Inside Caterpillar's Arizona Proving Grounds

26_Excavators II

By Tudor Van Hampton

As we approached Caterpillar's proving grounds outside Tucson, Ariz., we expected to see big yellow iron, but the sign on the gravel road read, "Caution: Desert Tortoise and Reptile Crossings."

We did find a small rattlesnake, but we weren't here to take in nature. We were here to see construction equipment manufacturer Caterpillar's Tinaja Hills Demonstration & Learning Center located deep in the Sonoran Desert. The 6,500-acre site covers a remote area of land south of Tucson along Interstate 19. For those of us who bleed yellow, it is hallowed ground.

Finding your way to this part of Arizona can be tricky, though, and if you reach Nogales, Mexico, you've gone too far. The highway signs along this stretch of I-19 offer directions in kilometers per hour, a holdover from Arizona's unsuccessful push long ago to go metric. Undeterred by the confusing roadside markers and equipped with an old-fashioned paper map courtesy of Caterpillar — it instructs would-be visitors to do things such as "turn left after metal pipe over road" — we recently visited to test-drive Cat's 789D mining truck for

Based in Peoria, Ill., Caterpillar uses about half of this vast facility for training technicians and operators from all over the world. Last year, Tinaja Hills hosted around 10,000 people looking to become certified in a piece of Caterpillar equipment, learn the latest maintenance practices or even discover tricks to make their machines operate more efficiently.

"Operator training is, by far, the biggest thing we do," said Jim Deputy, the facility manager and our tour guide. Don't think about coming here to take a machinery exam unless you already have experience, he said, adding that professional operators typically have at least eight to 10 years in the seat before they try to get certified. The cost to do so is about $1,200 for each Caterpillar machine family.

"When you come back for certification, we expect you to know the machines," Deputy said.

The other half of the Tinaja Hills property is Cat's proving grounds for large mining equipment. Caterpillar has four main locations it uses for training and testing. In addition to Tinaja Hills, it operates facilities in Illinois, Spain and Panama. In Arizona it employs about 25 people on the marketing side and 300 people on the research-and-development side.

We weren't allowed access the proving grounds — that area includes an active copper mine — because engineers were testing autonomous haul trucks and bulldozers, we were told. But we did come close to the entrance as we drove to the top of a man-made mountain only to find the biggest machine that Caterpillar makes — the Cat 7495 electric rope shovel — waiting at the summit.

"It's for sale," said Deputy, for only $36 million. The nearly 3-million-pound machine can scoop up 110 tons of rock at a time and load Cat's largest mining truck, a 400-ton model 797, in four passes. Seeing the gentle giant sitting there idle was a sobering reminder that the mining industry was — and still is — experiencing a slow period that has Caterpillar forecasting revenue sliding 9 percent this year to $50 billion.

We ventured into demonstration arenas, where Caterpillar shows how its machines work in various scenarios, such as digging, backfilling and grading. About 72 machines representing much of the Caterpillar product line are put to work here.

As we toured the huge property, a water truck regularly sprayed down the dirt road to keep dust in check. The facility maintains an active well mated to a 465,000-gallon water tank for dust suppression. Tinaja Hills is powered by Caterpillar diesel generators and is mostly self-sustaining, Deputy said.

Near a service shop is what looked like a truck-stop fueling station, but this was for heavy equipment exclusively. A 20,000-gallon diesel tank and 800-gallon diesel exhaust fluid tank supplied the necessary reserves to the thirsty earth-moving machines.

In addition to housing big iron, Tinaja Hills also runs a fleet of nearly a dozen pickup trucks — they are all crew cabs — used to shuttle visitors and gear from place to place. With all the rocky roads, truck tires take a heavy beating. Deputy said he recently switched to Goodyears with Kevlar for added protection.

"This is pretty rough terrain," Deputy explained. "These trucks really never see asphalt or highways, so we do go through a lot of tires." photos by Tudor Van Hampton



21_Main Building II

The hacienda at Caterpillar's Tinaja Hills training and testing facility houses offices, classrooms, a cafeteria and a gift shop.


21b_DemoTruck II

About half of the 6,500-acre site is used for training and demonstrations, while the rest is a proving grounds for Caterpillar mining equipment.


22_Crush II

A material-handler operator sorts rock.


23_Test Track II

Roads are impeccably maintained but tough on tires. The facility's pickup-truck fleet runs on Goodyears with Kevlar for added durability.


25_Wet II

Water is sprayed frequently to keep dust down.


27_Hyrbid II

A Cat D7E, an innovative bulldozer with a diesel-electric powertrain, takes a rest.


28_Technicians II

Trainees from South America learn to service mining trucks in a shop setting.


29_Fuel II

A fueling station holds 20,000 gallons of diesel and 800 gallons of diesel exhaust fluid.


30_Shovel II

A giant cable-rope shovel, worth about $36 million, takes a nap.


31_Mine II

The road to the proving grounds. The top-secret area includes an active copper mine and is currently testing autonomous mining trucks and bulldozers.


32_Snake II

Watch out for rattlers and other vermin at the remote facility, which is deep inside the Sonoran Desert.


18_Operator II



Excellent article, thanks Mark.

Employ the rattlesnakes.

Thanks Mark,
Some interesting stuff.

The course seem quite cheap at $1 200, I would of thought they would cost more.

I like those big dump trucks. The D7 looks out of place, tiny.

This is the perfect story to run like dumping a bucket of ice water over the heads to get over the disaster of the last stories where panic is setting in cause the 2015 F-150 isn't selling.
This story is trying to make us forget about that.

I understand PUTC is trying to help and promote the F-150 and maybe they are getting pressure from the top but everybody knows the F-150 is in trouble.
I am trying to help Ford by pointing out their mistakes, it just breaks my heart they are ignoring me, my intensions are good cause I always owned an F-150.

@tom#3 Your ignorance never ceases to amaze.

Vermin? Snakes aren't vermin

"Roads are impeccably maintained but tough on tires."

I had a good laugh with that comment........ welcome to my world.

The comments to this entry are closed.