March 09, 2012

A Visit to BMW Welt, Munich

After the American Century

As part of the research for my forthcoming book on the assembly line (MIT Press, 2013), I have visited several factories. Here is my account of a visit to one of them.

It costs €8 to see the BMW plant in Munich, and it is necessary to sign up in advance. There is room for only two groups of 25 people each hour, one with an English guide. In contrast, the magnificent show room where the tours start, a vast building called “BMW Welt,” attracts much larger crowds. It is a temple where enthusiasts can see all the latest models, pose in the driver’s seat, look at exhibits about how (and of what materials) the car is made, sit on a BMW motorcycle, or go into the gift shop to purchase BMW T-shirts, mugs, jackets, key-chains, model cars, and much more. In the bookstore on the mezzanine level they can also buy books about automobiles, design, and the company history. The building is about consumption and pride of ownership. Its sinuous lines and the profusion of displays create the feeling that one is in a high-end shopping complex. A distinguished stream of customers constantly arrives, to be welcomed and ushered  into elevators to higher floors inaccessible to ordinary visitors. Most BMW buyers enjoy a fine lounge and restaurant where they await the arrival of their new car. A select few go to a more exclusive redoubt of luxury, so rarified that most of those who serve the thronging clientele have never seen it. Most tourists are not buyers. But if they ascend to the second level, seven meters about the ground floor, they can look across at the exclusive area where immaculate cars are driven in and delivered to new owners, who drive down a ramp that circles out into the city traffic. 

BMW Welt

The factory tour lasted two hours and covered three kilometers. Most of the time we walked on concrete floors and metal bridges, surfaces that punish the arches, the knees and the lower back. Fifty years ago such a factory tour would have been noisier and grittier, and one would have sympathized with the workers caught up in that environment every day. But today robots do much of the work. Looking a bit like giant orange insects, they move deliberately, pausing with some delicacy near the end of each maneuver, as sensors guide their pincers to just the right position. First, in the stamping plant they guide sheets of steel into a succession of enormous machines that crunch down over sheets of flat steel transforming it into the hood or roof or trunk, or perhaps a left or right door. In each case, before the die slams down on the smooth steel, the metal is sprayed with a mist of oil to lubricate the process. The massive first stamping creates the basic form, which is refined and completed in the smaller stampings that follow, as ends are trimmed or folded, small holes added, and further indentations made. In 1913 several workers were needed to feed blanks into stamping machines, take out the results, and send them on to the next machine. A century later all this work is done by machines, with only a few people keeping an eye on the process. Our guide declares this technological unemployment is just as well, for the work is boring and yet dangerous, given the tremendous force of the stamping machines. It is endlessly repetitive and also hard on the ears. Some skilled workers are needed because the dies in the machines must be changed at times to make spare parts for older models. A model is usually made for seven years, but after that BMW produces parts for another decade. 

The stamped parts are next transported, automatically, to the body assembly, where the left and right door frames are attached to the car’s floor. Then a roof is added, followed by smaller parts and then the doors. In many cases the stamped panels are first fixed in place with a fast-drying glue that also functions as a thin elastic layer that will cushion shocks and improve the car’s ride. The metal parts are then welded together, again by giant orange robots, eight of them working at once in an almost silent, rapid sequence that has been choreographed and fine-tuned. Hardly a worker has touched it yet, but the welded parts have become a car body, still without wheels, windows, seats, or drive train. 

Before these can be added, the bodies pass on to the paint building, where we trudged after our guide over steel bridges through strange smelling passageways. We had glimpses of machinery at times, and heard an occasional hiss or gurgling sound, until we emerged into a large white room with soft seats where we gladly sat for a five-minute lecture on the steps involved in painting a car. One might imagine that the process was like painting the outside of a house, with a primer and one or two coats of good paint, and indeed that is exactly what Ford did in 1913. Each coat then needed  hours to dry before the next one was applied.  But it was hardly so time-consuming in 2011, even though there are more layers. First, all the residual oil and any dirt are zealously washed off the bodies. Then they are baptized in a thick undercoat, through a total immersion of the whole body in a large pool of paint, which is then pulled up by a robot to drip off before passing through a heating shed, where it is first baked in infrared heat at 150 degrees C, driving off all the liquid in the paint, and then furiously blown over by artificial winds. 

