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Amygdaloid

Triangulation Station with unique pemanent tripod structure

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If you have ever been to Houghton Michigan, you may have caught a glimpse of one of a series of strange looking 3 legged steel structure with a pole mounted on top. The legs are arched T section steel  that are mounted to substantial concrete pylons. The pole on top is a substantial steel pipe of various lengths, Centered underneath the center of the pole you may find a 1 1/2" pipe with a pipe cap, or possibly a steel rod set in a drill hole (or maybe just the drill hole) in the bedrock. The arched lower portion of the structure is generally quite tall - you can easily walk underneath it. I've been pondering the origin of these since I went to Michigan Tech in surveying in the 80's. We even did a project near one in west Hancock during summer field camp. I'm sure I asked about them at the time, but if I received a detailed answer I've long forgotten what it was. I've seen 6 of them in the Houghton/Hancock area over the years since my college days, although 2 of those have been lost to construction over that time span.

I have several old Michigan Tech yearbooks from the early 1940's, and 2 of them have collections of photos from Surveying summer camp. In a couple of photos you can see either a complete tripod in the background or a portion of a leg and the distinctive concrete pylon it is mounted on. My father in law also grew up near the west Hancock Tripod in the 50's, and remembers seeing them as a boy and associating it with Michigan Tech.

Last week I was looking at my map of the NGS stations in the Keweenaw in prep for a long Labor Day weekend in the area, and clicked on a station I had never visited before that was categorized as a pipe cap and named "MCM T 107 MIGS 1934". I like hunting up the old Michigan Geodetic Survey (MIGS) marks, so I pulled up the data sheet for SG0237 to find this station description:

 SG0237'DESCRIBED BY MICHIGAN GEODETIC SURVEY 1934 (CMC)
 SG0237'NEAR COUNTY INFIRMARY IN SEC. 28, T. 55 N., R. 34 W., 80 PACES
 SG0237'N. 60 DEG W. MAG. OF THE ROOT HOUSE, IT BELONGS TO THE TRIANGULATION
 SG0237'SYSTEM OF THE DEPARTMENT OF MINING AND CIVIL ENGINEERING OF
 SG0237'THE MICHIGAN COLLEGE OF MINING AND TECHNOLOGY AND IS SURMOUNTED
 SG0237'BY A SUBSTANTIAL STEEL TRIPOD.  THE CENTER IS MARKED BY A CENTER
 SG0237'MARK IN THE CAP OF A PIECE OF 1-1/2-INCH IRON PIPE SET IN
 SG0237'CONCRETE, STAMPED MCMT 107 1930.

This was the first detailed documentation I have seen on the origin of one of these tripods with a date and tying it directly to Michigan Tech (or Michigan College of Mining and Technology, as it was called back then). There wasn't a geocache entry for this mark, so I had to go see for myself if this was the same as the mysterious tripods I've seen for so long. The station is located behind a gravel pit in the high ground west of Houghton. The gravel pit is posted, so I had to hike in the long way around to the back to avoid that, but much of the area is old farm fields so I was able to get there without to much difficulty. I found the tripod right where the coordinates indicated, located in a small clump of trees. The tripod is in great shape, and the cap is in place, although only the faintest indication of stamped lettering is present.

Now I'm wondering how many more of these may be located out of sigh in remote locations like this? What was the purpose of this triangulation system? The USLS had done triangulation work in the area in the 1870's, so perhaps this was just densifying the control along the Keweenaw waterway, or in support of the local mining industry? Or was it just purely for educational purposes? And what about these tripod structures? I don't see how they could be used like a traditional triangulation tower, they aren't really very tall and I don't see any way they could have supported a platform of any kind. I'm guessing a signal light was mounted on top of the pole, and there was visibility between them at ground level back in 1930. Has anyone seen anything like this anyplace else?

I think I will have to go to the Michigan Tech Archives on my next visit to see what I can find out now that I have a date and a college department to go on. If anyone has any information on this topic (I'm looking at you, Z15:)), please let me know.

Photo of tripod at SG0237 and the pipe cap.

. 59aee41d2052d_Tripod1.thumb.JPG.856817907c4971ddaf5be8577bfc8a30.JPG59aee42b73cd5_TripodCap.thumb.JPG.c4342bd10027fff8798450e2771349b7.JPG

Here is a photo of the tripod on a high point in Houghton just north of Sharon Ave and east of Portage St. Since I took the photo below It has been hit by something large and one of the legs is bent and the concrete pylon has been dislodged from the bedrock, but it's a lot easier to find this one since you can see it from the road.

