have a hollow box or channel section, the hollow acting as a socket into which the coupler is mounted. The minimum height of the main sill at the trucks (or stub sill, if one is used) and end structure bolsters tends to be determined by the coupler height, and the height required to clear the wheels. The height of the well deck is limited by the design envelope, be it Plate C, Plate F, or some other. In general, however, the height of the shear plate, or top flange of the bolster, to the well decking is less than the desired 33 inch bundle height. It is desirable for the top of the first layer of bundles stacked in the well to be at a height that permits the next layer of bundles to match the height of bundles stacked over the trucks. Consequently it would be advantageous to have a false deck, or staging, mounted above the shear plate, or if there is no end structure shear plate, then above the bolster, at a level to match the level of the top of the bundles carried in the well between the trucks.
One way to reduce the stress concentration at the knee is to make the side sill section of the end portion of the sill deeper. Another way to reduce the stress concentration at the knee is to make the knee member wider. On the longitudinally inwardly facing side of the knee (that is, the side oriented toward the lading in the well) the flange of the vertical leg of the knee may tend to extend perpendicularly. On the longitudinally outboard side, that is, the side facing the truck, the longitudinally outboard flange can be angled, or swept, resulting in a tapering leg, rather than one with parallel flanges. An increase in the section width, due to tapering the longitudinally outboard flange is desirable, as it permits a reduction in the stress concentration in the side sill assembly at the knee, and tends to provide greater truck clearance.
Where a dropped deck center beam car is used, the juncture between the posts and the medial portion of the center sill may leave a discontinuity in the lading contacting surface. That is, where the center sill is a straight-through center sill, such that (subject to any cumber) the top flange of the center sill runs continuously from one end of the rail road car to the other in a single horizontal plane, the lower bundles of the lading in the medial portions of the car are nestled snug against the laterally outwardly facing bearing surfaces of the medial portion of the center sill. The upper bundles nestle against, and the load securement cables are tightened to encourage snug securement against, the laterally outwardly facing flanges of the center beam assembly posts. Due to the practicalities of manufacturing, there may be a discontinuity between the lading contacting interface surface, or surfaces, of the medial portion of the center sill and the outwardly facing flanges of the posts. This discontinuity may be deliberate—as when the center sill has parallel, vertical webs, and the posts are tapered, or it may be inadvertent, as when the posts are slightly misaligned on installation, either being angularly mis-oriented such that the join is skewed, or translationally mismatched such that the join is not co-planar, or the weld at the join may not be ground flush and smooth, leaving a protruding asperity to damage adjacent lading.
It may therefore be advantageous to have, in the medial portion of the car, posts whose flanges extend the full height from the top chord to the deck of the medial section, presenting one continuous, planar bearing surface. Such a continuous surface may tend not to have local asperities due to mis-aligned adjacent members or poorly executed and finished weldments. To achieve this objective of a continuous bearing surface, it may be desirable, as shown and described herein, to employ a center sill medial portion whose external surfaces lie shy of (or put differently, not proud of) the profile of the bearing surfaces of the posts. To that end it may be advantageous to employ a shallow center sill, as in one aspect of the present invention, in which the upper flange of the center sill is not continuously planar, but rather has a depressed medial portion lying lower than the end portions. Further, it may be advantageous to employ a shallow, or very shallow, center sill in the medial, or dropped deck portion of the car, in which the upper flange of the center sill lies at a level corresponding to, or shy of, the level of the upwardly facing lading bearing interface of the medial portion of the deck structure. For example, the upwardly facing lading bearing interface of the deck structure may be either the support array formed by the upwardly facing surfaces of a series of risers, such as may be mounted over pitched cross-members, or, in a riserless car, may by the generally flat surface of the deck in a riserless car.
Optionally, a shallow center sill as shown and described in one aspect of the invention herein, may result in an eccentric moment being placed upon the center sill, as, for example, when the car is subjected to a longitudinal squeeze (i.e., buff) load. Such a squeeze load may be idealized as a longitudinal compressive load applied at the centerline of the couplers, with the tendency to cause the center sill to buckle. Where the centroid of the cross-section of the shallow portion of the center sill (or of the medial section of the deck in a center-sill-less medial portion, should such a novel structural feature be adopted in a center beam car) lies below the centerline of the couplers, there may tend to be a moment carried through the knees. In that circumstance it may be advantageous to provide a longitudinal reinforcement member for carrying at least a portion of the squeeze load, and, additionally, it may be advantageous for that longitudinal compression (or, indeed tension) carrying member to have the centroid of its cross sectional area located at a level at or above the centerline of the couplers. In such an instance, as shown and described herein in another aspect of the present invention, the compression member spaced upwardly from the center sill would also lie within the profile of the flanges of the posts.
It may be advantageous to be able to carry loads other than, for example, bundles of lumber, on at least a part of the return journey. While this can be done with center beam cars presently in use, the overhanging wings of the top truss may tend to complicate loading of the car from above. For example, it may be more convenient to load pipe, or other objects, using an overhead crane rather than to employ side loading using a fork-lift of perhaps more limited lifting capacity. Such loading would be facilitated by removal of the top truss. Further still, in addition to removal of the top truss, truncation of the central web at a level below the bottom of the uppermost row of bundles permits the top row of bundles to be loaded side by side. Strapping for securing the load, rather than being attached to the wings of the top truss, can be carried fully over the load to the winches at deck level on opposite sides of the car. In addition, the top chord can be made wider than the posts, such that the bundles bear against the smooth outside face of the top chord at a stand-off distance clear of the flanges of the posts.
Further, where, as described in one aspect of the invention herein, the top chord is relatively narrow, and is not surmounted by a top truss structure of significant lateral extent, it may be advantageous to provide a low-abrasion cover. It would be further advantageous if that cover could be manufactured from a single piece of stock, and if it could be installed in a manner where gravity might tend aid in keeping the cover in place.
Torsional loads applied to the center beam assembly are transmitted through the trucks and reacted at the rails. A significant portion of this load is transferred into the deck and main sill structure at the longitudinal location of the truck center by the main posts that extend upwardly from the deck above the truck center. It may be that the main post is narrower than the center sill top cap (i.e., upper flange), and narrower than the underlying center sill webs. It such circumstances it may be advantageous to provide web and flange continuity in the center sill beneath the main post.
SUMMARY OF THE INVENTIONIn an aspect of the invention there is a center beam railroad car having a longitudinal centerline. The railroad car is supported by rail car trucks at either end thereof. The railroad car comprises a cargo support structure borne between the trucks, upon which cargo can be carried. The center portion of the cargo support structure is depressed relative to the end portions. The rail road can has full height posts that extend from the depth of the depressed portion to the top chord. In this portion of the car, the top flange of the center sill is flush with, or lies below, the plane of contact of the lading with the load bearing interface of the deck of the depressed portion.
In another aspect of the invention there is a dropped deck center beam rail road car. It has a lading support structure carried on rail road car trucks for rolling motion along rail road tracks. The lading support structure has upstanding bulkheads mounted at opposite ends thereof, a laterally extending deck structure, and a central beam assembly standing upwardly of the laterally extending deck structure. A coupler is mounted at one of the ends of the lading support structure. The coupler has a coupler centerline height. The deck structure has a pair of end portions and a medial portion. The end portions are stepped upwardly relative to the medial portion. Each of the end portions and the medial portion of the deck structure have lading bearing interfaces upon which lading can be placed. The central beam assembly includes a webwork assembly extending upwardly of the medial portion of the deck structure to a longitudinally extending top chord member. At least a portion of the web work assembly extending to a height lower than the lading bearing interface of one of the end portions of the deck structure.
In an additional feature of that aspect of the invention, a coupler is mounted to at least one of the ends of the lading support structure. The coupler has a coupler centerline height, and at least a portion of the web work assembly extends lower than the coupler centerline height. In another feature, the web work assembly includes laterally outwardly facing lading contact surfaces against which to secure lading. The medial portion of the deck structure has an upwardly facing load bearing interface upon which to place lading, and the lading contacting surface extends downward to a level corresponding to the load bearing interface of the medial portion of the deck structure. In a further feature, the load bearing interface of the medial portion of the deck structure apparatus is chosen from the set of apparatus consisting of (a) an array of risers upon which to place lading; and (b) deck sheeting upon which to place lading. In a still further feature, the web work assembly includes a laterally outwardly facing continuous load contacting surface that extends over a range of height greater than 140 inches from bottom to top.
In a further aspect of the invention, there is a dropped deck center beam rail road car. It has a center sill carried by rail car trucks for rolling motion along rail road tracks, and a deck structure upon which lading can be side loaded. The deck structure extends laterally outward from the center sill and has a depressed medial portion. Upstanding bulkheads are mounted at opposite end of the deck structure. A central beam assembly stands upwardly of the center sill and runs longitudinally between the bulkheads. The center sill has end portions and a downwardly stepped medial portion. The end portions have uppermost flange members, and the downwardly stepped medial portion has an uppermost flange member. The uppermost flange member of the medial portion lies at a lower height than the uppermost flange member of one of the end portions.
In an additional feature of that aspect of the invention, a coupler is mounted at one end of the rail road car. The coupler has a coupler centerline height. The uppermost flange member of the medial portion lies at a lower height than the coupler centerline height. In another additional feature, the medial portion has a cross-sectional area. The cross sectional area has a centroid. The centroid lies between 12 and 18 inches below the coupler centerline. In a further additional feature, the depressed medial portion of the deck structure has a load bearing interface upon which to place lading, and the uppermost flange member of the medial portion of the center sill lies at in a location chosen from the set of locations consisting of (a) flush with the load bearing interface of the medial portion of the deck structure; and (b) shy of the load bearing interface of the medial portion of the deck structure.
In a still further additional feature, the downwardly stepped medial portion of the center sill is located between two end portions of the center sill. The end portions are upwardly stepped relative to the medial portion of the center sill. A longitudinally extending reinforcement member is spaced upwardly from the medial portion of the center sill. The longitudinally extending reinforcement member is connected to carry longitudinal loads between the end portions of the center sill. In another additional feature, the end portions of the center sill include respective center sill top flange portions, and the longitudinally extending reinforcement member has a flange portion mounted at a height to pass loads between the top flange portions of the end portions of the center sill.
In still yet another additional feature, the rail road car has a coupler, and a coupler centerline height, the longitudinally extending reinforcement member has a cross-sectional area, the cross-sectional area has a centroid, and the centroid of the cross sectional area lies at a level that is at least as high as the centerline height of the coupler. In a further feature of that feature, the centroid lies 12 to 18 inches above the coupler centerline height. In an alternate, or additional further feature of that feature, the medial portion of the center sill has a cross-sectional area, and the cross-sectional area of the medial portion of the center sill lies at a height between 12 and 18 inches lower than the coupler centerline height. In a yet further feature a first distance is defined between the centroid height of the reinforcement member and the coupler centerline height, a second distance is defined between the coupler centerline height and the height of the centroid of the medial portion of the center sill, and a ratio R is defined as (a) the product of the first distance multiplied by the cross sectional area of the reinforcement member, divided by (b) the product of the second distance multiplied by the cross sectional area of the medial portion of the center sill, and the ratio R lies in the range of 0.70 to 1.40. In a still further feature, a ratio R is defined as (a) the first distance divided by (b) the second distance; and the ratio R lies in the range of 0.5 to 2.0.
In a still further aspect of the present invention, there is a dropped deck center beam rail road car. It has a lading support structure carried on rail road car trucks for rolling motion along rail road tracks. The lading support structure has upstanding bulkheads mounted at opposite ends thereof, a laterally extending deck structure, and a central beam assembly standing upwardly of the laterally extending deck structure. The deck structure has a pair of end portions and a medial portion, the end portions being stepped upwardly relative to the medial portion. The central beam assembly includes a webwork assembly extending upwardly of the medial portion of the deck structure to a longitudinally extending top chord member. The web work assembly presents a laterally outwardly facing lading contact surface against which lading can be placed. The laterally outwardly lading contact surface is continuous from the medial portion of the deck structure to the top chord.
In an additional feature of that aspect of the invention, the outwardly facing lading contact surface of the web work assembly has slope continuity with the top chord. In another feature, the top chord has side faces against which lading can be secured. In a still further feature, the top chord is chosen from the set of top chords consisting of (a) a top chord mounted at a partial height elevation relative to the end bulkheads, wherein lading can be placed to either side of the top chord, and also carried thereabove; (b) a top chord mounted at a full height elevation relative to the bulkheads, and lading can be placed to either side thereof to bear laterally thereagainst, the top chord being unencumbered by laterally extending top truss members; and (c) a top chord member surmounted by a top truss mounted at a full height elevation relative to the bulkheads.
In another aspect of the invention there is a centerbeam rail road car having a truss-less top chord member. A removable plastic cover is provided for the top chord. The cover is made of a high molecular weight polymer, and provides a low friction surface against which to secure bundles of lading.
In an additional feature of that aspect of the invention, the cover is held in place by gravity. In a further additional feature, the cover is supplied in a plurality of sections to permit partial removal and replacement. In another feature, the cover is made from a roll formed plastic sheet. In another feature, the top chord has securement fittings be which to attach the cover to the top chord. In still another feature, the cover has an interference fit with the top chord. In another feature, the cover is resilient, whereby the cover can be flex to permit installation, and the cover is biased to snap or spring into place into place. That is, it is biased to retain itself in position. In another feature, the cover has an inwardly turned lip, and the lip is relieved to accommodate flanges of posts of the center beam assembly.
BRIEF DESCRIPTION OF THE DRAWINGS
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 which follows, 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 extending cross-wise 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 or orientation relative to a mid-span lateral section of the car, or car unit.
