Caledonian Earth King

Here be Monsters.


Hauling earth is dirty, difficult and downright lucrative work. The entrepreneurial spirit of American, George A. Armstrong founded Euclid in 1933 where he designed and built a reliable heavy duty dump truck, initially named the IZ Trac-Truck. Having built an enviable reputation through their war efforts, General Motors were tempted into purchasing Euclid business from the Armstrong family.

The now GM-owned Euclid dilated enough however to warrant a United States Department of Justice intervention, and in 1959, GM were forced to cease selling Euclid trucks for a total of four years and divest parts of the name and business[1]. The General being the General, GM contrived to develop their own trucks, not covered by the anti-trust ruling.

By 1970, GM chose to abandon the Euclid nomenclature for Terex, a Latin blend of terra (Earth) and Rex (king) with a move towards producing huge machines for mining and related industries. The General then decided to sell Terex in 1981 to German firm IBH Holdings, who then almost immediately declared bankruptcy, meaning the reins reverted back to GM. 

Another American entrepreneur, Randolph W. Lenz ran Northwest Engineering, scooping up two large Terex areas; in 1986, Terex USA, and the following year, the point of our focus today, Terex Equipment Scotland. Over the next twenty years, Northwest expanded Terex heavily with many acquisitions, making GM appear like amateurs. 

Terex 33-11E. Image:

Situated just off the M8 a few miles east of Glasgow, the Motherwell Terex plant was set up by GM in 1950 taking but four years to produce a thousand dump trucks. 1982 witnessed the plant designing, testing and creating their first articulated dump truck – the bright green 3204. But ten years later a rather ungentlemanly blip.

American businessman, Richard Carl Fuisz reported to the House of Commons that he had observed Terex making military vehicles in 1987. Purported to have been instructed by both British Intelligence and the CIA, these trucks were headed for Iraq. Vehemently denying the allegations, Terex took Fuisz along with the New York Times article writer, Seymour M. Hersh to court. Terex had no charges brought against them but did elicit a NYT apology.

On brighter notes, 1998 saw Terex dump trucks change hue from vivid green to white. The seventh generation launched in 2002, taking just thirty six months to produce another thousand. By 2011, their motive power source derived from Scania and remaining with the Scandinavian’s, Volvo Construction Equipment purchased what would become Terex Trucks in 2014 for $160M. VCE procured investments totalling over £35M in order to enhance the facility, launch the tenth generation truck in 2015 and in 2021 relaunch not only with a new beige/white livery but also in name – Rokbak.

The RA 30 and 40 can haul 28 tons (30.9 US Tons) and 38 tons (41.9 UST) of payload respectively, grossing at 52,000 Kgs and 70,000 Kgs. Visually externally similar, the 40 being just over 11 metres in length, the 30 a soupçon under ten metres, we find graphically different set ups beneath the vast yet handsome proboscis.

Dealing first with the RA 30, a five cylinder Scania DC9 diesel produces 276 bhp at 2,100 rpm with 1,880 Newton metres of torque at 1,400 rpm. ZF provides the eight speed fully automatic gearbox allowing the truck to reach 55 Kmh. Should you have the room and nerve, reverse tops out at 15 Kmh. More importantly is the time taken to empty the loaded 14 mm thick Hardox steel body – just twelve seconds and but seven point five to return – the same for both RA variants.

Front and rear frames consist of high-grade steel box sections; up front A shaped, the rear more Corinthian column. The frame articulates 45 degrees left and right making for easy manoeuvring alongside four turn, lock to lock hydrostatic power steering.

Suspension is comprised of double wishbones with four hydraulic dampers with coil over springs. If that sounds remotely car-like, the rest does not, pivoting inter-axle balance beams equalise the load. And the stopping power is expectedly beefy. A hydraulic system with oil cooled brake packs at each wheel with secondary and exhaust brakes combined with a transmission retarder.

Regardless of payload, the RA 30 is a thirsty brute but not necessarily in expected ways. Before shifting a gram of material, the truck requires practically 1,400 litres of various fluids simply to operate. The fuel tanks brims at 370 litres. The hydraulic system 164, the cooling system almost fifty. The engine crankcase alone holds 34, the transmission another fifty. Then add 150 more with front, centre and rear differentials. Yet Valvoline need not be on speed dial as transmission oils need changing every 4,000 working hours on the 30; big brother 40, every 6,000.

Staying with the 40, the engine has become a DC13, in-line six cylinder pumping out 440 bhp at 2,100rpm along with 2,255 Nmt at a lazy 1,300rpm. Allison provide the six speed box which has a two speed transfer, making twelve forward (but just one reverse) gears. Hustling makes 64 Kmh – reversing just 8 Kmh.

With frame and brakes mirroring its sibling, suspension here consists of four trailing links with a singular Panhard rod with heavy duty dampers for ‘excellent handling and ride.’ The payload bodywork gains an extra millimetre, the steering just 2.5 turns but best bring your uprated wheel brace for either model lest you suffer a puncture; the 30 wears a dozen studs, the 40 a withering nineteen per wheel. Aping Oliver Reed, the 40’s fuel tank now consumes 500 litres, hydraulics rise to 341 with those other essentials vastly increasing. 


Operating conditions vary wildly. Inclement weather may disrupt your plans but these machines are built to work, regardless. A Winter kit allows for prolonged exposures down to minus 25 degrees Celsius. Your quarry colder? The Arctic kit keeps everything toasty even when it’s minus forty out. Both kits comprise thermo-heaters, engine independent heaters allowing warming fluids to circulate long after the shift ends ensuring nothing freezes up – and easy restarts for the morning. And best use Arctic Fuel in such conditions, regular diesel would congeal into a waxy gel.

Unconfined to this sceptered isle, on relaunch, many global orders rolled in – they’re now making one of these per day. The name may be new but with a healthy seventy-odd years reputation, along with Volvo backing; whether it’s for that new motorway junction or extracting the minerals required for myriad modern purposes, Rokbak are there.

[1] Parts of the ruling did not apply to GM operations in foreign countries.

Author: Andrew Miles

Beyond hope there lie dreams; after those, custard creams?

24 thoughts on “Caledonian Earth King”

  1. Good morning, Andrew. Fascinating stuff. I just turned on John Prine’s ‘Paradise’ before I read today’s article, which is a surprising coincidence. For the uninitiated the song is about the Peabody Coal Company strip mining the town of Paradise in Muhlenberg County in Kentucky. I wonder if they used Euclid equipment.

    Here’s a shot of ‘Big hog’, the world’s largest shovel. You can just make out the dump truck in the back.

  2. There are few stories about objects with wheels that leave me cold. But although today’s story has brought me a lot of new knowledge, I can’t do much with the subject of lorries/trucks.

    It’s strange, but I’m obviously missing a gene.
    For me, a truck is a truck. Sometimes big, sometimes small, sometimes huge. It makes no difference to me.

    We have friends whose grandchildren go into ecstasy when they see a truck or an excavator. (I can’t tell you exactly, because when these friends tell me about their grandchildren, I usually don’t listen, because I can’t do anything with children either – obviously another gene I’m missing).
    I can’t remember ever playing with a truck as a child. With me as a child, the children’s toys couldn’t be two-door and flat enough. I was always different from other children in many ways – to the chagrin of my parents.

    Still, it’s fascinating to read about the amount of fluids that circulate inside such a monster to make it perform the function it needs to perform.

    1. For me I can appreciate the engineering and utter industrial might of such machines, but I do prefer when things involve more recognizable aspects of automotive design. These types of machines don’t do much for me, but I am interested in all the differences and design choices that separate a Scania from an Iveco, persay, since they aren’t too dissimilar to what make a Saab and a Fiat different. Or best yet, when they get all the coaches together for Coach Euro Test!

      I mean, they’re just reeeeealllly big estate cars, aren’t they? 😉

    2. My childhood memory of the subject is of passing the Newhouse works, with a yard full of shiny yellow “haulers” beside the M8, and being told that Euclid was a mathematician. I was old enough to know what a mathematician was – my mother was one – but struggled to make the connection with earthmoving machinery.

      Much later, and disappointingly, I found out that the company was named after the Ohio city in which it was founded, itself named after the Ancient Greek geometer and logician in the late 18th century.

      John Milton namechecked him in his Sonnet 21, which has a bit of Nostradamic prophecy about it:

      “Let Euclid rest, and Archimedes pause,
      And what the Swede intend, and what the French.”

  3. Good evening Fred and Freerk

    Thank you most kindly for your comments. That is one impressive excavator, Freerk.

    The word defence seems too strong here but I’ve been happily afflicted by an interest in matters four wheeled since birth, I believe. Cars have always been the mainstay but I too (as you can probably tell) have a great affinity when presented by a truck of this nature. Is it size, shape, colours (sand by the way, not beige) strength, characteristics? Difficult to say but such vehicles fascinate me. How can such a large and imposing thing travel and operate so easily? But like modern cars, the operating systems make it all a doddle.

    As a (practically) fifty two year old child myself, I fully understand your situation regarding actual children ; best left well alone. You never know where they’ve been…

    Returning to huge machinery, check out the Hambach mine for gargantuan mining equipment. It’s unbearably brutal yet (to me) fascinating to observe, especially with all the appropriate support vehicles such as Unimog’s as well.

  4. A few months back, I became curious about a detail I’ve noticed on many mining dump trucks.

    No, those are not headlamps, but the designers clearly want to give these trucks somewhat familiar, if not friendly faces.

    See the real headlamps below the… They are tanks, either vacuum or pressure, I believe for the brake systems.

    1. I doubt that the designers wanted to give these vehicles a friendly face. Rather, these luminaires, which are more of a work light or floodlight, are simply positioned in places from which a good illumination of the surrounding area is possible.
      I think one of these lamps turns a garden into day at night and it takes eight of them to turn a whole valley into day. I can practically hear the designer saying “more IS more”.
      For me the fascinating part are the ladders and railing. I think at first the eye sees it as ornamental, until you realise what dimensions this giant thing must have.

    2. Hi Fred, You won’t find any pictures with the covers off these “luminaires”, because they are tanks (if I recall correctly) associated with the hydraulic system.

    3. Ups, ohhh merde…

      A classic case of “talk is silver, silence is gold”.

    4. Don’t confuse the Rokback trucks with those gargantuan vehicles from Komatsu or Liebherr.
      The Rokbak can carry 30 or 40 tons of load, the white Liebherr has a capacity of more than 280 metric tons of load and a gross weight of nearly 600 tons. The Liebherr has wheels of just over four metres diameter (rim size 63 inches, no less) which should put its dimensions somewhat in perspective.
      In the mie-Nineties I was on a consulting job at (then) Demag-Komatsu’s factory where these giant trucks and fitting diggers (shovel size sixty tons) are produced. Watching these vehicles in their testing area was kind of weird fun – like Gulliver in giant’s land. Trucks and diggers are made-to-measure from standardised components, each of them a unique item. For every truck and digger there’s an individual workshop manual and parts list. Now imagine handling a recall in which a certain item in the hydraulic system has to be replaced on all of a certain group of vehicles – the background of my job then.

    5. The Liebherr’s headlights are the shiny items next to the fire extinguisher on the bumper – and they turn night into day.

    6. On the Komatusu the ‘eyes’ are air filter covers -you can see the sand separators under the box.
      Mines are dusty environments

    7. Dave, thanks for the clarifications. I was inspired to bring those other trucks into the conversation because of my memory of the former “largest truck in the world” entry in the Guiness Book of Records, which was the Terex 33-19 “Titan”.

      GM made only one, a prototype, in 1973. The Titan was designed for coal mining, for which there turned out not to be any demand. However, the prototype was put into service at a steel mine in 1978 serving until 1991. It remains on static display alongside a highway in British Columbia.

      Here’s a Terex ad from 1977 featuring the Titan:

  5. Euclid / Terex was once a major employer with a big presence in the Motherwell / Bellshill / Newhouse conurbation. They’ve scaled down now, but only because of the way the industry works, with the core activity being on-site fabrication of the chassis and load bed using on-site robotic welders and a painting facility. The completed chassis is then populated with components brought in from outside suppliers.

    Not so different from what Toyota or Nissan do at their UK factories, although at Newhouse the process is slower and the products far larger.

    The Newhouse factory is impressively compact and lean in its functioning, particularly given the amount of autonomy Rokbak appears to have within the Volvo group:

    It’s well worth watching the interactive factory tour – the main functions at Legbrannock Avenue broken down into 1-2 minute long videos:

  6. I’ve learned two things today: one is that Rokbak exists and much more significantly that a company owned by Volvo uses engines from their compatriot and rival Scania. Why they don’t use a Volvo one is a mystery.

  7. Great write-up and story telling. I admire it and I appreciate its inclusion into this “least influential motoring” archive.

    Plenty of information for me lesser-educated soul.

    Keep it up.

  8. Ah, the joy when eight year old Andy found a copy of the Observer’s Book of Commercial Vehicles in Bath Central Library, and 8yoAndy would pore over it, marvelling at the scale of some of the beasts, including what were then called Euclid trucks.
    I was never lucky enough to have any Tonka toys, but would happily excavate away with smaller scale Dinky and Corgi models, and the fascination is still there, reawakened when I drive along the A303 and A31 and see the single carriageway being dualled, though only with the relatively small Volvo articulated earthmovers.
    From the above it seems there are not too many of us, but it’s good to know that I’m not alone.

  9. I’m a day late to this particular class, mainly because these hugely impressive machines leave me somewhat conflicted: I cannot avoid emotionally associating them with the depletion of the Earth’s resources and scarring of its natural beauty. I’m fully aware that this is irrational and perhaps even hypocritical on my part, given that I enjoy the fruits of their labours, but so be it. Great write-up in any event, thanks Andrew.

  10. You take the words right out of my mouth, Daniel. That is exactly the reason why I wasn’t interested at first, but I must admit these machines fascinate me. Somehow off-topic, but the large scale proportions remind me of megalomanian housing projects like this one in Nancy. It’s fascinating but it is also horror.

    1. I took my boy to Diggerland a couple of years ago. We had a great time, thoroughly recommend it, though the scale is rather smaller.

  11. Like many of you, when I was younger I had no interest in big trucks. But when I bought my Tatra T2-603 in 1991, I also discovered the big Tatra trucks with their air-cooled V-12 motors. Of more interest was the drive line and chassis design. These units had a backbone central chassis tube, and inside was a series of drive shafts and crown wheels. Each of the 6 [or 8] wheels was part of an independent suspension, free to articulate. And the entire drive line has NO U-joints to fail [a common problem on big trucks]!

    In 1997 I attended the 100th anniversary of Tatra in the former East Germany, and while there I saw a unique heating system for the dump beds in extremely cold weather; As the big Tatra diesel V-12 engines were air cooled, Tatra simply ducted the engine cooling air back to a double-walled dump bed that kept the contents from freezing onto the steel bed.

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