Bighorn Fire personnel have been working 12- to 16-hour shifts for 14 days in a row in their war on the flames threatening hundreds of Tucson-area homes and the community of Summerhaven on Mount Lemmon, officials said.

About 700 people are collectively involved in hosing down hot spots, hacking through brush, digging fire lines and spreading water and flame retardant, and supporting the firefighting effort, the latest fire update shows.

There’s a vast amount of machinery and equipment involved in fighting the lightning-sparked Bighorn Fire. The cost so far to battle the blaze is $10 million, officials said Wednesday.

The tentative tab has added up quickly due to extensive use of planes and helicopters in rugged terrain inaccessible by ground crews, said Greg Heule, a fire information officer.

“Any time you’re using a lot of aircraft it gets very expensive, Heule said.

Most of the bill will likely be charged to the Coronado National Forest and be covered by federal taxpayers, he said.

Here’s a rundown on what the Bighorn firefighters are doing, and what they’re using to get the job done.

EIGHT HOTSHOT CREWS

A team typically has 20 members who are highly skilled in figuring out where a fire is headed and how it should best be attacked. Hotshots typically hike in and camp outside a fire’s perimeter, using chain saws, shovels and other tools to limit the fire’s spread.

Adam Hutton with the Smokey Bear Hotshots of Ruidoso, New Mexico, tosses away brush being cut near the mouth of Finger Rock Canyon during the Bighorn Fire.
SEVEN HAND CREWS (TYPE II)

Also with 20 members, a hand crew has skills similar to Hotshots but with less experience. The Type II designation indicates a skill or experience level a notch below the highest level.

27 TYPE 3 ENGINES

A four-wheel drive Type 3 Engine from Three Points Fire District headed up to Mt. Lemmon during the Bighorn Fire in the summer. One letter writer offers thanks for firefighters.

Similar in size to a UPS delivery truck, with four-wheel drive for rough terrain and a 500-gallon water tank. They usually fill up at fire hydrants, then carry the water into places bigger engines can’t navigate such as narrow, winding roads.

27 TYPE 4 and TYPE 6 ENGINES

A Type 6 engine, or brush truck, from Prescott National Forest.

Both are similar in size to an oversized, super-duty work truck but the Type 4 holds less water (200-300 gallons) than the larger version, which holds up to 500 gallons. They are more maneuverable and can fit into tighter spaces.

FOUR TYPE 1 HELICOPTERS

A Type 1 Sikorksy helicopter on The Bighorn Fire burning in in the Santa Catalina Mountains north of Tucson on June 11, 2020.

The largest choppers used for firefighting, they include Chinooks, recognizable by rotors at the front and back, and Sky Cranes, which have rotors on the top and tail and a bright orange paint job. They can dump 1,000 gallons of water at a time and refill their water buckets from lakes or rivers or from pumpkin-shaped water containers that hold up to 7,000 gallons and are stationed near work areas.

ONE TYPE 2 HELICOPTER

A UH-60 Type II helicopter on the Bighorn Fire burning in in the Santa Catalina Mountains north of Tucson on June 11, 2020.

Less water capacity than Type 1, (typically 500 to 800 gallons) they are smaller and more maneuverable in tight spots. Can also be used for dispensing fire retardant, for crew transport and for dropping hundreds of igniter pellets during back-burn operations.

TWO TYPE 3 HELICOPTERS

Used for observation or evacuations. They can carry a small water buckets of 200 to 300 gallons.

ASSORTED FIXED-WING AIRCRAFT

A huge DC-10 VLAT (Very Large Air Tanker) pulls up after dropping a load of fire retardant in a neighborhood just south of Catalina State Park during the Bighorn Fire burning along Pusch Ridge in Coronado National Forest north of Tucson on June 6, 2020.

Mainly used to apply fire retardant, the planes range in size from a hulking DC-10 with a 13,000-gallon capacity to single engine air tankers that can carry 800 gallons at a time. To refill, they will often fly to the Mesa airport or to an Army airport at Fort Huachuca southeast of Tucson, where personnel mix red fire retardant powder with water to create the slurry used in firefighting.

11 WATER TENDERS

A Northwest Fire District water tender

Water tank trucks, which are called “tenders” instead of tankers so as not to confuse them with air tankers. They hold from 1,000 to 10,000 gallons and their sole job is to obtain water from a lake, hydrant or other sources to have a ready supply at all times.

SIX BULLDOZERS

Used to denude strips of land around advancing flames to stop the fire’s spread.

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Contact reporter Carol Ann Alaimo at 573-4138 or calaimo@tucson.com. On Twitter: @StarHigherEd.