Abstract:
A railroad drive system for transporting, along a railroad track, a vehicle trailer having a front king pin and a rear king pin downwardly projecting from a lower surface thereof in vertically spaced relation above the railroad track includes a drive assembly having motorized wheels including a pair of differential axles. The drive assembly is carried on a support frame and operatively engages the railroad track and a front fifth wheel and a rear fifth wheel carried by said support frame and having a first position vertically below the lower surface of the trailer. A lifting assembly operatively selectively raises the front fifth wheel and the rear fifth wheel into coupled relationship with the king pins. An operator control station extends laterally outward of said support frame between said axles for operating the drive and lifting assemblies.

Description:
RELATED APPLICATION 
     This application is a continuation application of U.S. Ser. No. 09/053,056 filed on Apr. 1, 1998, now U.S. Pat. No. 6,123,029, in the name of J. T. Mobley and entitled “Intermodal Transportation System”. 
    
    
     BACKGROUND OF INVENTION 
     1. Field of Invention 
     This invention relates generally to intermodal transport systems and, more particularly, to an improved truck-train system for transporting both passengers and freight by railway. 
     Intermodal transport systems utilizing a combination of truck-train technology are well known to those skilled in the art. Many state and local governments have enacted legislation which taxes and regulates truck traffic to reduce road damage and traffic accidents. 
     To overcome these disadvantages the industry has devised many systems for combining truck-trailers with railroad equipment. Historically the first of these systems utilized railroad flatcars to carry truck-trailers in a so-called piggy-back method which eliminated to need to unload the contents of the truck-trailer. 
     It was soon recognized that the flatcar could be eliminated entirely and replaced by a railway dolly or so-called bogie. For example, U.S. Pat. No. 4,653,966 discloses such a system wherein a semi-trailer is driven onto a bogie. However, such a system requires a large truck turning area and a high degree of driver skill to accomplish the loading process. This system requires a separate incline ramp to load the trailer onto the dolly and if a separate incline ramp is not available at the destination, the trailer cannot be unloaded. 
     Another system is disclosed in U.S. Pat. No. 5,107,772 that uses a railway bogie incorporating a platform and pivot pin adapted to connect directly to a truck-trailer. The platform is raised by a pneumatic system integrated into the bogie to couple it to the underside of the trailer. 
     All of the prior art truck-train systems utilizing railway dollies or bogies have proven to be less than desirable by requiring additional equipment for their operation such as special lifting cranes necessary to mount the truck-trailers on the railway dollies and separate switching engines for moving the truck-trailers once they have been installed on a dolly. 
     Further, many of the prior art truck-train systems require the use of a railroad turntable device and a complex loading area to link the truck-trailers together for transport. 
     Thus, the Improved Intermodal Transport System of the present invention has been developed to overcome the deficiencies in prior art truck-train systems. 
     2. Description of Related Prior Art 
     U.S. Pat. No. 4,653,966 to Ballka et al. discloses a truck-train system wherein a semi-trailer is driven onto a bogie. Such a system requires a large truck turning area, a separate incline ramp, and a high degree of driver skill to accomplish the loading process. Further, if a separate incline rail is not available at the destination, the trailers cannot be unloaded. 
     U.S. Pat. No. 5,107,772 to Jacques Viens discloses a rail bogie for transporting semi-trailers comprising a truck having a wheel-mounted chassis and a fifth wheel frame above the chassis. Power jacks or inflatable balloons are mounted between this chassis and the frame for moving the latter vertically between a low and a high position relative to the chassis. The frame is raised by a pneumatic system to couple it to the underside of the trailer. 
     U.S. Pat. No. 4,416,571 to Robert A. Krause discloses a truck and rail transportation system wherein an elongated truck container can be carried either by rail or on a highway by a conventional truck tractor. The container includes a pair of dolly engaging pins fixed to its floor at the opposite ends thereof. The pins are adapted to engage a fifth wheel mechanism mounted on a dolly having wheels thereon adapted to engage conventional railroad rails. 
