An engineer at Rader told me that one problem was the rebuilt cars on the Marlboro train were too heavy for the trucks. Rader had just received newly cast Buckeye trucks designed to handle the much heavier loads involved, and would shortly be shipping off the bodies and new trucks. This certainly is a tough blow for Rader.

The author of this letter regularly appears on local Maine television stations pronouncing the benefits of nuclear power. We can only presume these appearances are not made on a pro bono basis.

Conflict of interest aside, one must take a dim view of such a narrow-minded analysis of a significantly more complex comparison of two very different sources of energy. Clearly, the use of solar power for large-scale electric power generation is no match for nuclear power. Consider for a moment, however, the electrical energy associated with heating 40 gallons of domestic water over a 100 degrees F rise for 2 million homes a day on an annual basis, roughly the annual output of a nuclear facility like Maine Yankee. Now consider a $10 billion price tag to build (decommissioning not included) a new nuclear plant versus investing $5,000 in each of those 2 million households to eliminate the need for electric domestic hot water. Many alternatives, including solar energy, are now on a more level playing field.

As is often the case, we must focus more effort on asking the right questions (demand-side management versus an unending thirst for energy) before delivering a simplistic and convenient answer. The hidden costs of operating a nuclear facility are becoming more difficult to hide now that the age of decommissioning is on the horizon. Engineering is a multidisciplinary occupation in which economics plays a key role in most decision-making processes. Those who ignore this reality are obviously not familiar with the fundamentals of capitalism and a free-market society.

The definition of "functional diameter" is published in ASME B1.7M. To summarize, it is the smallest or largest (pitch-diameter) perfect thread contour, one GO gauge length, that will fit onto the screw or into the nut thread, respectively. As the definition states, its value includes all of the form deviations of lead (pitch), thread angle, tapper, roundness, and so on. The functional diameter is a measure of the ability to assemble the thread.

The stripping failure mode in Table 2 was nut-thread stripping, as McKee suggested. The material strength of the nuts would have to be greater to cause screw-thread stripping. The data in Table 2 do show a reduction in strength as the minor diameter increases from 0.456 through 0.467 to 0.478. These data are the minimum values of the sublot tested, not a lot average. They are reported this way because product testing is normally judged by a minimum strength limit.

I recommend that you look at the test data that are included in the RR2 report from the Industrial Fastener Institute. These results do indicate a better correlation for nut minor diameter than the pitch diameter with either the average or minimum joint tensile strength.

The tensile failures in Table 3 are in the thread cross section and not the body of the hex-head cap screws. The torque tension test failures were also all screw-thread tension failures, not body, nut, or screw stripping failures.

It is nice to see that this article drew attention to one of the industry's current issues, fastener performance and product control.

Olsen possessed an extremely creative mind, with superb mathematical, mechanical, and analytical abilities. He dedicated virtually his entire working life to the practical application of the strength of materials. The technical information generated by his revolutionary designs enabled the engineers of the day to expand their technical horizons, which in turn assisted in the development of the country. Even today, engineers will come across one of his drawings in the archives and marvel at the complex mechanisms that he devised.

Although I have heard and told the Tinius Olsen story many times, your article effectively captured the precise human elements of his character and personality in an interesting and readable style. When I finished reading your version, I was both excited and proud.

A computer is only a tool, just like a calculator, slide rule, handbook, template, or phone, but it can be a very powerful tool. Unfortunately, the more "artificial intelligence" we have and rely on, it seems the less natural intelligence we use. (I recently saw an advertisement for a "computer-literate engineer" that required only a high school diploma.)

I have used finite-element analysis as a tool to help me solve difficult engineering problems, but I have also seen FEA used for cantilevered beams and other problems for which a handbook solution provides a better "feel" for the physics of the problem and is more efficient. I interviewed a job candidate who used FEA, but he had only "heard of" Roark's handbook. Sometimes the use of the tool--rather than an appropriate solution--becomes the goal.

The decline of engineering in understanding the laws of nature has displayed itself in the disposable products that we buy. Just because it can be drawn with CAD doesn't mean that it will work. Nor does it guarantee that it makes sense. Engineering education, experience, and judgment are necessary for that.

Because of recent computerization of engineering activities, it is much easier to "punch a button and get the answer." In the long run, I fear that this ability will push down priorities regarding real-world situations about how to establish educational processes that encourage creative thought and problem solving.

Don't get me wrong--I love computers and what they can do. I don't know if I could go back to the days of hand drawings (although things seemed to work well even then). During rush projects, however, I rely on my brain and drawing skills to outline, define, and propose solutions to a problem. I use a pencil to do so, and if the lead breaks I sharpen it--I don't have to ask a network administrator to "fix my working tool" to continue the work at hand.

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