{HEAD ~ The compressed substrate boat} comprises a stationary substrate boat and {TAIL ~ a movable substrate boat}, each may be loaded/unloaded independently 
comprises
{ HEAD ~ The compressed substrate boat } comprises a stationary substrate boat and { TAIL ~ a movable substrate boat } , each may be loaded / unloaded independently
HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH