Patent Publication Number: US-7900565-B2

Title: Passenger rail car

Description:
RELATED APPLICATIONS 
     This application is a Continuation of application Ser. No. 11/546,547, filed Oct. 12, 2006, which claims priority to U.S. Provisional Patent Application Ser. No. 60/798,773, entitled “Passenger Rail Car”, filed with the U.S. Patent and Trademark Office on May 9, 2006. The entire contents of the aforementioned applications are incorporated herein by reference. 
    
    
     FIELD OF THE INVENTION 
     The invention relates generally to passenger rail cars; and, in particular, to a multi-level passenger rail car having a forward control cab. 
     DESCRIPTION OF THE RELATED ART 
     In order to promote greater safety of conventional intercity and commuter railroads which operate on the general railroad system with other trains including freight trains, the federal government has promulgated regulations governing passenger rail safety and equipment. Local jurisdictions and operators acquiring new passenger trains for conventional intercity and commuter service have complied with and in some cases exceeded these regulations. For instance, one jurisdiction initiated a procurement for passenger equipment requiring crash energy management (CEM) or crush zones to be provided at both ends of each passenger rail car, to help absorb the impact of a collision with another train, or with an object or a vehicle at a highway-rail grade crossing. Other jurisdictions are similarly considering application of CEM for passenger railroad operations. 
     Many conventional passenger trains have a first “cab” car at the front of which is a cab for an operator (engineer), with space for passengers behind the cab, all on the same level. The other rail cars that couple with the cab car also carry passengers. The frontal location of the cab may place the operator at risk of serious injury in the event of a frontal collision. 
     In order to maximize capacity, passenger rail cars may have multiple levels. Multiple level passenger rail cars are commonly referred to as “bilevels,” with seating for passengers on upper and lower levels. As used herein, the term “bilevel” means at least two levels of passenger seating. 
     Several carbuilders make bilevels that operate in or near various North American cities, including Boston, New York, Washington, San Francisco, Seattle, Toronto, Miami, and Dallas. Some of these cab cars actually include three floor levels: one between the wheel trucks at 25″ above top of rail (TOR), one at 51″ above TOR at both ends over the wheel trucks, and one at 104″ above TOR. The operator&#39;s cab is typically positioned at 51″ above TOR, and is located at the very front of the rail car. No CEM is provided in such a cab car. Rather, the cab car has a rigid outer shell with no crush zones provided. 
     Several cab cars used in or around Chicago, Washington and San Francisco have a two-level “gallery” structure, with the lower floor being a full car length at 48″ above TOR, and with the upper floor at 104″ above TOR. Because of the low clearance between floors of approximately 56″, the upper level is split lengthwise to provide ample headroom for passengers standing along the center aisle way of the lower floor. There is a single row of seats on each of the upper level floors, and an open railing on the center side of each of the upper level floors. For this rail car, the control cab is located at the very front of the rail car, at 104″ above TOR. There are no CEM features provided, and some passengers may be located next to the operator&#39;s cab at the very front of the rail car. 
     There is also a bilevel rail car that provides intercity services in the State of California. This rail car includes an operator cab on the upper level floor, at 104″ above TOR at the very front of the rail car, and there are no CEM features. The passenger passage way between rail cars is provided at 104″ above TOR, which makes it incompatible with single level rail cars. 
     Among the objects of the invention is the provision of a passenger rail car that provides enhanced safety for all car occupants, including the operator, in the event of a frontal collision, and makes efficient use of space and energy. 
     SUMMARY OF THE INVENTION 
     According to at least one aspect of the invention, there is provided a bilevel passenger rail car with an elevated operator position and integrated crash energy management. In more detail, there is provided a passenger rail car that includes a lower passenger compartment that includes a plurality of passenger seats. The passenger rail car also includes an upper passenger compartment that includes a plurality of passenger seats. The passenger rail car further includes a crash energy management region provided at a front portion of the passenger rail car. The passenger rail car also includes a control cab for a rail car operator that is elevated above the lower passenger compartment, the control cab being forward of the passenger seats and behind the crash energy management region. 
     According to another aspect of the invention, there is provided a bilevel passenger rail car with an angled front end and an upper level operator position. In more detail, there is provided a passenger rail car that includes a front end that is slanted to provide a greater field of view for the rail car operator positioned within a control cab provided in a top half section within the passenger rail car. 
     According to yet another aspect of the invention, there is provided a crash energy management system for a rail car, which includes a forward-end crush zone. The forward-end crush zone includes a plurality of primary energy absorbers horizontally positioned in the crush zone. The forward-end crush zone also includes a plurality of secondary energy absorbers horizontally positioned in the crush zone. The forward-end crush zone further includes a plurality of load transfer plates vertically positioned in the crush zone. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The foregoing and other objects, advantages and features of the invention will become apparent upon reference to the following detailed description and the accompanying drawings of exemplary embodiments of the invention, in which: 
         FIG. 1A  is a top plan view of the upper passenger compartment of a cab car according to a first embodiment of the invention; 
         FIG. 1B  is a top plan view of the middle and lower passenger compartments of the cab car according to the first embodiment of the invention; 
         FIG. 1C  is a top plan view of the upper passenger compartment of the cab car according to a second embodiment of the invention; 
         FIG. 1D  is a top plan view of the middle and lower passenger compartments of the cab car according to the second embodiment of the invention; 
         FIG. 1E  is a right-side longitudinal sectional view of the cab car according to the second embodiment of the invention taken along line E-E in  FIG. 1D ; 
         FIG. 1F  is a left-side longitudinal sectional view of the cab car according to the second embodiment of the invention taken along line F-F in  FIG. 1C ; 
         FIGS. 1G ,  1 H,  1 I and  1 J are respective widthwise cross-sectional views at different positions along the cab car according to the second embodiment of the invention taken along lines G-G, H-H, I-I and J-J, respectively, in  FIGS. 1E and 1F ; 
         FIG. 2  is a perspective view of the inside of the top level of the cab car according to the first embodiment of the invention; 
         FIG. 3  is a perspective view of the outside of a front portion of a cab car according to a third embodiment of the invention; 
         FIG. 4  is a perspective view of the outside of a front portion of a cab car according to a fourth embodiment of the invention; 
         FIG. 5A  is a rear elevational sectional view of the front of the cab car according to the third embodiment of the invention; 
         FIG. 5B  is a side elevational sectional view of the front of the cab car according to the third embodiment of the invention; 
         FIG. 6  is a top plan schematic view of the cab car according to the third embodiment of the invention showing outward visibility angles; 
         FIG. 7A  is a rear elevational sectional view of the front of the cab according to the fourth embodiment of the invention; 
         FIG. 7B  is a side elevational sectional view of the front of the cab car according to the fourth embodiment of the invention; 
         FIG. 8  is a top plan schematic view of the cab car according to the fourth embodiment of the invention; 
         FIG. 9  is a front perspective view of a cab car according to an embodiment of the invention, showing collision posts and crash energy management components according to a first possible implementation; 
         FIG. 10  is a front perspective view of a cab car according to an embodiment of the invention, showing collision posts and crash energy management components according to a second possible implementation; 
         FIG. 11  is a front perspective view of a cab car according to an embodiment of the invention, showing collision posts and crash energy management components according to a third possible implementation; 
         FIG. 12  is a front perspective view of a cab car according to an embodiment of the invention, showing collision posts and crash energy management components according to a fourth possible implementation; 
         FIG. 13  is a perspective view of cab end crash energy management components of a crash energy management system according to a fifth embodiment of the invention; 
         FIG. 14  is a perspective view of the various structural components of a cab end crash energy management system according to the fifth embodiment of the invention, with the cab car body removed from view; 
         FIG. 15  is a bottom perspective view of the cab end components of the crash energy management system of  FIG. 13 ; 
         FIG. 16  is a top plan view of the cab end crash energy management system of  FIG. 14 , with the rail car body components removed from view; 
         FIG. 17  is a perspective view of non-cab end crash energy management components of a crash energy management system according to a sixth embodiment of the invention; 
         FIG. 18  is a perspective view of a cab end crash energy management system according to a seventh embodiment of the invention; and 
         FIG. 19  is a bottom perspective view of the cab end crash energy management system of  FIG. 18 . 
         FIG. 20  is a perspective view of the outside of a front portion of a cab car according to an eighth embodiment of the invention. 
         FIG. 21  is a perspective view of a cab end crash energy management system of  FIG. 20 , showing collision posts and corner posts behind the crash energy management system and at the end of the zone occupied by passengers and the car operator. 
     
    
    
     DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS 
     Referring to  FIGS. 1A and 1B , in a first embodiment of the invention, there is provided a multi-level cab car  100 . The cab car  100  includes a lower passenger compartment level  120  that includes a plurality of passenger seats  105 , an upper passenger compartment level  102  that includes a plurality of passenger seats  105 , and a middle compartment level  125 A,  125 B with a plurality of passenger seats  105 . The middle compartment has portions  125 A,  125 B at each end of the cab car  100 . Front portion  125 A has steps  130 A that allow a passenger to move from the front portion  125 A to the upper passenger compartment  102 , and steps  130 C that allow a passenger to move from the front portion  125 A to the lower passenger compartment  120 . Rear portion  125 B has steps  130 B that allow a passenger to move from the rear portion  125 B to the upper passenger compartment  102 , and steps  130 D that allow a passenger to move from the rear portion  125 B to the lower passenger compartment  120 . The front portion  125 A ends at a first opening (or door)  125 D at one end of the cab car  100 , whereby passengers from a forwardly-positioned car of a train of cars can enter into the cab car  100  through that first opening  125 D. Similarly, the rear portion  125 B ends at a second opening (or door)  125 D at the other end of the cab car  100 , whereby passengers from a rearwardly-positioned car of the train can enter into the cab car  100  through that second opening  125 D. The passengers enter and exit the cab car  100  via side doors  126  at the lower passenger compartment level  120 . Side doors (not shown) may also be provided on the middle compartment level  125 A,  125 B. 
     By way of example and not by way of limitation, the lower passenger compartment  120  is positioned approximately 25″ above top of rail (TOR), the upper passenger compartment  102  is positioned at approximately 104″ above top of rail (TOR), and the middle compartment  125 A,  125 B is positioned at approximately 51″ above top of rail (TOR). The middle compartment  125 A,  125 B extends from each end of the cab car only to the steps  130 A-D. 
     Referring to  FIG. 1A , which shows the upper passenger compartment level  102 , a protective operator cab (also referred to herein as “protective cab” or “operator cab” or “control cab”)  115  is positioned at a front-right end of the upper passenger compartment level  102 , behind a crash energy management region (described below). The rail car operator enters and exits the control cab  115  by way of an aisle portion  110 A. The aisle  110 A and/or the control cab  115  spans approximately one-third (⅓) the width of the cab car  100 . Alternatively to what is shown in  FIG. 1A , the aisle  110 A and control cab  115  may be provided at a front-left end of the upper passenger compartment level  102 . This alternative configuration is possible assuming that stairways, seating and other parts of the cab car allow for such a configuration. 
     At least one extra passenger seat may be positioned adjacent the aisle  110 A in the upper passenger compartment  102 . By way of example and not by way of limitation, for a cab car having a full width clearance, the upper passenger compartment aisle  110 A and/or control cab  115  can extend ⅓ of the full width from one side (e.g., the right side) of the cab car  100 . 
     Referring to  FIG. 1B , the lower passenger compartment level  120  is positioned beneath the upper passenger compartment level  102  in the central portion (with respect to a length-wise direction) of the cab car  100 , between stairs  130 A,  130 C and stairs  130 B,  130 D, which are adjacent the middle compartment level portions  125 A,  125 B. Middle compartment level portions  125 A,  125 B are disposed over the cab car&#39;s wheel trucks (not shown), while the lower passenger compartment level  120  is disposed between the wheel trucks. It is preferable that all of the passenger seats  105  face backwards (opposite to the direction of travel), as illustrated, to provide for greater passenger safety in the event of a frontal collision when the cab car  100  is leading. Alternatively, at least some of the passenger seats  105  may face forwards. 
       FIGS. 1C-1J  show several different views of a cab car  180  according to a second embodiment of the invention. In contrast to the first embodiment described above, the aisle  110 B of the second embodiment may not be adjacent any passenger seats, thereby allowing greater room for the operator to navigate to and from the control cab  115 . The other features shown in  FIGS. 1C-1J  are also found in the first embodiment. 
       FIG. 2  shows the front portion of the upper passenger compartment level  102  of the first embodiment of the cab car  100 , including the front stairs  130 A that connect the upper  102  and middle  125 A levels of the cab car  100 , the aisle  110 A, and the control cab  115 . The control cab  115  may be enclosed at the end of the passenger area by a transverse partition and hinged access door  111 , to protect the operator in the case of an unruly passenger or other threat. In the first embodiment, the aisle  110 A may be positioned adjacent a single column of seats  105  running forward from the steps  130 A. A similar view of the second embodiment would omit the right-hand column of passenger seats  105 . 
     A crash energy management region having a crush zone is provided at both ends of the cab car according to the first and second embodiments, whereby, by way of example and not by way of limitation, the crush zone is approximately 60 inches in thickness, and spans the entire width of the cab car at respective front and back ends of the rail car. In the first and second embodiments, the crush zone that is located at the front end of the cab car  100 ,  180  where the protective cab extends upwards from the bottom portion of the cab car and extends between the bottom portion of the cab car  100  and a bottom surface of the control cab  115 . The crush zone may extend the entire distance between the bottom portion of the cab car  100  and the bottom surface of the control cab  115 , or the crush zone may extend only partially along the distance between the bottom portion of cab car  100  and the bottom surface of the control cab  115 . Since the rail car operator is situated within the protective cab  115  at a high position at the upper passenger compartment height of the cab car, the rail car operator is in a position that would be above the height at which another non-passenger train or a vehicle on a road intersecting the railroad tracks would make impact with the cab car. 
     The control cab  115  is positioned rearward of collision posts and the crush zone at the front part of the cab car according to the first and second embodiments. To provide the operator with the maximum forward visibility, a lower edge of a windshield is positioned to allow the operator to view the tracks that are located 18 feet and further from the front end of the cab car. There may also be provided a windshield and side window opposite the cab site and an additional windshield between collision posts, to provide for greater viewing angle by the operator. The control cab  115  is located above the mid-level ceiling and next to the rail car passageway, to provide for greater visibility and operator comfort. 
     With the protective cab  115  being provided at the upper passenger compartment level  102  in the first and second embodiments, the front of the cab car where the protective cab  115  is positioned can be shaped such that resistance to impacting objects, wind or the like is minimized. Due to the positioning of the protective cab  115  for the rail car operator up and back from a conventional position, a slanted front end shape can be provided, whereby impacting objects may be deflected, and faster speeds and more efficient energy consumption can result from such a better design. Furthermore, the rail car operator is provided with a better field of view due to his/her higher position within the rail car as compared to conventional rail car operator locations, and also due to the slanted front end of the cab car that provides for a greater field of view as compared to a vertical or box-shaped front end. Accordingly, the slanted front end shape of a cab car according to third and fourth embodiments, to be described in detail below, are compatible with either of the cab cars according to the first or second embodiments. 
     In a third embodiment, as shown in  FIG. 3 , the front end of a cab car  300  has a left-side region (e.g., ⅓ the total width of the cab car) that is mostly slanted, a right-side region (e.g., ⅓ the total width of the cab car) that is mostly slanted, and a box-shaped middle region (e.g., ⅓ the total width of the cab car) having an upright lower portion that includes an entry/exit door, and a slanted top portion. The entry/exit door  340  is provided for enabling passengers to enter and exit the cab car  300  to an adjacent car, or for passage when the train is stationary, in case of emergency if the cab car  300  is the first car in the train. The top (roof) of the box-shaped structure  340  is slanted at a greater angle than the left and right portions of the front end. The slant of the top left- and right-side regions  310  of the front end may be set at a value between 30 degrees and 60 degrees, and the slant of the top portion above the entry/exit door  340  at the middle portion of the front end may be set at a value of 70 to 75 degrees, all as measured from the vertical. Other slant angles are possible, while remaining within the spirit and scope of the invention. The front part of the entry/exit door  340  is substantially upright, to allow for close positioning of door  340  with a door (not shown) provided at the back end of an adjacently coupled car. The lower portions  320  of the left- and right-side regions of the front end are substantially vertical (flat, or straight up and down, with some minor slant possible in some configurations) down to the bottom of the front end. 
     In a fourth embodiment of a cab car  400 , as shown in  FIG. 4 , a top portion  410  of substantially the entire width of the front end is slanted, except for a lower portion  420  that is not slanted (or that has a minor slant in some possible configurations). A door  440 , which is provided at the middle part of the front end according to the fourth embodiment, is also slanted at the same angle. The slant of the top portion  410  of the front end may be set at a value between 30 degrees and 60 degrees from vertical. Other possible angles of the slanted and non-slanted portions of the front end are contemplated, while remaining within the spirit and scope of the invention. In the fourth embodiment as shown in  FIG. 4 , the door  440  includes a first door portion and a second door portion which are capable of closing the doorway by the first and second door portions coming into contact with each other, and which are capable of opening the doorway by at least one of the first and second door portions moving away from the other one. The door  440  does not extend outward from the slanted front end of the cab car  400 , to provide a streamlined front end portion of the cab car. 
       FIGS. 5A and 5B  are two views, one looking from behind the operator toward the front of the car and one from the longitudinal center of the car facing the right side (cab operator side) of the front end of the cab car  300  according to the third embodiment, in which a large field of view  310  for an operator positioned in the cab can readily be seen. The field of view  310  allows for an operator in the cab to see an object on the rails as close as 18 feet from a front of the rail car. As mentioned earlier, the third embodiment&#39;s front end structure is compatible with either the first or second embodiments.  FIG. 6  shows the field of view  310  for the operator located within the protective cab of the cab car  300  according to the third embodiment. 
       FIGS. 7A ,  7 B and  8  are similar to  FIGS. 5A ,  5 B and  6 , and show the field of view  410  for an operator positioned in the cab in the cab car  400  according to the fourth embodiment, whereby the fourth embodiment&#39;s front end structure is compatible with the either the first or second embodiments. 
     The Federal Railroad Administration (FRA) regulations, the American Public Transportation Association (APTA) voluntary industry standards, and at least one contract technical specification for one specific procurement require that the occupied volume of a train car that includes the train operator be within a car shell containing collision and corner posts at its extremities. The FRA regulations require collision posts and corner posts at each end of the car. The APTA voluntary industry standards require collision posts at both ends of occupied vehicles, and at part of the end frame, with corner posts at extreme corners of the car body structure and at part of the end frame. The contract technical specification requires collision posts at both sides of the end opening and at part of the end frame, and corner posts at the corners of the car and at part of the end frame. 
     Different implementations for providing collision posts and corner posts for protecting the front end of the cab car of the first through fourth embodiments are shown in  FIGS. 9-12 , in which the thick-sized lines correspond to the locations of the collision posts. The regular-sized lines depict the outer frame of the cab car, which supports the outer metal skin (not shown). In particular,  FIG. 9  shows two collision posts  910 ,  920  provided at the front end of the car at opposite sides of the end door of the car, with the collision posts having top portions extending substantially diagonally and having bottom portions extending substantially vertically at the front end of the car.  FIG. 10  shows two collision posts  1010 ,  1020  having a similar construction to the ones shown in  FIG. 9 , but with longer diagonal portions and shorter vertical portions.  FIG. 11  shows two collision posts  1110 ,  1120  that are provided along the sides of the end door of the car, with diagonal portions, horizontal portions, and vertical portions. In the crush zone construction of  FIG. 11 , the end door is fully mounted on the collision posts  1110 ,  1120 , providing a simple and strong design. 
       FIG. 12  shows two collision posts  1210 ,  1220  that extend substantially diagonally from top to bottom at the front of the car. In more detail, the collision posts utilized in a crash energy management system (having a crush zone provided at a front end of a cab car) are located transversely on each side of the end door opening, as provided in each of the four crush zone constructions shown in  FIGS. 9-12 . Such a construction enables an end sill (which is a component of an underframe structure of a crush zone of the cab car) to transmit the required anti-climber, buffer beam, coupler carrier, coupler shank, and overturning loads into the collision posts in addition to distribution into the draft sill. The collision posts in each of the four constructions shown in  FIGS. 9-12  extend from the bottom of an end underframe, vertically to the top of the end door, and then extend at an angle to an anti-telescoping plate at or near the roof level of the cab car. Collision posts are closed box sections and fully penetrate the end underframe and the anti-telescoping plate at or near roof level. The description of the transmission of energy from the crush zone to other components of the rail car will be discussed in detail at a later portion of this specification. 
     The collision posts are designed to withstand specified static loads and are able to absorb a minimum of 135,000 ft-lbs of energy. When a collision post is overloaded in bending, the top post connection and supporting structure deforms plastically by buckling and bending of the members to accommodate the collision post plastic bending failure. Further, overloading of bottom connections will likely crush or buckle underframe members, whereby shearing or fracturing of the posts is not permissible. The collision posts may be made from light alloy high tensile steel (LAHT), or other suitable material, such as stainless steel. 
     Like the collision posts, the corner posts are part of the cab car end frame (such as shown in, for example,  FIGS. 20 and 21  as reference numeral  2040 ), but are located at the corners of the cab car. Corner posts are continuously provided from the bottom plate of the end sill to the roof of the cab car. Corner posts extend from the bottom of the end underframe vertically and then extend at an angle to the anti-telescoping plate at or near the roof level of the cab car. Corner posts provide a closed box section and fully penetrate the end underframe and the anti-telescoping plate. 
     The corner posts are designed to withstand specified static loads and are able to absorb a minimum of 120,000 ft-lbs of energy. When the corner posts are loaded to their yield strength, the yield strengths of the connections and supporting structure to which the corner posts are attached should not be exceeded. Additionally, when the corner posts are overloaded to its ultimate bending strength, the top post connections and supporting structure should withstand the load without failure. Bottom attachments develop the full shear value of the post and overloading of the bottom connections is likely to crush or buckle underframe members, whereby shearing or fracturing is not permissible. The corner posts may be made from low alloy, high strength (LAHT) material, or other suitable material, such as stainless steel. 
     Given that a crash energy management region having a crush zone is provided on a front end of the cab car, and is encased within the skin of the car, the control cab provided at the top level of the car is positioned further inward from the front of the car than the control cab for conventional cars that do not have crush zones. Rather, a conventional cab car, whether single or bilevel, has a sturdy exterior shell, with no crush zones provided at the ends of the car. In the first and second embodiments, the control cab is positioned behind the crush zone, at an upper level of the car. This provides both better line-of-sight for the operator as well as better protection for the operator in the case of a collision with another train, object, or vehicle at a highway-rail grade crossing. In addition, the crash energy management region enhances safety for passengers in the lead car. 
     By way of example and not by way of limitation, the crush zone at the cab end is capable of absorbing a total of 3 million foot pounds of energy, within 38 inches of crush of the crushable structure comprising the cab end crush zone. The crush zone at the non-cab end is capable of absorbing a total of 2 million foot pounds of energy, within 24 inches of crush of the crushable structure comprising the non-cab end crush zone. This is accomplished by the crushing and/or crumbling of components within the crush zone. The crush zone is configured to first impact an object during a collision and crush and/or collapse, if necessary, in a controlled manner to absorb energy from the collision. Collision posts, as required by applicable regulations, are intended to withstand forces up to a certain load without crushing. The collision posts are not necessarily part of the crush zone. 
       FIGS. 13 and 14  show the locations of collision posts  1350  and corner posts  1360  for different possible implementations of a crush zone  1300  according to a fifth embodiment, for protecting the front end of the cab car of the first through fourth embodiments. As shown in the perspective cab end crush zone view of  FIG. 13 , the cab end crush zone  1300  includes a plurality of primary energy absorbers  1310 , a plurality of secondary energy absorbers  1320 , an end frame (post support box beam)  1325 , and a plurality of load transfer plates  1330 .  FIG. 14  shows the support components provided for the cab end crush zone  1300 , whereby the support components include collision posts  1350 , corner posts  1360 , primary and secondary absorbers  1310 ,  1320 , a draft sill  1410 , end sill beams  1440 , and a collision/corner post support box beam  1325 . Frangibles  1450  are also shown, which are support structures for the outer metal skin of the cab car. 
       FIG. 15  shows an underframe provided for the cab end crush zone according to the fifth embodiment. Push back coupler  1370 , sliding sill  1520 , shear bolts  1530  and end frame (fixed sill)  1540  can be readily seen in that figure. 
     In more detail, the crushable zone of the cab end is outboard of all occupied areas, with a vestibule wall separating the crushable zone from the passenger compartment, and with a metal skin that covers the crushable zone (to reduce wind resistance for a train that includes the cab car). A primary energy absorption system that includes the primary energy absorbers  1310  is located at the underframe level. A secondary energy absorption system that includes secondary energy absorbers  1320  is located above the underframe level at various levels behind the corner posts, in order to absorb energy and provide structure to help meet the post static requirements, and to act as guides to provide deflection of energy away from the passenger compartment. 
     Load is transferred from the contact points to the end frame through the load distribution transfer plates  1330 . The load distribution transfer plates  1330  are supported by lateral members  1331  that are connected to the corner posts  1360  and the collision posts  1350 . In operation, the upper, angled portion of the corner posts  1360  and the collision posts  1350  buckle during crush, in order to absorb some of the energy of the crash. 
     A coupler  1370  is also shown in  FIGS. 13 and 15 . The coupler  1370  is supported by a sliding sill  1520 . The sliding sill  1520  is a large tube-shaped structure attached to a fixed sill  1540  by a fuse mechanism (such as shear bolts or pins). When the push back stroke of the coupler  1370  reaches a certain value (such as, for example, approximately 20 inches), the fuse mechanism is activated, and the coupler  1370  and sliding sill element  1520  move back into the fixed sill  1540 . In one possible implementation, the outboard end of the sliding sill  1520  is connected to the rear end beam of the car&#39;s main underframe. Also, in the crush zone structure, the primary energy absorption elements are supported at their inboard ends by the main underframe structure of the cab car. 
     The underframe of the cab car according to the first and second embodiments includes two end underframes positioned at the front end and back end crush zones, with a central underframe that is connected to the two end underframes and respective ends of the central underframe. The end underframes may be made of LAHT material, whereas the central underframe of the cab car can be any of stainless steel or LAHT. Stainless steel is preferred for the central underframe to facilitate the formation of various profiles and due to ease of resistance welding. 
     For crash energy management considerations, the end structures are constructed to absorb specified amounts of collision energy, whereby the crush zones are provided to facilitate and accommodate a continuously progressive crush to maximum stroke (e.g., 38 inches of stroke), in addition to having additional space to accommodate the crushed material. 
     For static strength considerations, the draft sill  1410 , the end sill  1440 , the side sills  1420  and their respective connections are structured to withstand high compression and other forces and moments without exceeding specified stresses. Accordingly, the draft sill  1410  and the side sills  1420  are designed so that they are not easily crushed under accidental overloads in a normal sense of crushing, and whereby the draft sill  1410  and the side sills  1420  are provided so as to facilitate the progression of crush to the maximum stroke for proper absorption of the specified energy. 
     In view of the above, sliding mechanisms are utilized in the end underframes to allow the side sills  1420  and the draft sill  1410  to slide backward in a controlled and measurable manner as crushable elements are successively consumed to the maximum stroke.  FIG. 16  shows the sliding nature of the side sills  1420  and the draft sill  1410  provided at a cab end crush zone according to the fifth embodiment, whereby the side sills  1420  and the draft sill  1410  both slide inwards in the event of a crash. Also shown in  FIG. 16  are an end sill  1440 , the primary absorbers  1310 , the secondary absorbers  1320 , shear bolts  1605 , and a body bolster  1610 . 