This is just the beginning, as four more layers will be applied, including one that is a bit rubbery, to make the surface more resistant to flying gravel or hailstones. The next to last layers are the paint proper that give the car its distinctive color. Ninety percent of all BMW buyers want their vehicle to be black, silver, or white. The other eleven colors are seldom used. New avatars of the same orange robots, made in Augsburg just an hour away from the plant, apply these layers. They spray the paint evenly, and digital cameras record the results. During each new round of coatings the car is given an electrical charge that attracts the tiny droplets to its surface. Not much paint sails wide of the mark, but any waste falls into a continuously rushing stream, a mini-Niagara under each painting station. The paint is extracted from the water, which is reused. Indeed, the water usage of the BMW plant has been reduced 90 percent in recent decades.

Once the BMW bodies have been repeatedly painted and baked, they pass into a room with six levels of shelves on each side where they are carefully stored. In the passageway between the shelves a machine that is both an elevator and a powerful robot lifts one body at a time, lowers it to ground level and sends it on its way to the final assembly plant. More than half of the shelf space is empty, for the factory makes only cars that have been ordered. It produces each body just in time for final assembly.

The guide next takes us to the other great tributary stream to the final assembly, the engine manufacturing plant. Most of the engines made here are powerful 4 cylinder 2.0 liter affairs that get 16 kilometers to the liter (or more than 30 mpg). Half the labor that goes into them is human, half robotic. The V8 engine for larger BMWs is 80% made by human beings, and the top of the line engine for the Rolls Royce is 100% man-made. (To be precise, 95% of the workers at the Munich BMW plant are men, and the few women are clustered in certain jobs.) In the motor plant the guide does not show us the casting of engine blocks or their precision drilling. Once the work of extremely skilled labor, this too has been progressively automated. Already in 1913 Ford had a purpose built machine that simultaneously drilled forty-five holes in an engine block, from four directions. A century later, the early stages of engine production have few workers. We see obviously skilled men building parts into these blocks as they pass down the line. Inspections also are continuous, until motors are complete and they can be harnessed to the drive train. 

At this point the two streams of work come together. The bodies meet the engine and drive trains they are destined to mate with, or “marry” as the workers put it. The bodies gently fall down as the engines rise up, with a brief pause before the last centimeters of drop and the two become one.  Final assembly can then begin. This part of automobile production still attracts the most public attention, as hundreds of parts and pre-assembled units like the dashboard are put in, typically with no more than a minute for each operation. Painting, by comparison, is repetitive and not as interesting to watch, and not even shown on many assembly line tours. Final assembly is much faster. One man unbundles and lays out a car’s electrical wiring and secures it in position, and a moment later another worker is covering the wires and the entire bottom of the car with a perfectly cut felt-like layer. Visitors walk much faster than the crawling line, and to them each task seems to take considerably less than a minute. One man with the help of a robot lifts and puts in the dashboard. The back and front seats, the emergency brake, the headlights and many small details are quickly and expertly installed. The windshield goes in. In half an hour one has traversed much of the line, and the cars are nearing completion. The doors, earlier removed to allow easier access to the interior, are reinstalled. At the end of the line some gasoline is pumped in, and each car is started, tested, and driven out of the factory. 

The BMW tour in Munich is by no means unusual. The industrial tourist can visit similar factories in all parts of the world. The newest are often designed as tourist sites. Visitors have been coming to see such marvels of assembly since Ford's managers first created the line in 1913. For a century, the public has remained enchanted. When I visited BMW the tours were sold out, but the factory's  “romance of production” was less central to the public than the “romance of consumption” in the showroom. In both places the car was treated as an almost enchanted “thing in itself,” an icon of modernity. For many it has become the ultimate consumer product, especially because now the assembly line can produce individualized automobiles, made to the consumer’s specifications. Henry Ford made his cars identical. But today, using the computer to keep track of the entire process from ordering to delivery, the assembly line produces individualized objects. Paradoxically, an assembly line with many robots and far fewer workers than in 1913 makes a more highly differentiated line of automobiles.

See also the blog on America's Assembly Line