{TAIL ~ An elongate drive shaft} extends from an engine mounted fore of the concavity to {HEAD ~ the impeller} 
{ TAIL ~ An elongate drive shaft } extends from an engine mounted fore of the concavity to { HEAD ~ the impeller }
TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD