Pipeline transport 1994, a 15 km milk pipeline ran between the Dutch island of Ameland and Holwerd on the mainland, of which 8 km beneath the Wadden Sea. Every day, 30.000 litres of milk produced on the island were transported to be processed on the mainland. In 1994, the milk transport was abandoned. In places, a pipeline may have to cross water expanses, such as small seas, straits and rivers. In many instances, they lie entirely on the seabed. These pipelines are referred to as "marine" pipelines (also, "submarine" or "offshore" pipelines). They are used primarily to carry oil or gas, but
Pipeline transport costs similar to CNG, the technology is proven. Most hydrogen is produced at the place of demand with every 50 to an industrial production facility. The 1938 Rhine-Ruhr hydrogen pipeline is still in operation. , there are of low pressure hydrogen pipelines in the US and in Europe. Two millennia ago, the ancient Romans made use of large aqueducts to transport water from higher elevations by building the aqueducts in graduated segments that allowed gravity to push the water along until it reached its destination. Hundreds of these were built throughout Europe and elsewhere, and along with flour mills were