Machine Design

Silliness at 40 below

Many years ago a college classmate of mine told a funny story about his summer job testing communications gear for a defense contractor. He spent his time alternately freezing the radios to –40°C and heating them to 85°C, while operating them to make sure they’d work at these extreme temperatures.

Trouble was, most of the radios wouldn’t pass this test. To fix the problem, the contractor had to go through a redesign, which took more than a month, putting the project behind schedule. Once the electronics had been fixed, my buddy drew a lot of overtime running radios in temperature chambers, trying to catch up. In fact, the pace was so hectic that nobody bothered to check the radios at room temperature.

You may be able to guess what happened. It was only as things slowed down that QA discovered the revamped radios often sputtered out when operating in ambient temperatures.

With that situation in mind, I was amused at a tale told in the memoirs of former General Motors Corp. Vice Chairman Bob Lutz to illustrate some of the whacky design practices he encountered when he joined GM in 2001. He discovered the ashtray of a new Cadillac STS had a lot of spring pressure. When opened, it shot out as though launched from a cannon, and once deployed, was tough to push in with just one finger. This was in contrast to the ashtray on an Acura, which glided open and took a single effortless push to close.

Lutz figured the ashtray design in the Cadillac had to be a mistake, so he was flabbergasted when a senior interior-trim engineer said it operated that way on purpose. The reason: So it could meet an internal GM standard that dictated ashtrays had to function after a night spent at –40°F.

Lutz says loopy situations like the Cadillac ashtray were not at all uncommon in those days. They arose because GM had a habit of engineering its vehicles for extreme situations. That was a noble idea, but it came at the expense of alienating thousands of GM owners on a daily basis.

You might wonder what happened to the –40°F ashtray spec. Lutz says his team eventually eliminated it and 90% of the other sacred but silly engineering do’s and don’ts that had somehow become embedded in GM culture. He also opined that the existence of these disconnected-from-the-real-world practices was a “testimony to a culture that was inwardly focused in pursuit of its own goals, with the customer left out of the equation.”

I would put it a little differently than Lutz did. Both in the case of the bad radios and with the ashtrays that operated superbly only at –40°C, the designers had lost sight of the trade-offs they were making. There is a lesson here for any engineer who’d like to avoid having something they designed be the butt of jokes, or who doesn’t want their work to wind up as a humorous incident in someone else’s memoir.

— Leland Teschler, Editor


© 2012 Penton Media, Inc.

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