Using the Underground Traverse Calculator

Team #1 Begins a Traverse

• Luke Skywalker and Sandra Bullock begin an underground traverse as Team #1

• There first action is to go to Grate above their “Mine Shaft” and hang their two plumb bobs

They Carefully Measure How Far the Plumb-Bobs are from the

corners

1 foot

1 foot

1 foot

1foot

Now They Enter Their Data in the Spreadsheet

The Spreadsheet calls for these distances to be entered in inches

They Set Up Their Instrument Underground

• So that they can sight directly across the strings that hold the plumb bobs

• They set the backsight angle on their Nikon 20 Total Station to 0

• They measure the distance to the closest plumb bob (called plumb-bob 2 by the spreadsheet)

• And they measure their height of instrument.

They Enter Their Measurements into the Spreadsheet

The distance fromThe plumb bob toTheir instrument was10.25 feet

The height of theirInstrument is 4.6 feet(note that the unitsMust be by decimalFeet)

The spreadsheet is now reporting their backsight azimuth and the coordinatesOf their station location.

Luke and Sandra Set Up a Foresight Point Through Where the

Pipes Cross the TunnelThey put in theirAngle to the right(289 30 00)

And their verticalAngle(92 05 00)

They put in oneTo indicate theyWorked DMS

And another 1 toIndicate they hadA zenith angleinstrument

They Also Put In Their EDM Data

The Coordinates of the Foresight Point Appear

Luke and Sandra Next Move to Point B and Shoot Down the

Tunnel to Where there is a BranchCalculation of Foresight Point Location

Instrument Location B Coordinates of Foresight Point

Back Sight Point A Northing Easting Elev

Foresight Point C 381097.7 2570623 434.6192

Instrument Used Nikon 20

Survey Date Sept 11 2021Angle Conversions Grads Mills Degrees Minutes Seconds

Horizontal Angle 90 20 10Zenith Angle 1 Vertical Angle 90(1=Yes, 2=Horizontal) Set 1 by units 1

Shot DataBack Sight Present Station Angles Rod Readings EDMAzimuth N E Elev Height Ins H to Right Vert Angle Center R Upper R Lower R Dist Height Pole275.5017 381082.8 2570622 434.6192 4.6 90.33611 0 15 4.6

Offset to Left side #DIV/0!Offset to Right side

They put in their Horizontal andVertical Angles Their EDM dat

Their height of instruments

And the 1’s that indicateThey had a Zenith AngleInstrument working inDegrees Minutes and Sec.

They Move Down to Point CStation 3 Point information

Instrument Location C

Back Sight Point B

Instrument Used Total Station

Survey Date Sept 18 2021

Back Sight Present StationAzimuth N E Elev Height Ins185.8379 381097.7 2570623 434.6192 4.3

Grate(intermediate shot points)

ManholeGrate(intermediate shot points)

Foresight Point

From Here They Will TakeThree Types of Shots

1- They will turn and takeA side shot down theBranch Tunnel. (TheSpreadsheet calls this aBranch shot)

2- They will shoot down toA manhole using a sideShot. (The SpreadsheetCalls this an intermediateShot).

3- They will shoot to aForesight where the tunnelturns

They Take the Side Shot Down the Tunnel and Put in the Data

Calculations for the Coordinates for Branch ShotBranch Shot 1 from point C

Instrument Location C Coordinates of Sideshot PointBack Sight Piont B Northing Easting ElevSideShot Point C1 381089.6 2570701 434.6192Instrument Used Nikon 20Survey Date Sept 11 2021

Angle Conversions Grads Mills Degrees Minutes SecondsHorizontal Angle 270 10 0

Zenith Angle 1 Vertical Angle 90(1=Yes, 2=Horizontal) Set 1 by units 1

Shot DataBack Sight Present Station Angles Rod Readings EDMAzimuth N E Elev Height Ins H to Right Vert Angle Center R Upper R Lower R Dist Height Pole185.8379 381097.7 2570623 434.6192 4.6 270.1667 0 78 4.6

Offset to Left sideOffset to Right side

Angles EDM Data

Height of Instrument

Instrument Type

They get the coordinates at the end of the side tunnel

They Take A Shot Down the Tunnel to Where the Reflector is Placed

Beneath the Manhole CoverCalculation of Intermediate Shots from Point C

Instrument Location C Coordinates of Intermediate Shot PointBack Sight Piont B Northing Easting ElevSideShot Point C2 381366.6 2570647 431.085Instrument Used Total StationSurvey Date Sept 11 2021

Angle Conversions Grads Mills Degrees Minutes SecondsHorizontal Angle 179 15 0

Zenith Angle 1 Vertical Angle 90 45(1=Yes, 2=Horizontal) Set 1 by units 1

Shot DataBack Sight Present Station Angles Rod Readings EDMAzimuth N E Elev Height Ins H to Right Vert Angle Center R Upper R Lower R Dist Height Pole185.8379 381097.7 2570623 434.6192 4.6 179.25 -0.75 270 4.6

Offset to Left sideOffset to Right side

They get the coordinates under the Manhole Cover.

Then they Take the Foresight Shot to Where the Tunnel Turns Sharply

LeftCalculation of Foresight Point Location

Instrument Location C Coordinates of Foresight Point

Back Sight Point B Northing Easting Elev

Foresight Point D 381473.8 2570661 429.6713

Instrument Used Nikon 20

Survey Date Sept 11 2021Angle Conversions Grads Mills Degrees Minutes Seconds

Horizontal Angle 179 56Zenith Angle 1 Vertical Angle 90 45(1=Yes, 2=Horizontal) Set 1 by units 1

Shot DataBack Sight Present Station Angles Rod Readings EDMAzimuth N E Elev Height Ins H to Right Vert Angle Center R Upper R Lower R Dist Height Pole185.8379 381097.7 2570623 434.6192 4.6 179.9333 -0.75 378 4.6

Offset to Left side #DIV/0!Offset to Right side

They get the coordinates of the next pointThey will occupy

Sandra and Luke Continue Their Survey

• They work their way down to where they will get the coordinates of the two points used by other teams to go further down the tunnels

• Of course their own tunnel did a T at one point. Now they must go back and survey where the Tunnel went the other direction.

Here is Their Situation

They reset their instrument underTheir Point B (which they already have theCoordinates of)

They set a plumb-bob on their old station C(Which they also have the coordinates of).They will use point C as a Backsight

They set up a Foresight Point down the Branch ofThe tunnel they will now survey.

The Spreadsheet is Arranged Like This

Team #1 calculations Starting at the Plumb-Bobs hangingDown the shaft.

Calculations for any other team starting a survey givenTwo known points (surveyed in by another team thatBrought control positions and directions in from thePlumb-bobs hanging down the shaft).

Luke and Sandra Take A Look At This Area of the Spreadsheet

Beginning of Surveys Using 2 Initial PointsN E Elev

Point 1 200 200 443Point 2 225 170 443

Assume that instrument is set up Under Point 2and is backsighting point 1

Sandra and Luke note that virtually any team that started withTwo points provided by another team would begin here.

Point 2 is where they are set-up

Point 1 is the backsight.

They Put in the Point Coordinates and Get the Direction of Their

Backsight Line

N E ElevPoint 1 381098 2570623 434.6Point 2 381083 2570622 434.6

Assume that instrument is set up Under Point 2and is backsighting point 1

Delta N 15Delta E 1Quadrant 1Azimuth 3.814075

Now They Get Ready for Their First Foresight Shot Down the Tunnel

Calculation of Foresight Point LocationInstrument Location Point 2 Coordinates of Foresight Point

Back Sight Point Point 1 Northing Easting Elev

Foresight Point B 381065 2570621 434.6

Instrument Used Nikon 20

Survey Date Sept 18 2021Angle Conversions Grads Mills Degrees Minutes Seconds

Horizontal Angle 180 15Zenith Angle 1 Vertical Angle 90(1=Yes, 2=Horizontal) Set 1 by units 1

Shot DataBack Sight Present Station Angles Rod Readings EDMAzimuth N E Elev Height Ins H to Right Vert Angle Center R Upper R Lower R Dist Height Pole3.814075 381083 2570622 434.6 4.6 180.25 0 18 4.6

Offset to Left side #DIV/0!Offset to Right side

They put in their data and get the coordinates of theNext station they will move on to occupy.

Things for You To Note

• This Slide Set Shows you how to– Establish a backsight direction and instrument position from two

plumb-bobs hanging down the shaft.– Establish a backsight direction and instrument position if you

have the coordinates of two points and set up under the 2nd.– How to take a shot down a tunnel that branches off of the main

tunnel– How to take a shot to an intermediate point down a tunnel such

as a manhole cover of vent grate

• These same operations should allow any of our Underground Survey Teams to get the coordinates of the points running down the center line of our underground steam tunnels.