An underground system and a few developments

In October, 1908, the Portland Railway, Light & Power Co., after serious consideration of the relative merits of the alternating current and direct current underground distribution, adopted plans for the construction of a complete system of underground conduits and cables within certain limits, which included the principal business section of the city of Portland. The Edison three-wire, 120/240-volt system was adopted, with the exception of a 600-volt distribution system in some sections of the city where the company had at that time heavy 600-volt customers, for both power and light throughout.