I once had a friend who described moles as being at of the extreme of land-based mammalian body parameters, or something along those lines. And, convoluted as it sounds, I see what he was getting at: moles are weird as hell, especially when compared with other mammals. They’re weird squishy oblongs with proportionally massive paddle-hands, but that’s because they’re designed for a very specific set of behaviors. Big trucks, especially cabovers, are sort of like this, too.
Compared to most of the vehicles we encounter, cabover trucks are definitely at the peripheries of automotive design. It’s strange to compare them to moles, seeing as how the differences in scale are so vast, but I think in this context that comparison can be made.
For example, how many other vehicles could you buy that offered so many gradations of size for one basic body type? Look at this:
That’s from an old ’70s Kenworth truck brochure, showing that you can get the cab in five different lengths! And look how minimally different that second-from-right variant is, the yellow-orange one! It’s only three inches longer than the one after it!
The overall proportions of cabs like these are deeply odd, too. Look at this GMC Astro cab diagram:
Can you think of any other mass-produced automobile that has a body that is twice as wide as it is long? I don’t think I can.
And, look at the chassis of one of these GMC Astro trucks:
That’s deeply weird, isn’t it? Out of context, at a glance, minus the wheels as shown here, I’m not sure I’d identify this as a truck chassis! The tall exhaust stack almost makes it feel like something nautical. The external side fuel tanks, the three axles/six wheels, the short length, and the whole packaging is just so different than what we’re used to seeing on automobile chassis, and yet this is still a common type of vehicle on the roads. It just feels weird.
Maybe it’s just from thinking about these without their trailers, which perhaps isn’t a fair way to look at them. They’re really not meant to be considered alone, they’re part of a larger whole. That huge trailer they pull defines so much of their design that, when separated from it, you can see just how much these diverge from the expected automotive layout in order to accomplish that one goal effectively.
The tilt-forward method to access the engine – that’s unusual, too! Also, I heard from someone I knew that used to repair trucks that on sleeper cab versions of these, a common danger was that a CRT TV set would come smashing through the windshield when folded down.
Also, these look so much like they’re respectfully bowing when they’re open.
Even the interior layouts feel different, because they are, of course. Unlike most cars, the interior of a big rig truck is someone’s place of work, their office, so a wraparound setup like this just makes sense.
I suppose all of these things are obvious, or at least are things we just take for granted, having been exposed to them for so long. But, I think every now and then it’s good to take a step back, forget what we know, and try and look at things with minty-fresh eyes.
Because then the familiar seems weird, and that’s sort of fun.
These are so fucking awesome like the one in T2 (Terminator) Skynet is coming for us all! (Fuck AI…Artificial STUPIDITY)
We need interiors like this now, at least along the lines of the 70’s Pontiac Grand Prix’s where half the dash/all the gauges, etc point towards the driver and the passenger doesn’t get shit…they can shut up and listen to what you play, etc. They don’t get their own FUCKING SCREEN. Fuck the passenger (Well, if they’re a hot girl that’s great!)
I almost want to from now on no matter who’s in my car…the whole time have all windows open, heavy metal blasting to 11, and smoking the whole time (and absolutely no phones- shut up, enjoy the ride, and look out the window for once in your life)
Cabovers were a product of the overall length laws of the time. The shorter the tractor, the longer the trailer you could pull. One that went away, so did COEs. And one of the reasons that the Europeans still love them, the other being that they are a heck of a lot handier on small narrow streets than a conventional.
But the US is a land of wide open-spaces, and we relatively rarely send big-ass trucks into the tight confines of our older cities compared to those guys. We have the space to deliver to a big trans-shipping terminal in the ‘burbs, then send a smaller truck for the last few miles most of the time. Some of the urban delivery companies keep some REALLY old COE tractors on the road, like the old Ford C series trucks, the newest of which are now 35. Still see them occasionally in Boston and NYC pulling short trailers.
Speaking of Euro vs. US trucks, one of the things I find amusing is that even though Europe has draconian speed limits and required speed limiters for trucks, their trucks are usually WAY more powerful than US trucks – with Scania offering up to 770hp stock. Because if you can only ever go 90km/hr, you need to be ALWAYS going 90km/hr no matter how steep the hills get. In the US you can crawl up the hill at 35 and then blaze along at 75 to make up for it (and most of the US is pretty flat to start with), though even in the US many big fleet trucks are now limited to 65-70 or so. But I have had older trucks haul ass past me when I was doing 80+ out west… No better “tow” than a CB-equipped semi in a hurry!
Please please write more about trucks! You don’t know 5% of the cool smart stuff I realized while working on them. Because of the need to be extremely practical, they are far quirkier than cars. I’m speaking for European cab-overs mainly.
Tilted the cab forward on a 97 COE Freightliner to remove the rad once, heard a horrific noise. Found the twin 12″ subs in a box hanging by their cables mere inches from the windshield. Never since have I assumed that ANYTHING in a COE truck is secure.
I work on COE trucks, and were always supposed to check and clear the cab before tilting, *even though the customer is responsible and has to pay in case a windscreen breaks*. I have heard some stories, but the biggest thing I missed were sunglasses. The most interesting thing I needed to take out was a camping chair. That could have done some damage.
More fun, look up the Crackerbox GMC and then the Willeme WR8 that preceded the Citroen as the Michelin tire tester
The schnoz on the Willeme would have made Jimmy Durante proud!
There is an even weirder cabover in Europe. For maximum cargo volume some trucks have a short cab with a single sleeper in the roof. This makes for a very tall cab but most of these are truck/trailer combinations rather than semis so the cab blends into the body
And there are vans (Sprinters for example) with overhead beds as well!
Cabover trucks used to be a lot more common in the US because it meant getting around length restrictions, but those seem to have gone away so there’s a lot more conventional trucks now. Only place you really see cabover trucks all that much is in urban places where the shorter length is a benefit. And in Europe where there are stronger length restrictions.
Not just Europe. Also Japan, China, Australia, New Zealand, most of the world TBH…
Forgot to say how heavy they are… 10 tonnes easily, plus another 10 for the wagon leaves just 20 tonnes useful load….
“just” it can carry its own weight on the back, that’s a better ratio than light trucks and cars normally achieve. Relative to the load they carry they are actually quite lightweight.
“Also, I heard from someone I knew that used to repair trucks that on sleeper cab versions of these, a common danger was that a CRT TV set would come smashing through the windshield when folded down.” “CRT TV set” is trucker for dead hooker.
Somehow i’m not surprised by the initially perceived definition, or the real definition.
Torch must be using his brain wave scanners, because I OWN A CABOVER SEMI NOW! I know nothing about them so I’ve been learning a lot.
Basically, when I was around 7, my dad bought a white/freightliner COE to tow his 32′ Cabin Cruiser. He used to tow everything with 70s cadillacs, but wanted to step it up, since the boat weighs 9,500lbs. So he sold the caddy, and bought a used Freightliner from Allied trucking company for DIRT cheap.
He then spent the next 15 years improving it; the pneumatic leather seats are out of a much newer Volvo, new bumper, new fuel tanks, polished 6″ stainless steel lake pipes, refreshed the engine, straightened and repainted the entire cab to match the boat graphics, all hand sanded/polished stainless hardware on the exterior, upgraded wheels. Even the frame of the truck was modified; all the extra holes that weren’t needed were welded shut and ground smooth and resprayed.
He went SO Fing HARD with it, and made it so clean, he quit using it. He occasionally took it to ‘truck shows’, but just borrowed a semi from someone else whenever he needed one. This thing has been in storage, indoors, for 15-20 years at this point.
Here are some pics, from when he first got it, to close to being done customizing it; the front wheels now match the rear ones in the last few photos.
https://imgur.com/a/cabover-X30C1Mu
Yeah, that’s me in the bomber jacket lol
That’s a sweet truck, looks like it has a sleeper cab and everything. I hope you can resist the temptation to pick up any hobbies (a draft horse team, boating, a carnival ride) that a big tow rig would enable.
I have 6 boats 😛
One for walleye, one for perch, one for bass, one for skiiing, two spares?
WOW.
Wish you were closer, we could go check it out and see if we can get it started and take it for a spin.
Oh man, I need to drive that some day. That looks like a LOT of fun!
