What fuel did the Zeplin use?

Zeppelins primarily used hydrogen as their lifting gas, which provided buoyancy due to its lighter-than-air properties. However, hydrogen is highly flammable, leading to safety concerns. In some later models, helium was used as a safer alternative due to its non-flammable nature. The propulsion systems of Zeppelins typically relied on internal combustion engines running on various fuels, including gasoline or diesel.