Bm Dnf Might Be Missing

[+bullionhunter]

I was out today and searched for BM LW3513. I Found the 3 ref. marks in good condition. I would like to log some kind of find for this but relize that the original bm was not found. I think it may have been dug up but not sure. I'm tempted to return to the sight at a latter date to justify my feelings. How do you other BM hunters feel about a log on this?

[+Black Dog Trackers]

bullionhunter -

 

It is excellent that you found the 3 reference marks for LW3513! However, since you haven't yet been able to find the station itself, it is not correct to claim "Found it", disappointing as this is. Using "Write note" as you did is fine, or selecting "Didn't find it" is fine too (that's the one I would use, since I only use Note for explaining why I didn't actually search although I was there).

 

I don't know if you know, but you can click on "view original datasheet" to see the exact distance and true-North bearing from the station to each of the reference marks. If you do careful measurements, you should be able to use this data on the 3 reference marks to pinpoint the station's position within a very few inches. (Note that the bearings are true-North, not magnetic North so if you want to use them, you need to visit the website that gives the difference between these norths for your space and time. With distances and 3 reference marks, you can get by without using bearings, though.)

[+bullionhunter]

Thanks. That was what I figured I should do. I think I'll go back and hunt around again sometime. I enjoy doing the BM so I think that I should bring a good measuring device as well. Happy hunting.

[+Black Dog Trackers]

Here is the site that will give you the declination. Click on Declination, then "Compute your declination".

 

Be careful of how you add and subtract the declination from the true bearing on the original datasheet to get a magnetic bearing to read on your compass.

 

There's also the bizarre situation where some surveyors used 0 degrees to mean South!

No way of knowing which it is for your PID. A casual look around on location will tell you, of course.

[2oldfarts (the rockhounders)]

bullionhunter,

 

If you have a good 'eye' you can line up the arrows on the RMs and see where they intersect. That is where you should find the BM. You might try using a probe in that spot or maybe a metal detector if you have one available.

 

Good luck,

 

John

[evenfall]

Billionhunter,

 

There is a lot of info here in the Forum on how to go about hunting these things, Feel free to take a look back!

 

Blackdog raised a point we discussed while back as well...

 

"There's also the bizarre situation where some surveyors used 0 degrees to mean South!

No way of knowing which it is for your PID. A casual look around on location will tell you, of course."

 

We worked that problem in this thread:

 

http://forums.Groundspeak.com/GC/index.php...wtopic=81352&hl

 

Now it is a really long thread but well worth the read, But for the sake of saving time, the lowdown on Geodetic azimuths, which is why those surveyors used Bizarre methods back in the day is in there, Just scroll about half way down and try picking it up from there. It is a very technical thread.

 

Looking at the datasheet for your stations, all the RM's were called out in the narrative in Cardinal directions, Not bearings, The Box score compares with the Grid Azimuth so if these had use the old Geodetic Azimuth at one time, it appears to have been corrected in the data.

 

LW3513'REFERENCE MARK NO. 1 IS A STANDARD DISK STAMPED

LW3513'HERRING-1937-NO. 1 WEDGED IN A DRILL HOLE, IN OUT CROPPING

LW3513'BEDROCK, ABOUT 2 FEET LONG AND 1 FOOT WIDE. IT IS 73.00 FEET

LW3513'NORTH OF STATION.

 

LW3513| CB7769 HERRING RM 1 22.244 METERS 00547 |

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

 

REFERENCE MARK NO. 2 IS A STANDARD DISK

LW3513'STAMPED HERRING-1937-NO. 2 WEDGED IN A DRILL HOLE, IN OUTCROPPING

LW3513'BEDROCK, ABOUT 3 FEET LONG AND 2 FEET WIDE. IT IS 64.10 FEET

LW3513'NORTHEAST OF STATION.

 

LW3513| CB7770 HERRING RM 2 19.542 METERS 07009 |

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

 

REFERENCE MARK NO. 3 IS A STANDARD DISK

LW3513'STAMPED HERRING-1937-NO. 3 WEDGED IN A DRILL HOLE, IN

LW3513'OUTCROPPING BEDROCK, ABOUT 4 FEET LONG AND 3 FEET WIDE. IT IS

LW3513'79.68 FEET SOUTH-SOUTHEAST OF STATION.

 

LW3513| CB7771 HERRING RM 3 24.296 METERS 16923 |

 

I concur with everything based off grid N Azimuth, and not a possible Geodetic azimuth of South. This First order Station was primarily surveyed using a Bilby Tower.

 

LW3513'HEIGHT OF LIGHT ABOVE STATION MARK 13.4 METERS. First Time.

LW3513'HEIGHT OF LIGHT ABOVE STATION MARK 18 METERS. Second Time.

LW3513'HEIGHT OF LIGHT ABOVE STATION MARK 60 FEET. Third Time

 

And the fourth time... LW3513'THE RIDGE ON WHICH THE STATION IS LOCATED IS NOW HEAVILY WOODED,

LW3513'AND THE USE OF TOWERS OR SELECTIVE CUTTING WOULD BE NEEDED TO USE

LW3513'THE STATION MARK.

 

To convert meters to feet, divide the number of meters by.3048 to get feet. Reverse the bearing to the RM's 180 degrees to find your way fromm the RM's to the Station Mark

 

Enjoy!

 

Rob

Edited April 4, 2005 by evenfall

[holograph]

If you have a good 'eye' you can line up the arrows on the RMs and see where they intersect. That is where you should find the BM. You might try using a probe in that spot or maybe a metal detector if you have one available.

If the team who set the RM's were't drinking at the time. LY2619 in my neighborhood had me looking in the wrong direction for a while, and unfortunately, the description didn't have reference mark azimuths. The yellow arrow shows where the station actually is in relation to the RM.

 

[+bullionhunter]

Thank You all. I got some good reading to do. I did try the arrows on the rm's but still sent me to same area. I like the probe and maetal detector idea. Wish I had a metal detector. Thanks again. bullionhunter