59aee4351e9a3_Tripod2.thumb.JPG.cea285f30c41b9c1dbb4f774878f8300.JPG

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It was a teaching aide.  They were constructed so students could set up on one point and site the tower at another point.  Way back in the late 1970's when we were (MDOT) surveying for M26 relocation from the bridge we had in our possession a big old map of these stations.  The party chief, JP Smallwood (deceased) lived in Houghton, an CE and LLS for the state DOT for over 40 yrs, also once taught at MCM back in the 50's, knew all about this tech triangulation system.  I recall have the big map laying on the drafting table in our office trailer.  Matter of fact back in the day the a Prof. at MTU (Prof. J Service)  was in charge of Michigan Geodetic Survey work in the area. 

The Survey dept at MTU would have this info, not the archives.  I have no idea who runs that dept now. All the ones I know have died or retired, Chuck Hein RLS from Calumet (deceased), ID retired back to Sri Lanka. 

http://www.mtu.edu/technology/undergraduate/surveying/faculty/

 

This one is off Sharon Ave near the Mineral Museum and the MTU CORS (MDOT) station.  There was one by the water tank on Ingot st, up from scenic lookout on US41 1/2 way up Quincy Hill, another used to be up at the fair grounds.  I say use to be because I have not been by them in years so they may be gone.  There used to be one on the Hancock end of the bridge, on top of hill in front of house, up the sidewalk and to the lelf.  Gone now but point may still be in, homeowners used it as fire pit. Had to access from thru yard of home.  One of Houghton Canal road just past UPPCO on right.  Back circa 1979 JPS showed us where all these were.  The points may be still there even if the towers are gone.  As I recall there were no descriptions for most of them, just the survey map.  

The NGS Data Sheet

 
PROGRAM = datasheet95, VERSION = 8.12.2
1        National Geodetic Survey,   Retrieval Date = SEPTEMBER  6, 2017
 SG0220 ***********************************************************************
 SG0220  DESIGNATION -  MCM 91
 SG0220  PID         -  SG0220
 SG0220  STATE/COUNTY-  MI/HOUGHTON
 SG0220  COUNTRY     -  US
 SG0220  USGS QUAD   -  CHASSELL (1975)
 SG0220
 SG0220                         *CURRENT SURVEY CONTROL
 SG0220  ______________________________________________________________________
 SG0220* NAD 83(1994) POSITION- 47 06 43.99026(N) 088 33 06.00395(W)   ADJUSTED  
 SG0220* NAVD 88 ORTHO HEIGHT -   274.    (meters)      899.    (feet) SCALED    
 SG0220  ______________________________________________________________________
 SG0220  GEOID HEIGHT    -        -33.961 (meters)                     GEOID12B
 SG0220  LAPLACE CORR    -        -19.10  (seconds)                    DEFLEC12B
 SG0220  HORZ ORDER      -  FIRST
 SG0220
 SG0220.The horizontal coordinates were established by classical geodetic methods
 SG0220.and adjusted by the National Geodetic Survey in February 1997.
 SG0220.
 SG0220.The orthometric height was scaled from a topographic map.
 SG0220
 SG0220.Significant digits in the geoid height do not necessarily reflect accuracy.
 SG0220.GEOID12B height accuracy estimate available here.
 SG0220
 SG0220.The Laplace correction was computed from DEFLEC12B derived deflections.
 SG0220
 SG0220. The following values were computed from the NAD 83(1994) position.
 SG0220
 SG0220;                    North         East     Units Scale Factor Converg.
 SG0220;SPC MI N     -   260,005.927 7,882,240.356   MT  1.00000718   -1 07 17.5
 SG0220;SPC MI N     -   853,037.82 25,860,368.62   iFT  1.00000718   -1 07 17.5
 SG0220;UTM  16      - 5,218,802.827   382,281.829   MT  0.99977031   -1 08 13.3
 SG0220
 SG0220!             -  Elev Factor  x  Scale Factor =   Combined Factor
 SG0220!SPC MI N     -   0.99996238  x   1.00000718  =   0.99996956
 SG0220!UTM  16      -   0.99996238  x   0.99977031  =   0.99973270
 SG0220
 SG0220:                Primary Azimuth Mark                     Grid Az
 SG0220:SPC MI N     -  WHEAL KATE 2                             243 17 03.2
 SG0220:UTM  16      -  WHEAL KATE 2                             243 17 59.0
 SG0220
 SG0220_U.S. NATIONAL GRID SPATIAL ADDRESS: 16TCT8228118802(NAD 83)
 SG0220
 SG0220|---------------------------------------------------------------------|
 SG0220| PID    Reference Object                     Distance      Geod. Az  |
 SG0220|                                                           dddmmss.s |
 SG0220| SG0233 WHEAL KATE 2                        APPROX. 9.5 KM 2420945.7 |
 SG0220| SG0216 MCM 83                              APPROX. 3.4 KM 2623205.7 |
 SG0220|---------------------------------------------------------------------|
 SG0220
 SG0220                          SUPERSEDED SURVEY CONTROL
 SG0220
 SG0220  NAD 83(1986)-  47 06 43.98620(N)    088 33 05.98023(W) AD(       ) 1
 SG0220  NAD 27      -  47 06 44.25200(N)    088 33 05.53000(W) AD(       ) 1
 SG0220
 SG0220.Superseded values are not recommended for survey control.
 SG0220
 SG0220.NGS no longer adjusts projects to the NAD 27 or NGVD 29 datums.
 SG0220.See file dsdata.pdf to determine how the superseded data were derived.
 SG0220
 SG0220_MARKER: B = BOLT
 SG0220_SETTING: 66 = SET IN ROCK OUTCROP
 SG0220_MAGNETIC: N = NO MAGNETIC MATERIAL
 SG0220_STABILITY: A = MOST RELIABLE AND EXPECTED TO HOLD
 SG0220+STABILITY: POSITION/ELEVATION WELL
 SG0220_SATELLITE: THE SITE LOCATION WAS REPORTED AS SUITABLE FOR
 SG0220+SATELLITE: SATELLITE OBSERVATIONS - June 27, 2008
 SG0220
 SG0220  HISTORY     - Date     Condition        Report By
 SG0220  HISTORY     - 1939     MONUMENTED       CGS
 SG0220  HISTORY     - 1977     GOOD             NGS
 SG0220  HISTORY     - 1986     GOOD
 SG0220  HISTORY     - 1990     GOOD             NGS
 SG0220  HISTORY     - 19940901 GOOD             NGS
 SG0220  HISTORY     - 20010503 GOOD             MIDT
 SG0220  HISTORY     - 20020213 GOOD             WILCOX
 SG0220  HISTORY     - 20080627 GOOD             MIDT
 SG0220
 SG0220                          STATION DESCRIPTION
 SG0220
 SG0220'DESCRIBED BY COAST AND GEODETIC SURVEY 1939 (FBQ)
 SG0220'ABOUT 3/4 MILE SOUTH OF HOUGHTON.  SPECIAL IRON PIPE INNER
 SG0220'AND OUTER TOWER HAS BEEN PERMANENTLY ESTABLISHED OVER THIS
 SG0220'STATION BY THE MICHIGAN COLLEGE OF MINES.  IT IS 0.4 MILE
 SG0220'WEST OF THE MAIN GATE OF THE CEMETERY ON CEMETERY ROAD, 30
 SG0220'FEET SOUTH OF THE CENTER OF THE ROAD, 19-1/2 FEET NORTHWEST
 SG0220'OF A POWER LINE POLE, 80 FEET EAST-NORTHEAST OF ANOTHER POLE
 SG0220'AND 1 FOOT SOUTH OF THE RIGHT-OF-WAY FENCE.  THE MARK IS A
 SG0220'1-INCH COPPER BOLT CEMENTED INTO THE BED ROCK, AND PROJECTS
 SG0220'1-1/2 INCHES ABOVE THE BED ROCK.
 SG0220'
 SG0220'NO ADDITIONAL MARKS WERE ESTABLISHED.
 SG0220'
 SG0220'TO REACH FROM SPERR HALL AT THE INTERSECTION OF COLLEGE
 SG0220'AVENUE AND CEMETERY ROAD, DRIVE UP HILL FOR 0.4 MILE ON
 SG0220'CEMETERY ROAD TO THE CEMETERY GATE, TURN RIGHT ON A GRAVEL
 SG0220'ROAD AND DRIVE 0.4 MILE TO THE STATION AT THE LEFT (SOUTH)
 SG0220'SIDE OF THE ROAD.
 SG0220'
 SG0220'HEIGHT OF LIGHT ABOVE STATION MARK - 20 METERS.
 SG0220
 SG0220                          STATION RECOVERY (1977)
 SG0220
 SG0220'RECOVERY NOTE BY NATIONAL GEODETIC SURVEY 1977 (WOM)
 SG0220'STATION MARK AND THE FOUNDATIONS FOR THE STEEL TOWER WERE
 SG0220'RECOVERED.  NO REFERENCE MARKS WERE SET AT THIS STATION.
 SG0220'
 SG0220'TO REACH FROM THE INTERSECTION OF COLLEGE AVENUE (U.S. HIGHWAY
 SG0220'41) AND PEARL STREET IN HOUGHTON, GO SOUTH ON PEARL STREET FOR
 SG0220'0.1 MILE, THENCE EAST ON HOUGHTON AVENUE FOR 0.05 MILE TO GARNET
 SG0220'STREET.  TURN RIGHT, SOUTH, ON GARNET STREET AND GO 0.45 MILE
 SG0220'TO TOP OF HILL AND A T-ROAD.  TURN LEFT AND GO EAST ON GRAVELED
 SG0220'STREET (SHARON ROAD) FOR 0.1 MILE TO THE STATION ON THE RIGHT,
 SG0220'JUST BEFORE THE ROAD DROPS OFF SHARPLY TO THE EAST AND A SMALL
 SG0220'DIRT PULL OUT AREA ON THE LEFT.
 SG0220'
 SG0220'STATION IS A 1-INCH COPPER BOLT CEMENTED INTO THE BEDROCK AND
 SG0220'PROJECTS 1 INCH ABOVE THE ROCK.  IT IS 30 FEET SOUTH OF THE
 SG0220'CENTER OF SHARON ROAD, 19 FEET NW OF A POWER LINE POLE AND 5.7
 SG0220'FEET NW OF THE REMAINS OF A 2-INCH IRON PIPE SET IN CONCRETE
 SG0220'(WAS THE SE LEG OF THE STEEL TOWER MENTIONED IN THE ORIGINAL
 SG0220'DESCRIPTION).
 SG0220'
 SG0220'THIS STATION HAS SOME VISIBILITY TO THE EAST AND WEST, BUT WOULD
 SG0220'REQUIRE A 77 FOOT TOWER TO CLEAR THE TREES TO THE NORTH.
 SG0220'
 SG0220'AIRLINE DISTANCE AND DIRECTION FROM NEAREST TOWN
 SG0220'IN SE EDGE OF HOUGHTON.
 SG0220
 SG0220                          STATION RECOVERY (1986)
 SG0220
 SG0220'RECOVERED 1986
 SG0220'RECOVERED IN GOOD CONDITION.
 SG0220
 SG0220                          STATION RECOVERY (1990)
 SG0220
 SG0220'RECOVERY NOTE BY NATIONAL GEODETIC SURVEY 1990 (DH)
 SG0220'RECOVERED IN GOOD CONDITION.
 SG0220
 SG0220                          STATION RECOVERY (1994)
 SG0220
 SG0220'RECOVERY NOTE BY NATIONAL GEODETIC SURVEY 1994 (CFS)
 SG0220'NOTE--CONTACT THE PUBLIC SAFETY OFFICE PRIOR TO OCCUPATION SO THEY CAN
 SG0220'UNLOCK THE GATE.  OFFICE IS MANNED 24 HOURS.  STATION IS LOCATED IN
 SG0220'HOUGHTON, ON MICHIGAN TECH CAMPUS, ON A KNOLL.  OWNERSHIP--MICHIGAN
 SG0220'TECH UNIVERSITY, 1400 TOWNSEND DRIVE, HOUGHTON, MI 49931.  PHONE
 SG0220'906-487-2216 (PUBLIC SAFETY OFFICE) .  TO REACH FROM THE JUNCTION OF
 SG0220'U.S.  HIGHWAY 41 AND STATE HIGHWAY 26 IN HOUGHTON, GO SOUTH ON HIGHWAY
 SG0220'26 FOR 1.6 KM (1.00 MI) TO SHARON AVENUE.  TURN LEFT, EAST, ON SHARON
 SG0220'AVENUE FOR 2.7 KM (1.65 MI) TO GARNET STREET ON THE LEFT. TURN LEFT,
 SG0220'NORTH, ON GARNET STREET FOR 0.08 KM (0.05 MI) TO A CROSS STREET.  TURN
 SG0220'RIGHT, EAST, ON HICKORY LANE ABOUT 20 M (65.6 FT) TO A GATE.  PASS
 SG0220'THROUGH THE GATE AND CONTINUE EAST ON THE DIRT ROAD FOR 0.08 KM (0.05
 SG0220'MI) TO TOP OF KNOLL AND THE STATION ON THE RIGHT. STATION IS A 1 INCH
 SG0220'COPPER BOLT CEMENTED INTO BED ROCK AND PROJECTING 4 CM ABOVE THE BED
 SG0220'ROCK.  THE BOLT IS UNSTAMPED WITH A PUNCH MARK IN THE CENTER OF AN 'X'
 SG0220'ETCHED IN TOP OF THE BOLT.  IT IS 9.8 M (32.2 FT) SOUTH OF THE CENTER
 SG0220'OF THE DIRT ROAD AND 2.4 M (7.9 FT) NORTHWEST OF A METAL WITNESS POST.
 SG0220
 SG0220                          STATION RECOVERY (2001)
 SG0220
 SG0220'RECOVERY NOTE BY MICHIGAN DEPARTMENT OF TRANSPORTATION 2001 (MPR)
 SG0220'THE MARK IS NOT A COPPER BOLT.  IT IS A 1-1/8 INCH HEXAGON STEEL DRILL
 SG0220'BIT PROJECTING 1-3/4 INCH ABOVE AND SET IN CONCRETE ON BEDROCK.
 SG0220'REMAINS OF CONCRETE PADS AND PIPES FOR THE (REMOVED) TOWER WERE
 SG0220'UNCOVERED, THE MARK FITS THE CENTER AND APPEARS OF SIMILAR VINTAGE.
 SG0220'5.3 FT S OF CARSONITE WITNESS POST,  ABOUT 2 FT LOWER THAN LANE.
 SG0220
 SG0220                          STATION RECOVERY (2002)
 SG0220
 SG0220'RECOVERY NOTE BY WILCOX ASSOCIATES INC 2002 (SP)
 SG0220'RECOVERED AS DESCRIBED
 SG0220
 SG0220                          STATION RECOVERY (2008)
 SG0220
 SG0220'RECOVERY NOTE BY MICHIGAN DEPARTMENT OF TRANSPORTATION 2008 (BLJ)
 SG0220'RECOVERED IN GOOD CONDITION.

 *** retrieval complete.
 Elapsed Time = 00:00:01
Edited by Z15
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Z15 - I figured you would have the back story! That was some elaborate teaching aid. I sure would like to see that old map! Chuck and ID were the main faculty when I was there. I'm sure I asked Chuck about it when we did field work by the one in Hancock near the fair grounds, but I don't remember what his response was. I see Paul Buda is still on the faculty, he was teaching back then also so maybe he will have some info also. Would the DOT possibly have something on it still?

I looked for SG0220 last weekend, but there is a frisbee golf tee right in the area that gps led me to so I didn't look to hard (wife was losing patience with the whole endeavor by that time also!). The 2001 recovery note says the tower and concrete pads had been removed.

 

 

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Anything the DOT had would be in the state archives in Lansing and buried in field notes, if its even there.   I got a MCM map of other control...

https://www.dropbox.com/s/y7arc2vpfvuxf59/MCM map.pdf?dl=0

Don't know Buda, heard of him but when I was working, I recall he was the computer survey guru at MTU?   He was doing the assessor plats for a local surveyor on Quincy Hill and there was a conflict with the US-41 ROW.  So our PLS had to go show him where they missed a jog in the ROW line. I was going to lay claim to the 1320 x 10 ft strip of land that lain between the ROW and the Plat Line. LOL

We (DOT Surveys) helped ID with a GPS class by loaning him the use our GPS equipment and being facilitators, going with the students.  I took several out to  Tri Sta ARCADIA to show them the field procedures.   2 of the kids in the class had co-oped with us the prior summer. 

Edited by Z15
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I looked for SG0220 last weekend, but there is a frisbee golf tee right in the area that gps led me to so I didn't look to hard (wife was losing patience with the whole endeavor by that time also!). The 2001 recovery note says the tower and concrete pads had been removed.

It should be there, I drove in a NGS witness post in 2001.  There was and probably still is a locked gate across the road from the west. I recall back then they had problems with people dumping here so hence the gate was put in.  

MCM91_zpsta0pppmv.png

Edited by Z15
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