who is credited with inventing the electric third rail for trains used in the subway system?

Question by diego: who is credited with inventing the electric third rail for trains used in the subway system?

Best answer:

Answer by rdenig_male
The first 3-rail system was shown by the German firm of Siemens & Halsk at the Berlin Exposition of 1879. The first underground line to use the system was the City and South London Railway opened in 1890, although it had been used on a couple of above ground tourist lines before that, notably the Volks Electric Railway in Brighton, England (from 1886) which claims to be the world’s first electric railway and which is still operating.

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