Shelter construction

A shelter formed of a plurality of panels, each of said panels comprising:

• first and second panel skins;
• a core between said skins and secured to said skins to space said skins apart a first dimension;
• an extruded attachment bar of substantially uniform cross section positioned between said skins and having a thickness substantially equal to said first dimensions, said attachment bar having an extrusion opening therethrough, said attachment bar having first and second walls, said first and second skins extending past said core to extend at least partway respectively across said first and second walls, said skins being secured to said walls of said attachment bar;
• said attachment bar having a nose defined by a front web and a center wall, a center web extending transversely to said nose, said front web being attached to said first attachment bar wall and to said center wall, said center web being attached to said center wall and to said second attachment bar wall so that said first attachment bar wall is secured to said second attachment bar wall, said extrusion opening being defined by the interiors of said walls and webs, said attachment bar having a recess defined by said center wall and said center web, said nose and said recess each being substantially equal to half said first dimension;
• said noses and recesses on attachment bars on the edges of adjacent first and second panels being interengaged so that said walls and webs of said noses and recesses lie against each other and said front web on said first panel lies in line with said first wall of said second panel when said panels are interengaged at right angles and said first wall of said first panel lies in line with said second wall of said second panel when said panels are interengaged in line with each other;
• and
• tensile fastening means engaged on said adjacent walls and webs within the interior of said attachment bars to compressively secure said adjacent walls and webs against each other.