Cracks on engine bodies, no matter main engine or auxiliary one, are very dangerous defects, extension of which will lead to the engine discarded or serious accident.
船舶主机和辅机等机械设备的机体裂纹是非常危险的缺陷，裂纹延展会导致机器报废或发生严重事故。
2
Cracks in Marine main engine or auxiliary engine body may lead to scrap of the machine or serious accident, which is a badly hidden trouble for safety of a vessel.
船舶主辅机机体裂纹的延伸会导致机器报废或发生严重机损事故，这对船舶安全营运是一大隐患。
3
Just as its name implies a instructor has to do well "auxiliary" and also "lead".