Back in the early days transformers like the one seen on the pole along the right were made with a cast iron casing...and really heavy!!

Fuse cutout disconnects...the kind sometimes seen in our hobby with a pull-out porcelain handle...are mounted on each side of the middle crossarm. These porcelain units contained a small fuse wire which protected the transformer from overload. These were wired on the primary side which was typically 1,100 or 2,200 volts around the time this photo was taken.