I have worked on many Subs around Auckland, including this one, all kitted up in safety gear and fully schooled up in what hazards there are. No doubt about it, its a dangerous place to work at, I have a new respect for all those in the Electrical field.
Have no fear, the cache is away from all danger, you dont have to go any where near it.
An electrical substation is a subsidiary station of an electricity generation, transmission and distribution system where voltage is transformed from high to low or the reverse using transformers. Electric power may flow through several substations between generating plant and consumer, and may be changed in voltage in several steps.
The whole purpose is to take very large voltage Electricity from the National grid and transform it into a lower voltage , then distributing it to the green power boxes in our streets and then to our houses.
A substation that has a step-up transformer increases the voltage while decreasing the current, while a step-down transformer decreases the voltage while increasing the current for domestic and commercial distribution. The word substation comes from the days before the distribution system became a grid. The first substations were connected to only one power station where the generator was housed, and were subsidiaries of that power station.
Just an example of how dangerous Substations can be--check out this clip on Utube-- link>
Cache is a nano, hang it all.