At least two frame engaging members of the frame support structure are moved to position the side members of {HEAD ~ the frame} in {TAIL ~ a desired configuration} 
At least two frame engaging members of the frame support structure are moved to position the side members of { HEAD ~ the frame } in { TAIL ~ a desired configuration }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL