On a different note, the chief of maintenance at the Campus where I worked told me that there were only around a dozen or so transformers like the ones we had in the entire US ready to be delivered at any given time. I asked him what would happen if we had a catastrophic transformer failure of multiple units, and he said we would need to get the Governor to send in the National Guard. Imagine what would happen to a place like Chicago or NYC if you had a few dozen of them all fail simultaneously.