     The body bolster  1610 , the draft sill  1410 , the end sill  1440  and the end portions of the side sills  1420  are the major load carrying members of the end underframe of the first and second embodiments. In order to facilitate proper load transfer, flanges and webs of major components are aligned to provide continuity and to avoid unnecessary eccentricities. 
     The end underframe of the cab car is constructed to withstand static end compression on the end sill  1440 , static end compression on the line of draft, anti-climbing loads, coupler shank and coupler carrier loads, buffer beam loads, lateral bypass loads, and overturning loads as specified by FRA and other technical specifications. The end underframe also is structured to support loads resulting from the plastic bending failures of the collision posts and corner posts. In addition, the body bolster  1610  is utilized to transmit loads away from the rail car body, and the draft sill  1410  is utilized to transmit loads to the side sills  1410  and a center sill. 
     With respect to the central underframe, a center sill is utilized to meet the FRA longitudinal compressive load requirements and work in conjunction with the performance of the CEM structure according to the first and second embodiments. The center sill, which is positioned along a same axis as the draft sill  1410 , provides longitudinal center support to the draft sill  1410  and offers continuity to the draft sill  1410 , in tandem with the side sills  1420  provided on the sides of the cab car, thereby facilitating a controlled crush. The center sill also provides better camber control and improves the overall longitudinal and torsional stiffness of the cab car body. 
     Cross bearers and floor beams may also be installed at regular intervals in the central underframe, to prevent buckling of the center sill and to provide vertical load distribution to the center sill (and draft sill  1410 ) and the side sills  1420 . Such an underframe is expected to have better resistance to loads, including diagonal loads. 
     As discussed earlier, the draft sill  1410  moves with the crush zone in a controlled manner to allow for optimal operation of crash energy management. To facilitate draft sill movement with the progression of the crush zone, the draft sill  1410  contains a shearing mechanism. The portion of the draft sill  1410  within the crush zone will shear under a predetermined crush load and then slide into a fixed portion of the draft sill  1410  extending outboard of the body bolster  1610 . By way of example and not by way of limitation, this movement can be set equal to the maximum specified stroke of 38 inches, for example. 
     By way of example and not by way of limitation, the coupler  1370  undergoes approximately 13.75 inches of deformation until the specified energy absorption has occurred. The coupler  1370  has a shear mechanism that will fail when a sufficient crash force occurs, allowing the coupler assembly to travel back into a draft sill cavity. By way of example and not by way of limitation, total longitudinal travel makes up for 20 inches of coupler push-back plus additional distance needed to accommodate CEM crush. 
     Two possible implementations for providing a sliding draft sill  1410  according to a cab car according to the first or second embodiments are described herein. One implementation has the coupler  1370  mounted on the fixed portion of the draft sill  1410 , and the other implementation has the coupler  1370  mounted on the movable portion of the draft sill  1410 . 
     For the first implementation in which the coupler  1370  is mounted on the fixed portion of the draft sill  1410 , a cavity is provided within the draft sill  1410  to allow the coupler  1370  to travel backward into this free space (the cavity) during CEM system activation. A hollow cylinder may be mounted on the fixed portion of the draft sill  1410 , or the coupler  1370  may also slide into the cavity of the fixed portion of the draft sill  1410 . In this implementation, the draft sill shear mechanism and the coupler shear mechanism trigger at approximately the same time to allow progression of the crush zone. This implementation also uses a long shank coupler in order to span across the crush zone, whereby its length may be approximately 50 inches in one possible construction. 
     For the second implementation in which the coupler  1370  is mounted on the movable (e.g., the sliding) portion of the draft sill  1410 , a shorter shank coupler than what is described with respect to the first implementation is utilized, since the coupler mounting moves with the draft sill  1410 , and therefore is independent of any crush zone allowance. 
     With respect to the side sills  1420  in the crush zone according to the fifth embodiment, the end portions of each side sill  1420  shear off and slide into a fixed portion of each side sill, in concert with the collapse of the crush zone. The shearing mechanism may contain rivets, bolts, pins, and/or weldments. 
     A cab car non-cab (rear) end crush zone structure  1700  according to a sixth embodiment is shown in  FIG. 17 , and includes an end frame load distribution transfer structure  1710 , primary absorbers  1720 , and second absorbers/plates/guide tubes  1730 . The end frame load distribution transfer mechanism includes a plurality of horizontally and vertically positioned posts, with the primary and secondary absorbers  1720 ,  1730  provided between front and back sides of the end frame load distribution transfer structure  1710 . The cab car non-cab end crush zone  1700  absorbs the crash and thereby lessens the impact of the non-cab end of the first cab car of a train with the front end of a second car of the train, whereby the second and other cars may have their own front and back end crush zones similar in construction to the non-cab end crush zone of the cab car. 
