Onomatopoeia for the shouts of group manual labor — pulling boats, lifting timbers, hauling rope. Closely associated with the
黄河船夫曲 (Huánghé Chuánfū Qǔ, Yellow River Boatmen's Song) and labor folk songs. Closest English equivalents: 'heave-ho', 'yo-heave-ho'. CC-CEDICT lists this only under
哟 (yō);
嗨 here is a colloquial cry.