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6.7 Closed Traverse

A closed traverse is a series of connected lines whose lengths and bearings are measured off these lines (or sides), which enclose an area. A closed traverse can be used to show the shape of the perimeter of a fire or burn area. If you were to pace continuously along the sides of a closed traverse, the finishing point would be the same as the starting location.

Note in the following sketch how the traverse is followed clockwise. If the direction was followed counterclockwise at any point, the bearing letters would change to their opposites but the numbers would not, as shown in the first sketch (1) below. The second sketch (2) is a closed traverse. Here, the series of lines completes a distance area, and the starting and ending points are the same.
 

Traverse Examples

Example 1 - Jeff paced the perimeter of the Zavala fire. His pace is 13 paces/chain. The declination for his current location is 14.5°E. The direction, distance, and travel for Jeff is as follows: Jeff begins at point 1 and goes N42°W for 27 paces; from point 2 he goes N75°W for 16-1/2 paces; from point 3 he goes N31°W for 24-1/2 paces; from point 4 he goes N36°E for 29-1/2 paces; from point 5 he goes S65°E for 22 paces; from point 6 he goes S13°E for 52-1/2 paces; from point 7 he goes S21°W for 10-1/4 paces back to the starting point, point 1.

Convert the bearings to magnetic readings. Adjust the magnetic readings to true north readings. Plot the closed traverse in feet using an engineer's tenth ruler and protractor.

Step 1. Convert paces into feet. Jeff's pace is 13 paces per chain. Set up the cancellation table (Section 2.1) and solve for distance in feet.

cancellation table
Repeat this step for each distance.

Step 2. Convert the bearings to magnetic readings. See Section 6.1.

The NW quadrant is between 270° and 360°. 360° - 42° = 318° 
The SE quadrant is between 90° and 180°. 180° - 65° = 115°
The NE quadrant is between 0° and 90° so those values are used as recorded.
The SW quadrant is between 180° and 270°. 180° + 21° = 201°

The resulting magnetic reading are listed in the table below. 

Step 3. Adjust each magnetic reading to a true reading following the guidelines in Section 6.5.

Closed Traverse

Step 4. Choose a scale. 1/10 inch = 10 feet

Step 5. Using a protractor (angles measured in degrees) and an engineer's scale or tenth's ruler, plot the plan view of the traverse horizontal distance (feet) and the bearing (degrees) between points.

image of protractor measuring angles

image of engineer's rule

Step 5a. Set the protractor so the 0°/180°line is up (north) and on a north-south axis.

Step 5b. Put a point in the middle hole. This will be point 1.

Step 5c. Read 318° on the outer scale of the protractor.
Put a dot to mark the point.

index point on protractor


Step 5d. Draw a line from point 1 up to the dot that is 13-7/10 marks (each inch has 10 marks).

ruler with points

Step 5e. The end of this line will be point 2. Put the hole of the protractor on point 2. Follow steps 5b and 5c with each of the values.

When plotting the values that are in the southern quadrants with a semicircle protractor, rotate the protractor so the 0°/180°line is down (facing south) and read the numbers on the inner scale. Continue to complete all the points. The end result should be a closed traverse as shown.

Step 5f. Convert the true readings to bearings. 

P1 to P2 = 360° - 332.5° = N27.5°W
P2 to P3 = 360° - 299.5° = N60.5°W
P3 to P4 = 360° - 343.5° = N16.5°W
P4 to P5 = 0° + 50.5° = N50.5°E
P5 to P6 = 180° - 129.5° = S50.5°E
P6 to P7 = 181.5° - 180° = S1.5°E
P7 to P1 = 215.5° - 180° = S35.5°W

Label the lines of the traverse with the corresponding bearings.

 

NWCG Latest Announcements

NWCG Equipment Technology Committee Releases New Equipment Bulletins

Date: September 27, 2024
Contact: Equipment Technology Committee

The Equipment Technology Committee (ETC) has released three new Equipment Bulletins:

  • ETC-EB-24-003 Diesel exhaust fluid (DEF) in fuel containers.
  • ETC-EB-24-004 Two-compartment fuel and oil container (Dolmar) unavailable in the United States (US) and reminders for upkeeping current inventories.
  • ETC-EB-24-005 Personal Protective Equipment (PPE): Inspection, Care, and Maintenance.

These bulletins remind field going personnel of important issues related to equipment for wildland firefighting efforts.

