{HEAD ~ Channels} 44 accommodate webs 30 and open portions 46 accommodate {TAIL ~ first and second ends} 26 and 28 of the grid 20 
{ HEAD ~ Channels } 44 accommodate webs 30 and open portions 46 accommodate { TAIL ~ first and second ends } 26 and 28 of the grid 20
HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH