Preproduction Chevrolet Volt nears end of assembly line.
Preproduction Chevrolet Volt nears end of Hamtramck assembly line. Left to do are mounting the tires, two water bath and vibration tests over a bumpy cobblestone roadbed. Each vehicle's work order is taped to the hood. Photo courtesy of GM.

Inside Detroit-Hamtramck

A quick tour of where the Volt is born

By Bill Moore

It sprawls over 365 acres that include a wild life preserve and a civil war-era cemetery. Under its 3.6 million square feet are 24 miles of conveyors holding 1600 automobiles at a time, all in various stages of assembly, from newly welded steel shells to ready-to-roll Cadillac DTS sedans and Buick Lucernes.

And scattered here in there on Hamtramck's 24 mile line are a smattering of Chevrolet Volts, the last of 89 pre-production models destined for "internal customer" tests by various General Motors employees. Once the last vehicle passes the hurricane-force water bath and cobblestone vibration test this week, the program will take a momentary breather. Starting next month, production of the first 10,000 customer-destined Volts will start at the back of the building in the form of thousands of stamped, dull gray steel parts hanging on racks like suits of clothes: doors, fenders, roofs, floor pans.

Those ten thousand electric cars will represent about one-fifth of the production coming out of Hamtramck, which was built in 1985 and produced its first vehicles in 1986. Designed for a maximum capacity of 250,000 vehicles annually, last year it turned out just under 36,000 units. This number will rise to slightly less than 50,000 this year, largely produced during a single 10-hour shift by some 1,100 employes, over 950 of which are contract workers belonging to UAW 22. Many of these men and women occupy a 21 feet space along sections of the line where engines and suspensions, seats and instrument panels are installed with the assistance of ergonomically-designed and power-assisted lifting devices. Very little muscle is needed anymore to assemble the black Cadillacs and pearlescent white Lucernes, or the black and silver, red and white, extended range electric cars.

Our tour began near the front of the building and end of the line where finished cars awaited final tire mounting. As they crept along, employees ran the engines for the very first time and checked the electrical systems. Exhaust gases are sucked down and out of the building. A single Volt sat wedged between a Cadillac and a Buick, its front hubs spinning counter-clockwise.

GM public relations representative, Chris Lee bid we climb aboard the awaiting electric shuttle trams, where safety glasses and wireless headsets sat on each seat. With cautions about keeping our arms in, especially during right turns around shop floor, some 30 of us set out through the maze of twisting conveyors.

What strikes you after the taking in the enormity of the facility, is the almost leisurely pace at which production proceeds; and how relatively quiet and comfortable it is inside the plant. Teri Quigley, the petite brunette who runs the the facility, earlier explained that the facility's production capacity is a function of the speed at which the line operates, as well as the number of shifts per day. Presumably, the pace can become a lot more frenetic than it was during our tour.

The first Volt-specific stop was at a wire-caged welding station consisting of six-to-eight robotic welders that have 49 seconds to make 285 welds on each steel body shell. As they do, yellow sparks splinter in a brilliant, crackling cascade, some reaching nearly to our shuttle; hence the safety glasses. Because the Volt operates nearly silently for its first 25-50 miles (the new, more realistic numbers GM is now using), engineers determined that it needed an additional 400 welds to ensure there would be no unwanted squeaks or rattles, which would normally be masked by the vibration of the gasoline engine.

Further along the tour, we wound past positions where metal workers inspected each newly assembled steel frame for pits, dings, dents and other imperfections in the metal work before it heads for the paint shop, the largest energy consumer in the plant, and the one that is strictly off-limits to everyone but authorized employees, who work in clean room conditions where even the after shave or perfume they use can cause a bad paint job.

Our next Volt stop was a bit anti-climatic. It's the station where the battery pack is installed underneath the vehicle and secured in place. Since the last run of 89 vehicle had already passed this point, there were no batteries to be seen. Undeterred, Lee explained how a worker lifts the 400-pound (181kg) T-shaped pack that is assembled at GM's Brownstown facility near Detroit, with a hoist and swings it onto a robotic shuttle vehicle. Following a guideway buried in the pavement floor, it will move the pack into position where the Volt dips down from the overhead conveyor. A pneumatic hoist lifts the pack up to the chassis and workers bolt it securely in place. Further down the line where V-8 and V-6 engines are installed under assigned vehicles -- and how carmakers like GM keep track of this is amazing in itself -- workers bolt up the 1.4 liter engine generator, as the same time as the front and rear suspensions.

From here, assembling the finished Volt proceeds like any other car on the line. Near the end of the tour, a dozen of so completed cars waited outside the factory for their run down the rumble strip and the second and final water bath test.

Because the car does have its own set of unique features, especially a 330V battery, GM and the UAW has taken extra precautions to train workers on the car. The preproduction models not only help engineers work out any last minute bugs or fit and finish problems, but also help assembly workers prepare to the real thing, cars that will end up in consumer hands. Watching the process of assembling an automobile remains a wonder of team work, human ingenuity and carefully considered risks. Compared to building thousands of rather ordinary Cadillac DTS's or Buick Lucernes, introducing a car as technologically advanced as the Volt not only has to fill the 1,100 workers at Hamtramck with a certain amount of pride, but it also just a bit of apprehension. The reputation of GM and the plant rests not just on the quality of the engineering, after all, but also the execution, and that's in the hands of the men and women that drive through the plant gate each day.

Times Article Viewed: 7203
Published: 21-Oct-2010


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