There’s a continuously evolving saying in the off-road four wheel drive world regarding ever-increasing tire diameters; once upon a time, 30 or at most 33 inch (overall diameter, on 15 inch rims in those days) were considered large. Then 35 inch tires became popular aftermarket upgrades on daily drivers and even some OEM option packages. Hence the meme “35’s are the new 33’s”. Except that quickly became “37’s are the new 35’s” and then “40’s are the new 37’s”.
But this truck I saw in the California desert a few weeks ago puts those wimpy 40” tires to shame.
These 40R57 Michelins are 140” in diameter on 57” rims. And they weigh over 8000lbs (3700 kg). Each.
On the way home from a camping and exploring trip in the eastern Mojave desert, I decided to pull off the freeway at a place I’ve passed many times, but never stopped. The Borax Visitor Center in Boron, California, sometimes referred to as the 20 Mule Team Borax Visitor Center. Not to be confused with the 20 Mule Team Museum in Boron, nor the Borax Museum in Death Valley National Park. There’s also an aerospace museum in Boron, an unincorporated community of about 2000 hardy souls and at least three museums, in Kern County, California. For what it’s worth, Kern County is about the same land area as New Jersey but is less than half the size of neighboring San Bernardino County.
Borax is a mineral typically comprised of sodium, boron, oxygen and hydrogen. Its most famous use is perhaps Boraxo, a household cleaner, but is also used in plastics, pesticides, charcoal briquets, and as a wood preservative. It’s mined in a handful of places in the world but predominantly in two locations in the Mojave Desert of Southern California. The Visitor Center (museum and gift shop, yes there is a wide selection of borax-themed gifts available, but I left empty-handed) overlooks the mine and once you see the scale of the mine, those tires don’t seem so big.
But back to the truck. It was posed outside the Visitor Center, along with a life sized replica of its predecessor, a twenty mule team hauling a wagon.
The truck was yellow, so I assumed it was a Caterpillar but it’s more complicated than that. Inside the museum, I found a flyer which described it as a Terex Unit Rig. Between the flyer and the Internet, I learned a bit more about these trucks.
Terex is a multinational manufacturer of heavy equipment, but they don’t actually make or sell these trucks anymore. Its origin goes back to a company formed in Oklahoma in the 1930’s, Unit Rig and Equipment, making oil field machinery. In the late 1950’s they worked with General Electric to adapt GE’s diesel electric powertrains from locomotives to heavy mining trucks. The trucks were sold under various brand names and the company changed ownership a few times, including Terex, Bucyrus Erie, and finally Caterpillar. This particular version uses a Cummins 60 liter V16 diesel to power a generator which in turn powers AC motors in each wheel. Interestingly, GE’s locomotive powertrains competitor was of course GM’s ElectroMotive division, which is now part of Caterpillar, and current versions of this truck apparently use the EMD powertrain, so I’m not sure if this one is GE or GM.
Another truck we saw out in the mine was the water truck, which wets the roads to reduce dust. It sprays the water in an on/off pattern, about 50 feet on and then 50 feet off. According to our friendly tour guide, a second generation Boronian (?) whose father, husband and kids all worked there, this is to allow the dump trucks to use the dry sections to regain traction if needed. I suppose 10000 ft-lbs of torque can cause a bit of wheelspin, even with 865000 lbs (about 400000 kg) gross vehicle weight pressing down on those tires. The current versions of these trucks do have traction control. They also have dynamic retarding braking rated at 4400 hp, to go along with 46” front and 37” rear oil-cooled disc brakes.
I did have a chance to see similarly powered diesel-electric locomotives at the site. Most of the borax is hauled away from the processing plant on rail cars. Above is a scale model from a Visitor Center display. This mine is Burlington Northern & Santa Fe’s (BNSF) largest California customer. Though having crossed the desert alongside the BNSF tracks many times, I’d say that Amazon containers are even more numerous.
One last view of the truck. It’s 24’ tall and 26’ wide (7.3 meters and 8 meters). According to Caterpillar’s spec sheet, it also has two cupholders.
Fascinating, now I have a new place to go visit .
-Nate
I’m with you on that Nate. Lots to see on the backside of California along 395 down to the Mojave.
Actually Kern is 3rd largest county, with Inyo in second place and San Bernardino in first being bigger that 9 U.S. states.
The factory used to be in Hudson, Ohio. It was closed in the early 1980s when General Motors rid itself of Frigidaire and other entities. The factory is vacant now, and available for sale or lease.
