{HEAD ~ Contoured stationary plows} are included at a downstream end of the contiguous belt spans to assist in turning {TAIL ~ the envelopes} over 
{ HEAD ~ Contoured stationary plows } are included at a downstream end of the contiguous belt spans to assist in turning { TAIL ~ the envelopes } over
HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH