{HEAD ~ The traction unit} is provided with {TAIL ~ a counter traction unit} with at least two traction ropes which extend outwardly out of the lower frame and are connected to the top of the upper frame 
{ HEAD ~ The traction unit } is provided with { TAIL ~ a counter traction unit } with at least two traction ropes which extend outwardly out of the lower frame and are connected to the top of the upper frame
HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH