{HEAD ~ The upper half shell} 24 is secured to the lower half shell 22 by {TAIL ~ suitable means} such as welding 
{ HEAD ~ The upper half shell } 24 is secured to the lower half shell 22 by { TAIL ~ suitable means } such as welding
HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH REL REL OTH OTH OTH OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH