{TAIL ~ A chain drive system} within each of the pair of trollies mounts {HEAD ~ a support arm assembly} on which a fire proof cab is removably mounted 
{ TAIL ~ A chain drive system } within each of the pair of trollies mounts { HEAD ~ a support arm assembly } on which a fire proof cab is removably mounted
TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH