I believe they are 4160 volts (measured line to line with 2400 from each line to ground). That's the voltage at which the utility delivers power to the museum. Yeah, the size of the insulators would have you think it is more.
But where does it go? Is there a substation down the line?
The section of line that was damaged was built to resemble a typical interurban railroad.
The top arm is 34kV construction resembling the sub-transmission line which would have supplied substations along the route of a railroad.
In this case, It is 2400/4160 volt distribution that feeds the signal system for the entire 5 mile railroad. Near each signal location there is a transformer that reduces the voltage to 120 volts. At each signal hut the transformer supplies 120/240 volts due to the increased power requirements in the hut.