During World War I and II, there was a limited supply of gasoline. One alternative to cars running on gasoline was the gas bag vehicle. Cars and buses were converted to being fueled by uncompressed gas, which was stored on the roof of the vehicle in a balloon tank.
These gas bag vehicles were built in France, the Netherlands, Germany and England and were an improvised solution to the gasoline shortage. The fuel in the balloons were powered by what was called “town gas” or “street gas,” which is a by-product of turning coal into coke (which is used to make iron.) The tanks were either hard or soft bag-like structures, put on the top of cars and buses. The tanks were large, since more gas was needed to get adequate mileage.
With the gas bag vehicles, it was easy to tell how much fuel was left since the gas bag would deflate as the car was driven. One risk of using the vehicles was the risk of fire, and obstacles that were overhead. Drivers had to know the heights of bridges before driving underneath. The vehicles could only go 30 mph, so that the fuel tank would stay secure on top of the vehicle.
Gas bag buses could still be seen in China in the 1990s, mostly in the area of Chongqing where the vehicles were used as a cheap public transportation option.
Today gas bag buses are not in use – but are interesting examples of how rising energy prices can drive energy technology innovation.
Links: