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