The transportation of fluids by pipeline has been known since early civilization. The Chinese are believed to have used pipes made from bamboo or clay about 5000 BC. Evidence can still be seen in Italy of the large aqueducts and the lead pipes constructed by the Romans about 2000 years ago to bring fresh water to the cities. Until the mid-nineteenth century, pipes made from wood or lead were mainly used for this purpose, laid sloping so that the water could flow under the force of gravity. Today cast iron or cement pipes are used, joined with spigot and socket joints, enabling water flow under pressure.
With the development of commercial crude oil production, which commenced more than 100 years ago in the U.S., pipelines became necessary. The first, 6 miles (10 km) long and of wood, was soon superseded by cast-iron pipes. Steel pipes were later introduced, mechanical joints being used until recent years when the all-welded system was adopted. Steel pipes are not, however, well suited to carrying water, because corrosion can occur on the inside of the pipe. Where steel is used it is given an internal anticorrosion coating. The most famous pipelines carry oil or natural gas. The Trans-Alaska, which extends about 800 miles (1300 km), carries oil from northern to southern Alaska.
In 1981 the Trans-Mediterranean Pipeline was completed, its 1500 miles (2400 km) running from Hassi R’Mel in the central Sahara to Minerbio in Northern Italy. Submerging twice in its trip from the Tunisian coast to the toe of Italy, the pipeline breaks the previous depth record by three times as it passes across the deep trough that separates Africa from Europe. Much of the blasting that was necessary was done by remote control.
In Europe steel pipeline systems were slower to develop, because most of the demand for petroleum products was met by the import of crude oil from the Middle East, there being little indigenous crude production. Refineries were usually located near to the coast and close to major areas of consumption, and product transportation was via road or waterway. The last 25 years have, however, seen a considerable growth of pipeline networks in Europe for moving crude oil or oil products, and natural or manufactured gas. This increase has been brought about partly by the increasing size of tankers used for crude shipment, which in many cases can only berth at terminals that have water depths in excess of 60 ft (18 m). The discovery in recent years of vast deposits of crude oil and natural gas off the shores of Europe has also led to the demand for transporation systems both inland and offshore.