References:

NWCG Alerts

ETC-EB-24-003 Diesel exhaust fluid (DEF) in fuel containers

ETC-EB-24-004 Two-compartment fuel and oil container (Dolmar) unavailable in the United States (US) and reminders for upkeeping current inventories

ETC-EB-24-005 Personal Protective Equipment (PPE): Inspection, Care, and Maintenance

The Experiential Learning Subcommittee is looking for your feedback on Staff Rides

Date: September 20, 2024
Contact: Ashleigh D'Antonio and George Risko, Leadership Committee

The Experiential Learning Subcommittee needs to hear from the field about where the greatest need lies regarding staff rides and their accessibility.

  • Do you have an event you would like to turn into a learning experience?
  • Do you have a staff ride built, but are struggling to implement the delivery?
  • Do you need help building capacity?
  • What other ideas do you have to support experiential leadership training?

Fill out this short survey below to help us help you.

References:

Staff Rides: Feedback

Staff Rides

Updated NWCG Single Resource Casual Hire Information, PMS 934

Date: September 19, 2024
Contact: Incident Business Committee

The Incident Business Committee has updated the NWCG Single Resource Casual Hire Information, PMS 934. This update expands the provisions for hiring emergency personnel.

References:

NWCG Single Resource Casual Hire Information, PMS 934

IBC Memorandum 24-03

NWCG 2024 Spring/Summer Highlights

Date: September 13, 2024

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Welcome to our latest highlights from the National Wildfire Coordinating Group, where we explore the latest updates, insights, and efforts that develop interoperable wildland fire operations among federal, state, local, Tribal, and territorial partners.

The Performance Support Package, which for ABRO includes the Incident Position Standards and Next Generation Position Task Book were developed through the Incident Performance and Training Modernization (IPTM) effort. The Performance Support Package will support trainees, those qualified in the position, and evaluators.
 

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NASA JOINS NWCG!

The National Aeronautics and Space Administration (NASA) is officially an associate member of NWCG. As such, NASA is beginning to collaborate with wildland fire management agencies with the goal of increasing collaboration across agencies and leveraging NASA data, technology, and innovation for nation-wide efforts in wildland fire management. NASA has a rich history of research, development, and technology transfer in the areas of Earth science, space technologies, and aeronautics that support the NWCG mission.

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WWW.NWCG.GOV HAS A NEW LOOK AND DESIGN

The NWCG web team dedicated the past two years to making a significant upgrade to the www.nwcg.gov site. This upgrade involved a comprehensive redesign of over 7,700 web pages.

The modernization of NWCG’s website involved migrating to Drupal 10, a cutting—edge content management system, and leveraging Amazon Web Service GovCloud for secure and efficient hosting. These upgrades help ensure that the NWCG website remains current in content management practices, offering enhanced customization, improved performance, and an overall superior user experience.

NWCG Leadership Committee

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The Wildland Fire Leadership Development Program announced the Professional Reading Program’s 2024 list!

The years books include:

  • Young Men and Fire by Norman Maclean
  • The Wisdom of the Bullfrog by William H. McRaven
  • The Art of Clear Thinking by Hasard Lee
  • Emotional Agility by Susan David
  • Writing to Persuade by Trish Hall

Learn more at the NWCG Leadership Committee

INCIDENT PERFORMANCE AND TRAINING MODERNIZATION

In 2023, NWCG kicked off the Incident Performance and Training Modernization (IPTM) effort. A training system overhaul focused on developing a performance-based training system designed to shift training to on-the-job when appropriate.

Over the next five years, NWCG intends to analyze all positions within the NWCG Standards for Wildland Fire Position Qualifications, PMS 310-1. To date we are currently working on 30 incident positions, and planning for 20+ in calendar year 2025.

Subject Matter Experts from a variety of geographical areas and agencies recently completed the position analysis for 16 positions. From this analysis, Incident Positions Standards and a Next Generation Position Task Book will be developed for each position.

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Incident Performance and Training Modernization

NEXT GENERATION POSITION TASK BOOK

In April 2024, NWCG launched the new Next Generation Position Task Book (Next Gen PTB) which is a key component of the IPTM effort. This revised evaluation tool is designed to work in conjunction with the newly developed Incident Position Standards.

Major Next Gen PTB changes:

  • Structured to improve constructive conversations between evaluators and trainees.
  • Reference new Incident Position Standards.
  • Include only tasks required to be evaluated for successful performance.
  • Trainees will be rated on their performance vs. initialing whether a task was completed.
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  • Will be position specific (no combined PTBs).
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NWCG’s training course catalog is now available on the Wildland Fire Learning Portal (WFLP).

To access the training course catalog, visit WFLP and either set up an account or login as a guest.