...The word "Ruhr" (pronounced something akin to roo-er) can either refer to a river or a region in Germany. This node is mostly about the later.
This industrial area has variable boundaries and is often mistaken for one city, but generally refers to the land that's squashed between between the northern Lippe and southern Ruhr river and the western town of Moers and the eastern town of Hamm. In German, one refers to it as Ruhrgebiet or informally as Ruhrpott. It contains nearly 9 million people living within a 40 kilometer by 80 kilometer area, which makes this the most dense part of Germany and one of the most densely populated places in Europe. It contains over 20 towns, most notably Duisburg, Oberhausen, Bottrop, Mülheim, Essen, Gelsenkirchen, Bochum, Herne, Hagen, and Dortmund.2 It has about 10% of the population of West Germany and lies in the middle of the western border.
The river itself starts in the town of Winterberg and is a tributary of the Rhine. It's 146 miles long and is used as a supply of water.
There have been settlements in the Ruhr since the Paleolithic era, but the interesting parts of the Ruhr's history start around 1,000 years ago, when goods shipped on the Rhine were unloaded and carried along the Hellweg. Towns were founded and prospered along the Hellweg, which stretched all the way to the Weser river. The availability of resources such as iron ore and wood along with incentive to produce goods resulted in many skilled workers settling in the Ruhr. At the start of the Industrial Revolution the Ruhr was easy to reach by road and rail and the workers easily adapted to the new work. Food wasn't even a problem, as the lowlands further north had fertile soil where crops could be grown in abundance.
Alfred Krupp and August Thyssen were industrialists during the 19th century that were the first to use the Ruhr to achieve the new means of the Industrial Revolution. A new process for making iron in 1849 that involved coke coincided with the invention of steam driven pumps that enabled mines to go more deeply into the earth. The Ruhr, later earning the nickname Kohlenpott or "coal scuttle", was rich in coking coal for use in smelters. These men greatly contributed to Germany's industrialization and later helped prepare the nation for The Great War1.
World War I and II
Unfortunately for Germany, the loss of World War I and consequently Alsace-Lorraine along with Silesia (both being rich in coal and iron ore) meant that the Ruhr was even more important than ever. The German government helped the Ruhr recover, but the harsh demands that the vengeful French levied on Germany included giving up coal and coke from the Ruhr region. When the Germans failed to deliver enough resources to please the French, troops occupied Düsseldorf, Duisburg, and Ruhrort.3 The Germans passively resisted, causing the formation of the Dawes plan and the collapse of the German currency.
The area never fully recovered until it's newfound best friend Adolf Hitler came into power. Seeing the logistical need for steel production in warfare, he supported the cartels that had popped up to stay afloat during difficult economic times. Unemployment fell and the Ruhr was soon working at optimal efficiency. Unfortunately, the Ruhr was heavily bombed during World War II. Germany's loss meant that the allies now controlled a lovely area that was three fourths ruins and scattered with coal mines that had suffered severe damage. Not fully realizing that Russia was the biggest problem they'd have to worry about in the next half century, the Allies set off on dismantling Ruhr industrial equipment so that Germany could not start a third war. Ironically, the Marshall Plan more or less rebuilt the Ruhr area soon after the war with shiny new equipment. The cartels were broken up, and the Ruhr was under various ruling powers until the creation of the West German republic1.
Resources and Industry
Ruhrkole AG is now the sole remaining company to have coal mines in the Ruhr. Thanks to falling crude oil prices and increased efficiency in coal mining, most coal mines have been closed and the government of Bonn subsidizes Ruhrkole. The Ruhr sits on a coalfield that extends for 6,200 square kilometers. Mining can be problematic since seams lie at a steep angle and not all coal is economically valuable. Despite this, the Ruhr boasted a high productivity with 4.07 tons per man in 1975, making it the most efficient coal mine in Europe. In the late 20th century, most of the mining occurred in the Emshcer valley but mines are slowly moving north as resources are depleted.
Towns like Essen and Bochum are centers for advanced steel production. The Krupp company is most noticeable in this area, as it has a variety of projects such as blast furnaces, iron foundries, and factories that have employed over 100,000 workers during the last quarter of the 19th century. Regardless, employment has a tendency to waver as corporations merge and more efficient plants are built. Most of the displaced workers find jobs in new light industry and higher technology firms.
As the other industries began to shed workers some people found jobs in the expanding chemical industry. Famous for producing things like aspirin and synthetic rubber, companies in the area now also produce everything from medicine to pesticides to dyes. The chemical giant Bayer has its main works in Leverkusen and there are other companies scattered in the Emscher valley. Despite this, the chemical industry didn't help out the faltering coal mines because they preferred to use cheaper and more easily processable oil and natural gas over coal1.
Layout, Transit and Planning
Good transport was essential to the early development of the Ruhr and the local governments still work on keeping the infrastructure in good shape. Sometimes to the detriment of local commuters, the Ruhr works as a hub in Germany with routes that link countries like Scandinavia and Italy with Western Europe. The major road that links Berlin with Eastern Europe also runs through here. The railway system is also one of the most extensive in Europe with lots of connections that span the continent and local S-Bahn services. For wary business travelers Lohausen International Airport is located right outside Düsseldorf.
The Ruhr, nicely stated, started out as an urban planning nightmare. Rapid growth at the dawn of the 19th century meant that houses and factories were plopped down without much thought of livability or environmental effects. The Ruhr has been divided into three developmental regions to combat local issues. After industry fled, the southern zone is now mostly residential development and a source of cleaner water. The central zone is where most of the heavy industry is concentrated. Population density is very bad here coupled with the problem of having older, more polluting industries. The northwestern, looming developmental zone is designed to attract people out of the central zone and into the newer, cleaner industries. The developers in all zones are concentrating on developing things like green belts and other niceties to make living there more pleasant1.
Sources and further reading:
1Margaret Wightam. The Ruhr
3"Ruhr." Encyclopedia Britannica. 2001