Bulk TransportationLarge oceangoing tankers have sharply reduced the cost of transporting crude oil, making it practical to locate refineries near major market areas rather than adjacent to oil fields. To receive these large carriers, deepwater ports have been constructed in such cities as Rotterdam (Neth.), Singapore, and Houston (Tex.). Major refining centres are connected to these ports by pipelines. Countries having navigable rivers or canals afford many opportunities for using barges, a very inexpensive method of transportation. The Mississippi River in the United States and the Rhine and Seine rivers in Europe are especially suited to barges of more than 5,000 tons (37,000 barrels). Each barge may be divided into several compartments so that a variety of products may be carried. Transport by railcar is still widely practiced, especially for special products such as LPG, lubricants, or asphalt. Cars have capacities exceeding 100 tons (800 barrels), depending on the product carried. The final stage of product delivery to the majority of customers throughout the world continues to be the familiar tanker truck, whose carrying capacity is about 150 to 200 barrels. The most efficient mode of bulk transport for petroleum is the network of pipelines that are now found all over the world. Most crude-oil-producing areas are connected by pipeline either to refining centres or to a maritime loading port. In addition, many major crude-oil-receiving ports have extensive pipeline distribution networks to inland refineries. Centrifugal pumps usually provide the pumping power, with booster stations installed along the line as necessary. Most of the major product lines have been converted to fully automated operation, with the opening and closing of valves carried out by automatic sequence controls initiated from remote control centres.
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