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3.1 Volume or Capacity

Volume is used to indicate the capacity of a tank or container. It is used by firefighters to answer questions like "How much water is left in the tank?" and "At 15 gallons per minute (gpm), how many more minutes before the tank is empty?" 

VOLUME OF A RECTANGULAR OBJECT

The volume of a rectangular container is determined by multiplying the length (l) by the width (w) by the height (h).

volume

Volume = length × width × height
V = l × w × h

Example 1 - Determine the volume of the tank in gallons.

Example 1 Image

Step 1. Use the equation for determining the volume of a rectangle. V = l × w × h

Step 2. Identify the length, width, and height. l = 5 ft, w = 6 ft, h = 8 ft

Step 3. Set up the problem and solve. V = 5ft × 6ft × 8ft = (5 × 6 × 8) (ft × ft × ft) = 240 ft3

Step 4. Determine the appropriate conversion factor. 1 cubic foot = 7.4805 gallons

Step 5. Set up the cancellation table so all units will cancel except gallons (see Section 2.1).

Cancellation Table

The volume of the tank of water is 240 cubic feet or 1,795 gallons.

Example 2 - The water tank on a newly designed engine is 34 inches wide, 5 feet high, and 12 feet long. What is the capacity of the water tank in cubic feet? In gallons?

Example 2 image

Step 1. Use the equation for determining the volume of a rectangle. V = l × w × h

Step 2. Identify the length, width, and height. l = 12 ft, w = 34 in, h = 5 ft

Step 3. Convert all the measurements to the same units, feet.

Inches to Feet
Step 4. Set up the problem, and solve for volume. V = 2.83 ft × 5 ft × 12 ft = 170 ft3

Step 5. Set up the cancellation table so all units will cancel, except the desired unit, gallons.

Ft3 to Gallons

The volume of the tank is 170 cubic feet or 1272 gallons.

VOLUME OF A CYLINDER

The volume of a cylinder is found by multiplying the area of the base times the height, h. The base of a cylinder is a circle, A = π × r2, where π = 3.14. 

Volume Example

Example 3 - A cylindrical tank of foam concentrate is 5 feet tall. The tank diameter is 2.5 feet. What is the capacity, in gallons, of the tank?

Step 1. Use the equation for determining the volume of a cylinder.
V = π r2 × h

Step 2. Draw a sketch. Label the height and diameter.

Height and Diameter

π = 3.14, r = 1/2 d = 1/2 × 2.5 ft = 1.25 ft, h = 5 ft

Step 3. Set up the problem and solve. V = 3.14 × (1.25 ft)2 × 5 ft = 24.5 ft3

Step 4. Set up the cancellation table so all units will cancel, except the desired unit, gallons.

Ft3 to Gallons

The tank capacity is 183.3 gallons.

 

NWCG Latest Announcements

The Incident Position Standards and Next Generation Position Task Book are now available for Medical Unit Leader (MEDL)

Date: October 16, 2024
Contact: Incident Medical Subcommittee

NWCG is excited to announce that the NWCG Incident Position Standards for Medical Unit Leader, PMS 350-39 and NWCG Position Task Book for Medical Unit Leader (MEDL), PMS 311-39 are now available.

The Performance Support Package, which for MEDL 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.

References:

NWCG Medical Unit Leader Position Page

NWCG Incident Position Standards for Medical Unit Leader, PMS 350-39

NWCG Position Task Book for Medical Unit Leader (MEDL), PMS 311-39

The Wildland Fire Learning Portal is Now Available

Date: October 9, 2024
Contact: Wildland Fire Learning Portal

The Wildland Fire Learning Portal (WFLP) is back online following a migration to a new learning management system (LMS) application. The WFLP team is actively addressing any issues that may arise as a result of the update, and appreciates your patience as the team works to enhance your experience. NWCG will share information from the WFLP as it is available.

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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.

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