3D Scanning Manholes

Lately I've been using an AP20 tilt sensor together with candy cane style pole extenders to shoot inverts. Yields really accurate invert elevations.   These scans are super cool, but may be overkill in most cases.

@norman-oklahoma Are you getting pipe sizes just at the opening or do you add some kind of attachment to get further in?

Posted by: @totalsurv

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Are you getting pipe sizes ....

Using this scanning device will get you a lot more detail, no question.  Whether there is any need for such detail is another matter. There may be a niche.

Also of note is that an AP20 costs upwards of 5 times what this device costs. But the AP20 is something that will get a lot of everyday uses. 

Thank you Norman_Oklahoma and totalsurv. Certainly valid questions and comments. By all means, if using what is in your tool box gets you what you need, then you may not need to add other tools.  What we are finding is that there are a growing number of companies that are trying to capture the manhole or vault or other asset using 3D.  We believe this is mainly do to owners wanting to develop digital twins asset information. So more than just invert info. Many are using expensive equipment to try and do this. Our solution is another inexpensive option. Also, you can even put it on your AP20 pole! 🙂 

Posted by: @norman-oklahoma

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Posted by: @totalsurv

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Are you getting pipe sizes ....

Using this scanning device will get you a lot more detail, no question.  Whether there is any need for such detail is another matter. There may be a niche.

Also of note is that an AP20 costs upwards of 5 times what this device costs. But the AP20 is something that will get a lot of everyday uses. 

We would usually need more than just the inverts.

I really wish Trimble would catch up and produce something like the AP20. I would use it all the time.

Posted by: @totalsurv

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We would usually need more than just the inverts.

OK.  Why? What are you doing with all that extra data? I once worked for a guy who said that the equipment he bought didn't cost money. It made money. Explain to me how this device will make me money. How do I sell this data to my clients?   

Posted by: @dotproduct

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trying to capture the manhole or vault or other asset

I see some value in capturing the interior of vaults. These are of various sizes and contents.  Most manholes are consistent sizes and forms. 

Posted by: @norman-oklahoma

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Posted by: @totalsurv

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We would usually need more than just the inverts.

OK.  Why? What are you doing with all that extra data? I once worked for a guy who said that the equipment he bought didn't cost money. It made money. Explain to me how this device will make me money. How do I sell this data to my clients?   

Engineers need to know pipe sizes for capacity. I wasn’t advocating scanning manholes. I was curious as to your workflow with the Ap20 but that seems to have been misunderstood.

Posted by: @totalsurv

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Engineers need to know pipe sizes for capacity.

We generally rely on as-builts for pipe sizes. Back in the day we would climb down the ladder and measure. That ended some time back.

I confess that I have not read the article yet, but my experience with scanning would suggest that you will not be getting a valid reading on the IE of flowing MH.  Nothing better than a thin rod to get through the tampons, toilet paper and brown trout and give you a physical reading. 

If you create a point cloud for the interior of the manhole. the invert can be derived from the portions of the pipe that are exposed even when there is flow in the manhole.

I've done a few sewer asset inventories where that would have been useful and would likely have made us money. Even with a big mirror or high lumen light, it was difficult to assess deep MHs. 

Our engineers use the scans for visual confirmation of the structure condition and pipe sizes. It also is useful for non-sewer manholes (ie. electrical, water, or communication). We use them as a rough check on our disto shots from the lid for sewer structures. When we want them geo-referenced, we use Dot3d with an iPhone. When we just want the scan, we use 3d Scanner App. A scan takes about 3 minutes if you do not care about geo-referencing. Since we are usually taking them in the roadway, we would rather take a digital "copy" of the structure with us.