A center beam railroad car is indicated in
The structure of a center beam car is analogous to a deep beam having a tall central structure to approximate the web of a beam, or a web-like structure or truss assembly, a wide flange at the bottom, and a wide flange at the top. In the case of car 20, the central web assembly is indicated generally as 30 and runs in the longitudinal direction (that is, the rolling direction of the car), the top flange function is served by a top truss assembly 32, and the lower flange function is performed by center sill 3b, from which extends an assembly that includes a lateral support structure 34, in the nature of a deck, or frame, or staging upon which cargo can be placed. Lateral support structure 34 generally includes deck structure 26, and its outboard left and right hand side sills 42 and 44.
It will be appreciated that aside from fittings such as hand grabs, ladders, brake fittings, and couplers, the structure of car 20 (and the other embodiments of railroad cars shown and described herein) are symmetrical about the longitudinal plane of symmetry 24, and also about a transverse plane of symmetry 31 at the mid-length station of the car. In that light, a structural description of one half of the car will also serve to describe the other half. The features of car 20 thus enumerated are basic structural features of a center beam car having a depressed center deck.
In detail, center sill 36, is a fabricated steel box beam that extends longitudinally along car 20, having couplers 38 mounted at either end. Cross bearers 40 extend outwardly from center sill 36 to terminate at a pair of longitudinal left and right hand side sills 42, 44 that also run the length of the car. In the various embodiments of rail cars shown herein, cross-bearers are indicated as item 40 and cross-ties are indicated as item 41. These cross bearers and cross ties extend laterally outward from center still 36 on approximately 4 ft centers. Decking 46 is mounted to extend between cross-bearers 40, and cross-ties 41 providing a shear connection between adjacent cross-bearers when side loads are imposed on the car. Structural members in the nature of tapered risers 48 may be mounted above the cross-bearers and cross-ties to form the base of a bunk for carrying loads. Risers 48 are tapered so that loads stacked thereupon will tend to lean inwardly toward the center-line of car 20. Where risers are used, the upper surfaces of risers 48 define respective end decking portion and medial decking portion load-bearing interfaces upon which lading my be placed.
As noted above, deck structure 26 has a first end portion, namely end deck portion 27, a second end deck portion, namely end deck portion 28, and a medial deck portion 29. At each of the transitions from either end deck portion 27 or 28 to medial deck portion 29 there is a knee, indicated as either 47 or 49. Not only is deck structure 26 stepped in this manner, but so too are side sills 42 and 44, each having end members 41, 43, and a medial span member 45.
At either end of car 20 there are vertically upstanding fore and aft end bulkheads 50 and 52 which extend from side to side, perpendicular to the central longitudinal plane 24 of car 20. Running the full length of car 20 between end bulkheads 50 and 52 is an array 54 of upright posts 73, 74. Array 54 may include tapered fabricated posts 73 having a generally H-shaped cross-section and tapered posts 74 having a generally C-channel shaped section. In alternate embodiments, as noted below, variations of array 54 with straight-sided posts may include seamless steel tubes of rectangular cross-section, identified as 56, and square steel tubes of main posts 55 mounted over the truck centers in some embodiments, and channel members of constant section identified as 57. Posts 56, 57, 73 and 74 may be employed in either long or short versions, the long versions being for employment in the medial deck portion of the cars, and the short versions being for employment with the end deck portions of the cars. In several embodiments, the end bays have solid shear bay panels 75, 76 respectively. End diagonal struts 77, 78 extend upwardly and longitudinally outboard away from the respective truck centers. Structural reinforcement members in the nature of left and right hand short two-bay inboard diagonal braces, are indicated as 79, 80. Array 54 is reinforced by long diagonal braces 58, 59, that provide a shear path for vertical loads. There are many different possible configurations of posts and diagonal bracing.
The array 54 of posts 56, 57 is surmounted by an upper beam assembly 60 and deep beam top chord assembly 62. An open framework top truss 64 is mounted atop deep beam top chord assembly 62. Truss 64 has lateral wings 65 and 67 that are mounted to extend outboard from the central plane of car 20 in a cantilevered manner. Truss 64 has longitudinal stringers 66, cross members 68 and shear plates 69.
In each embodiment shown and described herein, and the combinations of features of the various embodiments that may be made without departing from the spirit and scope of the present invention, the array of posts 54 surmounted by an upper beam structure form a central beam assembly standing upwardly of the deck structure. In this central beam structure, array 54, and the diagonal braces co-operate to provide a shear transfer web-like structure between center sill 36 and the top chord, whether in the form of a single beam top chord, or top chord, both indicated generically as assembly 62, as may be the case, such that the overall structure may tend to perform like a deep truss under vertical bending loads.
In car 20, and in all of the other rail road cars described herein, staging, or other end deck support structure upon which lading can be placed is carried above the respective end deck portions. This support structure of the end deck portions is offset from the lading supporting structure of medial deck portion 29 by an upward step height increment indicated as 8 (
The following description will address straight post cars, such as cars 70 and 80 of
Center sill 36 has a pair of first and second end portions, 84, 86, and a medial portion 88 lying therebetween. Medial portion 88 is joined to end portions 84, 86, respectively, by first and second center sill transition sections, or knees 89, such that a dog leg is formed at each knee and medial portion 88 is eccentrically offset downward relative to end portions 84 and 86. Center sill 36 has an upper horizontal member in the nature of upper flange 102, and a pair of spaced apart vertical shear carrying members in the nature of left and right hand center sill webs 103, 104, thus forming three sides of a box. The fourth side of the box is formed by a lower horizontal member, in the nature of a center sill lower flange 106. Lower flange 106 has an end portion, running along the outboard portion of center sill 36, in a manner similar to a stub sill, indicated in
As seen in
Generally triangular knee brace portions 90 are formed from center sill web extension portions 91, 93 and inclined top flange transition portion 92, portion 92 being formed to extend as the hypotenuse of the triangular shape so formed. The inboard end of portion 92 is rooted to flange 87 immediately longitudinally outboard of the first vertical post longitudinally inboard of each respective knee. The spacing of web extension portions 91, 93, and the width of flange transition portion 92 is less than the width of posts 73, 74, such that the transition lies shy of the plane of contact of the posts with the lading.
In car 20, the posts along the middle section of the deck structure, designated the “long posts”, whether they are channels, H-shaped, or four sided seamless steel tubes of rectangular cross section (as illustrated in
It will be noted that in this example, the side flanges of the long posts, namely those facing laterally outward toward the lading, extend from the top chord 62 downward to a level lying below the level of the top flange of the end portion of center sill 36, below the level of the upper wall of the draft pocket, below the level of the centerline 25 of the coupler, and below the level of the bottom flange of the end portion of center sill 36.
In the embodiment of
As seen in
Web 114 has a tapered portion 118, and a continuous lower flange 120 that follows the profile of the lower edge of portion 118 between side sill 42 (or 44, as may be) and center sill 36. Each upper flange 116 of each cross bearer 112 may have mounted on it a riser 124 that is tapered in profile, being shallowest closest to the car centerline 25, and deepest at its outboard extremity so that lading borne thereon will tend to have an inward slant. As viewed from above, the distal, or outboard, end of upper flange 116 and lower flange 120 are flared and radiused to meet the inner face of longitudinally extending medial side sill portion 126. The upper flange 130 of side sill portion 126 lies flush, and co-planar with, upper flange 116, the outboard end of riser 124 overlying side sill flange 130. As noted above, those portions of flange 87, flange 116, and flange 130 that remain exposed provide a peripheral lap surface upon which floor sheets 127, 128 can be welded, providing a shear connection between those elements.
As seen in
Straps 136 (
The construction of the embodiment of end deck portion 28 (or 27) of car 70 or 80, is shown in
Knee 47 (or 49 of opposite hand) is located at the transition, or step, between end portion 28 (or 27) and medial deck portion 29. Knee 47 is located at a mid-bay longitudinal station between the longitudinal stations of formed post 152 and post 154 (
The upright portion, 164 (
Longitudinally outboard rear facing flange member 168 is made from a bent plate cut to the desired profile. An upper leg 188 of member 168 runs along the lower edge of upper web portion 170 to abut the lower flange 187 of side sill end portion 43; and a lower leg 190 that runs downwardly from the end of leg 188 on an angle along the edge of quadrilateral web portion 170. Leg 190 also has an inwardly tending toe 192 cut to a similar profile to leg 182 and toe 184. A gusset 194 seats within the end section of side sill medial section 45 in the plane of toe 192, in a manner similar to gusset 186.
As thus described, the upright portion of knee 47, (or 49) is tapered, being narrower at the bottom and wider at the top. That is, the width measured between items 166 and 168 at the level of lower flange 187 of side end portion 43 is greater than the width measured between items 166 and 168 at the level of upper flange 130 of side sill portion 45.
Lower cross member 178 is a fabricated T-section having leg 196 lying in a vertical plane, perpendicular to the longitudinal centerline of car 20, between side web 103 (or 104) of main sill 36 and the trimmed transition of front flange member 166. The horizontal other leg 195 of member 178 lies in a horizontal plane between, and is welded to, the outer edge of bottom flange 106 of main sill 36 and the juncture of the back, or web 134, and upper flange 130 of medial side sill portion 45. An intermediate bulkhead sheet 180 is welded between web 104 (or 103 as may be) and overlapping flange member 166, the vertical leg of angle section member 174, channel stiffener member 176, and leg 196 of lower cross member 178.
A stringer in the nature of a U-section with the legs orientated up, longitudinally extending stiffening member, in the nature of a channel 198 extends from a hangar bracket web mounting on the underside of member 178 to the first cross-bearer 112. The lower framework of the medial deck portion, namely that extending between the lower flange of main sill 36, the top flange of side sill medial portion 45, and the top flanges of the cross-bearers of medial portion 29 and of channel 198 are overlain by, and welded to, the deck sheets 193 of medial portion 29.
Another longitudinally extending stiffener, in the nature of a channel member 179 is mounted between bolster 200, cross-tie 150 and cross member 174 about half way between main sill 36 and side sill end portion 43. The upper flange 102 of main sill 36 is carried at a height corresponding to the height of the end deck portions 27 or 28. The overlying shear panel sheet 199 lying at that height is welded to the upper flange 102 of main sill 36, overlaps the upper flange of side sill end portion 41 (or 43), and overlies the upper flanges of the cross-ties and bolsters of end decking portion 27 (or 28), and the upturned toes of channel member 179.
Each of center beam cars 70 and 80 has an array of center beam web posts, indicated generally as 54. As shown in
Each post 55 is, as noted above, a square steel tube extending upwardly from the deck above the respective truck centers. Post 55 is narrower (in the longitudinal direction of car 20) than the spacing of the webs of main bolster 200, and consequently narrower than main bolster web continuation plates 201, 203 mounted within main sill 36 in line with the bolster webs at the truck center. Similarly, post 55 is narrower (in the lateral direction across car 20) than the spacing of that portion of webs 103 and 104 of main sill 36 extending outboard of ‘X1’, past main bolster 200 toward coupler 38, namely plates 212, 214 defining the width of the draft pocket. Top flange 102 of main sill 36 has an access opening in the nature of a rectangular cut-out 101 at the truck center. Post 55 is welded, at its lower, or base end, to a matching rectangular plate 105 that mates with cut-out 101. A pair of first and second web continuation plates in the nature of gussets 207, 209 extend in longitudinally oriented vertical planes from the bottom side of plate 105. A pair of first and second flange continuation plates, in the nature of gussets 211 and 213 extend in transversely oriented vertical planes from the bottom of plate 105. Gussets 211 and 213 are welded along the side edges of gussets 207 and 209. Gussets 211 and 213 extend beyond gussets 207 and 209 to meet web continuation plates 202 and 204. This structure provides longitudinal and lateral reinforcement to the built-in connection of post 55 to main sill 36.
As shown in
Posts 55, 56 and 57 (
As shown in
As seen in the end view of
In car 70, the lateral inboard force on bundles L5 is reacted by the large, smooth bearing faces of webs 238 and 240 of top chord 62.
The end portions of center sill 36 at the location of the draft pocket are relatively tall, being more than 18 inches deep, and preferably about 27 inches deep. The end portions of center sill 36 lying outboard of bolster 200 have an aspect ratio of height (measured over the outboard end portion of upper flange 102 and the outboard portion 108 of lower flange 106), to width (measured across the inside faces of the webs that accommodate the draft gear) greater than 1:1, lying in the range of 1.5:1 to 3.0:1, and, in the preferred embodiment, of about 2:0:1, namely 27 inches as compared to 12⅞ inches. As above, a relatively taller main sill end portion may tend to simplify construction.
Returning to
As above, the dropped deck portion of the deck ends at left and right hand knees, indicated as 47, 49.
In this embodiment it will be noted that the upper flange of main sill 356 is carried at a height corresponding to the height of the medial deck portions.
The incline of flanges 496, 498 is roughly at right angles to the inward taper of risers 374 (or 48 as the case may be). This permits generally square cornered bundles to be stacked neatly in the clearance opening of the bunk defined between the underside of the top truss 64 and risers 48 (or 374).
In the one embodiment, cars 20, 70, 80 or 90 may have a well deck portion intended to provide 40 ft of usable internal length, being about 40-41 ft in length, namely 40 ft-6 in. long. The internal lading height of the well, that is, the nominal loading height of the bunk defined between the medial decking portion load bearing interface and the wings 65, 67 (
Although a 40 ft., 6 in. medial deck, or well deck, is preferred, a shorter well deck could be employed, such as 28 ft. 6 in., 32 ft. 6 in., or 36 ft. 6 in., it being advantageous that the well deck be at least 28 ft. long.
Each of center beam cars 20 and 90 has an array of center beam web posts, indicated generally, and generically, above as 54. Each of these arrays includes fabricated tapered posts, having a generally H-shaped cross-section, and roll formed posts having a generally C-shaped cross-section or square or rectangular steel tubes as previously noted. In these embodiments the posts mounted on the end portions of the respective railcars are formed to have web and flange continuity with main sill extensions, such as gussets 192 and 194.
A description of post 73 will serve also to describe the other posts having H-shaped cross-section in the various embodiments of rail road cars described herein. Similarly, a description of post 74 will serve to describe the other posts having C-shaped cross-sections in the various embodiments. Each of posts 73 has a central web lying in a vertical plane perpendicular to the plane 24 of car 20 or 90. The web of post 73 is tapered from a wide bottom adjacent main center sill 36 to a narrow top. At the outboard extremities of the web there are left and right hand flanges 496 and 498 (
A horizontal cross-section of post 73 will generally have an H-shape, with web 494 lying centrally relative to flanges 496 and 498. Post 74, by contrast, although tapered in a similar manner to post 474, has a horizontal cross-section of a U-shaped channel, with its web being the back of the U, and the flanges being a pair of legs extending away from the back.
Whether parallel sided or tapered posts are used, each diagonal member 58 (or 59 or struts 77, 78 or braces 79) has a first end rooted at a lower lug 97 welded at the juncture base of one of posts 55, 56 or 73 adjacent to the juncture of that post with main center sill 36, and a second diagonal end rooted in an upper lug 99 at the juncture of another adjacent post 56 or 73 and top chord assembly 62. Midway along its length, diagonal member 58 (or 59 or struts 77, 78 or braces 79) passes through post 57 or 74 intermediate the pair of posts 55, 56 or 73 (as may be) to which diagonal 58 (or 59 or struts 77, 78 or braces 79) is mounted. It is intended that the respective laterally outwardly facing sides, or flanges, of the various posts lie in the same planes on either side of the central plane 24 of car 20 (or 70, 80, or 90) to present an aligned set of bearing surfaces against which lading can be placed, that aligned set of surfaces running from the top flange of the center sill at a level corresponding to the load bearing interface of the medial and end portions of the deck structure, up to the top chord. The sides of the top chord may also be co-planar with the posts.
The variations of top chord will now be described. In the case of the embodiments of
As a preliminary matter, each of the top chord members of cars 70, 80 or 90 of
Further, cover 512 may have the channel shape shown, having a back or web 514, and legs 516, 518. The distal tip of legs 516, 518 may have an inwardly formed bead or lip 520 running therealong for the purpose of achieving a “snap fit” on the top chord. Bead 520 may be formed as a series of intermittent blisters with a gap 521 between the blisters to accommodate the flanges of the posts. In a further alternative, a securement fitting, which may be in the nature of a hard eye 522 may be provided in each lip, or bead, 520 to permit mechanical fasteners 524 to secure cover 512 in place. A cleat or stud 526 may protrude downwardly from the top chord to provide a securing point for the mechanical fastener 524. The mechanical fasteners may include tumbuckles, cables, or nylon tie wraps. In a still further alternative or additional feature, the upward face of the top chord member may be provided with securement fittings, such as an upwardly standing cleat or stud 528 for co-operation with an aperture 530 formed in cover 512. A mating capture member for securing cover 512 in place, in the nature of a threaded nut, or cap 532 may then engage cleat or stud 528, as may be, to discourage cover 512 from moving. While it may be possible to provide cover 512 in a single extending fully between the end bulkheads, (typically about 72 to 73 ft) it may be preferable to obtain cover 512 in modular sections, of about 6, 8 or 12 ft in length. Of these, section for placement oh 8 ft centers would be preferred. On installation, legs 516, 518 are splayed apart to allow lips 520 to be pushed over top chord 62. When lips 520 reach the lower edges of top chord 62, they may tend to seat as shown in
In the embodiment of
Straps 136 (
The embodiment illustrated in
Deep beam section 510 is shown in cross-section in
Gussets 572 and 574 are welded inside formed section 550 and 540 respectively at longitudinal stations along the length of car 20, (or 70, 83, 85, 90, 92, 94, 350) corresponding to the various longitudinal stations of the webs of posts 73 and 74 respectively, thus providing a substantially continuous web from main sill 36 to top truss 64. There is, however, a web discontinuity between gusset 572 and gusset 574 indicated by gap ‘G’, seen in
In this way, when assembled, legs 554, 555 and 544, 546 form respective left and right hand outwardly facing bearing surfaces against which a load may bear, and over which a reaction force to tension in the tightening straps can be spread. In the span between the stations of adjacent posts (whether 73 or 74), the skirts, or bearing surfaces, formed in this way are reinforced by the laterally inward web, (that is, back 552) which connects both skirts (that is, legs 544 and 554, and legs 546 and 555). The laterally inward reinforcement need not be immediately behind the respective skirt or facing, but rather can be offset, as illustrated in
In an alternative embodiment shown in
In the alternative embodiment of
On assembly, L-shaped gussets 636, 637 are welded in each of sections 628, 629. Gussets 636 and 637 each have a profile to match the inside profile of the upper regions of main sheet portions 630, 631, legs 632, 633 and toe 634, 635. The toes of gussets 636 and 637 are welded along their outboard edges to the inside face of main sheet portions 630, 631. Sections 628 and 629 are welded along the centerline seam between abutting toes 634 and 635. A further, main, gusset 640 is trimmed to a shape to permit welding of its top edge to the underside of the toes 638, 639 of gussets 636, 637, its side edges to the inner face of the lower regions of main sheet portions 630 and 631; once welded in this manner, the base leg 642 of gusset 640 can be welded to toes 626 and 627 of angle irons 622 and 624, with a plug weld formed to fill the longitudinal gap therebetween. Gusset 640 is also trimmed to have reliefs 644, 645 to permit entry between the upwardly extending legs of angle irons 622, 624. Gussets 636, 637 and 640 are located at longitudinal stations that correspond generally to the longitudinal stations of posts 56 and 57 as the case may be. Legs 632, 633 of sections 628, 629 form, ideally, a flat surface to weld to top truss assembly 64, as before. Similarly, when installed, main sheet portions 630, 631 have slope continuity with flanges 496 and 498.
In the alternative embodiment of
In the alternative embodiment of
The alternate embodiment of deep beam 720 of
In this instance a large gusset 738 is welded inside section 722, and plates 732 and 734. Gusset 738 has a vertical leg 740 having a profile cut to yield the desired slope continuity with the flanges of posts 73 and 74.
The alternate embodiment of deep beam 750 of
In the embodiment of
The embodiment of
Panel 830 could be as thick as ½ or ⅝ inches. Although panel 830 is preferably a metal sheet welded to posts 820, a different fastening means, such as rivets, bolts or the like, could be used. A smooth steel face is preferred, but other metals, such as aluminum, could be used, or a suitable, rot resistant, UV resistant polymer could be selected, either as a solid sheet or as a face coating or layer, or sheet, upon a metal substrate. It is preferred that the material chosen be a non-consumable material, that is, one that may tend not to be prone to require frequent replacement such as may be required if softwood lumber battens are used, and also one that has little or no tendency to develop wood rot or to support the growth of molds
Panel 830 need not be integrally formed with bent toe 832, but could be fabricated by using a flat sheet 840 as the external face plate, with an angle iron 842, or similar stiffener, welded along the inward facing bottom edge of the face plate between pairs of posts 820, as indicated in the other half view shown in
In each of the embodiments illustrated in
The embodiment of
The embodiment of
In the embodiment of
In the embodiment of
In alternative embodiments, the level of the bottom edge of the legs could be as little as one board (1 and ½ inches, kiln dried wood) below the top edge of the design bundle height, but is expected to be most commonly 12 inches, 24 inches (as in the preferred embodiment) or 30 inches deep when measured from the join to the top truss.
It is possible to manufacture a generally similar center beam car to fall within the loading profile defined by AAR plate ‘F’, or some other height. In that case, the desired load limit height is the height that is the largest integer multiple of 33 that is less than the clearance opening. The minimum height of the bottom edge of the leg, or skirt, is desirably 1 and ½ inches or more below the nominal load height, typically such that the overall height of the skirt is, nominally, an integer multiple of 6 that is at least 12 inches. Preferably, the skirt extends to a height that is at least half way down the top bundle of the nominal design load, and possibly to a height that is the full depth of the top bundle.
Although the main deck could be a continuous decking structure, this need not necessarily be so. The main deck, or lower beam structure could be in the form of an open truss, or grid work. Car 20, and the other rail road cars described herein, are preferably of all-steel construction. However, although the web work assembly of the center beam, and the top truss section is preferably a welded steel fabricated structure, it could be made of aluminum.
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, but only by the appended claims.
Claims
1. A dropped deck center beam rail road car comprising:
- a lading support structure carried on rail road car trucks for rolling motion along rail road tracks, said lading support structure having upstanding bulkheads mounted at opposite ends thereof, a laterally extending deck structure, and a central beam assembly standing upwardly of said laterally extending deck structure;
- a coupler mounted at one of said ends of said lading support structure, said coupler having a coupler centerline height;
- said deck structure having a pair of end portions and a medial portion, said end portions being stepped upwardly relative to said medial portion;
- each of said end portions and said medial portion of said deck structure having lading bearing interfaces upon which lading can be placed;
- said central beam assembly including a webwork assembly extending upwardly of said medial portion of said deck structure to a longitudinally extending top chord member; and
- at least a portion of said web work assembly extending to a height lower than said lading bearing interface of one of said end portions of said deck structure.
Type: Application
Filed: Feb 7, 2006
Publication Date: Nov 2, 2006
Applicant:
Inventors: Mohamed Khattab (Burlington), David Keats (Brantford)
Application Number: 11/349,047
International Classification: B61D 17/00 (20060101);