Haven't we all heard this tune before?
The lowballer gets the job, well, because he's the lowballer and the first thing he does is claim that the control is out; so he'll have to re-run all of it, causing a huge change order from the get go.
Same old song and dance; bid it low, make it up in change orders.....
Didn't Bruce Small post something similar a few months ago? Something about the staking surveyor claiming no site benchmark and needing to run one in from a long ways away?
Meet with the client and the contractor; show them that the control you set is within .02'-.04'; show them the error of the staking surveyors ways and tell them to send your bill to the offending surveyor....:snarky:
Actually- all written correspondence regarding this needs to be stapled to a letter for the Signature of the Appropriate DOT official having the surveyor removed from the project under the competent workman portion of the standard specifications.
Here's the Spec. recently used to remove someone from Projects at this latitude...
Then that all needs to be forwarded with a complaint to the BOR of the State. The DOT's could do alot to address these type of issues....unfortunately...
:-/
Kent,
I gotta side with you on this one. What is wrong with a surveyor checking control? Isn't that what a surveyor is supposed to do?:-S
Dave
The lowballer gets the job, well, because he's the lowballer and the first thing he does is claim that the control is out; so he'll have to re-run all of it, causing a huge change order from the get go.
Same old song and dance; bid it low, make it up in change orders.....
That's the odd thing, I don't think he even understands that much about it!!
But one thing's for sure, the control isn't changing, I just feel sorry for the project manager that is going to have to babysit the entire construction if this is the start of it, imagine how it's all going to work out? How do you explain the obvious?
Moe,
"The DOT knows that, I knew it wasn't going to check to OPUS, anyone that's a surveyor should know that."
I guess I don't know anything about surveying, then. Why doesn't it check with an OPUS number? If another surveyor says he doesn't agree with your numbers, instead of getting angry, you should be asking him questions and figuring out a solution.
Dave
Once you have a local coordinate base, you can get there with OPUS
Not really! At least I can't see how correctly. I suppose you could do some odd kind of calibration, but these points come with Latitudes, and longitudes provided along with ellipsoid heights, geoid heights, elevations, state plane and surface coordinates. So OPUS shouldn't be used at all. Ever!!
If you go putting OPUS numbers on these points it would be a mess and for gods sake why would you, just take the file and set up on them, no calibration please and don't change a single number. There's no need for it.
The surveyor should check the control and make sure it is good. That is his job, and that is more than likely in his contract to do. If he is saying that all of the control is wrong because he checked it...and it isn't, then that surveyor might be incompetent.
I think you have identified the problem and I wouldn't necessarily fault the other surveyor so quickly. If the contract says I'll be given NAD83 to work with, then it is NAD83 at the date of the contract, unless otherwise specified. If it takes more work to tie into and check and maybe convert from an earlier epoch then it's going to cost more. Maybe it's the DOT or maybe it's the construction company. But I'm thinking this other surveyor is of the opinion they were not provided with what the contract specified.
Tom,
Possibly, but what if he's right? I just can't understand MM's anger. MM even says his points don't agree with an OPUS solution. WHY NOT?
Dave
I guess I don't know anything about surveying, then. Why doesn't it check with an OPUS number? If another surveyor says he doesn't agree with your numbers, instead of getting angry, you should be asking him questions and figuring out a solution.
Well firstly they aren't my numbers, I didn't set the control, I did check them and yes he should check them again when he started. The problem is he didn't check them, he put an OPUS number on them which was sure to be wrong and declared some kind of a problem. That isn't a check, he should occupy the control and go along the 10 miles and recover what he can and see if they check; using the lats, longs, heights, northing, easting and elevations provided in the control documents. The only thing we allowed to float were the heights, otherwise everything was spot on. Let me ask you: How could OPUS or CORS which wasn't available (the near CORS points didn't even exist) at the time the original control was run check? What would make you think it would, could or even should? Why do you think that? It really, really confuses me that any surveyor would think that.
If the contract says I'll be given NAD83 to work with, then it is NAD83 at the date of the contract, unless otherwise specified. If it takes more work to tie into and check and maybe convert from an earlier epoch then it's going to cost more.
Yes you are absolutely correct. If that was what happened, but that's not how it works.
DOT sends out control spread sheets with: state plane coordinates, surface coordinates, ellipsoid heights, geoid heights, latitudes, longitudes, the state plane zone and that its NAD83 and in this case 1993 EPOCH, included is the combined adjustment factor and how it should be applied. On the sheets are shown how the control was derived, static, fast static, RTK, leveled, and so on for each point. Also they show the computer program that ran the adjustments the HARN points used to adjust to control, their values at the time of adjustment and more than that, but you really don't need more. It's all there! Really this is so easy, why do surveyors fight it? I don't understand!
Again they can't check to OPUS and they aren't my numbers, why is this so hard to understand, why would you expect old control to check to OPUS? I don't understand your confusion. And I'm not angry, frustrated for sure, and a little scared about what surveyors are doing out there. Holy Smokes!!!!
MM,
Thank you for letting me know that OPUS is worthless. All these years I've been unwisely using it! If only I'd talked to you, you could have set me straight.
I guess I'll just go back to what I know. (Where do you want me to pound that hub in?)
One of the best surveyors I know said, "Surveying is nothing more than a constant series of checks." If a total station traverse didn't agree with an RTK traverse, and a static observation put through OPUS didn't agree with either of those two, wouldn't you want to know why? Does it really matter what tool was used as long as the measurements were carefully and competently made? I just don't understand why you want to hang that "incompetent" surveyor that sought to check the locations of control he will be using.
Dave
Good relative positions is what they are concerned about, not the numbers.
Sigh!
Not worthless for everything, but sure would be for this application, but you know that, your just pulling my leg;-)
Yes exactly.
Understand though, engineering design plans, culvert, bridge locations, ties to intersecting roads, property corners and on and on were all derived from these control points. So use them as they are given to you, just imagine what a mess you would have if you held the OPUS values and were .6' vertically off. That's a lot of dirt over 10 miles of highway. And I've been through this exact same mess with a county road so I know of what I speak.
Of course you may be right, and maybe you run into this stuff all the time. But you did say the construction company got the contract, and then the construction company retained a surveyor. Isn't it possible the construction company does not know the difference and their contract with the surveyor they hired mistated things, and/or did not supply the documents for review before bid? Maybe the construction company realized after the fact that it was going to be a problem with their machine control and intentionally left out needed information. I have found that clients do not supply the necessary information no matter how hard I drill it into them that I need "everything" they have, no matter how insignificant it may seem to them. Invariably they do not supply it all.
There's a lot of negative comments about surveyors by surveyors in this thread. Seems to me there are no shortage of others who will denegrate us. I'm going to give the benefit of the doubt to the surveyor first. But if it was the surveyor who screwed up, then of course they need to eat the extra cost, or learn what to do, or hire someone who does. If that's the case, and I were you, I might offer my services to help them complete and help them learn what they did wrong. If it's truly a lowballer who doesn't know what they're doing, educating them can only help matters in the long run.
I know one thing, I would be scared to death to have him surveying on my job. I assume you have long term design projects and have to recover old control to match design, it really isn't that big a deal, but.........seems to be a difficult concept.
I just don't understand why
> I have no clue what you're talking about, OPUS has nothing to do with the project control. The project control was set using local HARN control (NAD83, 1993 EPOCH), which by the way is clearly stated on the documents given to everyone; if he wanted to check to the HARN, then he should have occupied the HARN monuments and ran static to the project control monuments (but that would have been work-since they vary from 30-70 miles from the project) using the given coordinates of the HARN monuments.
So, if you were in the other surveyor's role, it wouldn't occur to you that the easiest approach to verifying the project control is to determine the NAD83 coordinates of the control points and compute the transformation that relates them to the Epoch 1993.0 coordinates that your office generated? The advantage to that approach is that even if all of the project control points get destroyed, you're only a few good OPUS solutions plus transformation away from being able to carry on.
I'm kind of surprised at the confusion. There are numerous flavors of NAD83 even through the history of OPUS. Those various realizations vary. HARN derived coordinates determined in 1993 from a young CORS network will not precisely match OPUS derived coordinates in 2013. Regarding previously established control, the guy who built it made the call to go with HARN. So it's HARN. OPUS may be newer and shinier but that's not the point. The control is only wrong if the points exceed relative tolerance. OPUS could be used to check relative accuracy but this guy is probably just comparing absolute coordinates and seeing the difference in HARN and OPUS.