Patent Publication Number: US-10308161-B2

Title: Intermodal chassis

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 14/923,440 filed on Oct. 27, 2015, now U.S. Pat. No. 9,908,453 issued on Mar. 6, 2018, which claims the benefit of U.S. provisional application Ser. No. 62/069,147 filed on Oct. 27, 2014, the entireties of which are incorporated herein by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     The technical field of the invention pertains generally to intermodal chassis designs, and, more particularly, to improvements in an intermodal chassis especially suited for 53 foot domestic use intermodal containers and that provides for improvements in load capacity and ease of use, while meeting state specific transportation regulations. 
     Intermodal chassis are semi-trailers used for hauling intermodal shipping containers over the road. Intermodal shipping containers are used for shipping product via road, rail, or ocean. The 53 foot (53′) shipping container is also referred to as a “long box” shipping container, or a “high cube” container because it provides expansive capacity with a typical height of (9′6″) 114″, width of (8′6″) 102″, and length of 53′. This is 1 foot taller than standard height containers. Another common container length is 48′. International shipments typically utilize intermodal containers that are 6″ narrower and typically either 20′ or 40′ in length. 
     The 53′ intermodal long box container is the most common type of container used for domestic shipping within the United States. The 53′ container was constructed and introduced primarily for domestic over-the-road/highway and railroad shipping. 53′ containers are typically constructed of 14-gauge (14 Ga) corrugated steel throughout, with 1⅛″ thick marine plywood flooring on the interior. 
     A typical intermodal chassis for a 53′ container consists of front and rear bolsters which engage with the lower edges at the front and rear of the container, with a frame extending between and interconnecting the front and rear bolsters, tandem axles positioned toward the rear of the chassis, and a forward portion of the chassis near the front bolster that has a raised surface section sized to fit within a corresponding tunnel depression (3⅛″ deep) section on the underside of the container. The typical intermodal chassis is constructed of steel, with a standard leaf spring type suspension, standard sized steel hub wheels (8¼″×22.5″ hub), and standard sized tires (11R22.5 tire). The kingpin for connection with the fifth wheel of a towing tractor is typically set back from the rear face of the bolster by 36″. 
     The 53′ long box/high cube containers typically require careful loading arrangements to achieve load balancing and distribution between the front nose of the container and locations within the container forward of the chassis tandems, in order to meet particular state highway transportation regulations (or so-called bridge laws). For example,  FIG. 1  shows a side view  100  of a typical truck  104  and semi-trailer  102  loading arrangement for meeting California Department of Transportation regulations. The kingpin-to-rear-axle (KPRA) length  108  must not exceed a length of 40 feet. Commercial vehicles may not exceed 80 k lbs GVW. Axle restrictions include a limit of 34 k lbs on the drive tires  112 , 34 k lbs on the tandem tires  114 , and 12 k lbs on the steer tires  110 . To meet these requirements, the typical semi-trailer  102  needs to have cargo  106  arranged to be secured forward of the rear tandems  114 , keeping product between the tandem axles  114  and the nose or front of the container. Carriers are advised to load heavier pallets in the nose of the container closer to the tractor cab  104 , followed by light pallets and then the lightest pallets rearward, yet still forward of the rear most axle. As shown in  FIG. 1 , the result is empty (unused/unusable) space in the container aft of the rear tandems  114 . Moreover, substantial effort and care is needed to distribute the weight within the container from left side to right side and from the nose of the container space to the rear most position of pallets and product, often using inflatable air bags or other dunnage (not shown) to stabilize separation and spacing of pallets and product. Because loads need to be scaled at the origin of a particular route (to ensure the load is legal for the destination state), considerable care is needed to properly load the cargo  106  into the trailer  102 . 
     What is needed, therefore, are improved intermodal chassis designs that provide for improvements in load capacity, cost of operation, and ease of use, and that adhere to state specific transportation regulations such as those established by the California Department of Transportation that apply to over highway shipping using 53′ intermodal containers. 
     The foregoing and other objectives, features, and advantages of the invention will be more readily understood upon consideration of the following detailed description of the invention taken in conjunction with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL DRAWINGS 
       For a more complete understanding of the present invention, the drawings herein illustrate examples of the invention. The drawings, however, do not limit the scope of the invention. Similar references in the drawings indicate similar elements. 
         FIG. 1  is a side view showing a typical semi-tractor and trailer loading arrangement for meeting California Department of Transportation regulations. 
         FIG. 2  is a side view of an improved intermodal chassis that allows for increased loading capacity, according to various preferred embodiments. 
         FIG. 3  is a top view of the improved intermodal chassis in  FIG. 2 , according to preferred embodiments. 
         FIG. 4  is a perspective view of the improved intermodal chassis in  FIGS. 2 and 3  as viewed from above and the rear and passenger side, according to preferred embodiments. 
         FIG. 5  is a perspective view of the improved intermodal chassis in  FIG. 4  as viewed from above and the rear looking toward the front of the chassis, according to preferred embodiments. 
         FIG. 6  is a side perspective view of an axle portion of the improved intermodal chassis in  FIG. 4  as viewed from the driver side, according to preferred embodiments. 
         FIG. 7  is a side perspective view of the axle portion shown in  FIG. 6  as viewed from the rear and driver side, according to preferred embodiments. 
         FIG. 8  is a perspective view of a gooseneck portion of the improved intermodal chassis in  FIG. 4  as viewed from above and the rear and driver side looking forward toward the front of the chassis, according to preferred embodiments. 
         FIG. 9  is a perspective view of an axle portion of the improved intermodal chassis in  FIG. 4  as viewed from below and rear, according to preferred embodiments. 
         FIG. 10  is a perspective view of a forward portion of the improved intermodal chassis in  FIG. 4  as viewed from above and rear looking forward toward the front of the chassis, according to preferred embodiments. 
         FIG. 11  is a perspective view of an axle portion of the improved intermodal chassis in  FIG. 4  as viewed from above and rear, according to preferred embodiments. 
         FIG. 12  is a perspective view of the improved intermodal chassis in  FIG. 4  as viewed from above and the rear and driver side, according to preferred embodiments. 
         FIG. 13  is a perspective view of a landing gear portion of the improved intermodal chassis in  FIG. 4  as viewed from below and the front and driver side looking rearward toward the back of the chassis, according to preferred embodiments. 
         FIG. 14  is a perspective view of the improved intermodal chassis in  FIG. 4  as viewed from above and the rear looking toward the front of the chassis, according to preferred embodiments. 
         FIG. 15  is a perspective view of the improved intermodal chassis in  FIG. 4  as viewed from above and the front looking toward the back of the chassis, according to preferred embodiments. 
         FIG. 16  is a front elevation view the improved intermodal chassis in  FIG. 4 , according to preferred embodiments. 
         FIG. 17  is a rear elevation view the improved intermodal chassis in  FIG. 4 , according to preferred embodiments. 
     
    
    
     DESCRIPTION OF PREFERRED EMBODIMENTS 
     In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the preferred embodiments. However, those skilled in the art will understand that the present invention may be practiced without these specific details, that the present invention is not limited to the depicted embodiments, and that the present invention may be practiced in a variety of alternate embodiments. In other instances, well known methods, procedures, components, and systems have not been described in detail. 
     Although preferred embodiments are presented and described in the context of an improved intermodal chassis design especially suited for 53 foot domestic use intermodal containers, numerous separable inventive aspects are presented that may be used in a wide variety of other over-the-road cargo hauling applications and with the use of a wide variety of other types (and sizes/lengths) of intermodal containers and freight hauling trailers (including 53′ length flatbed or other types and lengths of trailers). 
