Interesting on the 2-phase services in Inverness. It begs another question though: Why were these houses fed with all 3 lines of the old DC service instead of the usual 2-wire tapped from 3-wire?
Are we talkng about really big homes here, which would have had very heavy loads by 1930s standards? Or was this a localized example of a 120/240 (or thereabouts) DC system instead of the usual ~240/480V?
