The underside of each channel base provides a relatively large lateral dimension for fastening individual channels together by {TAIL ~ means} of {HEAD ~ a transverse stringer} or strut 
The underside of each channel base provides a relatively large lateral dimension for fastening individual channels together by { TAIL ~ means } of { HEAD ~ a transverse stringer } or strut
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH