A beam system, comprising: a first structural element (105; 605; 1105); and a second structural element (110; 605; 1110), wherein each of the first and second structural elements comprises a first end and a second end , and each of the first end and the second end comprises an upper corner (120; 135) and a lower corner (125; 140), and the beam system defines a supporting arch having a plurality of structural elements (105, 106, 110, 111; 605; 1105, 1110); each of the first and second structural elements (105, 605; 110, 605, 1110) comprises clevis components (145, 150; 155, 160) at each of the upper and lower corners; and a clevis component at the upper corner of the second end of the first structural element is connected to a clevis component at the upper corner of the first end of the second structural element to define a first clevis joint, and a clevis component at the lower corner of the second end of the first structural element is connected to a clevis component at the lower corner of the first end of the second structural element to define a second clevis joint, wherein each of the clevis joints comprises a clevis pin having a first hole and a second hole ; the supporting arch (400; 600) is connectable to an adjacent supporting arch by a plurality of stabilizing members , wherein each stabilizing member comprises a hole ; a nut is connectable to the clevis pin , the nut including a hole ; and characterized in that a distal end of a stabilizing member is connected to the clevis pin connecting one of the clevis joints, in that a first retainer is disposed through the hole in the stabilizing member and through the first hole in the clevis pin , and in that a second retainer is disposed through the hole in the nut and through the second hole in the clevis pin . a first structural element (105; 605; 1105); and a second structural element (110; 605; 1110), wherein each of the first and second structural elements comprises a first end and a second end , and each of the first end and the second end comprises an upper corner (120; 135) and a lower corner (125; 140), and the beam system defines a supporting arch having a plurality of structural elements (105, 106, 110, 111; 605; 1105, 1110); each of the first and second structural elements (105, 605; 110, 605, 1110) comprises clevis components (145, 150; 155, 160) at each of the upper and lower corners; and a clevis component at the upper corner of the second end of the first structural element is connected to a clevis component at the upper corner of the first end of the second structural element to define a first clevis joint, and a clevis component at the lower corner of the second end of the first structural element is connected to a clevis component at the lower corner of the first end of the second structural element to define a second clevis joint, wherein each of the clevis joints comprises a clevis pin having a first hole and a second hole ; the supporting arch (400; 600) is connectable to an adjacent supporting arch by a plurality of stabilizing members , wherein each stabilizing member comprises a hole ; a nut is connectable to the clevis pin , the nut including a hole ; and characterized in that a distal end of a stabilizing member is connected to the clevis pin connecting one of the clevis joints, in that a first retainer is disposed through the hole in the stabilizing member and through the first hole in the clevis pin , and in that a second retainer is disposed through the hole in the nut and through the second hole in the clevis pin . <EOS>