Archive for category engineering
Wright Brothers’ brilliant launch of modern aerospace experimentation
Posted by mark in engineering on June 7, 2026
In late April my wife Karen and I made a pilgrimage to the Wright Brothers National Memorial—accomplishing a lifelong mission of mine. I’ve worked for decades helping aerospace scientists with their design of experiments (DOE). For example, a few weeks ago I helped a US Air Force project engineer set up a DOE to characterize the flowfield of a jet via testing at Hypervelocity Wind Tunnel 9.
According to a 2010 Defense Visual Information Distribution Service (DVIDS) press release (cited below with the quote), Tunnel 9 compresses nitrogen to 30,000 pounds per square inch and heats it to 3,000 degrees Fahrenheit to create a pressure ratio of about 1 million. Who knows how much more T9 can do now—16 years later.
“Wind tunnels, the tools used to simulate airspeed environments to test flight capabilities, have come a long way since the Wright brothers built a box with fans to test a kite model.”
– Ian Graham, author of Wind Tunnel Explores Dynamics of High-Speed Flight.
Though use of wind tunnels for aircraft development dates back to 1871, the Wright brothers revolutionized the use of these devices for testing during their pioneering studies in 1901. Of all the amazing artifacts at the Memorial, I was most impressed by the lift and drag measurement equipment—see these described and pictured at this NASA post. With this test capability in place, the Wright brothers achieved a design breakthrough that enabled their great achievement of the first flight of a powered, manned, and controlled heavier-than-air aircraft on December 17, 1903.
If you have not been to the Wright Brothers National Memorial, I highly recommend doing so, not just for the history, but also to take in the epic surroundings of North Carolina’s Outer Banks.
Diverging diamond interchanges speed up traffic, but they feel weird
Posted by mark in engineering on July 3, 2025
Sarasota County, like all coastal areas in South Florida, gets jammed up by ‘snowbirds’ like my wife and I, who migrate there every winter to escape Minnesota’s painfully cold weather.
To alleviate traffic at its heaviest near the city of Sarasota, the Florida Department of Transportation (FDOT) converted the junction of Interstate-75 at University Parkway to a diverging diamond interchange (DDI)—the largest in the world at the time it was implemented in 2017. This development increased capacity by 33 percent to 80,000 vehicles per day and reduced the intersection delays by 50 percent. These improvements stem from a large reduction—over 50 percent—in the conflict points.
Soon the I-75 at Fruitville Road interchange will also be converted to a DDI by FDOT. Hundreds more are either already built or under construction across the USA. If you haven’t experienced a DDI, get ready for being disconcerted from the temporary reversal of lanes.
I hate DDI’s so much, that when forced to drive down University to pick visitors up at the Sarasota Bradenton Internation Airport, I exit I75 at Fruitville Road. But this resistance is fruitless (pun intended) due to the upcoming project by FDOT.
I also dislike roundabouts when traffic gets to the point where it becomes very difficult to break in on the flow. Sarasota County features a great number of traffic circles like this. The mix of slow senior snowbirds and aggressive Florida men aggravates the free-for-all.
All this makes route planning and timing essential when driving during Florida’s peak season. Fortunately, I enjoy challenges like this that involve multiple constraints. As the guru Sivananda Saraswati said, “the harder the struggle, the more glorious the triumph.”
An homage to an engineer extraordinaire—my dad
Posted by mark in engineering on February 3, 2025
James J. (Jim) Anderson, my dad (seen pictured in 1990 with former President Gerald Ford), passed away peacefully on Wednesday, January 29, at the age of 95 after being hit hard by influenza A (be careful out there—it’s spiking now across the USA). Both of us being engineers, him inspired by his dad—an engineer also, and me by him, we enjoyed many great talks in his later years about technical matters along the lines of this StatsMadeEasy blog. This is my homage to Jim’s engineering accomplishments, mostly based on what I gathered from his stories (which I will greatly miss) and my memories, thus off a bit on some of the particulars, but fairly accurate, hopefully. It’s quite a story!
Jim was a stellar masters civil engineer who specialized in wastewater treatment before the realization of the damage being wreaked on our rivers by unconstrained dumping. His first job after achieving his bachelor’s degree in sanitary engineering in 1952—a newly created specialty at University of Minnesota—was a demonstration project for The American Meat Institute aimed at cleaning up waste streams from the Hormel plant in Austin, Minnesota (where I was born in 1953). He then moved us (by then my sister Nancy also) to the Twin Cities for a job at Toltz, King, Duvall, Anderson, and Associates (now known as TKDA), being assigned as City Engineer for West Saint Paul.
Jim then took an engineering job at the aptly named Pigs Eye Wastewater Treatment Plant in Saint Paul. While there he became skeptical of sketchy studies dating back to the 1930s that led to heavy use of flocculants at a substantial ongoing cost. This seemed to produce little effect, but Jim knew it would take a definitive experiment to overcome the ‘common knowledge’ of its efficacy. Someone suggested that a fellow at University of Wisconsin by the name of George Box might provide some help on the design of experiments (DOE). Sure enough, the DOE designed by Box did the trick—no more wasteful use of chemicals after that.
In 1968, Jim completed his master’s thesis, which involved regression modeling—a tool undergoing rapid development at that time. He had to defend the methodology against a professor who doubted anything produced by a computer could ever be relied upon.
About then, Jim was at the right place at the right time by submitting a proposal to the Federal Water Pollution Control Administration (created in 1965 by the Clean Water Act) for ways to deal with secondary sewage—the surge of dirty water pouring through single-pipe systems in Saint Paul and many other cities after heavy rains. To his surprise, a grant came through in an amount that seemed overwhelmingly large at the time—$1,741,000.* Even more surprisingly his engineering manager went for it. Predictive modeling of rainfall based on regression was the key to Jim’s solution for dealing with overflow. Knowledge was power. Being able to anticipate the surges, weirs (small mechanical barriers inside the sewage pipe) and inflatable dams trapped the water long enough to then be released in a volume that would not overwhelm the wastewater treatment plant.
Other cities jumped on his solutions, starting with Cleveland, infamous for their 1969 Cuyahoga River fire. Jim then started a consulting firm called Watermation, which did a lot of good for major cities worldwide. The timing again was ideal due to the rapid development of computing power, such as the Digital Equipment Corporation (DEC) PDP-8 used by Jim and his team—the same machine that got Bill Gates going on Microsoft.
That’s enough to provide the gist of what Jim did that fascinated me from an early age and still amazes me as a chemical process development engineer and fan of stats and computers. Not only was he a great mind, Dad could do anything hands on—welding, wiring, soldering (a whiz at fixing TV’s and radios), plumbing, woodworking, etc. He brought me and my younger six siblings up to Saint Paul YMCA’s Camp DuNord for many years. Naturally when the time came to put up outhouses, he got volunteered. ; ) On of my proudest memories was Dad winning a contest for log splitting by cutting it in 4 parts with two chops—the advantage of being an engineer (and handy with an ax).
By the way, though a bit too young to serve in World War II, Jim graduated from training in Pensacola, Florida as a Naval Aviator before being honorably discharged in early 1949 due to reductions in the armed forces at the time. His service falls within the window of WWII vets, thus I feel that all-in-all he deserves consideration as an honorable member of the Greatest Generation. I can certainly say there will never be another individual of the caliber of James Joseph Anderson.
*Page down the Selected Urban Storm Water Runoff Abstracts, Second Quarterly Issue for #048 Interim Report to the Federal Water Pollution Control Administration on an May 1969 interim report on this demonstration project.
PS: A few more of Jim’s engineering achievements that I gleaned from searching the internet (probably not comprehensive):
- Publication of “Remote Control of Combined Sewer Overflows” (co-authored by his colleague Robert L. Callery) in the Journal of the Water Pollution Control Federation, Vol. 46, No. 11 (Nov., 1974), pp. 2555-2564 (10 pages)—see the abstract for some very impressive statistics on reduction of pollution due to work by him and Watermation.
- Him speaking on “Present Practice and Research Needs in Wastewater Collection System Design and Operation” for a workshop in 1975 sponsored by the EPA.
- US Patent 4,168,233 for an “Automatic activated sludge control system” (published 9/18/1979)