Your article on the redesign of the wheelchair was most interesting (“Rethinking the wheelchair,” May 22), but when you apply aerospace design, you get an aerospace price, something your article failed to mention. The base cost for this chair is $3,500, well beyond the reach of most wheelchair-bound people. And is that large cost covered by any of the medical insurance plans? In short, it is bright, innovative, and priced out of reach of most users.

Terry Shirrod

Believe it or not, $3,500 is not an outlandish price for a good wheelchair, one designed for young, active, but disabled adults. And most private medical plans and Medicare pay up to 80% of the cost for wheelchairs and allow replacements every three years.

Flipped for the cover
Maybe I’m wrong, but the picture of the Indy Car on Page 48 of the May 22, 2008 issue shows the Firestone brand backwards on the inside right front tire. I don’t believe Firestone would like that shown in that manner.

Michael Mallon

I noticed some “poetic license” in reversing the image of the IndyCar 2011. (The Firestone logo is backwards). It looks like you might have done the same thing with the image of the Striker Simulator as the track image on the screen indicates the car is making a right turn. The Indianapolis race, of course, only has left turns.

Glenn Seeger

Actually, we didn’t reverse the image. Take a closer look. The Firestone trademark on the other tire is buried in the gutter but it reads correctly as do the Marvel and DC logos on the body of the car itself. We don’t know why the Firestone logo is backwards on the front right tire. And we’re sure Firestone is delighted you recognize their logo even when its backward. As to the simulator, we never implied it could only replicate the Indianapolis Speedway. Obviously it was recreating some other race track when the photo was taken. (Or the driver was going backward at the Brickyard.)

Who’s fault is it?
I am writing regarding a complaint by W.C. Pezza in the Letters section (May 22) that degrades engineers from other countries, specifically those from China and India. For the last 10 to 15 years, U.S. companies have been outsourcing not only production but design and development as well, mostly based on cost. Over that same time, Indian engineers have become the brightest in their fields.

Meanwhile, engineering in U.S. has gone down the tubes with companies not willing to spend money on equipment or to train manpower. U.S. manufacturing has also been going downhill for a long time and politicians have done nothing to help it, but Pezza blames Indians and Chinese? Give them a break.

It saddens me when engineers complain without facts when engineers from other countries move up the ladder.

Sunil Chohan

I agree with both Messrs. Panelli and Pezza in that the engineering profession has not protected itself and has been mugged technically and economically as a result. Both the legal and medical professions have done a much better job of protecting their turf. Some of this is due to the limits they put on the number of doctors and lawyers allowed to practice. They artificially create a low supply despite a high demand. And even an engineer knows what happens in that circumstance. Big bucks.

On the flip side of the coin, liberties are taken in who can claim to be an engineer. Anyone can say they are an engineer. In fact, industry encourages it. How many of you have known sales engineers with only B.A. degrees? I have encountered many in my career. It took me four years to earn my engineering degree and title, but some get the title by proclamation.

Bottom line is that in many ways we are our own worst enemy.

Bruce B. Meyers

Helping kids
As a technical instructor, it is great to see outside people talking about the work that we do (“Kids like the technology. Now work on the parents,” May 22). I was disappointed that the editorial only focused on Project Lead the Way. Many of us have developed good and strong preengineering programs without being in the canned PLTW programs. We based our programs on the traditional industrial arts. Please continue to educate parents about the good courses being offered in many of our school districts.

R. Herkimer

I wish information of this type were sent to all parents and teachers. I have been exposed to First, thanks to my grandson and, as the article mention for PLTW, the kids get deeply involved. They become team workers and mature human beings. Although I love it from the engineering point of view, the greatest benefit I see is in how these boys and girls work together and prepare themselves for the future.

Bernie Lenders

Everything old is new again
Thanks for the timely editorial (“One less conspiracy,” May 8). It seems no matter how “new” some ideas may seem, there is a good chance that they have already been tried.

For instance, the opposed piston with common combustion chamber was used in the French Gordon- Brillie as far back as 1904. It was a monster four-cylinder/eight-piston engine that later became a six cylinder and was used into the teens. I also have a gasoline-powered version of what normally is a compressedair jack hammer. It has to date from the 1930s or 40s. But its power-unit piston and the spring-loaded piston for the hammer spike use the same combustion chamber. I never got it running, but can believe it must have been a handful.

Stan Smith

Bridge Collapse
I am writing in regard to the article about the I-35 bridge collapse (“Berke on safety: The I-35 Bridge: The truth is out there,” Jan. 24). My degree and PE license are in mechanical engineering, not structural, but I still know something about structures and stress analysis. The latest report is that the bridge failed because several gusset plates were only half as thick as they should have been. Maybe this is the reason the bridge fell.

I would suggest looking for binding in the expansion joints and bearing plates as a cause of failure. It was a hot day (94°F), and the bridge failed in late afternoon. If the expansion joints were jammed and could not move to absorb the bridge’s thermal expansion, this would put an axial load on the bridge. Steel bridges are designed to take vertical and lateral loads, but not compression loads along their length. Buckling takes place in compression. It is possible the bridge buckled in axial compression and fell.

The reasons you give are plausible and are likely right. I suggest buckling due to jammed expansion joints because no one has mentioned it and it seems plausible. It may well have happened in concert with other causes, including ones you listed. The biggest failure since that day, however, has been on the part of the Governor of Minnesota and MNDOT. Neither has said anything useful on the matter. The news media have pointed out that public documents show the bridge had a questionable safety inspection record. The head of MNDOT was a political apointee with no scientific or engineering background.

We have a surprisingly poor freeway system in the Twin Cities. After years of driving these roads I have concluded the cause is that politicians keep overruling civil engineers. Political skills trump technological literacy, and we are all the worse for it.

Ronald Corradin

1. Regarding the gusset plates; this was only offered as a possible reason. This is still to be seen.
2. I would think that expansion at 94°F would be well within design parameters.
3. The two items that have not been made public yet are the design of the original bridge and the engineering analysis of the bridge as it was undergoing repair. I am anxious to see those.
4. I can fully understand the Governor and MNDOT’s silence prior to completion of the full investigation. I believe they are acting responsibly on that issue. The last thing we need is for them giving a new half-baked theory to the media each day.
5. I can also understand the head of MNDOT being a political appointee, selected for his or her managerial expertise. That person will then hire managers to head up the different departments, including the engineering department.
6. As far as your last statement, I am afraid that I have to agree with it. —
Lanny R. Berke