Disclaimer on lifting plan 1

[delagina]

I was asked to do a lifting plan for a pipe valve. The valve has 4 lifting eyes so it was simple. I just had to compare the weight of valve vs the capacity of crane. And also add appropriate rigging/sling.

Client asked for another lifting plan drawing. Valve was transported in horizontal position and they need to lift this in that position for transporting to site and also to turn this valve to vertical position.

I called the manufacturer and asked. He was helpful and told me how they have done it in the past. Basically they just used 2 lifting eyes and choker on the pipe connected to the valve.
Don't know why client just don't call the manufacturer.
I believe they also want a lifting plan drawing that my company can produce.

Now since I wont be using the all 4 lifting eyes on some lifting instances, I want to protect myself by adding a disclaimer on this drawing.

Can you comment on this disclaimer:

Lifting plan drawing is just for recommendation.
Contractor must verify with manufacturer if the valve is being lifted on locations other than on four (4) lifting eyes of the valve.
Engineer of record is not responsible for damage during lifting.

 

[TehMightyEngineer]

Sounds reasonable to me. Are you being paid extra (or was it in original scope) for this plan? Also, how heavy is this valve?

Professional Engineer (ME, NH, MA) Structural Engineer (IL)
American Concrete Industries

http://www.americanconcrete.com

 

[MotorCity]

There is more to a lifting plan than meets the eye, be careful. Are you concerned about lifting in adverse weather? What if they use a crane different than what you assumed? Are you concerned about the soil pressure below the wheels or tracks of the lifting equipment? What about overhead clearances or power lines? I would make it very clear what is or is not included in your scope.

It seems like a simple, small lift. But the contractor is asking you for a lifting plan for a reason. He/she may not have experience lifting such pieces and wants something/someone to blame if he screws something up. The fact that he asked the engineer for lifting a valve is a red flag in my mind.

 

[SlideRuleEra]

I prepared a post that has the same thoughts that MotorCity expressed. Rather than saying it again, will second MC's post with a star.

http://www.SlideRuleEra.net

http://www.VacuumTubeEra.net

 

[delagina]

Valve is just around 30 kips and it will not be lifted above a building.
It is going to be lifted down around 10' below ground.
I think client just want lifting drawings because I've seen from previous project lifting drawings for small equipment.

This would have been very simple if valve was transported by manufacturer in vertical position but manufacturer said they can't transport it like that so they had to turn it horizontal.

 

[TehMightyEngineer]

Well, 30 kips is not a negligible load and lifting down into a hole may be risky because your capacity in the crane goes down the lower you go. Thus, if you overload the crane/ground the load will drop into the hole uncontrolled and drag the crane over with it. I'd definitely want to know what kind of crane was being used to make sure there was plenty of extra capacity in both the crane and the supporting ground. SRE definitely has great advice in establishing limits on your scope, your note about "recommendations only" is a good idea and I might go further by explicitly stating that means and methods of the actual lift are the contractors responsibility.

Professional Engineer (ME, NH, MA) Structural Engineer (IL)
American Concrete Industries

http://www.americanconcrete.com

 

[azcats]

I know almost zero about cranes and lifting. That being said, why does the capacity of a crane go down if you lower and item below grade? Additional cable weight?

 

[TehMightyEngineer]

Sorry, should have been clearer; a smaller boom crane, or excavator being used as a crane, will often loose capacity as they go down to horizontal. These are the kind of cranes I have usually seen used to lift the smaller 15 ton loads. If you have a larger crane with a pulley system then you're entirely right that this isn't a concern. My overall point was knowing the type of crane does indeed matter.

Professional Engineer (ME, NH, MA) Structural Engineer (IL)
American Concrete Industries

http://www.americanconcrete.com

 

[Lomarandil]

Nowadays, it's not uncommon for an owner to require a stamped lift plan for a critical component -- so that might be all that is going on here.

I think it's reasonable to defer to the manufacturer for the requirements of safely lifting and tripping (that's the industry term for rotating from horizontal to vertical) their valve from the valve's point of view. That said, I wouldn't phrase my disclaimer the way you put it.

It's important to limit our scope and liability to our areas of knowledge and influence, but it's also important that we end up delivering documents to a client that end up being useful and meaningful. It gets easy to try to write our way out of this caveat and that circumstance, and forget why the client is paying us.

If you do end up providing a lifting plan, I want restate the importance of the factors MotorCity pointed out. I'd say that proper equipment selection, proper ground preparation (either improved/competent bearing surface or spread the load) and utilities (protecting the crane from overhead power or protecting underground utilities from the crane weight) are the key factors for most lifts.

 

[delagina]

I know exactly what crane they are using. I've already did a lifting plan for them for this same valve. They just ask for another lift plan because the valve was delivered in horizontal position. The initial lifting plan I had was for vertical position of valve.

I already called the manufacturer and he told me how to lift this in this position. He told me to use only 2 lifting eyes and choker hitch on the pipe attached to the valve. That's where my slight concern is. Because I'm only relying on what the vendor said that choking hitch the pipe is ok although I don't see any reason to doubt him. They must have done this a hundred times.

The crane is way below capacity.

So what disclaimer is appropriate that also take into consideration that the client is paying me to do this lifting plan that I agreed to do.

 

[Lomarandil]

In my opinion, you either need to be willing to own it (and document what the vendor told you in case anything goes sideways)

Or show your best attempt and have a disclaimer noting:

"The integrity of all lifted components are the responsibility of the component manufacturer. Coordinate pick points, rigging details and lifting or tripping procedures (as applicable) with the manufacturer. If details vary from what is shown on this plan, coordinate changes with the lift plan engineer."

Or something like that.