What is my responsibility? 1

[KSor]

I have a question regarding my professional responsibility. I have been asked to convert some "napkin sketches" of a machined and welded part into real drawings that a fabrication shop can actually use. I have not been asked to "engineer" the part, just to make the drawing useable.

My question is, since I have had to add some details that were missing from the sketches, am I now responsible for the design? As well, since the drawings have now passed thru the hand of an engineer, is the design assumed to have been engineered?

If this was just a paperweight, I would not be so concerned, but the problem is that if this part fails, at best it will result in equipment damage, and at worst people could be killed. I know my first concern is to public safety, so I am very leery about just handing over the drawings and forgetting about it.

 

[sms]

I would say that you either need to "engineer" it so it will not be a threat to saftey of those around it, or you need advise the requester that the part is not safe and you will not be drawing it up...

I don't think you can simply draw it up and hand it over, unless the designer is a PE and will take responsibity for the design. Even then if you think it is unsafe you have a responsibility to advise him/her of that.

-The future's so bright I gotta wear shades!
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[zcp]

Sounds like you have a drafting job to take care of for your client. If, as an engineer, you see an issue with the design, it is time to sell the client on paying for your time to review the design and confirm it will work / is safe / etc. If they choose not to use that service, that is their choice. They own the design and you are making fab drawings.

If on the other hand you know the design is unsafe, then you MUST convince them to have you re-engineer it or you will have to walk away. You also might want to do a back of the envelope calc while doing the drafting just for your own comfort.

ZCP

http://www.phoenix-engineer.com

 

[DRC1]

Put a note on the drawing "Details require engineering review"

 

[JStephen]

My approach would be to draw it up, and put prominent notes to the effect that it hasn't been engineered and needs to be engineered for safety.

Or, if you don't really trust the customer, just don't draw it at all.

 

[GregLocock]

Sorry, I think the last couple of posts are unnacceptable.

Your job as a professional engineer is to prevent unsafe designs from being made.

Merely by looking at the sketch, never mind drawing it up, never mind adding a few details, you are now responsible to the public for the safety of that design.

So, you either engineer it properly, or you stop it from being made.

That's it.



Cheers

Greg Locock

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.

 

[JStephen]

I disagree, Greg. Not every drawing is a final drawing. That doesn't mean it can't be drawn. Nor is there some rule that the one engineer who draws a particular item is entirely and solely responsible for the safety of that item.

A drawing may be a concept drawing. It may be generated for review and comment of others. It may be generated as an aid to analysis. It may be the basis for test samples that may be used for further analysis. There are any number of legitimate reasons why one might detail a part that has not been fully engineered.

The rub is if you have some way of suspecting that a detail made only for concept or input is going to be used for production or some other application not intended.

 

[sms]

JStephan, reread the OP. That is exactly the point:

"I have been asked to convert some "napkin sketches" of a machined and welded part into real drawings that a fabrication shop can actually use."

This design is going directly to fabrication, he is being asked to do the final drawing...

-The future's so bright I gotta wear shades!
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[JStephen]

"This design is going directly to fabrication"
"he is being asked to do the final drawing"

In fact neither of those is stated in the original post. He says he's been asked to do drawings that a fabrication shop CAN actually use (as contrasted to a napkin drawing), but that doesn't require that those drawings be immediately turned over to the fabrication shop, nor does it imply that the drawings he's doing right now are the final versions of the final product.

If that original engineer through whose hands it passed is responsible for the design, then the drawings should go back to him for review. Or if neither that original engineer nor the poster are responsible for design, the drawings ought to go on to someone who is. The initial output shouldn't go directly to fabrication, and if misuse of that output is suspected, then that is the case where the drawings shouldn't be done in the first place. "I don't think you can simply draw it up and hand it over, unless the designer is a PE and will take responsibity for the design." (And in an exempt industry, the designer need not even be a PE.)

To give you an idea, I do quite a few drawings "that a fabrication shop can use"- and they are typically reviewed by my boss, by the customer, by the customer's consultants, etc- it's seldom a direct computer-to-shop transfer.

 

[civilperson]

Unsafe is a relative term. Failing after two million cycles of loading may be "safe" if the predicted loading is 600 times per year. A built in failure or fuse mechanism may be used to prevent more expensive components from extreme stress, thus rendering the entire system safe through the one component's failure. Just note your misgivings on the supposed weakness and go about the job assigned. More is learned from engineering failures than success.

 

[csd72]

As far as I understand the american legal system, I believe that you have a legal duty of care. This means that you should take into account any hazards e.t.c. that an engineer of your experience should reasonably be expected to know.

You have this duty of care regardless of what tasks you are performing. If you do not have any time to design it then you should see if one of the non engineering draftsmen can do it.

 

[KSor]

These drawings would have been sent straight to the fab shop, they were the final drawings. Even though I was asked to merely do the drafting on them, I decided that I had to do the full analysis. I know that the "napkin sketches" sent to me were not done by an engineer, nor would they have been reviewed by anyone other than me prior to being built and used.

Because this was the case, I decided that I had to go beyond the scope of my original assignment and do an analysis. I felt that even if I had just drafted the drawings, because I am an engineer, it could have been assumed that it was engineered, and that if I released the drawings they must be safe.

BTW, the parts turned out to be inadequate. I have not released the drawings. I'm sure I'll have some fun phone calls later today.

Question though: With regards to liability, if this assignment had been given to a drafter instead, and the parts later failed, would there be any legal repercussions for the company?

 

[SylvestreW]

I have to agree with Greg. If you KNOW the part will be designed based on your drawings, a disclaimer written on some paper doesn't absolve your responsibility. As a professional, your responibility is to the public first and foremost.
It's a common problem in our business where people think a design is a 10 min job and any joe can do it. Part of our responsibility is not just "engineering" something, it's educating people on what it takes.

 

[BrunoPuntzJones]

It's sounds to me like you ar doing the right thing KSor. I'm interested to hear if the client agrees with me.

 

[dozer]

Ksor, I'm confused as to just what your company's role is and who made this napkin sketch. You seem to be indicating that it would have been possible for the part drawing to have made it to the shop floor without ever having been engineered had they not happened to ask you to draft it. Is that correct?

It seems to me that your company would clearly be liable if this part failed. What am I missing?

Let me guess, your company is ran by bean counters, not engineers, right?

 

[JStephen]

"These drawings would have been sent straight to the fab shop, they were the final drawings...I know that the "napkin sketches" sent to me were not done by an engineer, nor would they have been reviewed by anyone other than me prior to being built and used."

Under those conditions, I would agree that you are doing the right thing.

As to liability, it would depend. If a non-engineer took a sketch to a draftsman and asked him to draw it up, and that's all there was to it, I don't think the drafting company (or a draftsman) would necessarily incur any liability. Of course, in an actual court case, it would depend on who had the most money (ie, deepest pockets). An engineering company would be a lot more vulnerable, it seems to me.

 

[PSE]

Ksor, are you working in an "industrially exempt" environment or one that would require licensure? If you are "industrially exempt", liability falls upon your employer. Otherwise, it would be best to have personal liability insurance. Off hand I am thinking it may be the latter as you feel the design needs review. Are you able to do such a analysis and review? Who asked you to convert the sketches (I am assuming a potential client)? Could you have been considered representing yourself as an engineer to the public and if so, are you licensed or at least an EIT? In any case, your concerns over the drawings and design would prompt me to think that an independent review by a licensed individual would be prudent. Should that individual choose to stamp the drawings, they have assumed the responsibility. Until then, it either remains with you or perhaps your employer.

Several times in my career I have been approached by individuals to "take a look at this and let me know what you think". I work under the industrial exemption here in the US and my response to those queries is that because I am unlicensed, I cannot legally (or ethically) give a analysis or a recommendation other than for them to seek someone who is licensed to review what they have. I would however, be pleased to help them seek an appropriate individual to do so. Generally I am rewarded with a surprised look and a "I did not know that engineers needed licenses." type of response. To which I respond that for public practice, they do.

Regards,

 

[dcasto]

How would a drawing ever get to a production model that could be tested? Does Toyota draw up a car 100%, run it through all the FEA and say its complete, then built it sell it? Drawings are made, sent to see if the item can be made and a prototype is created that can be tested and concurently, FEA or other engineering analysis is being done and the item worked until its approved. AT which point my Toyota above must be physically crashed and torn apart to assure compliance.

 

[GregLocock]

Toyota will treat all non certified cars as prototypes, and there will be strict protocols as to how they can be used.

They will typically be crushed (mostly) at the end of the development program.

That's how all car companies I've ever known deal with 'unproven' designs.

For example, an early dynamics prototype may only be driven on the test track, and may not exceed (say) 0.6g. It will have a sticker on the steering wheel detailing which systems don't work, and a five point harness, and possibly a roll cage.

If it is a complete new system, eg when ABS was first introduced, we had to do an FMEA of the prototype system and test procedures to establish a test program that would eventually allow us to drive the system at full performance.


Cheers

Greg Locock

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