Trig points - a general discussion

[Richary]

Personally I would suggest they should be archived if the trig points aren't there. But that's just my opinion. And I would still have no trouble with you claiming the FTF (and only find) for going up there and finding out. If you got a photo with the original base of it then that's probably fair.

Just my opinion though and other's mileage will vary of course.

[landau351]

Just throw some fuel on the flames.

These are in the database and have been since '09;

http://geocaching.com.au/cache/tp5254
http://geocaching.com.au/cache/tp5275

The following one is interesting. No metal structure at all, but there is a rock cairn. It would be visible from a distance but not entirely accurate as you cant identify the actual survey marker location from anywhere other than being on top of it.

So is this a trig?
http://geocaching.com.au/gallery/cache/tp5321

Now this one seems to be housed in the same metal frame as the one I logged, but I assume this one is (without any visible quadripod at all) a trig ??!!??
http://geocaching.com.au/gallery/cache/tp5402

This illustrates the confusion c@w mentioned.

[oz lurker]

Personally I would suggest they should be archived if the trig points aren't there. But that's just my opinion. And I would still have no trouble with you claiming the FTF (and only find) for going up there and finding out. If you got a photo with the original base of it then that's probably fair.

Just my opinion though and other's mileage will vary of course.

Yep, that's kind of what I thought at first, but then there are the 'on top of water tower/tall building etc ones that cant be reached but can sort of be seen sometimes, so I ended up just going with the flow and claiming them. A bunch of the trigs along the Eyre Hwy on the nullabor plain are on their last legs with graders etc taking them out partially if not fully, so I don't know where we'd go with archiving those. I mean my version of trashed may be different to someone elses and those trigs sure did break up that long drive.

I guess I've come to the conclusion that if I can find 'something' that's not natural bang on GZ, then that is better than nothing. I don't think geoscience Australia will be maintaining these trigs for us which would resolve the problem

[Tuena]

My 2 bobs worth.

If Geoscience Australia say its a trig station then it is regardless of whether there is a beacon or not. Those trig stations that were down loaded by GCA on 1 Sept 09 are just that.

If you decide to add a trig station that doesn't look like a Trig station then you need to properly identify its name. No point guessing. I can't find a record of Ben Cairn or Moyarra by doing a search of Geoscience Aust so those are probably just survey markers. Mt Baw Baw certainly looks like a trig station but is not listed on Geoscience Aust.

Trig station names often bear no relationship to their location. I found one near Currarong that was called Merimbula which is hundreds of miles down the coast. I've added a dozen or so & all bar one has been identified via topographic maps or a name plaque on the side of the trig. The one I guessed was to difficult to approach. I could identify it by purchasing a topo but ....

[Yurt]

The names are rather odd. From Hornsby (Sydney) north I've spotted a heap of them on old parish maps. They nearly all have girl's names like Millicent, Barbara, Lucy, Ethel, Poppy and so forth. They generally appear as a dot inside a triangle with the name in a largish sized font next to them and the elevation/altitude. Usually you can find these same names still in the Geoscience database but with useless coords (accuracy wise). It's been great fun to try and work out where they might be now matching topographical features on Google Earth and Maps and Nearmap. Sometimes you can even spot the trig on Nearmap or GE. We've tracked down quite a few of these locally and published the trigs if there is evidence.
We've more or less concluded that if there's no real structure of a trig but there is a permanent marker with the trig name then it's a trig. Either that or something else that refers to the trig name like a memorial. There are a few in the database that are only permanent markers now so probably don't really 'qualify'.

Another thing I've seen on certain old maps is a dot inside a circle with a name. These are usually in more remote areas and my feeling is that they are probably cairns rather than trigs but I don't know. Should look them up on Geoscience too.

Often the old maps have a trig marked on them in one position and now there's a trig nearby on a water tower. It's hard to know whether they should take the same name. Anyone with access to the top of these water towers to look at the trigs? Be nice to know if they have plaques.

[pjmpjm]

Often the old maps have a trig marked on them in one position and now there's a trig nearby on a water tower. It's hard to know whether they should take the same name. Anyone with access to the top of these water towers to look at the trigs? Be nice to know if they have plaques.

Thanks very much for the interesting update, Yurt. As you know, there are still some trig mysteries to solve to the north of Dural and I hope to get up there in my new 'GeoBuru2' in the months ahead.

Access to the top of water towers to look at the trigs? Now that's right up my alley! Would be happy to know (perhaps via a PM) what's possible. Anyone?

[Zalgariath]

I just found a Trig (The Concrete Kind, with Plaque) here in England! .... now. Should I list it? hahaha

[caughtatwork]

I just found a Trig (The Concrete Kind, with Plaque) here in England! .... now. Should I list it? hahaha

Yes, why not?
GCA has no boundary discrimination.

[Zalgariath]

I looked on opencaching.co.uk, but they dont have a Trig section... so I'll put it up here haha

[Trigg-A-Nomics]

If Geoscience Australia say its a trig station then it is regardless of whether there is a beacon or not. Those trig stations that were down loaded by GCA on 1 Sept 09 are just that.

If you decide to add a trig station that doesn't look like a Trig station then you need to properly identify its name. No point guessing. I can't find a record of Ben Cairn or Moyarra by doing a search of Geoscience Aust so those are probably just survey markers. Mt Baw Baw certainly looks like a trig station but is not listed on Geoscience Aust.

I'd certainly agree with this. I don't think that historical Trig points should be archived just because the metal structure has been vandalised or removed.

That being said, there still needs to be something there for you to find.

After reading Len Beadell's books I think we are probably one of the few communities who will maintain links to these little points of history.

Personally I would even expand the list to include survey marks. If someone, somewhere has used it as a reference point or marked it on a map as such and there's still something for me to find then it's a Trig point.

YOMV (Your Opinions May Vary)

[rogerw3]

While I would love to see Permanent Survey Markers as separate caches, it might prove impractical as in NSW alone there are over 300 000 of them an increasing all the time, unlike Trigs they are constantly used, well most of them anyway!
I have no idea how many you would find across Australia but I bet it would be 7 figures.

[Kerry]

Personally I would even expand the list to include survey marks. If someone, somewhere has used it as a reference point or marked it on a map as such and there's still something for me to find then it's a Trig point.

Trigonometrical stations (some might also call these "Trig points") and straight survey marks (PSm's, BM's etc) are something quite different and should be confused as being similar.

[landau351]

Personally I would even expand the list to include survey marks. If someone, somewhere has used it as a reference point or marked it on a map as such and there's still something for me to find then it's a Trig point.

Trigonometrical stations (some might also call these "Trig points") and straight survey marks (PSm's, BM's etc) are something quite different and should be confused as being similar.

OK, If Trig Points are the actual disk with Trig Point stamped on it then Sugarloaf (http://geocaching.com.au/gallery/cache/tp5298) is not a Trig point;

I know it was used as a Trig point for building the reservoir, but it is still only a Survey Mark that happens to have a quadripod above it. Check the gallery to see many photos of the Survey Mark.

As an analogy;
I can drive home a nail with a shifting spanner but that doesn't make it a hammer.

Would this be a fair assessment?

[ST_7]

Just throw some fuel on the flames.

These are in the database and have been since '09;

http://geocaching.com.au/cache/tp5254
http://geocaching.com.au/cache/tp5275

So is this a trig?
http://geocaching.com.au/gallery/cache/tp5321

Now this one seems to be housed in the same metal frame as the one I logged, but I assume this one is (without any visible quadripod at all) a trig ??!!??
http://geocaching.com.au/gallery/cache/tp5402

My thoughts & observations on the "is it a trig" discussion.

In Victoria, if it has a plaque with "Geodetic Survey Victoria - Triangulation Station" with a Triangle in the middle, it's a trig. Beacon or no beacon it's still a trig.

http://geocaching.com.au/gallery/cache/tp5321 Mt Baw Baw - This has the 'Triangle' so it is definitely a trig. It also has a cairn. State Survey Marks do not have Cairns.

http://geocaching.com.au/cache/tp5254 Ben Cairn - This is a trig as it has "Ben Cairn" stamped on it. State Survey Marks are identified with numbers eg. PM 123. Trigs are almost always given names. The exception being some Royal Australian Survey Corp trigs eg. H 151, E 520, G 123.
But why does it have a "Survey Mark" plaque? My Theory is that because it is a "50 pound penalty plaque" that it may predate the "Geodetic Survey Victoria - Triangulation Station" plaque???
If you suspect a "Survey Mark" plaque is a trig, look for 'witness posts' (GI pipes) or 'reference marks' (brass rod or star picket in concrete, or a hole drilled in rock)
anywhere for 1-10m from the plaque. Example http://geocaching.com.au/cache/tp5485

http://geocaching.com.au/cache/tp5275 & http://geocaching.com.au/gallery/cache/tp5402 These are not trigs. They are State Survey Marks.

OK, If Trig Points are the actual disk with Trig Point stamped on it then Sugarloaf (http://geocaching.com.au/gallery/cache/tp5298) is not a Trig point;

Technically this is not a trig. To me, it looks like during construction of the dam, 'Melbourne and Metropolitan Board of Works' have come along and made the ugliest Beacon you will ever see and put it over the State Survey Mark because it was already a known reference point. Thus making a 'trig'. They actually gave it a name too. MMBW 11338 'Lewis trig'. So in this case, I would have no problems with people claiming this as a trig.

[ST_7]

Often the old maps have a trig marked on them in one position and now there's a trig nearby on a water tower. It's hard to know whether they should take the same name. Anyone with access to the top of these water towers to look at the trigs? Be nice to know if they have plaques.

Yurt, have a look at this link. Unfortunately, there is no ID plate in the diagram for the 'type 10'.

http://www.lpma.nsw.gov.au/__data/asset ... er2009.pdf

Of course, this really doesn't prove anything. But a least now you can say "look, there's a 'type 10' on that tank" LOL