Boronite?
In November, 1976, on a school trip when finishing primary school, my class went to see what at the time was the largest hydroelectric dam being built in South America, crossing the Uruguay River, between the cities of Salto, Uruguay, and Concordia, Argentina. The sheer proportion of the undertaking was overwhelming for my 11 years, and those rigs…I just looked up and found pictures in Facebook. They were Terex, just as you say. But they look not as gigantic.
I agree with Nate and tbm3fan above that this is on my list of places to visit. I’ve never been to that part of the country, but at some point I’d love to go (outside of the summer months).
And I realized while reading this, that I never quite knew what Terex was. I’ve seen the name on these giant machines, but didn’t know the details, so thanks for the explanation.
Cool, I was on my way from Mojave airport to Vegas to fly home last october, and finally had the time to stop, definitely cool to see.
Nect stop I recommend, The Roadhouse at Kramers junction.
I’ll check out the Roadhouse sometime. Now that Hwy 58 bypasses the actual Junction I just zoom right by.
An impressive find, I’m very sure I will never come across something similar.
In the not-too-distant past, Terex was also the owner of German crane manufacturer Demag. An example from that era is the 2014 Demag AC 700 below, as caught at a 2021 truck show. Curb weight around 238,000 lbs.
I commented, picture didn’t load, once again (jpeg and not too big). Never mind, both sent straight to the trash bin.
I’ve noticed that sometimes pictures simply don’t attach in comments – for instance, that happens often when I try to attach images from other CC articles. I’ve found that saving the image as a separate jpg usually works. I guess it’s just one of the mysteries of the site/spam filter.
The problem with using images from CC is that ours are turned into WEPB files (for conservation of server space) and the comment system only takes jpeg files. I do a screen shot (snipping tool) when using images from CC. In fact I use that pretty much for any images I want to attach to comments, as they’re always going to be jpeg.
Thanks for the explanation!
So that’s where borax comes from! Well I’ll be damned!
I thought it was something that was manufactured.
When I was a teen I was an apprentice in a torpedo factory – we used borax mixed into a paste as a flux when brazing brass fittings on to the ends of copper high pressure air piping .
Interesting timing, as dman and I are currently at the natural hot springs in Saline Valley,which is an adjunct valley in Death Valley NP and is utterly undeveloped, essentially the most remote valley in the lower 48.. I’m connected to the web via my new Star Link Mini, which works like a charm. It’s stark and beautiful here, and the hot springs are sublime.
Here is an experimental coal truck, the Titan 33-19, at Sparwood, BC. Billed as the largest off-highway truck, with a capacity of 350 short tons. Although in service from 1978 to 1990, it turned out to be too complex and expensive to run for the extra volume it was able to haul, and spent a lot of its time parked while unique parts were made.
Oh, sheesh, everyone drives these in the outback here.
Which is of course a bald-faced lie, but there are lots of them in the outback mines. Having seen one close up years ago, it’s stuck in my mind as one of the most fascinating things I’ve ever seen. I think it’s the gigantism: they really do look like a Tonka toy, and it’s impossible to absorb the scale because one’s mind relates it to an identical everyday object that is a tiny proportion of that size.
As a kid, any old person’s laundry always seemed to have a box of Borax lying around, I think, possibly, as an ant-killer, or perhaps a child-repellant. The old-fashioned looking boxes looked scary, probably marked “keep out of the reach of children” (which clearly no-one did).
Like Buck Stradler, I had no idea it was a mined substance. I’ve always assumed Borax was a chemical factory creation.
Yes, Borax kills ants (and roaches too), which is what I use my box of Borax by the laundry area for. Now I feel like an old person.
Just to add to the scale confusion, those headlights are actually the air cleaners.
The real headlights are the parking lights at the bottom of the grille.
The 20 mule teams were actually 18 mules and 2 horses which were directly in front of the load. Mules are very intelligent animals and won’t pull on a dead weight no matter how much you whip them. The horses respond to the whip and get the load to move slightly and then the mules will start to pull.
If you have a week to spare and an interest in borax wagons, you can watch a set being built from scratch on YouTube:
Thanks for all the comments! I’m tagging onto Paul’s Starlink but I really need to sign off and enjoy this wonderful place that has zero cell coverage (or potable water or electricity). This is my second visit to the Mojave in three weeks. And it’s a 400 mile trip each way for me.