Forensic engineering consultant James A. Wingate won’t name the parties in one of his interesting recent uses of TK Solver—because it’s still being litigated. But the Taylors, South Carolina, retired engineer will sketch the broad outlines of the case. And he’ll tell you how TK Solver’s backsolving helped.
“It was a very large fuel oil storage terminal,” Wingate says. “An accident occurred involving a mechanical failure; it caused a water hammer event that ruptured a pipe, causing a huge fire that raged for several days and did millions in damage.
“I used TK to do a punching shear analysis on a piping component that was destroyed by the incident. I was able to go back through and back calculate from physical damage to the mechanical piping arrangement—which is really what forensics is—and determine exactly what had happened and to confirm my findings.
“That’s a place where being able to do a lot of sizing calculations—ballpark-type calculations—in a short period of time is very handy,” he continues, “and that’s my primary use for TK Solver and Roark’s (Formulas for Stress and Strain): all those good beam and structural mechanics formulas that are useful and usable are in there.”
Wingate’s forensic work centers on such pressure vessel and piping failures as this—using TK for “turn-the-crank solutions to existing formulas that are found either in ASME (American Society of Mechanical Engineers) codes or in Roark’s,” he says. His clients for the forensic work are law firms across the continental US. He also does pipe stress analysis as a contract and consultant engineer. One big client in this work is Intel, which requires large-scale utility installations—and code pipe stress analysis—for chip fabrication plants. “I put in several years’ work doing ASME piping code stress analysis for silicon wafer fab utility packages for Intel Fabs and others —in Ireland, Oregon, Texas, New York…all over the place,” Wingate says.
Wingate also uses TK in hydraulics problems—fluid mechanics formulas and the Plot Wizard to generate plots of families of curves, and built-in functions to solve differential equations. Both these uses serve another purpose: to provide material for two books he has authored, in the process of being published by ASME.
The two “Mister MechMentor” books reflect Wingate’s strongly felt conviction that there are dangerous gaps in engineering knowledge in the US.
“The books are written as mentoring volumes, not as typical textbooks,” he says. “American industry has gotten away from using its own permanent employees as its engineers. When American industry was being built, seasoned professionals mentored youngsters before being given a lot of responsibility. Important common-sense lessons were hammered into them. But not any more. Instead, these days it is mostly subcontracted at the bottom dollar to industry outsiders, by people who don't understand engineering themselves. Most of it is being shipped outside the US, and the few who are left behind aren’t getting much continuing education, and certainly no practical instruction or personal guidance on the job. Lessons are being learned the hard way.
“As a result, a lot of engineering is unsafe,” Wingate says. “I see it in my forensic work: you have piping failures and vapor cloud explosions, that sort of thing, that didn’t need to happen. I felt that one of the best things I could do was put down some of the lessons I had learned so that someone interested might avoid the mistakes that others had made.”
“I mention TK Solver in those books, as something every young engineer ought to have in his kit,” he says.
Wingate says his favorite TK feature is “the ability to solve a lot of little sets of equations without having to do a lot of programming.”
He used TK occasionally for about the last 10 years of his active career, but had been familiar with it from the days when TK was a Software Arts product. As with many users of earlier versions of TK, Wingate’s experience was with Fortran.
Wingate describes the unsuitability of “higher level” programming environments for his work: “I tried programming with the Visual Basic compiler: I had to write 10 lines of code for a line of Fortran or TK, and a lot of things were still undefined. You have to find things out by trial and error, then the thing will blow up and you’re not really sure why. It’s just not worth it.
“I’ve just really given up on programming, and I used to program a lot in Fortran,” he says. ”Now, when I have something that in the old days I would have written a short program for, I just throw it onto TK and let TK do it.”
Wingate sums up: “TK is a well-written and stable program. It’s like any other powerful tool: you have to use it a bit to become fluent in it. If it weren’t such a powerful tool it would be a lot easier to master right away, but it’s more than worth the effort that it takes.”