Changes and carbon footprints
Several readers expressed their views on the most important changes to the engineering profession over MACHINE DESIGN’s 80-year history. Another suggests a more straightforward way to determine how much a product or service impacts the environment which he claims is easier than trying to figure out its carbon footprint.
Changes over the last 80 years
The single most pervasive change in engineering has been the use and maturity of designing with 3D models — which includes rapid prototyping with 3D printing and model analysis and generating design documentation (“80 years of Engineering,” April 9). It has been an innovative process spanning many years from the earliest forms of 2D computerized drafting and wire-frame development. The current generation of software and hardware offers more design freedom, better analysis tools, and can make engineers far more productive. It also lets design teams share information over the Web, a feat no one dreamed of in the 60s, 70s and 80s. As a graphic example, take a look at current amusement park rides and their development process.
The biggest change in engineering was the introduction of the scientific calculator. I was just starting college when these calculators were coming out. I had been struggling with the slide rule, trying to keep track of the decimal points in my head. Calculators let us focus on the solution and have improved the precision of calculations tremendously. I realize that computers are extremely powerful tools, but I see them as an outgrowth or evolution of the scientific calculator.
Real cause of the Hyatt disaster
If Mr. Teschler properly quoted Dr. Abkowitz regarding the Hyatt Regency disaster (“Engineering is a risky business,” April 9), then the professor’s summary of the cause of the disaster is wrong. Construction flaws were not to blame, nor were there any such flaws for city inspectors to discover. It is even dubious to say that “rubber stamping of numerous design specs” was to blame. The fundamental cause of the failure was a single connection design, and more precisely, a change in the connection design. There is much that engineers can learn from history. It is essential it be remembered and repeated correctly. For an excellent look at the Hyatt disaster, check out Henry Petroski’s review of the Hyatt disaster in To Engineer is Human.
Duane K. Miller
The Hyatt Regency walkway collapse was attributed directly to a change in connector design, but there were numerous other contributing factors. As Abkowitz points out in his book, “Operational Risk Management,” the catalyst for the disaster was poor communication and an inability to follow procedures among the numerous parties involved in design and construction. For example, the firm which subcontracted to fabricate and erect the atrium steel asked designers to change the support design over the phone. Neither party followed up in writing. This undermined formal-review processes. The designers also made a drafting error by leaving the weight of the walkways off the sketch of the connection. And the walkways did not meet local building codes, yet were approved by inspectors anyway. There were a bevy of other lapses too involved to go into here. For an accounting of why this disaster was caused by much more than a simple design error, you should refer to Abkowitz’s book. — Leland Teschler
Authorized channels a waste?
I have problems with the common suggestion in a recent article encouraging customers to deal with authorized channels and distributors.
Most of the time, I find the authorized channel a waste of time and energy. Factory representatives typically know far less about the product than the right guy at the factory. And local distributors often have to go back up the chain to get me information on price and availability. Just two days ago, I was directed by a manufacturer to use its authorized channel only to then make several more phone calls to find out the local distributor did not carry the packaged quantity of tubing I wanted. I ended up going back online to find another maybeauthorized distributor. In an age with near free Internet, cheap national phone calls, and fast shipment, often overnight, authorized channels are anachronisms.
Skip carbon footprints. Check the price.
I just read the Vantage Point column by Phil Kingston (“Sizing up your carbon footprint,” Jan. 8). In the column, the author gives some details about one method of calculating carbon footprints. He also says the calculation is “clearly complex,” and I agree. He goes on to give examples of British retailers and a division of Frito-Lay putting carbon footprint data on consumer packaging. He takes the position that a carbon footprint provides a figure relating to energy use and emissions.
This might be true, but there’s an obviously better, more-direct estimation of energy and carbon emissions already on the package and available to the consumer. Its called the price.
The price of any good or service is the sum of human labor and energy to make, ship, and sell it. The cost (in whatever currency you use) captures the total resources used to create it. By the method described in the article, human labor does not have a carbon footprint. This would imply that spending more money on a product with a high manual-labor content lowers emissions. This is not true. Human laborers are not emission-free. They are paid money which is used to buy food, clothing, cars, gasoline, and everything people need to live. The same goes for marketing costs. We often see two products that perform identical functions, but one commands a premium price, often primarily due to marketing (iPod versus MP3 players, designer clothing versus generic). Although each item’s carbon footprint is likely calculated to be the same, the more-expensive brand has a larger footprint. The additional expense goes somewhere, usually to salaries or marketing. All the people receiving this money spend it on items they want or need, increasing the carbon footprint of the high-cost item.
Government regulations and taxes have footprints as well. People must be hired to assess and collect taxes, not to mention spend it. These people all consume products and services, resulting in emissions and a larger carbon footprint. Regulations have a similar effect, with emissions coming from the cost in human effort or increased energy consumed in complying with them.
Lastly, there’s the pure service industry. On the surface, jobs such as lawyers, software engineers, and such have little or no associated carbon footprint because they don’t make anything. They might not make anything durable, but they take money and then spend it on things.
Complicated calculations are an error-prone estimate of this reality. If your true goal is save resources and minimize emissions, buy the lowest cost product and save your money for tomorrow. It’s not as much fun, and you can’t brag about being “green,” but it’s the right thing to do.