company trying to grow into bigger projects 6

[ppsndmh]

I have been doing mostly residential and some light commercial structural work for about 14 years. The small company I am currently with has been mostly residential and maybe 5% light commercial for about the same amount of time. The owners have mechanical degrees and one of them has several years of experience at a mechanical firm, so they have gotten into MEP work since the second owner came aboard. They have hired another MEP engineer and several draftsmen for that side of the business. My problem that I am running into is that I am a one-man structural department with no drafting help…and the company has been bidding structural work to go along with the MEP work; structural work that is out of my wheelhouse, especially since I don't have a mentor to work with. They have recently put me in charge of two industrial projects. The first was a smaller tilt-up job and I had the tilt-up design guide, which has helped me get through it. There wasn't anything overly complex with that job. The other project is a bigger industrial job where complex equipment support design is involved. This is beyond anything I have done before and I have told one of the owners via email a few days ago that I am nervous about taking on this bigger job on my own, with no response from him - so I have continued on. I have a M.Eng. in civil (structural emphasis), which has helped, but I feel overwhelmed because I can't come up with the design as quickly as the client wants it done and am feeling the pressure. I kind of feel like what I would imagine a general practice family doctor would feel like if ordered to perform heart surgery on a patient. I think if I had a lot more time I could get the design dialed in, but I don't feel like I (being a one-man engineer/drafting show) have enough time to research what needs to be included in the design in the time frame that's being asked of me. Does anyone have suggestions as to how to approach this situation? My current thought is to suggest to the owner that I do not want to seal the structural drawings since I have never done a project of this magnitude - that he must contract or hire an engineer with experience in industrial design to take the lead on this project while I serve under him/her.

 

[hokie66]

Look at this as an opportunity. With 14 years experience, you should have the confidence to be able to handle it. You may have to spend some out of billable hours time getting up to speed, but go for it. With industrial work, be conservative. No one will thank you for saving a few tons of steel in supports for equipment that costs many times what the supports cost.

If you are truly stuck with a complex issue, then ask for specific assistance.

 

[MikeHalloran]

My summer job in college was drafting, mostly pipework for paper mills.

The new guy engineer, freshly ex-aerospace, proudly showed me his work product for three solid weeks, a structure to support half a ton of 8" water filters and switching valves. It was mostly made of 1x1x1/8" angle, and weighed next to nothing.

The boss fired him that day.
I asked why; I had seen the calculations, which were complete and appeared accurate or at least credible, and the sketches were beautiful.

The boss' reply:
"What happens, the first time it gets hit by a forklift?"
"Now, go and draw up a replacement structure, and don't use anything lighter than a W4x13, or I'll fire your ass too!"

Thus endeth the lesson in industrial structure design.



Mike Halloran
Pembroke Pines, FL, USA

 

[brandonbw]

Mike: That end result seems so wrong.

We encounter many problems that I haven't seen before or know exactly what to do. I end up spending a day on Google reading. Books and people are another great resource. Some of this has lead to a different path for the design which is even better. When asking a question I generally start it with I haven't done this before do you have any guidance or tips and be specific. As an example, I have had full calcs given to me exactly the way they want us to show something.

B+W Engineering and Design
Los Angeles Civil Engineer and Structural Engineer

http://bwengr.com

 

[MikeHalloran]

Receiving a template for your work product is a wonderful gift, for all parties concerned; it eliminates a lot of waste and misunderstanding.

The aero guy was at a huge disadvantage, because in his (former) world, you have to design just this side of failure, so you have to check everything, whereas parts for a factory don't have to fly, and may have random stuff hung on them or impacting them at any time, so the norm is (or was) to use what's available, apply a big factor of ignorance, and then apply a bigger factor so you don't have to sweat the small stuff.




Mike Halloran
Pembroke Pines, FL, USA

 

[hokie66]

Mike describes industrial structure design exactly as it is. You only have to go into a plant once to understand. Your first experience of seeing a major building column knocked askew, with its base at right angles to where it is supposed to be, will give you a healthy respect for what happens to industrial structures.

