Examples of hand written calculations and hand drawn sketches 2

Please elaborate.

Hi Trenno,
I started out doing calculations on a paper with pencil and a calculator.
Same with sketching.
Over period of last 20 or so years, I don't see any body working in the same way.
Due to preponderance of spreadshet, the calcs have got more complicated, and the presentaion of the logic for calcs has become very opaque.
As I need to train the fresh workers, Iam looking for a source, where in the calcs are handwritten and succint.
This will allow the beginners to start from simple formulations and as they mature they can move to more complicated ones .

Is this for submitting calculations or internal review? I would think that they should have learned how to properly show calculations with sketches/free body diagrams in college classes. I know all of my classes were very stringent about showing your work so other people could follow it.

Engineering calculations, whether handwritten, on a spreadsheet, or on a commercial computer program, shouldn't significantly obscure the formulas or logic used. When mentoring new EI's, and having them develop their own spreadsheets for some custom calculation, I always have them write out the entire formula used, all of the inputs, all of the intermediate steps, all of the outputs, including any necessary sketches, etc... just like they should be doing with hand calculations. This often requires multiple lines... maybe the first for the inputs, the next for the formula, the next for the inputs substituted into the formula, the last for the answer (all with units included). I even suggest color-coding inputs (i.e., red)/formulas (i.e., black)/outputs (i.e., blue), so that a visual cue is given to the user of what should be modified and what shouldn't. If you're looking at a hardcopy of a spreadsheet printout (i.e., no computer is available to run the spreadsheet), and can't tell where a number came from, or the exact formula that is used, imho it hasn't been done correctly and is really nothing more than just being sloppy.

Btw... this isn't unique to spreadsheets. I have also witnessed many hand calculations, including from prior mentors, in textbooks and online articles, as well as from many college professors who write out notes on the board during the lecture, where (sometimes many) steps are skipped, and they neglect to mention where numbers came from, or the exact formula that was used, and often leave off the units. Sometimes this is done out of laziness... sometimes it is assumed that the reader/viewer already knows where the number came from, or what the units are.

The spreadsheet should be a tool that allows one to modify inputs quickly, try different scenarios, and obtain output quickly (removing the need for manual calculation each time). It isn't an excuse to abbreviate your work and make it difficult for others to follow.

While it may be happening somewhat more now, with the preponderance of computers/spreadsheets/programs in use, the presentation of full formulas/logic in engineering calcs has always been an issue.

I copy my formulas on the excel sheet using the cutting tool. That makes a large spreadsheet, but no questions arise. Typically, young engineers should be well equipped to do hand sketches and calculations, since their homework in college required them to do so. However, we do live in an age where things should be done more efficiently, so the best thing to do is to have the young engineers map out what the do in excel, in excel, using text and pictures. When they look back at their spread sheet, they know exactly what they are looking at and have the values on hand.

And quote the relevant Code Sections, too.

You can't really appreciate a good set of calculations until you've seen a bad set. I hate calcs where "then a miracle occurs" and the answer just appears.

Angre - If you are looking for an example of calculations performed "the old way" (say pre-electronic calculator), I recently posted a couple of pages near the bottom of this thread: The only "modern" short cut was to use a calculator... instead of a slide rule (but could have done that, too)

There are many issues with relying on spreadsheets.
1.Beginners never learn to handsketch.This handicaps them, as they are not able to explain the situation they are in.
Hand sketching, while doing the talking, with a few calcs thrown in are a very effective way of communicating.
2.The thoughts are not structured, as spreadsheets allow a lot of refactoring by way of /deleting rewriting , cutting/pasting etc.
Hence the time taken to do even simplest of calcs is very long.
Now dont get me wrong,I use spreadsheets (mainly MathCAD annotated with VISIO), but there are plenty of occasions when it is much faster
to handsketch the situation, do a ball park calculation and arrive at least an initial conclusion,on a A4 or A3 sheet.Then just san it and send over to
client, to firm up the way forward.
There used to be a lot of books in which the calculations/sketches were done in handwritten format. I couldn't locate any of them on the net.

Angre,

There should be no difference between a hand written work to a computerized work. It depends on the type of job that you have and the man hour you have allocated to that job.

You can do the hand calcs and hand sketch as long as you can meet the deadline. There are jobs that would make you look like a goat if you give them a chicken scratch.

If you have to make your calculation, make sure you have not intended for other engineer to make himself like a dumb trying to cover while you are on vacation.

I would recommend for you to look for a colleague working in an oil and gas industry who could let you have a sample of what you have been looking for. They have a very good standard in calculation layout, engineering sketches and drawings.

"I can always be the best of the worsts and the best of the bests, it depends on how you want me to drive your innocence" - Alphaxy





Regards,
E104909

If you do spreadsheets, make sure they are reviewed and office approved for use. Backcheck the results by hand to make sure the results are cottect. Sometimes this is a hard point to get across to young engineers, let alone some older ones.

Mike McCann, PE, SE (WA)

How does cutting and pasting take a long time to do? Control C then control V? Reformulation should be an addition to the spreadsheet not a change. As far as sketches go, you can still do them by hand... but have your calcs in a spreadsheet that way you can spend an hour analyzing it and not a week. At my work if you are doing hand calcs, you won't last but a few months because you will be overloaded and overcharging.

In the formulas tab of MS excel use trace presidents & trace dependants cells for easier review of formulas.

Angre…

Mathcad is the electronic version of pencil and paper calculating and Mathcad worksheets are so much easier to read than anyone's printing/handwriting. With Mathcad, the equations are visible and live, not hidden like in Excel (discouting Formula View, which still requires much effort to figure out all but the simplest calculations). In addition, Mathcad handles units, unlike Excel which is unit-stupid.

So, if you're looking for examples of calculations, I suggest searching for Mathcad worksheets, many of which can be found online in Adobe Acrobat .pdf format, which means you don't actually need Mathcad itself.

The first place to look is the PTC Mathcad website: There are other non-PTC repositories (individuals, universities, even some engineering firms), but it can take some work to find them.

Over the past nearly two years, I have posted more than three dozen Mathcad worksheets on topics such as Logarithmic Interpolation, Telescope Visual Limiting Magnitude, calculating the date for Easter, etc. Most of my worksheets, though, are specific to civil engineering and can be found in the Civil Engineering Community ( ). Topics include estimating Darcy Friction Factors (explicit estimations of the implicit Colebrook-White Equation), Feet-Inches-Fractions Calculations, Natural Gas Distribution, Pipeline Thrust Restraint, Flexible Pipe Design, Hydraulic Capacity of a Street Cross-Section, Lat/Long-UTM Conversions, and so on.

You can find my worksheets pretty easily by first searching the site for "UTM". The first hit is my worksheet, and from there you can find the rest of mine. All of my worksheet posts include a .pdf version along with a Mathcad Prime 3.0 worksheet.

BTW, I'm 57, so I remember and did/do the old ways. I still use pencil/paper or Excel for some engineering calculations, but I prefer to use Mathcad instead. I organize my Mathcad calculations like I do my handwritten calculations, just better and neater, and they're easier to change if the need arises. I still sketch simple stuff by hand (I did one this morning for a rip rap detail), but if it's complicated I do it better, faster, and neater in Autocad. One of the reasons I still put pencil to paper is that I find that the thinking process is different than when using a computer. In fact, it's one of the reasons I still encourage young engineers to hone these skills along with their computer skills.

Fred

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"Is it the only lesson of history that mankind is unteachable?"
--Winston S. Churchill

Get "246 Solved Structural Engineering Problems" by C. Dale Buckner, Professional Publications, Inc. Hopefully still in print- I got mine for the 1995 Structural exam.

All the solutions are in handwritten form, with sketches.