     U.S. Pat. No. 5,431,110 to George W. Adams discloses a truck-train system that provides for the mounting and dismounting of a truck-trailer from a railway dolly employing a moment arm reaction locking mechanism that automatically centers and engages the truck-trailer in position on the railway dolly. 
     U.S. Pat. No. 5,020,445 to George W. Adams discloses a truck-trail system wherein a railway dolly or bogie is utilized to support the front end of one truck-trailer and the rear end of another truck-trailer. A pair of truck-trailer support members are pivotally connected to the railway dolly. They are provided with a fixed incline ramp to raise and guide the truck-trailer onto the respective support member. The railway dolly is provided with a pair of fifth wheel mechanisms and standard railway couplers at each end. 
     U.S. Pat. No. 5,601,030 to Michael F. Brouillette discloses a railroad bogie with a pneumatic system and lifting mechanism for connecting truck-trailers in an articulated train. The bogie functions to lift the rear end and the front end of adjacent truck trailers respectively off the ground for transport by rail. 
     U.S. Pat. No. 4,773,336 to Robert M. Orb discloses a road/rail transport system comprising rail bogies of the kind having two axles and being attachable to a semi-trailer to convert the same to railroad travel. 
     U.S. Pat. No. 5,537,931 to Thomas G. Donkin discloses a rail bogie for connection with an intermodal or rail highway trailer having convention highway wheels. The rail bogie includes an adapter engageable with a trailer and incorporates a lift mechanism for enabling the adapter to be lowered or collapsed for insertion beneath a trailer for raising the trailer wheels off the ground. 
     U.S. Pat. No. 5,017,064 to George B. Kirwan et al. discloses an intermodal transport system designed for use in hauling semi-trailers by means of railway bogies. The system combines a turntable and spring-loaded chock design to enable the efficient loading and unloading of semi-trailers. 
     U.S. Pat. No. 5,016,544 to Ronald F. Woollam discloses a convertible road/rail power vehicle including a tractor unit provided with retractable wheel sets and rail equipment that enable it to operated on either highways or railway tracks and when on rail to pull a plurality of railway cars. 
     Finally, U.S. Pat. No. 5,619,931 to Harry Madison discloses a road and rail vehicle having a truck tractor vehicle frame such that it is street legal, but also provides sufficient power to move freight cars on low density rail lines or at other desired locations. The vehicle has a transfer case to provide front wheel drive by road wheels when the vehicle is in a highway mode and to provide rear wheel drive by rail wheels when in a rail mode. 
     SUMMARY OF THE INVENTION 
     After much research and study of the disadvantages of the prior art systems, the present invention has been developed to provide an improved intermodal transport system which combines trucking and railway technology for the transport of passengers and freight in combination. The Super Rail System of the present invention integrates highway truck drive system components into powered vehicles suitable for pulling a combination of passenger coaches and highway type trailer containers by rail. 
     The Super Rail Train of the present invention differs significantly from the truck-train systems of the prior art in that the dollies or so-called bogie devices are replaced by a plurality of secondary drive units that are provided with computer controlled truck power systems which can be selectively operated during peak loads such as on rising grades when the Super Rail Train is in operation. Thus, the Super Rail Train can be operated with much greater fuel efficiency than conventional multiple locomotive trains. 
     In addition, the present Super Rail System includes a plurality of versatile tandem vehicles that interconnect the semi-trailer containers and are also self-powered which facilitates the assembly and disassembly of the Super Rail Train. 
     In view of the above, it is an object of the present invention to provide an improved intermodal transport system or Super Rail System which combines both trucking and railway technology and components. 
     Another object of the present invention is to provide an improved intermodal transport system which is capable of transporting both passenger coaches and truck trailer containers in the same train. 
     Another object of the present invention is to provide a Super Rail Train wherein primary and secondary drive vehicles are provided with highway truck running gear to improve fuel efficiency and to reduce maintenance and repair costs. 
     Another object of the present invention is to provide a Super Rail System wherein a plurality of self-powered secondary drive vehicles replace the conventional bogie devices that interconnect the passenger coaches within the train and which can be operated during peak loads such as rising grades by an on-board computer system. 
