A change over apparatus of {HEAD ~ exhaust gas} for {TAIL ~ use} with a vessel of a dump truck having an exhaust pipe connected to an engine of the dump truck, said vessel having a plurality of hollow ribs integrally formed therewith, said change over apparatus comprising: 
for
A change over apparatus of { HEAD ~ exhaust gas } for { TAIL ~ use } with a vessel of a dump truck having an exhaust pipe connected to an engine of the dump truck , said vessel having a plurality of hollow ribs integrally formed therewith , said change over apparatus comprising :
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL 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 OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH