What aspect of Murray's work remains a cornerstone of the modern electrical grid, even if the specific hardware has been upgraded over the last century?

Answer

The underlying engineering principles he established

The longevity of the principles he patented—the necessity of robust isolation, the mechanics of load breaking, the methods of securely joining high-tension conductors—is what truly underpins the reliability of the grid today.

What aspect of Murray's work remains a cornerstone of the modern electrical grid, even if the specific hardware has been upgraded over the last century?
inventioninventorThomas E. Murray