What is the average lifespan of an Alstom Metropolis?

Question

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Answer 1

Each Train is custom built for particular city it will be used in, 25-30 years is about right but with proper maintenance and overhauls they can last quite a bit longer.

Answer 2

Trains of this type are built with an expected life of about 20-25 years. They may have a mid-life rebuild, and could, of course, soldier on for much longer if their operators couldn't afford new stock.