sentences:  Pairs of bullocks were matched for size and yoked together using a wooden yoke secured to each bullock by a metal bow which was fixed in place by key on top of the yoke.Each pair was connected by a special chain, which ran from a central ring on each yoke to the next pair, thus coupling the team in tandem fashion.The “wheelers” or “polers” were the older, heavier, trained bullocks which were closest to the dray or jinker and helped to slow the load when necessary.