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A serious question for a change….
Posted by jitterboogie on January 11, 2022 at 4:40 pmWith the Advent of of all the newest bleeding edge technology, is anyone using or developing workflows with the R12i to dip manholes and see what the results are yet?
I’m planning a few test runs on some not too deep storm grates to see what the real limits are, because this could be a great augmentation of the leany thingy they tout so highly….(ok so maybe not toooo serious)
If this works, I might forgive them for not doing anything to remediate the low receiver battery issue that sometimes destroys an entire day of data collection(really, still in the year 2022? cmon… Lets go Trimble!!!!)
rough idea is to use rod extensions at known lengths to get to the inverts, and see if the IMU can offset accurately enough to speed up the process. will be interesting.
chris-mills replied 2 years, 3 months ago 12 Members · 15 Replies- 15 Replies
Tried scanning manholes. It was just too much time and effort to use routinely. If my purpose had been to document the precise condition and configuration of the MH it might be worth it, but as a means of getting simple measure downs it is just too time consuming.
@norman-oklahoma
scanning them will become a thing eventually, the GeoSlam people are trying hard to make it happen. Either way, dropping an expensive device into a no go in there location isn’t worth the financial risk to lose for sure.
I must be the only surveyor who doesn’t mind a day of opening and measuring structures.
I really don’t think that it’s all that difficult by measuring with the 25′ rod.
It’s not about the topic or nastiness, just work flow and accuracy.
The slop in a invert measurement is huge, even with a pipemic, and I just want to see if they have any ideas for the use in this manner.
There’s no question being outside for a nice day of dipping manholes beats the office except for the traffic, and the occasional 60in SAN main flowing about 4ft deep…that’s a better day to be in the office.
I don’t mind popping manholes or basins. The rod measurement method is probably the best method we have at this point. I don;’t see how you can scan he structure if there is water or effluent flowing through the pipes.
The R12i would be just fine for inverts if you can keep the rod tip stable enough while measuring. Since the IMU needs some movement to maintain a heading solution, that might be a bit tricky.
The other piece is making sure that your pole alignment is decent – a 25′ rod rarely stays perfectly straight when angled.
But assuming you are tracking with a decent RTK+IMU solution and able to keep the rod mostly straight, the R12i would likely be a decent compromise and probably at least as good as the standard manual method. At the very least it would cut down on blown manual readings.
The biggest benefit, IMO, would be that with collection software one could use a custom feature code library specifically for inverts, with codes and attributes that could be pushed into CAD and automatically generate labels. Manually generating invert labels from paper field notes takes a lot of time, and there’s a lot of room for fat-fingering, transposing numbers, and mistaking directions. Would probably cut down 80% of the office time.
(To answer the question, no we haven’t tried this routine yet. Being a corporate survey outfit, we can barely get crews to be consistent in labelling their job file names and taking the minimum of field notes…)
“…people will come to love their oppression, to adore the technologies that undo their capacities to think.” -Neil PostmanWe had to get an invert in a main flow line that was not far from the treatment plant, When we opened it, the odor was eye watering, and the flow was so strong it was hard to even insert the rod to the bottom. Nearby there was a new home under construction with the framing underway. Soon enough that noxious greenish tinted air drifted over to the framers who began to drop like flies (very vocal flies). It still makes me smile just remembering that we weren’t suffering alone.
@gordon-svedberg I once had a co-worker who hated popping manholes. He’d be 35-40 feet upwind taking notes and be gagging because he said he could still smell it. We’d just laugh and start describing the scene below especially if it was a nasty one. He puked till there wasn’t anything left and then went to dry heaving. Too funny.
In all honesty you’re one of the people that I was expecting a good answer from and yeah that’s the reason that I’m trying to figure it out because no one’s tried it here but it doesn’t mean it can’t be done.
Regarding the multi-section rod slop I’m sure there’s plenty of older kind of beat up carbon fiber rods sitting around that can be utilized and it sure as hell isn’t any worse than the multi-section crain rods.
I’ll try to keep good notes to see if it works because of the workflow part of it’s what I’m trying to get at especially if it’s going to be deployed across multiple groups of people.
@gordon-svedberg
Yeah, our rule of thumb was if it was 3 ft or larger in the main was flowing full speed at the plant close to where you were talking about we didn’t dip it at all I just went from plans because it’s clearly flowing there’s no reason to a destroy the rod or cause problems if the rod gets pulled out of your hands and stuck at the grate down at the bar screen.
The 20 ft storm main I opened once was flowing about 4′ deep and my chief looked in and said “If you drop my new rod into that giant pipe I’ll make sure you get fired”
So estimated for the depth and moved on
Again. Flowing full speed isn’t a condition for dipping.
I do the same thing. It’s faster and easier. ????
- Posted by: @jitterboogie
In all honesty you’re one of the people that I was expecting a good answer from and yeah that’s the reason that I’m trying to figure it out because no one’s tried it here but it doesn’t mean it can’t be done.
Regarding the multi-section rod slop I’m sure there’s plenty of older kind of beat up carbon fiber rods sitting around that can be utilized and it sure as hell isn’t any worse than the multi-section crain rods.
I’ll try to keep good notes to see if it works because of the workflow part of it’s what I’m trying to get at especially if it’s going to be deployed across multiple groups of people.
Next, build a pipe network for the asbuilts.
-All thoughts my own, except my typos and when I am wrong. I’ve been thinking about using a remote point setup with my MS50. The gun shoots two prisms on a pole a known distance apart with and a known distance from the end. I just need a little time to give it a try and a couple of section of aluminium rod. Sounds easier to clean than the old fiberglass rod.
I’m sure I commented on something similar a couple of years ago. If you are sticking anything down a sewer where you might not be able to recover it should the worst happen, it needs to be CHEAP. Your insurer won’t accept the cost of anything expensive heading downstream.
It should be easy to keep a pole near enough plumb (its called a bubble) and to get to the pipe invert we have a set of flat metal strips which can screw into the bottom of the rod to form an “L” shape. Different lengths to allow for inverts being offset from under the cover, 30cm. 50cm, 1 metre, 1.2 metre. Further offset than that and you probably aren’t going to be ab le to get a sight from the cover anyway. One advantage of this is that pipes at high level under the cover slab can be measured using one of the longer offsets (just as long as you can see (with a mirror) or feel where they are with the end of the strip.
Yes, there might be a slight inaccuracy of the odd cm. or two but if it is that critical then how about checking the full invert length of all the pipes. The main channel is normally easily accessible (yes, except when there’s a sump).
Final advantage – the poles that do down the sewer are separate from the one under the GPS which you are going to have to carry and use for the rest of the day.
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