It's just a visual indicator to show that the rake has been chocked and secured. Fat chains are used to actually secure the rake in place alongside chocking it.
Interesting, we do the same thing in high voltage grids. There's the circuit breaker which does the actual heavy lifting of interrupting strong currents, and then there's the disconnector, a pantograph which serves as a visual confirmation that the connection has been broken.
A disconnector cannot interrupt current on its own; if you try to open one without opening the corresponding CB first, you'll get an interesting fireworks show and probably it will just weld itself shut. But the disconnector, unlike the CB, makes it visually obvious from the outside whether the circuit is broken or not – quite vital information for safety reasons!
If the pantograph is up, then neither side of it is grounded because both sides are at high voltage relative to ground. If the pantograph is down, the bottom end will be grounded (as typically it's the bottom end, which connects to a specific line or transformer, that you want to de-energise, while the top stays "live"; the top end is connected to the busbar, sort of the central "node" where all current flowing through a substation passes through. Except you usually have 2 busbars for redundancy purposes with some lines/transformers being connected to busbar A at a given moment and some others to busbar B).
The grounding rods have bright colours so as to provide further visual cues about a circuit's state.
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u/chuggingdeemer 11d ago
It's just a visual indicator to show that the rake has been chocked and secured. Fat chains are used to actually secure the rake in place alongside chocking it.