India’s first hydrogen-powered passenger train, said to be the longest of its kind in the world, reached 120 km/h during a test run on the Jind–Sonipat route in the state of Haryana. The train consists of 10 railcars, has a capacity of up to 2,600 passengers, and still needs to complete compliance procedures before entering commercial service.
Hydrogen leaks into any steel casings slowly interacting with the carbon molecules found inside steel alloys, making any pipes or tanks brittle
You do not have to make pipes with exposed steel.