GM Oshawa powers up fuel-cell Equinox

Gerry Malloy

SPECIAL TO THE STAR

General Motors announced a year ago that it planned to build 100-plus hydrogen fuel-cell-powered Chevrolet Equinoxes in Oshawa beginning in 2007 for real-world customers to evaluate.

But rather than simply carving up production vehicles to make fuel-cell powertrains and their related componentry fit into them, the Equinox Fuel Cell vehicles were designed, partly at GM's Canadian Regional Engineering Centre in Oshawa, specifically for the purpose.

Besides providing the vehicles required for evaluation, the Equinox program has helped develop and prove processes that can be applied to the mass production of future fuel-cell and electric-drive vehicles, according to Dick Kauling, senior manager at the centre. These might include the electric-drive Chevrolet Volt, tentatively scheduled for production in 2010.

Among other things, the Equinox Fuel Cell required a major redesign of the vehicle's underbody to accommodate the fuel-cell module, battery pack and hydrogen pressure tanks needed, and to ensure the necessary structure to satisfy all the test requirements of a regular production vehicle – including crash testing.

Those changes were too dramatic to be incorporated in the online body-build process at the CAMI plant in Ingersoll, where the Equinox is built.

For that reason, said Kauling, bodies for the fuel-cell vehicles are diverted from Ingersoll before painting to an outside supplier's shop in Michigan. There they are cut apart and the new underbody members welded in place.

Those modified bodies are then returned to Ingersoll for painting and completion of the body-build process, including installation of interior components and trim.

There, one whole wing of the engineering centre's garages is devoted to Equinox Fuel Cell production. Rather than a moving production line, 12 build stations are occupied by vehicles on lifts in various stages of completion.

Each will spend about 18 days from arrival to shipping, Kauling said, which translates to an average production rate of one vehicle every 1 1/2 days – not that different from a number of other low-volume production operations around the world.

Virtually all the powertrain and underbody components, including the fuel-cell module, battery pack, hydrogen fuel tanks, suspension, and wheels and tires, as well as front fascia and cooling ducts, are installed in Oshawa as part of the final assembly process.

The fuel-cell stack is shipped from GM's fuel-cell research, development, and construction facility in New York. The boxes that contain each stack are fitted with sensors to show any rough handling en route that might potentially damage them.

While the fuel cell itself is similar in size to a conventional engine, the built-up assembly, as installed in the vehicle, looks massive – too massive to fit in the relatively small CUV.

But it does fit – a fact verified in advance by three-dimensional computer visualizations that permit engineers to virtually pre-fit every piece into the vehicle whole.

To demonstrate the point, Kauling showed me the centre's new visualization room where, wearing high-tech 3-D goggles, I was able to virtually hold in my hands a complete model of the Equinox Fuel Cell vehicle, with all its parts, checking everything from panel gaps to airflow paths.

Air flow is a big deal in fuel-cell vehicles. Because fuel cells must run cooler than conventional engines they require more cooling, which dictates more and larger radiators, and more cooling air flow.

The radiator mounted to the front of the fuel-cell module is responsible for much of its apparent size. It also bristles like a porcupine with a plethora of pipes, hoses and wires, each with a specific purpose.

That module also includes the single electric motor that drives the front wheels. A battery pack to supplement the fuel cell's output fits behind it, under the passenger compartment floorpan.

At the rear, the cargo compartment floor is kicked up slightly to accommodate the uppermost of three high-pressure hydrogen tanks, constructed by Quantum Fuel Systems in California.

The composite-construction tanks, which have been designed and tested to endure the most extreme abuses, including fire and gunshots, store hydrogen at 10,000 p.s.i. Although the system is tested for leaks, the charging of the tanks is the only part of the final assembly process not completed in Oshawa.

About 65 vehicles had been completed at the time of my visit, so the production will continue for some time yet, particularly given that the "plus" part of the 100-plus number has not yet been quantified.

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