I could hear the Great American Gelding snoring away like a planing mill.
我能听到 Great American Gelding 的鼾声， 就像一台刨刨机一样。
英语百科
Planing mill
A planing mill is a facility that takes cut and seasoned boards from a sawmill and turns them into finished dimensional lumber. Machines used in the mill include the planer and matcher, the molding machines, and varieties of saws. In the planing mill planer operators use machines that smooth and cut the wood for many different uses.