     Other major cab carbody structure includes floors, roof, sides, equipment mounting brackets, and pilots. The upper level floor is structured to carry maximum passenger loads, and provisions are made for HVAC ducts, lighting and other fixtures. The roof structure is structured to support rollover loads and maintenance crew loads. In addition, roofs may also be subject to car wash loads caused by pressure and velocity of pressure washers. The side structure, in addition to supporting vertical loads, also is structured to carry rollover and side impact loads, such as the loads set forth in APTA standards. Equipment mounting brackets are provided to support heavy equipment, such as equipment heavier than 150 pounds. Cab ends of cab cars may be provided with pilots having clearances to prevent objects from going under the car, whereby the pilots may be constructed to carry the specified loads. 
     With the crush zone provided at the front end of the cab car and with the control cab provided at a top level of cab car behind the crush zone, the operator is positioned further back from the front end as compared to conventional cab cars that do not have CEM. This provides additional protection for the operator due to the higher position and set-back-from-front location of the control cab. 
     A cab end crush zone structure  1800  according to a seventh embodiment is shown in  FIG. 18 . The cab end crush zone structure  1800  includes primary absorbers  1810 , an absorber tie plate  1820  (one provided at each side of the front side door), an end frame  1825 , and load transfer plates  1830  (one provided at each side of the front side door). A coupler  1850  that is a part of the underframe structure of the cab end is also shown in  FIG. 18 . The absorber tie plate  1820  is provided for crush stability. 
     The underframe structure for the crush zone  1800  is shown in  FIG. 19 , and includes a coupler  1850 , a sliding sill  1910 , and a fixed sill  1920 , which operates similar to the operation of the underframe structure as shown in  FIG. 15 . The primary absorbers  1810  are provided as a set of four (4) absorbers both on a front side and a back side of the absorber tie plate  1820 , for crush stability. Accordingly, eight (8) primary absorbers  1810  are utilized in the seventh embodiment. A secondary absorption system (not shown in  FIG. 19  but see  FIG. 14 ) may also be utilized in the crush zone  1800  of the seventh embodiment. 
     In an eighth embodiment, as shown in  FIG. 20 , a top portion  2011  of substantially the entire width of the front end of the cab car  2000  is slanted, except for a lower portion  2012  that is not slanted (or that has a minor slant in some possible configurations). A door  2020 , which is provided at the middle part of the front end according to the eighth embodiment, is also slanted at the same angle as the top portion  2011  and bottom portion  2012 . The slant of the top portion  2011  of the front end may be set at a value between 30 degrees and 60 degrees from vertical. Other possible angles of the slanted and non-slanted portions of the front end are contemplated, while remaining within the spirit and scope of the invention. In  FIGS. 20 and 21 , an end frame  2040  including the collision posts  2050  and corner posts  2060  may be seen. The collision posts  2050  and corner posts  2060  do not extend out towards the very end of the front end of the cab car  2000 . The collision posts  2050  and corner posts  2060  include a slanted portion that reaches from a top portion of the cab car  2000  toward a front end of a control cab  115  and a substantially vertical portion that is rearward of the outer skin of the cab car  2000  and a crush zone of the crash energy management region. 
     The components of the crash energy management region of the eighth embodiment are shown in  FIG. 21 . The cab end crush zone structure includes primary absorbers  2070 , secondary absorbers  2080 , lateral members  2071  and load distribution transfer plates  2072  (one provided on each side of the front end door  2020 ). A coupler  2090  that is part of the underframe structure of the cab end is also shown in  FIG. 21 . The primary energy absorbers  2070  extend substantially perpendicular to the collision posts  2050  and corner posts  2060 , and the primary energy absorbers  2070  connect (directly or indirectly) the load distribution transfer plates  2072  to the front end of the cab car  2000 . As can be seen in  FIGS. 20 and 21 , the crush zone is located forward of and below the control cab  115  for an operator. 
     According to another embodiment of the invention, equipment lockers may be located within the CEM structural area. 
     Embodiments of the present invention have been described in detail. Other embodiments of the invention will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein, which are considered as exemplary only. For example, while the embodiments have been described with respect to a bilevel cab car that is a part of a train having other cars, the features described above with respect to cab cars are also applicable to other rail cars without propulsion means or other rail cars with their own propulsion units, such as bilevel Multiple Unit (MU) cars, which have their own traction motor(s) or other means of propulsion for moving a train of cars that includes the car with the control cab, irrespective of whether any other cars of the train have propulsion unit(s); bilevel Diesel Multiple Unit (DMU); bilevel Electrical Multiple Unit (EMU) cars; or any other passenger rail cars that have their own means of propulsion.