HYDRAIL hy·drail \'hī-drāl\ n 1. a propulsion device that runs on rails and is fueled wholly or partly by hydrogen 2. a self-electrified propulsion device that uses hydrogen fuel and travels a fixed path.

Hydrail Overview

Hydrail, short for hydrogen rail, is a generic term of art used to reference an emerging class of rail-based transportation technology that uses hydrogen as fuel. Hydrogen fuel is most commonly used in fuel cells which provide electric current, but it can also be directly combusted like diesel fuel. Hydrail technology is essentially self-electrified railway propulsion and has a wide array of applications.


  • Specialized Niches: The first hydrail device was a mining locomotive developed for underground operations by the Fuel Cell Propulsion Institute. Hydrail is advantageous in this application because diesel is impractical for use in enclosed spaces due to its air emissions, and batteries can only operate for a limited time without recharging and have high maintenance costs.
  • Commuter Rail: Existing diesel-powered commuter rail lines can reduce noise, air pollution, and fossil fuel consumption by transitioning to hydrogen-fueled locomotives that use the same railway infrastructure. Diesel-based locomotives can also use hydrogen fuel cells to provide supplementary power for acceleration, greatly reducing diesel consumption, or auxiliary power while the train is stationary.
  • Streetcar/Trolley: Mass transit systems in urban areas, particularly transit systems in the planning stage, may find that hydrail streetcars (hydrolley – short for hydrogen trolley) offer the most overall value compared to the alternatives. Specifically, hydrolley technology provides the benefits of fixed-path mass urban transit with limited infrastructure costs, no unsightly or restrictive overhead catenary wires, no air emissions, little noise, and the flexibility of self-electrified vehicles.