Transformer oil is there primary for cooling and secondary for corrosion resistance. When you see transformer burning, it's the oil inside. Larger transformers

Transformer oil is there primary for cooling and secondary for corrosion resistance. When you see transformer burning, it's the oil inside. Larger transformers cycle oil through pipes visible outside. In the Czech Republic (or at least in some parts) pole numbers and their positions are shared with emergency services. If you are disoriented, reading the number identifies your exact position. Works for railway crossings as well. Update: typos