- Source: Carquinez Strait Powerline Crossing
Carquinez Strait Powerline Crossing was the world's first powerline crossing of a large river. It was built in 1901 for a 60 kV powerline operated by Bay Counties Power Company to deliver electric power from their Colgate powerhouse to Oakland, California. For this a crossing of Carquinez Strait was required, which has at its narrowest point at Dillon Point a width of 838 metres (0.52 mi). Such a span width was impossible with wooden poles, which were common in those days. Installing an underwater cable was considered, but for reliability reasons an overhead power line was installed, which used at the north site of the river a 68 metres (223.10 ft) tall lattice tower and at the south site one with a height of 20 metres (66 ft).
External links
[1] (Japanese)
Historic American Engineering Record (HAER) No. CA-191, "Carquinez Straits Transmission Span", 27 photos, 14 data pages, 2 photo caption pages