Abstract:
The present anti-ballistic shelter is a reinforced unit configured to comply with both ISO standards for size and weight, and with the U.S. Department of State Certification Standard for Forced Entry and Ballistic Resistance of Structural Systems. Each end and side wall of the unit is reinforced with wall studs that penetrate the unit&#39;s structural framework. Even though these wail studs are welded into place, penetration of the wall studs into the framework ensures acceptable blast, ballistic, and forced entry resistance even if the welds are flawed.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This patent application is a continuation-in-part and claims the benefit of U.S. patent application Ser. No. 13/886248 filed May 2, 2013, which claims the benefit of U.S. Provisional Application No. 61/641,877 filed May 2, 2012. The above applications are incorporated by reference herein in their entirety. 
     
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
       [0002]    The invention described herein was made by an employee of the United States Government and may be manufactured and used by the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefore. 
     
    
     FIELD OF INVENTION 
       [0003]    This invention relates to the field of armor and more specifically to construction of armored structures which comply with both ISO and State Department Standards. 
       BACKGROUND OF THE INVENTION 
       [0004]    The U.S. Army Corps of Engineers (USACE) currently uses shipping containers as components for transportable shelters to protect troops from ballistics and explosives. This system is known in the art as a Hardened Alternative Trailer System (HATS). 
         [0005]    The HATS structures must comply with the U.S. Department of State Certification Standard for Forced Entry and Ballistic Resistance of Structural Systems, SDSTD01.01, without exceeding stringent ISO weight and dimensional specifications. USAGE has conducted considerable laboratory research to develop a HATS shelter which concurrently meets most standards. U.S. patent application Ser. No. 13/886,248 (the &#39;248 Application) teaches precise specifications developed by the government to meet ISO Standard No. 668:2013 for twenty-foot structures. 
         [0006]    At present, over four hundred structures having the specifications taught in the &#39;248 Application have been fielded “in theater.” At a cost of several hundred thousand USD per structure, this technology represents investment in the range of $100,000,000 to the U.S. government. 
         [0007]    Despite the commercial success of the technology taught in the &#39;248 Application, there is an unmet need in the art for a system which complies with the requirements of ISO Standard No. 668:013 for larger forty-foot structures. 
       BRIEF SUMMARY OF THE INVENTION 
       [0008]    An anti-ballistic shelter system includes a base assembly, a top assembly first and second end wall assemblies, and two sidewall assemblies. 
         [0009]    The base assembly includes channeled floor/roof support beams extending between floor girders and connected to floor/roof support beams. A floor connects to the floor girders. One of the floor girders has stud apertures spaced 16 inches apart at center. 
         [0010]    Each of the channeled floor/roof support beams has a length of 9.59375 feet, a width of 3 inches, a height of 2 inches, and a weight of 7.1 lbs. per foot of length. Each of the floor girders has a length of 39.125 feet and a hollow structural cross-section of 10 by 5 by ⅜ inches. Each of the floor/roof support beams has a length of 7.125 feet and a hollow structural cross-section of by 3 by 5/16 inches. The floor has dimensions of 39.5 feet by 7.395833 feet, 
         [0011]    The top assembly includes channeled floor/roof support beams extending between top girders and connected to floor/roof support beams. A roof connects to and is located above the top girders, while an interior roof connects to and is located below the top girders. The top girders have stud apertures spaced 16 inches apart at center. 
         [0012]    The top girders have a length of 39.833 feet and a hollow structural cross-section of 5 by 3 by ½ inches. The roof has dimensions of 39.95833 feet by 7.95833 feet. The interior roof has dimensions of 39.20833 feet by 7.125 feet. 
         [0013]    The first end wall assembly includes two ISO right freight container corner fittings and two ISO left freight container corner fittings, with a bottom frame and a top frame connecting the two ISO right freight container corner fittings to the two ISO left freight container corner fittings. Corner columns connect the two ISO right freight container corner fittings and the two ISO left freight container corner fittings. Exterior and interior plates connect to the bottom frame, the top frame, and the corner columns. The bottom frame and the top frame have stud apertures, with wall studs extending through the stud apertures into the bottom frame and the top frame. 
         [0014]    The bottom frame has a length of 6.9270833 feet and a hollow structural cross-section of 10 by 5 by ⅜ inches. The top frame has a length of 6.9270833 feet and a hollow structural cross-section of 5 by 3 by ⅜ inches. Each of the corner columns has a height of 9.166 feet and a hollow structural cross-section of 5 by 5 by ⅜ inches. Each of the wall studs has a height of 9.166 feet and a hollow structural cross-section of 3 by 2 by ¼ inches. The exterior plate has dimensions of 7.125 feet by 8.270833 feet. The interior plate has dimensions of 7.125 feet by 8.270833 feet. 
         [0015]    The second end wall assembly includes two ISO right freight container corner fittings and two ISO left freight container corner fittings, with a bottom frame end and atop frame end connecting the two ISO right freight container corner fittings to the two ISO left freight container corner fittings. Corner columns connect the two ISO right freight container corner fittings and the two ISO left freight container corner fittings. Exterior and interior end walls connect to the bottom frame end, the top frame end, and the corner columns. The bottom frame end and the top frame end have stud apertures, with wall studs extending through the stud apertures into the bottom frame end and the top frame end. 
         [0016]    The bottom frame end has a length of 7.125 feet and a hollow structural cross-section of 10 by 5 by ⅜ inches. The top frame end has a length of 6.9270833 feet and a hollow structural cross-section of 5 by 3 by ½ inches. The exterior end wall has dimensions of 7.125 feet by 8.270833 feet. The interior end wall has dimensions of 7.125 feet by 8.25 feet. 
         [0017]    The sidewall assemblies include exterior and interior sidewalls connected to one of the floor girders and the top girder, with wall studs extending into the top girder and one of the floor girders through the stud apertures in the top girder and one of the floor girders. The exterior sidewall has dimensions of 39.125 feet by 8.25 feet while the interior sidewall has dimensions of 39.125 feet by 8.25 feet. 
     
    
     
       BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWING(S) 
         [0018]      FIGS. 1-49  illustrate the components of an exemplary embodiment of an anti-ballistic shelter unit.  FIG. 1  illustrates the unit including a base assembly, a top assembly, an end wall assembly with door, an endwall assembly with window, and sidewall assemblies with windows. 
           [0019]      FIG. 2  illustrates the base assembly including floor girders floor/roof support beams, channeled floor/roof support beams, and floor.  FIGS. 3 and 4  illustrate floor girders.  FIG. 5  illustrates the floor/roof support beam.  FIG. 6  illustrates the channeled floor/roof support beam.  FIG. 7  illustrates the floor.  FIG. 8  illustrates base assembly welds. 
           [0020]      FIG. 9  illustrates the top assembly including floor/roof support beams, channeled floor/roof support beams, top girders, roof, and interior roof.  FIGS. 10 and 11  illustrate the top girder.  FIG. 12  illustrates the roof.  FIG. 13  illustrates the interior roof.  FIG. 14  illustrates the top assembly welds. 
           [0021]      FIG. 15  illustrates the end wall assembly with door, including ISO right freight container corner fitting, ISO left freight container corner fitting, door frame assembly, bottom frame for middle door, corner column, top frame for middle door, wall stud, exterior plate for middle door, and interior plate for middle door.  FIG. 16  illustrates a cross section of end wall assembly with door.  FIG. 17  illustrates the ISO right freight container corner fitting.  FIG. 18  illustrates the ISO left freight container corner fitting.  FIGS. 19-20  illustrate door frame assembly, vertical door frame, and door header.  FIG. 22  illustrates the door frame assembly welds.  FIG. 23  illustrates the bottom frame for middle door.  FIG. 24  illustrates the corner column.  FIG. 25  illustrates the top frame for middle door.  FIG. 26  illustrates the wall stud.  FIG. 27  illustrates the exterior plate for middle door.  FIG. 28  illustrates the interior plate for middle door.  FIG. 29-31  illustrate the end wall with door welds. 
           [0022]      FIG. 32  illustrates the end wall assembly with window, including bottom frame end, top frame end, wall studs, bottom jack studs, top jack studs, exterior end wall, interior end wall, and window frame assembly.  FIG. 33  illustrates the bottom frame end.  FIG. 34  illustrates the top frame end.  FIG. 35  illustrates the window frame assembly.  FIG. 36  illustrates the horizontal window frame.  FIG. 37  illustrates the vertical window frame.  FIG. 38  illustrates the vertical window molding.  FIG. 39  illustrates the horizontal window molding.  FIG. 40  illustrates the window frame assembly welds.  FIG. 41  illustrates the bottom jack stud.  FIG. 42  illustrates the top jack stud.  FIG. 43  illustrates the exterior end wall.  FIG. 44  illustrates the interior end wall.  FIG. 45  illustrates a cross section of the end wall assembly with window. 
           [0023]      FIG. 46  illustrates the sidewall assembly with windows, window frame assemblies, wall studs, bottom jack studs, top jack studs, interior sidewall, and exterior sidewall.  FIG. 47  illustrates the interior sidewall with punchouts.  FIG. 48  illustrates the exterior sidewall with cutouts.  FIG. 49  illustrates the sidewall assembly with windows welds. 
           [0024]      FIGS. 50 and 51  illustrate looter components of an exemplary embodiment of the anti-ballistic shelter unit. 
           [0025]      FIG. 52 a  through 52 c    illustrate a flowchart of an exemplary method for making the anti-ballistic shelter system. 
       
    
    
     TERMS OF ART 
       [0026]    As used herein, the term “hollow structural cross-section” refers to a measurement of a hollow member including, a first dimension, a second dimension, and a wall thickness. 
         [0027]    As used herein, the term “inches apart at center” refers to the distance between the centers of spaced structures. 
         [0028]    As used herein, the term “ISO freight container corner fitting” refers to a cast metal fitting forming the corner of a structure, having a hollow interior and at least one elongated aperture allowing insertion of the mobile portion, of a twistlock. 
         [0029]    As used herein, the term “twistlock” refers to a two- or three-portion connector, wherein at least one mobile portion of the connector may be inserted into an elongated aperture in a structure and rotated to prevent removal of the mobile portion from the elongated aperture and separation of the connector from the structure. 
         [0030]    As used herein, the term “welding interface” refers to a joint created by welding to or more pieces of metal together. 
         [0031]    As used herein, the term “welding scaffold” refers to a removable frame work used to hold the components of a welded structure in place during fabrication. 
       DETAILED DESCRIPTION OF THE INVENTION 
       [0032]      FIGS. 1-49  illustrate the components of an exemplary embodiment anti-ballistic shelter unit  100 .  FIG. 1  illustrates unit  100  including base assembly  10 , top assembly  20 , endwall assembly  30  with door, endwall assembly  40  with window, and sidewall assemblies  60  with windows. Unit  100  has a weight of approximately 58,970 lbs., well within the requirements for ISO containers. 
         [0033]      FIG. 2  illustrates base assembly  10  including floor girders  11 , floor/roof support beams  12 , channeled floor/roof support beams  13 , and floor  14 . Base assembly  10  has a weight of approximately 6,900 lbs. 
         [0034]      FIGS. 3 and 4  illustrate floor girders  11 , which have a length of 39.125 feet and a hollow structural cross-section of 10 by 5 by ⅜ inches. As seen in  FIG. 4 , floor girder  11  may include multiple stud apertures  15  spaced apart  16  inches apart at center. This critical dimension provides optimum structural integrity to any assembly utilizing stud apertures  15  without increasing weight to the point that it violates ISO standards.  FIG. 5  illustrates floor/roof support beam  12 , which has a length of 7,125 feet and a hollow structural cross-section of 3 by 3 by 5/16 inches.  FIG. 6  illustrates channeled floor/roof support beam  13 , which has a length of 9.59375 feet, a width of 3 inches, a height of 2 inches, and a weight of 7.1 lbs. per foot of length.  FIG. 7  illustrates floor  14 , which has dimensions of 39.5 feet by 7.395833 feet.  FIG. 8  illustrates base assembly  10  welds. 
         [0035]      FIG. 9  illustrates top assembly  20  including floor/roof support beams  12 , channeled floor/roof support beams  13 , top girders  21 , roof  23 , and interior roof  24 . Top assembly  20  has a weight of approximately 13,719 lbs. 
         [0036]      FIGS. 10 and 11  illustrate top girder  21 , which has a length of 39.833 feet and a hollow structural cross-section of 5 by 3 by ½ inches. Top girder  21  includes multiple stud apertures  15  spaced apart 16 inches apart at center.  FIG. 12  illustrates roof  23 , which has dimensions of 39.95833 feet by 7.95833 feet.  FIG. 13  illustrates interior roof  24 , which has dimensions of 39.20833 feet by 7.125 feet.  FIG. 14  illustrates top assembly  20  welds. 
         [0037]      FIG. 15  illustrates end wall assembly  30  with door, including ISO right freight container corner fitting  31 , ISO left freight container corner fitting  32 , door frame assembly  33 , bottom frame  34  for middle door, corner column  35 , top frame  36  for middle door, wall studs  37 , exterior plate  38  for middle door, and interior plate  39  for middle door. In the exemplary embodiment, end wall assembly  30  with door has a weight, of approximately 5,472 lbs. 
         [0038]    Exterior plate for middle door  38  and interior plate for middle door  39  are made from sheets of steel 0.0625 inches to 1 inch thick. Thicker sheets (0.5 inches to 1 inch thick) may be used for units  100  which will see deployment in areas where more protection may be needed. In embodiments without openings in an endwall assembly, additional wall studs  37  may be added, and exterior end plate  38  and interior plate  39  have neither punchouts nor cutouts for insertion of door frame assembly  33 . 
         [0039]      FIG. 16  illustrates a cross section of end wall assembly  30  with door.  FIG. 17  illustrates ISO right freight container corner fitting  31 .  FIG. 18  illustrates ISO left freight container corner fitting  32 .  FIG. 19  illustrates door frame assembly  33 , which includes two vertical door frames  33   a  and one door header  33   b.  Door frame assembly  33  has a height of 7.25 feet and a width of 3.84375.  FIG. 20  illustrates vertical door frame  33   a,  which has a height of 7 feet and a hollow structural cross-section of 8 by 3 by ¼ inches.  FIGS. 21  illustrates door header  33   b,  which has a length of 3.84375 feet and a hollow structural cross-section of 8 by 3 by ¼ inches.  FIG. 22  illustrates door frame assembly  33  welds.  FIG. 23  illustrates bottom frame  34  for middle door, which has a length of 6.9270833 feet and a hollow structural cross-section of 10 by 5 by ⅜ inches. Bottom frame  34  for middle door includes multiple stud apertures  15 ,  FIG. 24  illustrates corner column  35 , which has a height of 9.166 feet and a hollow structural cross-section of 5 by 5 by ⅜ inches.  FIG. 25  illustrates top frame  36  for middle door, which has a length of 6.9270833 feet and a hollow structural cross-section of 5 by 3 by ⅜ inches. Top frame for middle door  36  includes multiple stud apertures  15 . 
         [0040]      FIG. 26  illustrates wall stud  37 , which has a height of 9.166 feet and a hollow structural cross-section of 3 by 2 by ¼ inches. Wall studs  37  are inserted into stud apertures  15  and welded into place during assembly. Wall studs  37  provide critical anti-ballistic, -blast, and -forced entry properties.  FIG. 27  illustrates exterior plate  38  for middle door, which has dimensions of 7.125 feet by 8.270833 feet.  FIG. 28  illustrates interior plate  39  for middle door, which has dimensions of 7.125 feet by 8.270833 feet.  FIG. 29-31  illustrate end wall with door  30  welds. 
         [0041]      FIG. 32  illustrates end wall assembly  40  with window, including bottom frame end  41 , top frame end  42 , wall studs  37  bottom jack studs  43 , top jack studs  44 , exterior end wall  45 , interior end wall  46 , and window frame assembly  50 . In the, exemplary embodiment, end wall assembly  40  with window has a weight of approximately 3,507 lbs. 
         [0042]    In the exemplary embodiment, exterior end wall  45  and interior end wall  46  are made from sheets of steel 0.0625 inches to 1 inch thick. Thicker sheets (0.5 inches to 1 inch thick) may be used for units  100  which will see deployment in areas where more protection may be needed. In embodiments without openings in an endwall assembly, wall studs  37  replace bottom jack studs  43  and top jack studs  44 , and exterior end wall  45  and interior end wall  46  have neither punchouts nor cutouts for insertion of window frame assembly  50 . 
         [0043]      FIG. 33  illustrates bottom frame end  41  which has a length of 7.125 feet and a hollow structural cross-section of 10 by 5 by ⅜ inches. Bottom frame end  41  includes multiple stud apertures  15 .  FIG. 34  illustrates top frame end  42 , which has a length of 6.9270833 feet and a hollow structural cross-section of 5 by 3 by ½ inches. Top frame end  42  includes multiple stud apertures  15 . 
         [0044]      FIG. 35  illustrates window frame assembly  50 . which includes horizontal window frames  51 , vertical window frames,  52 , vertical window moldings  53 , and horizontal window moldings  54 .  FIG. 36  illustrates horizontal window frame  51  which has a length of 2.4166 feet and a hollow structural cross-section of 3 by 2 by ¼ inches.  FIG. 37  illustrates vertical window frame  52 , which has a length of 2.4375 feet and a hollow structural cross-section of 3 by 2 by ¼ inches.  FIG. 38  illustrates vertical window molding  53 .  FIG. 39  illustrates horizontal window molding  54 .  FIG. 40  illustrates window frame assembly  50  welds. Window frame assembly  50  also includes glass or another transparent material. 
         [0045]      FIG. 41  illustrates bottom jack stud  43  which has a height of 3.9166 feet and a hollow structural cross-section of 3 by 2 by ¼ inches. Bottom jack studs  43  are inserted into stud apertures  15  and, welded into place during assembly. Bottom jack studs  43 , similarly to wall studs  37 , provide critical anti-ballistic, -blast, and -forced entry properties for areas which include a window assembly  50 .  FIG. 42  illustrates top jack stud  44 , which has a height of 2.28125 feet and a hollow structural cross-section of 3 by 2 by ¼ inches. Top jack studs  44  are inserted into stud apertures  15  and welded into place during assembly. Top jack studs  44 , similarly to wall studs  37  and bottom jack studs  43 , provide critical anti-ballistic, -blast, and -forced entry properties.  FIG. 43  illustrates exterior end wall  46 , which has dimensions of 7.125 feet by 8.270833 feet.  FIG. 44  illustrates interior end wall  47 , which has dimensions of 7.125 feet by 8.25 feet.  FIG. 45  illustrates a cross section of end wall assembly  40  with window. 
         [0046]      FIG. 46  illustrates sidewall assembly  60  with windows, window frame assemblies  50 , wall studs  37 , bottom jack studs  43 , top jack studs  44 , interior sidewall  61  with punchouts, and exterior sidewall  62  with cutouts. In the exemplary embodiment, each sidewall assembly  60  with windows has a weight of approximately 14.185 lbs. 
         [0047]    In the exemplary embodiment, interior sidewall  61  and exterior sidewall  62  are made from sheets of steel 0.0625 inches to 1 inch thick. Thicker sheets (0.5 inches to 1 inch thick) may be used for units  100  which will see deployment in areas where more protection may be needed. In embodiments without openings in a sidewall assembly, wall studs  37  replace bottom jack studs  43  and top jack studs  44 , and interior and exterior sidewalls  61  and  62  have neither punchouts nor cutouts for insertion of window frame assembly  50 . In certain embodiments of unit  100 , one sidewall assembly  60  may have one or more window frame assemblies  50  while another sidewall assembly does not have any window frame assemblies  50 . 
         [0048]      FIG. 47  illustrates interior sidewall  61 , which has dimensions of 39.125 feet by 8.25 feet.  FIG. 48  illustrates exterior sidewall, which has dimensions of 39.125 feet by 8.25 feet.  FIG. 49  illustrates sidewall assembly  60  with windows welds. 
         [0049]      FIGS. 50 and 51  illustrate footer  70  components of an exemplary embodiment of anti-ballistic shelter unit  100 . 
         [0050]    Unit  100  includes at least one floater  70  embedded in the ground below unit  100 . Footer  70  is a concrete platform  71  having at least one metal protrusion  72  extending therefrom. Footer  70  extends below first or second end wail assembly  30  or  40  from one ISO freight container corner fitting  31  or  32  to another ISO freight container corner fitting  31  or  32 . This enables connection of metal protrusion  72  to ISO freight container corner fitting  31  or  32 . Certain embodiments use multiple footers  71  below a unit  100 , or use a single footer  71  with multiple metal protrusions  72  beneath unit  100 . 
         [0051]    In certain embodiments, footer  70  has a rectangular or trapezoidal cross-section. In certain embodiments, metal protrusion  72  is a cone-shaped steel protrusion extending through an aperture in ISO freight container corner fitting  31  or  32 . In other embodiments, metal protrusion  72  is a vertical twistlock  80  extending through an aperture in ISO freight container corner fitting  31  or  32 . 
         [0052]      FIG. 52 a  through 52 c    illustrate a flowchart of an exemplary method for making the anti-ballistic shelter system. 
         [0053]    In step  202 , method  200  removably connects 4 ISO right freight container corner fittings  31  to a welding scaffold. 
         [0054]    In step  204 , method  200  removably connects 4 ISO left freight container corner fittings  32  to the welding scaffold. Each ISO left freight container corner fitting  32  is located directly opposite a corresponding ISO right freight container corner fitting  31 . 
         [0055]    In step  206 , method  200  welds a corner column  35  between each pair of ISO right freight container corner fittings  31  and each pair of ISO left freight container corner fittings  32 . 
         [0056]    In step  208 , method  200  weld bottom frame  34  between an ISO left freight container corner fitting  32  and a corresponding ISO right freight container corner fitting  31 , and welds bottom frame end  41  between another ISO left freight container corner fitting  32  and another corresponding ISO right freight container corner fitting  31 . Bottom frame end  41  is parallel to bottom frame for middle door  34 . 
         [0057]    In step  210 , method  200  welds one floor girder  11  between an ISO left freight container corner fitting  32  and a corresponding ISO right freight container corner fitting  31 , and welds another floor girder  11  between another ISO left freight container corner fitting  32  and another corresponding ISO right freight container corner fitting  31 . Floor girders  11  are parallel to each other, and perpendicular to bottom frames  34  and  41 . 
         [0058]    In step  212 , method  200  welds floor  14  to floor girders  11  and bottom frames  34  and  41 . 
         [0059]    In step  214 , method  200  inserts wall studs  37  into stud apertures  15  in one floor girder  11  and bottom frames  34  and  41 . 
         [0060]    In step  216 , method  200  welds wall studs  37  to one floor girder  11  and bottom frames  34  and  41 . 
         [0061]    In optional step  218 , method  200  inserts bottom jack studs  43  into stud apertures  15  in one floor girder  11  and bottom frame end  41 . 
         [0062]    In optional step  220 , method  200  welds bottom jack studs  43  to one floor girder  11  and bottom frame end  41 . 
         [0063]    In step  222  method  200  inserts the wall studs  37  of step  214  into stud apertures  15  in top girder  21 , top frame  36 , and top frame end  42 . 
         [0064]    In step  224 , method  200  welds wall studs  37  to top girder  21 , top frame  36 , and top frame end  42 . 
         [0065]    In optional step  226 , method  200  inserts top jack studs  44  into stud apertures  15  in top girder  21  and top frame end  42 . 
         [0066]    In optional step  228  method  200  welds top jack studs  44  to top girder  21  and top frame end  42 . 
         [0067]    In step  230  method  200  welds top frame  36  between an ISO left freight container corner fitting  32  and a corresponding ISO right freight container corner fitting  31 , and welds top frame end  42  between another ISO left freight container corner fitting  32  and another corresponding ISO right freight container corner fitting  31 . Top frame end  42  is parallel to top frame for middle door  36 . 
         [0068]    In step  232 , method  200  welds top girder  21  between an ISO left freight container corner fitting  32  and a corresponding ISO right freight container corner fitting  31 , and welds another top girder  21  between another ISO left freight container corner fitting  32  arid another corresponding ISO right freight container corner fitting  31 . Top girders  21  are parallel to each other, and perpendicular to top frames  36  and  42 . 
         [0069]    In step  234 , method  200  welds roof  23  and interior roof  24  to the floor/roof support beams  12 , channeled floor/roof support beams  13 , and top girders  21  of top assembly  20 . 
         [0070]    In step  236 , method  200  welds exterior plate  38  and interior plate  39  to bottom frame  34 , corner columns  35 , and top frame for middle door  36  of end wall assembly with door  30 . 
         [0071]    In step  238 , method  200  welds exterior end wall  45  and interior end wall  46  to bottom frame end  41 , corner columns  35 , and top frame end  42  of end wall assembly with window  40 . 
         [0072]    In step  240 , method  200  welds exterior sidewalls  62  and interior sidewalls  61  to floor girders  11 , top girders  21 , and corner columns  35 . 
         [0073]    In optional step  242 , method  200  welds window frame assembly  50  into endwall assembly  40  or sidewall assembly  60 . 
         [0074]    In optional step  244  method  200  welds door frame assembly  33  into endwall assembly  30  or sidewall assembly  60 . 
         [0075]    When fabricated, unit  100  conforms to ISO standards for shipping containers, having outer dimensions of 40 feet long, 8 feet wide, and 8.5 feet tall, and a maximum weight of 66.139 lbs. Unit  100  also meets the U.S. Department of State Certification Standard for Forced Entry and Ballistic Resistance of Structural Systems, SDSTD01.01 
         [0076]    It will be understood that many additional changes in the details, materials, procedures and arrangement of parts, which have been herein described and illustrated to explain the nature of the invention, may be made by those skilled in the art within the principle and scope of the invention as expressed in the appended claims. Moreover, the term “approximate” as used herein may be applied to modify any quantitative representation that could permissibly vary without resulting in a change in the basic function to which it is related. 
         [0077]    It should be further understood that the drawings are not necessarily to scale; instead, emphasis has been placed upon illustrating the principles of the invention.