Another consideration is the relationship. between insulation class, temperature rise, and ambient temperature. The insulation. class rating designates the maximum. operating temperature for a winding. The. temperature rise is the difference between the.
China claims it has discovered the world's largest hole, and it's in one of the most dangerous places on the planet. 1  Jul.  Good news: China claims it has discovered the world's largest hole. On Wednesday, state broadcaster CCTV announced that the newly found dragon's hole, a 984-foot (300-meter) cavern in the disputed waters of the South China Sea, is now the world's largest hole.
The vast Qattara west of Cairo, Egypt is the largest natural sinkhole in the world, measuring 80km long by 120km wide. This dangerous, sludge-filled quicksand pit is unearthly in its appearance and shocking in its size.