     Another object of the present invention is to provide a plurality of self-powered tandem vehicles which are capable of independent operation during the hitching and unhitching process to break down the train at its destination. 
     Another object of the present invention is to provide a Super Rail System wherein pre-existing highway truck-trailers can be retrofitted with attaching hardware so as to be capable of adaptation to the present system. 
     Other objects and advantages of the present invention will become apparent and obvious from a study of the following description and the accompanying drawings which are merely illustrative of such invention. 
    
    
     BRIEF DESCRIPTION OF DRAWINGS 
     FIG. 1A is a perspective view of a preferred embodiment of the Super Rail Train of the present system showing a single primary drive vehicle attached thereto; 
     FIG. 1B is an alternative embodiment of the Super Rail Train of the present system adapted for transporting freight containers on flat cars; 
     FIG. 1C is a perspective view of an alternative embodiment of the Super Rail Train of the present system having a primary drive vehicle attached at either end thereof for bi-directional operation; 
     FIG. 2A is an exploded perspective view of the primary drive vehicle as shown in FIG. 1A showing both a lead drive unit and a secondary drive unit; 
     FIG. 2B is a plan view of a fifth wheel unit utilized in the present invention; 
     FIG. 2C is an exploded perspective view of an alternative embodiment of the Super Rail Train showing a railroad flatcar being coupled to the primary drive vehicle by a secondary drive unit; 
     FIG. 3A is side elevational view of the primary drive vehicle generally showing the configuration of the drive system components in the lead drive unit and the secondary drive unit; 
     FIG. 3B is an enlarged schematic view of the lead drive unit showing the arrangement of the drive system components thereof; 
     FIG. 4 is an exploded plan view of the lead drive unit showing the arrangement of the front and rear modular frames; 
     FIG. 5 is an enlarged schematic view of the secondary drive unit showing the configuration of the drive system components; 
     FIG. 6 is an exploded plan view showing the arrangement of the drive system components within the secondary drive unit; 
     FIG. 7 is a front elevational view of a conventional railroad wheel and axle assembly disposed on a railroad track; 
     FIG. 8 is a perspective view of the wheel and axle assembly of FIG. 7 shown traversing a curved section of railroad track; 
     FIG. 9 is a perspective view of an automotive/truck type differential axle of the present invention having railroad wheels mounted thereon; 
     FIG. 10 is a perspective view showing a tandem device of the present invention coupled to a semi-trailer container of the type used in the present system; 
     FIG. 11 is a side elevational view of the tandem device of the present invention showing the arrangement of the axles and the small drive engine thereof; 
     FIG. 12 is a perspective view of the air spring system utilized on-board the tandem device; 
     FIG. 13 is a perspective view of a section of the support frame of the tandem device showing an axle locking mechanism with the axle in a deployed condition; 
     FIG. 14 is a perspective view of a section of the supporting frame of the tandem device showing an axle thereof in an upwardly retracted condition; 
     FIG. 15 is a side elevational view of a semi-trailer container of the present invention showing the rear and front modules of the tandem device attached thereto; 
     FIG. 16 is a rear elevation of a semi-trailer container of the present invention shown in proximity to a staging device of the present system; 
     FIG. 17 is an exploded perspective view of the sliding rear bumper assembly of the present invention; 
     FIG. 18 is an exploded perspective view of the switching ramp of the present invention and the pit structure wherein it is deployed in transverse relation to the railroad tracks; 
     FIG. 19 is a plan view of the switching ramp of the present system showing a trailer container deployed thereon for disassembly from the train; 
     FIG. 20 is a plan view of the switching ramp of the present system showing a trailer container being shifted on the ramp into alignment with an adjacent railroad track parallel to the main railroad track; 
     FIG. 21 is a plan view of the switching ramp whereon a second semi-trailer container is being loaded for disassembly from the remainder of the train; and 
     FIG. 22 is a plan view of a third semi-trailer container being loaded onto the switching ramp for disassembly from the remainder of the train. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     With reference to the drawings there is shown therein a Super Rail Train which forms a part of the present invention, indicated generally at  10  and illustrated in FIG.  1 A. The embodiment shown in FIG. 1A is a passenger/freight train having a total capacity of 370 passengers and capable of pulling 20 highway trailer containers at a time. The passengers are transported in a plurality of passenger coaches  12  having all of the amenities comparable to conventional passenger trains. 
     In an alternative embodiment shown in FIG. 1B, another passenger/freight train  10 ′ is depicted wherein the passenger coaches have been replaced by a plurality of flat cars  14  carrying freight containers  16  which are pulled by a primary drive vehicle  18 . 
     In yet another alternative embodiment of the Super Rail Train as shown in FIG. 1C, a mass transit train  10 ″ is depicted having a pair of primary drive vehicles  18  disposed at either end of the train for bi-directional transport on a typical commuter run. 
     As more clearly shown in FIG. 2A the primary drive vehicle  18  includes a lead drive unit, indicated generally at  20  having a diesel engine, transmission, and a plurality of truck type drive axles, which is mechanically coupled to the forward passenger cab  15  by a kingpin  22  disposed on a bottom surface of the front end of the cab  15  engaging a so-called fifth wheel unit  24  carried on the lead drive unit  20 . 
     The specific construction of the fifth wheel unit  24  does not form an integral part of the present invention. However, in order to facilitate the loading and unloading procedure, of the present system, the fifth wheel units  24  are preferably of a type manufactured under the trade name Simplex Lite manufactured by American Steel Foundries, East Chicago, Ind. and illustrated in FIG.  2 B. 
     Since such fifth wheel units are well known to those skilled in the art, further detailed discussion of the same is not deemed necessary. 
     A secondary drive unit, indicated generally at  25 , interconnects the passenger cab  13  with the adjacent passenger coach  12  by use of kingpins  22  carried thereon which also engage fifth wheel units  24  carried on either end of the secondary drive unit  25  as shown in FIG.  2 A. 
     It will be understood that the secondary drive unit  25  is also provided with a diesel engine, transmission, and a plurality of truck drive axles to provide additional tractive effort for the train under peak load situations such as climbing grades as hereinafter described. 
     It will be appreciated by those skilled in the art that the secondary drive unit  25  can also serve to interconnect the forward cab  13  with an adjacent flatcar  14  in the train configuration shown in FIG.  2 C. 
     Critical to the present invention is the incorporation of conventional truck drive system components into both the lead drive unit  20  and the secondary drive unit  25  of the Super Rail Train. As more clearly shown in FIGS. 3A and 3B the lead drive unit  20  includes a conventional truck engine such as a 600 hp Cummins Diesel and a computer controlled transmission  28  such as an Allison transmission which are operatively connected to a plurality of truck type drive axles  29  having a power divider unit (not shown) operatively connected thereto. The engine  27 , transmission  28 , and drive axles  29  are arranged front to back as shown in FIG. 3B in the manner of a conventional truck drive system having rear wheel drive. 
     Further details of the construction of the primary drive unit  20  are shown in FIG.  4 . The engine  27 , transmission  28  and the forward drive axle  29  are integrated into a modular frame system indicated generally at  21 . It will be appreciated by those skilled in the art that the engine  27 , transmission  28 , and forward drive axle  29  can be removed from the lead drive unit  20  as an assembly to facilitate overhaul of the drive unit  20  in the shop and to reduce down time for repairs by replacing the entire module frame  21  as a unit. Similarly, a rear modular frame  23  containing a plurality of drive axles  29  may be removed from the drive unit  20  as an assembly to facilitate repair. 
     The removal of both modular frames  21  and  23  is facilitated by the use of quick connect/disconnect fittings (not shown) for the on-board fuel, electrical, pneumatic, hydraulic, and coolant systems of the primary drive vehicle  18 . 
     Since such quick connect/disconnect fittings are well known to those skilled in the art, further detailed discussion of the same is not deemed necessary. 
     Referring now to FIG. 5 there is shown therein a secondary drive unit  25  which is utilized in the present system to interconnect the primary drive vehicle  18  with an adjacent passenger coach  12 , flatcar  14 , or highway trailer  15  within the train. The drive system of the secondary drive unit  25  differs substantially from that of the lead drive unit  20  in that the engine  27 ′ and the transmission  28 ′ are disposed intermediate a pair of drive axles  29 ′ situated at either end of the unit. In this configuration the output of the transmission  28 ′ is operatively connected to each of the pairs of drive axles  29 ′ such that both sets of axles provide tractive effort when the secondary drive unit  25  is operating. 
     Further details of the construction of the secondary drive unit  25  are shown in FIG.  6 . The secondary drive unit  25  is operated only during peak load conditions such as when the train starts from a dead stop or when climbing uphill grades to provide maximum tractive effort. 
     The output functions of the primary drive vehicle  18  are monitored by an on-board computer (not shown) and the operating characteristics of both the lead drive unit  20  and the secondary drive unit  25  are changed in response to increased loads on the train. Thus, the secondary drive unit  25  may be activated when the output of the lead drive unit  20  is insufficient to maintain the train at a desired speed. The selective operation of the secondary drive unit  25  during peak load conditions reduces fuel consumption and maintenance on the primary drive unit  20  providing obvious economic advantages. 
     It will be appreciated by those skilled in the art that the use of the conventional truck drive system in both the lead drive unit  20  and the secondary drive units  25  overcomes inherent mechanical disadvantages of the conventional locomotive drive train. 
     Initially, a fundamental problem which occurs in the standard railroad axle and wheels will be explained with reference to FIG. 7 wherein such a standard railroad axle  31  is illustrated. The conventional railroad axle  31  and wheels  30  are a solid, unitary construction. The standard train wheels  30  are rigidly attached to the axle  31  and bearings  33  are disposed at either end of the axle  31  being installed in the supporting frame  34  of a conventional locomotive, railroad car, or so-called bogie device (not shown). 
     This standard railroad axle and wheel configuration inherently causes a spinning/dragging problem when being rolled on a curved train track  35  as illustrated in FIG.  8 . In this situation the wheel  30 A to the outside of the curve must travel a longer distance along the track  35  than the wheel  30 B to the inside curve causing it to spin on the inside track while the wheel  30 A is dragged along the outside rail. 
     This dragging/spinning problem is well known to railroad engineers and costs the railway industry millions of dollars annually in repairs to both wheels and track and the associated maintenance and labor costs. 
     This problem is effecfively eliminated by the use of a conventional automotive or truck rear axle as depicted in FIG. 9 wherein each wheel turns independently on a separate axle shaft  39  which engages the differential  38 . The differential  38  permits the difference in rotational speed of the axles and wheels around a curve. 
     This automotive type wheel/axle configuration will be utilized in the lead drive unit  20  and the secondary drive unit  25  of the Super Rail Train. Use of the truck/automotive type drive axle virtually eliminates the dragging/spinning problem described hereinabove and significantly reduces the maintenance and repair costs associated with the problem. 
     The use of multiple drive axles in the lead drive unit  20  and the secondary drive units  25  enables the tractive effort to be distributed along the entire length of the Super Rail Train during peak load conditions such as starting from a dead stop and pulling uphill grades. The multiple drive axles are mechanically interconnected by the use of a Power Divider (not shown) which apportions the driving effort to all axles  29  to provide maximum tractive effort on demand. 
     Since such Power Dividers are well known to those skilled in the art, further detailed discussion of the same is not deemed necessary. 
     Another novel feature of the Super Rail System is the tandem device, indicated generally at  40  and illustrated in FIG.  10 . The tandem device  40  provides numerous advantages to the Super Rail System. 
     Each tandem device  40  includes two separate self-powered modules i.e. a forward module, indicated generally at  42  and a rear module, indicated generally at  44  as shown in FIG.  10 . Each module includes a small drive motor  45  as shown in FIG.  11  and is equipped with station  40 ′ having operator controls to allow an operator to move up to five fully loaded trailer containers  15  by rail during the hitching and unhitching process without the aid of a train locomotive or truck tractor. 
     However, the forward module  42  of each tandem device  40  is provided with a detachable railroad coupling (not shown) capable of engagement with a locomotive hitch (not shown) to make the present system compatible with standard rail equipment. 
     Each tandem device  40  includes four highway type straight axles  54  rated at 25,000 pounds to provide a gross vehicle weight capacity of 100,000 pounds. The average highway trailer  15  container including a full load is 50,000 to 65,000 pounds which can be easily handled by an individual module  42  or  44  when secured to the fifth wheel unit  24  carried on each module. 
     The modules  42  and  44  are interconnected by an air hitch mechanism (not shown) that operates off of the compressed air system of the train shown in FIG.  9 . Thus, when disconnected from the compressed air supply, the individual modules  42  and  44  can be separately operated and controlled from a foldout driver&#39;s seat  47 . 
     In the preferred embodiment the tandem device  40  is equipped with an air spring or air-ride system illustrated in FIG.  12 . In this system a plurality of air springs  52  supplied by an on-board air compressor (not shown) and a reservoir  54  of compressed air function to raise and lower the fifth wheel units  24  into and out of engagement with the kingpin  22  of a trailer container  15  during the hitching or unhitching process. 
     The air spring system is also utilized to lift a wheel/axle assembly of the tandem  40  off the railroad track when it is in need of repairs until the tandem device  40  can be switched out at a repair terminal along the railroad line. Thus, in the case of an axle or wheel failure, the affected axle  54  can be lifted clear of the track as shown in FIG. 14 to permit the train to continue on its run at a reduced speed until arrival at a repair terminal. 
     As shown in FIG. 13 the tandem  40  includes a generally rectangular frame, indicated generally at  60  whereon the individual straight axles  54  are pivotally mounted on axle supports  55 . 
     Each axle  54  is provided with a locking mechanism, indicated generally at  58  which is also pivotally attached to the frame  60  to permit the axle  54  to be locked down into contact with the railroad track as shown in FIG. 13 or, in the alternative, lifted up into a retracted position as shown in FIG. 14 when temporarily out of service. 
     An air braking system (not shown) is also utilized on the tandem device  40  to ensure adequate stopping control and to prevent brake lockups. The brake system also contributes to reduced track and wheel wear. 
     The method of assembling a train of truck trailers  15  will now be described in detail. In the prior art truck-train systems described hereinabove after the highway trailer has been attached to a railway dolly or bogie using separate lifting devices or special mechanical devices incorporated into the dolly itself, a so-called switching engine (not shown) is required to transport the assembled train of highway trailers and bogies to the rest of the train. In the alternative the train locomotive can move sections of the train into position for hitching. In the present invention this function is accomplished by the tandem device  40  without the need for a separate switching engine. 
     Initially, in order to be compatible with a tandem device  40  the highway trailer container  15  must of the type wherein the rear axles are capable of sliding forward and rearward with respect to the body of the trailer container  15  as shown in FIG.  15 . This is accomplished by use of a sliding axle carriage frame  62  which engages a mating undercarriage  64  that is attached to a bottom surface of the trailer container  15 . A plurality of apertures  65  formed in the frames  62  and the undercarriage  64  are brought into alignment and a carriage pin  63  is inserted therethrough to secure the axles in the desired position to properly distribute the load. 
     The repositioning of such a sliding axle carriage is typically carried out by removing the pins  63  from the axle carriage frame  62  and driving the tractor trailer rig in either a forward or reverse direction until the desired position is achieved and the pins  63  can be replaced. 
     However, this procedure is more easily accomplished in the present system by the use of a staging device, indicated generally at  70  and shown in FIG. 16, which is a lifting device that engages the trailer container  15  at a pad member  71  mechanically coupled to an underside of the trailer container  15  adjacent the undercarriage  64 . The staging device  70  is essentially a pneumatic/hydraulic jack mechanism which lifts the truck container  15  to take the weight off the trailer container wheels  66  and axle  67  to facilitate changing the position of the axles. 
     The staging device includes a pneumatic/hydraulic cylinder  68  including an extendable piston  69  that is mechanically coupled to an adjustable lift arm  73  which is designed to engage the pad member  71  during the lifting operation. 
