{HEAD ~ The signal lamps} 3 for a swimmer is equipped at {TAIL ~ a starting block} 4 which is provided at the starting side of a swimming pool 1 so as to project at the front of the starting block 4 
is equipped at
{ HEAD ~ The signal lamps } 3 for a swimmer is equipped at { TAIL ~ a starting block } 4 which is provided at the starting side of a swimming pool 1 so as to project at the front of the starting block 4
HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH REL REL REL TAIL TAIL 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