crane chaser; dogman
Construction site worker who directs crane operators, often using hand signals or radio. The term is technical and may not be widely known outside the industry.
At the construction site, the crane chaser is directing the crane's movements.
The derivation is uncertain; the kanji 鳶 (kite, a type of bird) and 子 (child) may be associated with the idea of someone who works high up like a bird, but this is speculative.