     The lift arm  73  is capable of horizontal movement as shown in phantom outline in FIG. 16 to accommodate trailer containers  15  of different widths. 
     A control box  74  encloses the electronic components and circuitry necessary to provide the functions of the staging device  70 . 
     In addition to the sliding axle equipment described hereinabove, a trailer container  15  must also be equipped with a rear kingpin  22  as shown in FIG. 17 suitable for engagement with the standard fifth wheel unit  24  carried on the tandem device  40 . Such a kingpin  22  will be installed as standard equipment on all of the trailer containers  15  of the Super Rail System and can easily be retrofit to adapt to pre-existing trailer containers of the present system. Of course, a kingpin  22  is carried as standard equipment at the forward end  15   a  of virtually all tractor trailer containers presently on the road. 
     Further, a trailer container  15  compatible with the present system will require that the rear bumper  58  of trailer container  15  also be capable of forward sliding movement to the position shown in FIG. 15 to provide clearance for the tandem device  40  to be installed under the rearward end  15   b  of the trailer container. 
     In the preferred embodiment the rear bumper  58  is adapted for sliding movement from its normal position adjacent the rear end  15   b  of the trailer container by a sliding bumper frame assembly, indicated generally at  85  and illustrated in FIG.  17 . The bumper frame assembly  85  which attaches to the rear bumper  58  is adapted for sliding engagement with the undercarriage  64  attached to the bottom surface of the trailer container  15 . The bumper frame assembly  85  includes a quick release mechanism, indicated generally at  82  which permits the entire bumper assembly to be slid forward of the kingpin  22  to provide clearance for the tandem device  40  during the hitching process. 
     In a basic assembly procedure of the Super Rail Train of the present system, the trailer container  15  is drawn into a position in alignment with the railway tracks  35  at a terminal loading ramp and detached from the highway truck-tractor (not shown). The separated modules  42  and  44  of the tandem device  40  are positioned on the track on either side of the trailer container  15  and driven by an operator under both ends thereof ensuring that sufficient clearance is available. 
     Thereafter, the air spring system of the tandem device  40  is actuated such that the tandem device is raised into a position of engagement with the respective kingpins  22  raising the trailer container  15  off the ground to the position shown in FIG.  15 . 
     Thereafter, the loaded container  15  may be driven by an operator utilizing either module  42  or  44  and connected with a mating module on the next adjacent trailer container  15  in the train. 
     It will be understood that in the present system the rearward tandem module  44  will always be disposed at the forward end  15   a  of a trailer container  15  and the forward tandem module  42  will always be disposed at the rearward end  15   b  of a trailer container  15  as shown in FIG. 15 to ensure mating engagement between adjacent containers  15  in the train. 
     Another novel feature of the Super Rail System of the present invention is a specially designed switching ramp, indicated generally at  75  and shown in FIG. 18 which functions to expedite hitching and unhitching of trailer containers  15  upon arrival or departure from the Super Rail Train. 
     In the preferred embodiment, the switching ramp  75  is a generally rectangular concrete slab structure  76  wherein a plurality of parallel sets of railway tracks  35  are embedded. The slab structure  76  is a steel reinforced construction and surrounded by a supporting frame  78 . 
     The slab structure  76  is of sufficient capacity and dimensions to support a plurality of loaded trailer containers  15  during the hitching and unhitching procedure upon joining or departing from the train. 
     The switching ramp  75  is designed to traverse a pit structure, indicated generally at  80  to move the ramp  75  into alignment with adjacent parallel sets of tracks  35  disposed in the terminal yard, indicated generally at  85 , for routing to other trains or for conversion back to highway use. 
     The pit structure  80  is also a generally rectangular concrete construction having a plurality of sets of parallel railway tracks  35  embedded therein. The pit structure is of sufficient length to permit both end tracks  35  on the slab  76  to be brought into alignment with all of the parallel sets of tracks which are interrupted by the pit  80  as shown in FIG.  18 . 
     The slab  76  is adapted for rolling movement within the pit structure  80  being mounted on a plurality of railroad bogie devices  72  or other similar devices having sufficient load capacity to support the weight of the slab  76  and the fully loaded trailer containers  15 . In addition, one or more tandem modules  42  or  44  are attached at either end of the slab to pull the same during operation. 
     Since such railway dollies or bogie devices are well known to those skilled in the art, further detailed discussion of the same is not deemed necessary. 
     The switching ramp  75  will be installed at various terminal locations along the route served by the Super Rail System. In practical use as a Super Rail Train arrives at the terminal on the main railway track  35 A, the train crosses over the ramp  75  and stops at a position wherein the first trailer container  15  to be unloaded from the train is positioned on the ramp  75  as shown in FIG.  19 . It will be noted that the train is positioned on the first set of tracks of the ramp  75 . 
     A first tandem device  40  disposed at the juncture of the last passenger coach  12  and the first trailer  15 A is separated into modules  42  and  44  and the passenger coach  12  together with the primary drive vehicle  18  proceeds to the terminal to unload and reload the passengers. 
     Thereafter, the passenger portion of the train  10  will return to the ramp for a different trailer train or proceed to its destination depending upon its schedule. It will be noted that such additional trailer trains have been omitted from the drawings for purposes of this explanation. 
     Next, the first trailer container  15 A on the ramp  75  is unhooked from the remaining portion of the trailer train which is backed clear of the ramp  75 . 
     Thereafter, the ramp  75  is shifted to the left to align with the next adjacent set of tracks  35 B as shown in FIG.  20 . The operator now lowers the landing gear  48  of the trailer container  15  and unhitches the tandem modules  42  and  44  by releasing their respective fifth wheel units  24 . 
     Next, each of the tandem modules  42  and  44  are backed off of the ramp  75  on to aligned tracks  35 B as shown in FIG. 21 where the modules  42  and  44  will remain until needed for the next trailer container  15  to be placed on the ramp  75  for routing. 
     Simultaneously, the second trailer container  15 B in the train is driven onto the second set of tracks of the ramp  75  using its attached tandem module  44  as shown in FIG.  21 . When this trailer container  15 B is properly positioned on the ramp  75 , the operator of the tandem module will stop and unhook the container  15 B from the train by separating the tandem modules  42  and  44  at the rear end thereof. The remaining portion of the trailer train is backed up until it clears the ramp  75  and the ramp is again shifted to the left until the second container  15 B is aligned with the tracks  35 B adjacent to the main track  35 A as shown in FIG.  22 . 
     In similar fashion the landing gear  48  of the second container  75 B is lowered and the tandem modules  42  and  44  are released by lowering their respective fifth wheel units  24  and the modules are backed off of the ramp  75  by the operator. 
     It will be appreciated by those skilled in the art that this process is repeated until all of the trailer containers  15  which are to be unhooked from the train at a particular location have been moved to adjacent tracks for routing to other trains or back to highway use. 
     The tandem modules  42  and  44  accumulated on the side tracks  35 B are stored for future use and the above process is essentially reversed to create new trailer container trains for transport on the present system. 
     From the above it can be seen that the Super Rail System of the present invention provides an improved intermodal transport system combining trucking and railway technology. 
     The present system includes a Super Rail Train which offers the advantages of highway type drive train and suspension systems which are more cost efficient and maintenance free than conventional railway locomotives. 
     The Super Rail System provides novel features such as a secondary power unit controlled by an on-board computer system which operates during peak load conditions. The present system also provides a unique, self-powered tandem device which replaces the conventional railway dolly or bogie in the transport of highway trailer containers. 
     The terms “upper”, “lower”, “side”, and so forth have been used herein merely for convenience to describe the present invention and its parts as oriented in the drawings. It is to be understood, however, that these terms are in no way limiting to the invention since such invention may obviously be disposed in different orientations when in use. 
     The present invention may, of course, be carried out in other specific ways than those herein set forth without departing from the spirit and essential characteristics of such invention. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive, and all changes coming within the meaning and equivalency range of the appended claims are intended to be embraced therein.