One possibility is to install {TAIL ~ such a module} in {HEAD ~ the region} 206 after the lower sand face completion section has been assembled but before the upper sand face completion section 204 is installed 
One possibility is to install { TAIL ~ such a module } in { HEAD ~ the region } 206 after the lower sand face completion section has been assembled but before the upper sand face completion section 204 is installed
OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH