The DeWalt DCH263 I have is excellent. Drill holes around in a square spade shape with long bit. Flick off the seal layer and then swap to the chisel bit to get through remaining layers of gravel.
I went for biggest one on 18v/20v platform so could use other range of tools also rather than higher voltage systems which have more limited skins.
This guy tests a bunch of them: https://m.youtube.com/@BoltahDownunder
About four years ago I found a 4 pound hammer with a wedge axe bit on one side. I could chew through eight inches of asphalt in under a minute. Best tool I'd found for the job.
Last year I replaced that hammer with a 30 something party chief built like a tank. I can watch him tear through asphalt, clay, and even soft rock without sweating a drop.
Excuse my ignorance but why do you need to dig through asphalt so frequently that you need a special tool for it? Are your monuments in the road for whatever reason?
In Australia, the worst cases I've seen is someone making a new driveway or footpath over a buried pipe or concrete block. Then it's a matter of how much do you need that mark and how much of a headache it will be to dig under the concrete to find it. Legally, you could go through the concrete but I haven't heard of any surveyor actually doing that.
@minbarwinkle Many of our roads follow lines of our public lands survey system or subdivision lines. There are countless controlling monuments buried in intersections. They must be recovered to do a proper survey.
Policies are changing in some jurisdictions to allow reference monuments in place of those in the street. My life will be over before we make much progress. The alternative is placing a 'well casing' over the monument for easier access.
We do a lot of road improvement work, which requires a diligent search at every corner of record. In some cases that's every three hundred feet from one end of town to the other. If the town is old you could be digging several feet through decades of overlays. Loads of fun on a 100 degree day...
I've heard you can really loosen hard pack, asphalt and even most rock by hitting it with your purse.
We do a lot of road improvement work, which requires a diligent search at every corner of record. In some cases that's every three hundred feet from one end of town to the other. If the town is old you could be digging several feet through decades of overlays. Loads of fun on a 100 degree day...
What about cars? Where do they go? We have a few marks in the road that were grandfathered in through various road widenings but they're usually in a box. If you're brave and quick enough and the traffic is not too busy, you can duck in there and get a shot, but technically you're supposed to stop traffic for safety reasons. I can't imagine digging through layers of asphalt and subgrade for a mark without getting in some kind of trouble.
What do you do once you find it? Does the intersection inherit a pothole courtesy of Surveyors Inc? Do you fill it up with concrete or put a box over it for the next guy? Sorry for the excessive questions, but what you're telling me seems a bit wild.
What do you do once you find it? Does the intersection inherit a pothole courtesy of Surveyors Inc? Do you fill it up with concrete or put a box over it for the next guy?
If the contract allows, I'll have a construction company install a valve box, but that requires a lot of advance planning. What I usually do if I've had to dig down more than a couple of tenths is tie out the point, backfill almost to the top with whatever I dug out, then finish the last couple of inches with some cold patch, bringing the point to the surface with a rebar or spike (depending on depth). If everything is tamped down well, it leaves a pretty durable finish.
What about cars? Where do they go?
In the middle of the busiest intersections there will be an area I like to call the "diamond of safety". An area where gravel and debris accumulates because cars never pass through it. That is where the monument, cased or otherwise, commonly is. Put out some cones and do your work.
I have dug up thousands of monuments in roads. Lately, I've come to appreciate a 3" hole saw on a hammerdrill. Locally, it is customary to set Mag nails in the road for new subdivisions where the lot lines intersect the centerline in the second to last course of asphalt. It is forevermore necessary to dig up the nails.
Locally, it is customary to set Mag nails in the road for new subdivisions
I find this disturbing.
If I cannot make the original monument accessible I do not set a mag or pk at the surface.
Two years ago I spent a week digging up monuments where the crew found mag nails. The originals were eight to ten inches down with a few over a foot. We found the same situation every few hundred feet for about three miles. The nails were out of position as much as a few tenths. While not earth-shattering it is inexcusable in this day and age not to do better. Leaving conflicting evidence behind is just poor practice. The nails ended up misleading the crew. Had we not revisted the originals would have been destroyed with no modern ties in place. Put a well in or reference it and remonument.
A few yrs ago, I tied into a PK nail, in a paved road. I recently tied it. It had MOVED about 3-4 tenths. And, it was under about 2" lift of pavement. It was a place near a stop sign. Where large vehicles would apply their brakes. I suspect the pavement was moving. I'm a believer in good monuments. Drive a monument down into the base of the road. PK's and Mag Hubs just don't seem to be attached to anything, but floating asphalt.
Nate
Simply put, MAG nails, especially those in asphalt or in sidewalk joints, should be considered temporary markers and not permanent monuments.
I want to recommend a particular pick. It's an Estwing Burpee Pick.
It's small, very good metal, and just about right for scraping around for many monuments.
If you google that, or I'm sure Amazon has them.
I got one from here:
https://www.ascscientific.com/products/estwing-burpee-pick?_pos=1&_sid=975c7a13b&_ss=r
It fits in my hammer loop, and hangs long enough to not get turned over easy, and it's not real heavy.
Nate
Here in New Zealand a nail in seal would only be classed as temporary.
We also masonry anchors drilled into concrete - usually in kerbs.
But our earthquakes have proven that these also are not stable.
Iron rods, like you americans use for boundary markers, or pipes driven into clay have proven to be the most reliable and stable long term marks that are easily installed.
Is your statement based on common practice or is there some statute law or regulation involved?
By common practice. The survey regulations we work under require:
"must be likely to remain usable and not be disturbed in the foreseeable future, and accordingly be—
(a) made of durable material; and
(b) set in stable material; and
(c) located in a suitable position."
and a nail in seal wouldn't meet all of those criteria.
Our (Torrens/recording) survey system also works differently to North America. We prepare two plans, a survey plan with all measured vectors, old/new traverse marks and permanent reference marks (masonry tap-in anchor in concrete, rebar/galv pipe buried in soil etc. in safe locations from future works) and then a title plan which has the old/new boundary vectors and boundary monuments shown (we use wooden/plastic pegs in soil, or disk's marked "boundary"). Bit more work but makes it easier for the next surveyor. The plans are prepared and submitted digitally since 2007. No physical plots signed and submitted here. As a solo operator I don't even own a printer or plotter and in 5 years have yet to need to run off to copy shop to print anything.
The legal precedent is boundary monuments control but in practice it is the traverse/PRM marks that prove the monuments are reliable and are what surveyors rely on (top of a 16mm rebar much better defined than a 75mm x 50mm boundary peg!).
You will need an SDS Max that has hammer only mode to use a clay spade or ground rod driver. Mine was working decently for frozen ground this winter.
Well, I bought one of these:
Milwaukee 2718-22HD M18 FUEL 1-3/4" SDS MAX Rotary Hammer ONE KEY Kit 2-Battery with two 12 AH Red lithium batteries, charger, and case.
Paid 958.11. It's HUGE. HEAVY. POWERFUL. I selected what I thought was the biggest, baddest, hole digger.
I suspect, the smaller one, 2717- with 1-9/16 capacity would have done it, for a bit cheaper.
It will really dig a hole though!
I will occasionally report back.
Nate