tow cables, regardless on a tank, or heavy machinery, steel,alloy or stainless, are supposed to be either paint impregnated or most likely heavily lubricated or greased to prevent ANY rust— only the very outermost strands where lube or paint has left to be worn off would show signs of oxidation-- rust on cables in WWII was sometimes common due to lack of proper maintainance or materials------------tread[8D][2c]