     The present inventor(s) discovered new, unique, and truly innovative methods, systems, and apparatus for improving an intermodal chassis design especially suited for 53 foot intermodal containers. Various embodiments are illustrated and described in the figures, sketches, details, descriptive materials, and pictures submitted in incorporated by reference herewith. The various embodiments include separable inventive aspects which are separately patentable. The listed inventive aspects are not exhaustive or comprehensive, and further/additional separable inventive aspects are included in the submitted materials but may not be specifically or particularly identified or described in words due to the need to capture (in many instances in detailed illustrations, pictures, or sketches) the many separable inventive aspects in this disclosure. 
     The present inventors invented an intermodal chassis that allows shippers to ship more freight into and out of the state of California via the railroad using stack train intermodal containers while complying with California vehicle bridge weight limitations. Loads into and out of Nevada are also affected by California bridge laws because the actual rail terminal is in California. 
     The chassis invented, prototyped, and tested helps shippers with products which occupy most of the cube of a 53 foot intermodal container utilize the entire 53 foot container space without having to cut pallets off at the rear of the container to meet the bridge law restrictions in California. Most shippers with freight weighing 38500 to 43500 lbs and having high cube requirements are the shippers which have to reduce the quantity of pallets loaded in order to meet the bridge laws. 
     Dense shippers currently must load loads in a configuration whereby the axles are equalized and airbags or other dunnage are required to secure and spread the load, for example, as shown in  FIG. 1 . Using the present inventors&#39; chassis reduces dunnage costs and damage by allowing the entire 53 foot container space to be utilized and allowing for more freight to comprise the load before maxing out due to weight. 
     The present inventors&#39; determined that the directions from major intermodal companies direct shippers as to how to load trailers so that the California bridge law is not violated comprises legalizing the load by configuring the load differently and spreading weight out. High cube shippers, the present inventors&#39; found, are not able to effectively use this measure because the trailer is filled with product. The major intermodal companies limit the maximum gross weight of the load to 43500 lbs. By comparison, the present inventors&#39; improved intermodal chassis designs allow for the container to be loaded to a maximum of 47500 lbs. 
     As will be described further in the figures, the present inventors discovered numerous improvements that, when combined in preferred embodiments, provide for improved load capacity, lowered cost of operation, and greater ease of use, while solving problems of meeting the bridge law requirements. 
     The present inventors discovered major improvements in load distribution are achieved by separating the axles so that a forward positioned axle is at least 12 feet forward from the rear most (second) axle instead of using a standard pair of tandem axles. The separation between the axles, it was discovered, spreads the load, and the axles are counted as separate axles as opposed to tandem axles for purposes of calculating bridge loading and in compliance with the California bridge laws. 
     The present inventors discovered a dramatically lighter weight chassis frame design by strategically cutting circular holes from key portions of the chassis frame structure in areas where the material was not needed to maintain sufficient integrity and strength. The strategically place cutouts, the present inventors discovered, allows better fuel economy, reduced chassis weight, and increased available load weight. 
     Existing chassis designs use springs and not air bags because lowering a container onto the chassis effectively suddenly loads each of the forward and rear axles with 40,000 pounds, which would break the air bags. The present inventors discovered that bleeding out the air bags so that the frame rests all the way down on the axles such that the only “give” is pressure in the tires, works to avoid blowing out the air bags. To overcome the problems of bursting the air bags of the suspension when loading the container onto the chassis, the present inventors discovered automatically deflating the air bags when the chassis trailer brakes are locked prevented damage to the bags from harm when a container is dropped to quickly. 
     The present inventors discovered that replacing the standard spring suspension with a deflatable air ride suspension also achieved weight reduction and allows the driver to adjust the height of the container (being hauled on the chassis) to match differing dock heights. The new design provides a load leveling functionality not available in existing intermodal chassis designs. The driver is able to raise the load up to dock level or lower it down, by adjusting the amount of air in the air bags. 
     The present inventors discovered using smaller wheels, such as 19.5 inch wheels, achieves weight reduction, allows for lower height positioning of the chassis (due to lower axle height), and also reduces theft of chassis tires and wheels because the 19.5 sized wheels do not fit common truck trailers or other chassis. 
     The present inventors discovered further weight reduction by using aluminum wheels instead of typically used steel wheels. Importantly, reduction of weight at the wheels (as also for weight reductions associated with using air bag suspension instead of springs) provides for higher gross payload overall and weight latitude on specific axles. 
     The present inventors discovered that using air bags in the suspension allows for self-scaling and distribution of weight longitudinally to adjust weight over a given axle. Previously, the container would be loaded using best guessing, and the drive would hope it&#39;s legal until the driver is able to stop at a public scale. The risk is getting stopped with an improperly distributed load. Shippers do not typically have their own scales, so there are few ways to avoid this risk. With self-scalers integral to the chassis, which employ the air bags with hydraulics, the problem is addressed. The present inventors discovered that providing for the chassis to be self-scaling enables the driver to determine whether a load is leaving the yard in a legal fashion without going to a public scale, thus reducing the costs of scaling and potentially expensive highway fines for improperly balanced or overloaded conditions. 
     The present inventors discovered that adjustments in the location of the kingpin on the chassis from a standard 36″ aft of the rear face of the front bolster to positions incrementally rearward toward a position at 48″ aft of the rear face of the front bolster allows for more load to be placed in the nose of the container, thereby over the drive axles and increasing weight on the tractor. 
     The present inventors discovered using Teflon plates instead of the typical steel with grease applied, achieves cost savings in maintenance and reduces overall wear and tear. In one embodiment, the pickup plate is coated with a non-stick, self-lubricating material, and grease or other lubricants are unnecessary. 
     The present inventors discovered incorporating LED lighting reduces power consumption, improves lamp life, and improves safety characteristics of the chassis since LED lights are brighter, require less power, and last many times longer than the standard incandescent bulbs used on existing intermodal chassis designs. 
       FIG. 2  is a side view  200  of an improved intermodal chassis  202  that allows for increased loading capacity, according to various preferred embodiments. The left side or driver side of the chassis  202  is shown, with a front bolster  230  at a forward end and a rear bolster  228  (and rear bumper  226  therebelow) at a rearward or rear most end of the chassis, the two bolsters longitudinally interconnected by frame structure comprising a gooseneck portion  232  with a top surface  218  extending rearward from the front bolster  230 , and a main frame stepped down top surface portion  224  extending from the gooseneck portion  232  rearward to and including the rear bolster  228 . The raised gooseneck top surface  218  is preferably sized to fit within the corresponding depression or tunnel formed in the lower surfaces of the nose/front of a standard intermodal container. In one embodiment, the gooseneck top surface  218  is offset from the main frame top surface  224  by 3⅛″. The length ( 206  to  204 ) between the front of the chassis  206  and the rear end  204  of the rear bolter  228  is preferably 53′ 8⅞″. 
     Just aft or rear of a transition from the gooseneck top surface  218  to the main frame top surface  224  is an extendable jack stand or landing gear  220 , with sand shoes  22  for ground contact. Extending rearward are preferably two axle/wheel/tire assemblies—a forward trailer axle/wheels/tires assembly  208  and, separated rearward, a rear trailer axle/wheels/tires assembly  210 . In preferred embodiments, the vertically extendable landing gear  220  comprise a pair of sand shoes  222 , and each of the axle/wheels/tires assemblies  208  and  210  comprise an axle with wheels and tires. In preferred embodiments, the wheels comprise aluminum hubs and are smaller sized than standard semi trailer wheels, preferably comprising 19.5 inch wheels to provide a lower axle to ground height, thus allowing the chassis to be lowered to a lower height, and to provide weight reduction. The ground-to-main frame top surface  224  height is preferably nominally 48″ in normal operating conditions. 
     Several holes  214 ,  216 ,  212  are preferably strategically cut within the sides of the main frame for weight reduction, preferably similarly sized (for example, each having a diameter of 5″) and arranged in pairs, with twelve (12) holes in each main (I-beam) side, as shown. 
       FIG. 3  is a top view  300  of the improved intermodal chassis  202  in  FIG. 2 , according to preferred embodiments. In preferred embodiments, the center of the forward axle  310  and the center of the rear axle  308  are separated by at least twelve (12) feet so that each axle is considered a separate axle. In one embodiment the spread between the center of the forward axle  310  and the center of the rear axle  308  is 12′1″ (twelve feet, one inch). In preferred embodiments, the distance between the center of the kingpin (not shown) and the center of the rear axle  308  is just under 40′ to comply with state regulations. In one embodiment, the kingpin mount  338  is 40.25″ from the rear surface of the front bolster  230 , and the position of the rear axle  308  is set to be just under the 40′ kingpin-to-rear-axle (KPRA) limit. In other embodiments, the kingpin mount  338  may be positioned rearward from between 36″ toward  48 ″ aft of the rear surface of the front bolster  230 , with an increasingly rearward mounting position putting more weight on the tractor drive tires. 
     The front or gooseneck portion  232  of the chassis  202  preferably comprises gooseneck I-beams  332  and  330  arranged in parallel and interconnected to one another by cross members such as gooseneck (tubular) cross members  334  and  336 . The gooseneck I-beams  332  and  330  extend rearward from the front bolster  230  and transition to main I-beams  302  and  306  comprising a main frame portion of the chassis  202 , with the main I-beams  302  and  306  extending rearward from the gooseneck portion  232  past the landing gear  220 , front and rear axles  310  and  308 , respectively, and ending at the rear bolster  228 . Various cross members such as (tubular) cross members  324 ,  322  and diagonal (C-channel) cross members  328 ,  326  (and other cross members not numbered) interconnect the main I-beams  302  and  306 , which, as shown in  FIG. 3 , are parallel to one another and longitudinally aligned with the gooseneck I-beams  332  and  330 . In preferred embodiments, five (5) diagonal cross members such as  328  and  326  provide bracing in five (5) bays along the main frame between the landing gear  220  and forward and rear axles. 
     In preferred embodiments, air lines and electrical wires (not shown) are routed along the length of the chassis  202 , and at least one air tank (not shown) is mounted (such as in the location marked  320 ) for operation of air bags associated with the suspension for each of the axles  310  and  308  and corresponding wheels and tires—right (passenger) side forward tires  318 , left (driver) side forward tires  316 , right (passenger) side rear tires  314 , and left (driver) side rear tires  312 . Although each axle  310  and  308  is shown with a set of four (4) wheels/tires, further weight reduction may be achieved using two (2) double (or fat) wheels/tires for each axle. For example, one double wheel/tire may be used in place of the right side forward pair of tires  318 , that are configured and sized to provide similar ground contact and other characteristics, and likewise for the pairs of tires  316 ,  314 , and  312 . 
     In preferred embodiments, the width of the rear bolster  228  from left (driver) side to right (passenger) side is 96¾″ and the width of the bumper  226  from left side to right side is 88¾″. The outward ends of the top surface of the rear bolster  228  preferably comprises attachment points or (ISO) twist locks  304  to securely fasten with correspondingly formed corner castings of a standard intermodal container. 
       FIG. 4  is a perspective view  400  of the improved intermodal chassis  202  in  FIGS. 2 and 3  as viewed from above and the rear and passenger side, according to preferred embodiments. As shown, air bags  402 ,  404  are preferably used for suspension instead of typically used leaf spring suspension systems. In preferred embodiments, the air bags are deflated to prevent damage to the air bags when a container is loaded onto the chassis  202 . Preferably, the air bags automatically deflate when the chassis brakes are locked. In various embodiments, the driver/operator may adjust the amount of air in the air bags to adjust the level of the container for loading and unloading of the container at, for example, dock surfaces that may vary in height, and the amount of air in the air bags may be adjusted to level the chassis for transport. The air bags are preferably integrated into a self-scaling systems whereby the amount of air in the air bags, the pressure within the air bags, and/or measures of position and degree of inflation are used for determination of load weight over each of the forward and rear axles. 
     In preferred embodiments, the front bolster  230  comprises formed 10 Ga 1020 steel sheet metal, the rear bolster  228  comprises 7 Ga wall 1020 steel 8″ square tube, the rear bumper  226  comprises horizontal 3″ by 4″ 7 Ga wall 1020 steel tube and vertical ¼″ wall 1020 steel 3″ square tube, the main I-beams  302 ,  306  comprise 0.24″ thick 1020 steel 11.8″ tall 4″ flats (top and bottom), the gooseneck I-beams  330 ,  332  comprise 0.25″ thick 1020 steel 4.25″ tall 4.25″ flats (top and bottom), the cross members comprising 1020 steel tube or formed sheet. In preferred embodiments, the chassis I-beams, cross members, bolsters, and other reinforcements, bracing, and brackets are welded together and then painted. In one embodiment, an experimental use prototype was constructed by the present inventors—having substantially the characteristics shown in  FIG. 4 , including smaller aluminum wheels, air bag system, forward and rear axles spread apart at least twelve feet, and 5″ diameter holes cut in the main I-beams and cross members as shown—with an unladen weight (as licensed/registered with California) at 2915 lbs. 
       FIG. 5  is a perspective view of the improved intermodal chassis  202  in  FIG. 4  as viewed from above and the rear looking toward the front of the chassis, according to preferred embodiments. The chassis  202  preferably incorporates LED lighting  502  within the rear bolster  228  between twist lock  304  locations. 
       FIG. 6  is a side perspective view of an axle portion  600  of the improved intermodal chassis  202  in  FIG. 4  as viewed from the driver side, according to preferred embodiments. And  FIG. 7  is a side perspective view of the axle portion shown in  FIG. 6  as viewed from the rear and driver side, according to preferred embodiments.  FIGS. 6 and 7  more clearly show the separate forward axle  310  and rear axle  308 , and the air bags associated with each—right rear air bag  404  and left rear air bag  702 , for rear axle  308 ; and right forward air bag  402  and left forward air bag  602 , for forward axle  310 . Also depicted more clearly are holes  604  and  606  in the left side main I-beam  306 , which preferably comprise 5″ diameter cut outs arranged as shown. 
       FIG. 8  is a perspective view of a gooseneck portion of the improved intermodal chassis in  FIG. 4  as viewed from above and the rear and driver side looking forward toward the front of the chassis, according to preferred embodiments. From the front bolster  230  extending rearward and covering the lower surfaces under and between the gooseneck I-beams  232 , a pickup plate preferably fills the spaces  806 ,  808 ,  810 ,  812 , and  814  between the front bolster  230  and transverse channel  820 , between transverse channel  820  and gooseneck tube  334 , between gooseneck tube  334  and gooseneck tube  336 , and between gooseneck tube  336  and transverse channel  816 . Kingpin mounting  338  is preferably welded between gooseneck tubes  336  and  334 , as shown. Wing plates  802  and  804  stiffen the outer ends of the front bolster  230 . Three (3) transverse channel cross members  820 ,  816 , and  818 , along with three (3) gooseneck tube cross members  334 ,  336 , and  822  interconnect the right and left gooseneck I-beams that provide the gooseneck top surface  218 . Gooseneck transition tubes  824  and  826  angle downward to the forward face of a gusset  832  that forms a bulkhead and start/forward most portion of the frame structure providing the main frame top surface  224  that extends rearward all the way to the rear bolster  228 . Formed flat bar transitions  828  and  830  (with welded insert panels, not numbered) provide a transition from the gooseneck I-beams  232  to the main frame I-beams  302 ,  306 . 
     In preferred embodiments, the pickup plate ( 806 ,  808 ,  810 ,  812 ,  814 ) comprises one piece of sheet metal, smooth on its lower surface, exposing the kingpin mounted thereon, the kingpin extending downward from the pickup plate for engagement with the receiver of a semi-tractor when the chassis is to be towed. The wing plates  804  and  802  preferably comprise ¼″ thick 1020 steel. The front bolster  230  preferably comprises formed 10 Ga 1020 steel sheet metal. The kingpin mount  338  preferably comprises C-channel opened downward. The transverse channels  820 ,  816 , and  818  each preferably comprise C-channel opening rearward. The gooseneck tube cross members  334 ,  336 , and  822  each preferably comprise 3″ by 4″ 1020 steel rectangular tube with 0.25″ thick wall material. The gooseneck I-beams  330  and  332  (also referenced as  232 ) preferably comprise 0.25″ wall 1020 steel 4.25″ tall with 4.25″ top and bottom flats. The formed flat bar transitions  828  and  830  preferably comprise 5″ wide 1020 steel bar stock. 
       FIG. 9  is a perspective view of an axle portion of the improved intermodal chassis  202  in  FIG. 4  as viewed from below and rear, according to preferred embodiments. As shown, the forward part of the chassis includes a cross support  902  between the non-extendable tubes of the landing gear  220 . In preferred embodiments, the chassis  202  comprises eight (8) wheels and tires, a pair of wheels and tires on the each end of each axle. As shown, the forward axle  310  has an inner right forward tire  904 , an outer right forward tire  906 , an inner left forward tire  918 , and an outer left forward tire  916 . The rear axle  308  has an inner right rear tire  908 , an outer right rear tire  910 , an inner left rear tire  914 , and an outer left rear tire  912 . 
       FIG. 9  also shows the main frame I-beams in more detail. The right side I-beam is shown with (the underside of) a bottom flat  920  and (the underside of) a top flat  922 . The left side I-beam is shown with a bottom flat  924  and a top flat  926 . Preferably the I-beam comprises 11.8″ tall 0.24″ thick 1020 steel with the top and bottom flats being 4″ wide. The cross members  928 ,  930 , and  932  shown interconnecting the right and left I-beams to form the main frame, preferably comprise 8″ tall by 2″ longitudinally along the frame by 0.25″ thick 1020 steel rectangular tube. 
       FIG. 10  is a perspective view of a forward portion of the improved intermodal chassis  202  in  FIG. 4  as viewed from above and rear looking forward toward the front of the chassis, according to preferred embodiments. The chassis  202  preferably comprises six (6) cross members welded to and interconnecting the two main frame I-beams that are formed and configured the same as the C-channel shaped cross member  1032 . The formed cross member  1023  preferably has three (3) cut outs  1002 , each measuring 5″ in diameter, and each comprises 0.375″ thick 1020 steel sheet metal formed to have a height of 9″, lower longitudinal width of 3″, and an upper longitudinal width (at its right and left sides, where the cross member is welded to the inside surfaces of the main frame I-beams) of 7.5″. The three (3) five (5) inch holes are preferably equally spaced from left to right, as shown. And the open part of the formed “C” channel is directed rearward. Each of six (6) similarly formed cross members are preferably oriented in a similar way, including cross members  1032 ,  1010 ,  1012 ,  1014 ,  1016 , and  1018  (referencing the cross members from the rear of the chassis moving forward). The bulkhead gusset  832  shown in  FIG. 8  is preferably formed to be similar to each of the six (6) formed cross members  1032 ,  1010 ,  1012 ,  1014 ,  1016 , and  1018  except without the three (3) cutouts. Preferably, each of the cross members  1030 ,  1028 ,  1026 ,  1024 ,  1022 , and  1020  comprise the same construction as described for rectangular tube cross members  928 ,  930 , and  932  in  FIG. 9 . As shown in  FIG. 3 , one more cross member is shown between the formed cross member  1032  and the rear bolster  228 , and this cross member is preferably constructed to be similar to the other rectangular tube type cross members  1030 ,  1028 ,  1026 ,  1024 ,  1022 , and  1020 . Therefore, in preferred embodiments, there are seven (7) rectangular tube cross members and seven (7) formed cross members interconnecting the right main I-beam  302  and the left main I-beam  306 . 
     Preferably, the five (5) diagonal cross supports  1004 ,  326 ,  328 ,  1006 , and  1008  comprise C-channel 0.25″ thick 1020 steel, 3″ wide by 1.5″ tall, with the open end directed downward. A side view as in  FIG. 2  would show each diagonal cross support as having a height of 1.5″. A top view as in  FIG. 3  would show the width of each diagonal being 3″. 
       FIG. 11  is a perspective view of an axle portion of the improved intermodal chassis in  FIG. 4  as viewed from above and rear, according to preferred embodiments, and shows more clearly a relative positioning of right and left rear shock absorbers  1104  and  1102 , respectively. A similar shock absorber is configured for each of the four (4) air bags, as shown also in  FIGS. 6, 7, and 9 . 
       FIG. 12  is a perspective view of the improved intermodal chassis in  FIG. 4  as viewed from above and the rear and driver side, according to preferred embodiments, and shows the chassis  202  from the opposite side and at less of a downward angle than illustrated in  FIG. 4 . 
       FIG. 13  is a perspective view of a landing gear portion of the improved intermodal chassis in  FIG. 4  as viewed from below and the front and driver side looking rearward toward the back of the chassis, according to preferred embodiments. Preferably, holes  1322  and  214  are cut in the sides of the main I-beam  306  just aft of the landing gear  1302 . The holes  1322  and  214  preferably are 5″ diameter cutouts and are similarly sized as the other cutouts shown along main I-beams  306  and  302 . The landing gear  220  preferably comprises non-extendable tubes  1302  and  1304  from which telescopic members  1308  and  1306  may extend, each capped by a sand shoe  1310 ,  1312 . Stabilizer bracing  1316 ,  1318 , and  1320  and a lateral cross support  1314  are preferably used to further stiffen and support the landing gear  220 . 
       FIG. 14  is a perspective view of the improved intermodal chassis in  FIG. 4  as viewed from above and the rear looking toward the front of the chassis, according to preferred embodiments. As shown from this angle, the wing plates  1402  and  1404  between the main I-beam outward sides and the rear bolster  228  are visible. 
       FIG. 15  is a perspective view of the improved intermodal chassis in  FIG. 4  as viewed from above and the front looking toward the back of the chassis, according to preferred embodiments.  FIG. 15  more clearly shows the arrangement of cross members interconnecting the right and left I-beams. Six (6) cross members comprise the gooseneck portion—three (3) transvers channel and three (3) gooseneck tube. Fourteen (14) cross members comprise the main frame portion—one bulkhead cross member at the gooseneck-to-main frame transition, followed by five (5) formed cross members with holes, followed by six (6) rectangular tube type cross members, followed by a sixth formed cross member with holes, and lastly a seventh rectangular tube cross member. 
       FIG. 16  is a front elevation view the improved intermodal chassis in  FIG. 4 , according to preferred embodiments.  FIG. 17  is a rear elevation view the improved intermodal chassis in  FIG. 4 , according to preferred embodiments. 
     The terms and expressions which have been employed in the foregoing specification are used therein as terms of description and not of limitation, and there is no intention in the use of such terms and expressions of excluding equivalents of the features shown and described or portions thereof, it being recognized that the scope of the invention is defined and limited only by the claims which follow.