Leading end section 12 and {HEAD ~ trailing end section} 14 are spaced at {TAIL ~ a distance}, but substantially parallel to each other 
spaced at
Leading end section 12 and { HEAD ~ trailing end section } 14 are spaced at { TAIL ~ a distance } , but substantially parallel to each other
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH