LOCOMOTIVES
Locomotives comprising a chassis configured for receiving various modules such as, for example, fuel storage modules and/or power modules. By employing a selected combination of fuel storage modules and power modules, a locomotive may be constructed to employ any of one or more types of fuel, such as liquid fuels and gaseous fuels. Batteries may be employed to maximize energy use. Multiple locomotives may function together as a 'consist' having differing types of engines and using different types of fuel. A control system may be employed to optimize use of the engines by prioritizing factors such as cost, fuel efficiency, noise reduction, emissions reduction, etc.