 

[tygerdawg]

Sort of like in the case when I was young, I was fortunate enough to get a dose of the Crusty-Old-Warhorse-Engineer-Straightening-Out-Young-Whippersnapper speech: "Steel is cheap, use plenty of it."

TygerDawg
Blue Technik LLC
Virtuoso Robotics Engineering

http://www.bluetechnik.com

 

[kylesito]

ppsndmh,

Yes, you should consult with a outside structural engineering firm if you aren't comfortable stamping something (and those above you aren't willing to do it themselves). It may be a tough conversation to have with your bosses but infinitely more comfortable then the conversation you will have if there is a failure later.

MikeHalloran's example of industrial design is accurate...."when in doubt, make it stout". But even industrial design is based on prescribed loads. I recommend factoring in at least a 30% impact factor on any live loads and use a standard 6k horizontal force for anything that might need to prevent the passage of a vehicle (similar to a guardrail).

Pipe and mechanical supports are sometimes complex to lay out but often not overly design intensive. The suggestion to use standard W4, W6, or even W8 columns would be a good one from a practical construction approach. And then maybe use a C8X11.5 or similar to mount base plates to. This would eliminate some of the design as you would then be just checking that something was under capacity. Of course, without knowing the ins and outs of the project this may be entirely off base, but you can apply similar logic to your specific needs.

A good lesson I learned when moving to a new company that designed larger structures (out of one VERY similar to your current one) was that even the biggest buildings are designed of the same beams, columns, and braces that smaller ones are. Just a few more of them. Solve what piece you can first, then work on the rest.

PE, SE
Eastern United States

"If a builder builds a house for someone, and does not construct it properly, and the house which he built falls in and kills its owner, then that builder shall be put to death!"
~Code of Hammurabi

 

[EngineeringEric]

Maybe you have done it, but talk to the Facility Engineers or Maint. guys. Get a feeling for what they have, how thick their slabs are (8" isn't anything atypical, 4"-5" never!). Ask what they are looking for, try to fish specifics from them and then design it based on what they say, try and see examples throughout that facility. We work with 4 large multi-national facilities that do some serious work. Often times projects between them coordinate and we can borrow something we see at facility A and use at B. or from one place in A for somewhere else in A.

Just take it all in, and do not take photos unless given permission

FYI: W section columns are nice since they hide anchor bolts inside the flanges so they do not get bent/damaged/tripped over.

 

[tys90]

I think you are right on track - hire someone who has experience to lead these projects or contract with an outside firm to help you through a few projects until you know what you don't know. If you go with the outside firm, you may have to find someone who won't be in direct competition with you, now or in the future.

 

[TLHS]

I've worked with lots of people coming from commercial to industrial. The hardest part is learning that you don't design to the bone and you want to avoid fiddly bits as much as possible because it's possible the guy installing your steel is a piper or something. Also, your stuff isn't hidden away and everyone ends up seeing it. In a practical sense, it means it's more important that the structure 'looks' right so the client doesn't worry. What that means varies, but often involves wandering around a site and seeing how existing structures are put together.

That being said, equipment support is probably the trickiest thing. If you haven't seen a bunch, it's really easy to get stuck going in circles trying to get it right. Vibrations and detailing are a big deal and the first request from the vendor/mechanical group generally involves unrealistic structural requirements.

What's important is to keep in mind the size and criticality of equipment. If it's reasonably small, just brute force it. Give it a bunch of mass and tie it down nice and tight. If it's big *and* important, then you might need to get into more complicated analyses and those will take a certain amount of research to figure out. Really, you just have to sit the person bidding these projects down and explain that you can't do it in the time given to you.

If you're nervous, add more material. In most situations when I'm doing industrial I probably average a 30% capacity buffer on major members. At some point someone will come along and try to hang a 30 inch pipe off of your structure or will want to upgrade the machine. In a working industrial site there's rarely a single piece of structure that hasn't had something added to it over the years.

 

[Jboggs]

Many years ago I too had one of those crusty old farts teach me an unforgettable lesson for industrial design: when he was checking drawings he employed what he called The 747 Rule, which states that if a fully loaded 747 came crashing through the roof landing directly on the device you are designing, it should still work. Nuf said.