Hit me up on IG, hope to have it running this spring
That’s a pre 78 since it says White Freightliner, and they parted ways in 78, and Mercedes bought Freightliner in 81
In the early 60s, my dad bought a conventional Autocar tractor. I don’t know why. He sold it a few months later. Maybe ten years later, he decided he had had enough commercial salmon fishing and went to work for a company and pulled bottom dump trailers used to deliver dirt and gravel to construction sites. His first truck for that was an IH with a 4×4 transmission and a 6V-71 Detroit Diesel. Once he was financially on his feet, he sold that and replaced it with a brand-new Kenworth with a Cummins 350 and a 13-speed RoadRanger. I got to drive it once, without trailers. It was fun and terrifying at the same time.
There were some guys that were pulling those trailers with a COE. Their short wheelbases apparently made for an even more abusive ride over the rough stuff they had to drive over to build the nice smooth roads we drive on.
He helped build the stretch of I-5 around Yreka and Montague along with countless streets in new subdivisions around Sacramento. I think of that every time I drive through there down to California and back.
I’m pretty sure that I really Optimus Prime 🙂
That GMC Astro pictured in the article was one of the most advanced for its day for driver visibility and ergonomics. Most cabovers had more limited view angles, and a less driver-focused ergonomic “cockpit” area. Most controls were ahead of the driver on either side of the wheel, which the driver had to reach around and under to get to. Or the driver had lean over further to the right to reach them. (Which is why you’ll see pictures of them with toggle switches equipped with big 2-inch-long extensions.) Once in a while, a manufacturer would move the AM radio and heater controls to a panel on the side of the engine “doghouse” for convenience, but it was usually an afterthought and they were actually stuffed too close to the driver’s arm or elbow. The Astro interior was pretty ground-breaking. The driver’s seating position was so high that truckers used to joke that somebody on the ground could see you scratch your… (…Well, you get the idea — it’s trucker humor. ????)
I don’t really think of them as weird. Cabovers or moles. I think I consider them as “more fit for purpose that most” or maybe “super-specialized”.
Most vehicles and land mammals are more general purpose, adaptable to many environments and behaviors, but cabovers and moles are designed for a single purpose – dragging round huge loads and being subterranean grub-seeking cruise missiles, respectively.
Another cabover danger from the 60s…my buddy’s Dad was killed when a sudden gust of wind blew the cab back to its regular position and crushed him as he was working on the engine.
That is something I have always wondered about but figured there was some sort of safety latch that engages when the cab is tilted forward. Either way what an awful way to go out.
Most of them did, either a folding lock stock or a stop rest on the jack mechanism so the cab couldnt blow back or leak down if it was older.
But safety was kinda the 3rd row seat passenger in alot of cases those days, like the murder split rings or the chin buster dayton wheels.
There is in fact a safety latch that engages when the cab is tilted.
Thanks for the new semi-irrational fear.
I don’t remember the movie, but I think I saw that happen in the trailer.
Ain’t nothing looks as cool as a Billy Joe MacKay Aerodyne Cabover Kenworth.
Billie Joe McKay
Ducking autocorrect. 🙂
You mean second-from-right?
Does the brochure mention why they offer it in such sizes? I’m guessing it has to do with maximizing your cab space relative to the length of the trailer you were going to be using since overall length was regulated then. Would be interesting to know which cab size was meant for which kind of trailer.
I kept waiting for Jason to actually explain the differences!
Yep, all due to a very complex landscape of individual state’s length and axle weight regulations. It’s gotten a bit better since then.
You mean second-from-right?
Even experienced bloggers occasionally forget that the internet is like a mirror. Once you post, it all gets flipped.
Indeed, a skeuomorphic relic dating to the printing press.
Alot had to do with the icc, iirc, with overall length, so to accommodate a 47, 53, 57 or even a 60 odd ft trailer, cab length with frame was dictated as an overall package.
Once it died and rules relaxed alot, could rock a sleeper w900 with a 57 footer in most states thereafter.
Were certain trailer types usually a certain length, like was it specific to what you might intend to haul most often? Say, livestock, for example.
I know most dry and reefer are between 53 to 56, pretty sure a hog hauler would be around 64, but generally speaking it kinda depended where it was gonna operate than what it hauled.
Iirc, indiana per say was pretty loose from what my old folks told me about it.
Where to some like michigan and ohio were sticklers, so a 56 would need a day cab COE, where here it couldve been longer with a sleeper COE or a conventional.
It’s still weird to me driving through Oregon to see trucks pulling a semi-trailer and two more trailers. Three big, long boxes. Reminds me of the “road trains” of Australia.
Yeah, the turnpike and rockies combos were always a sight.
Hell triples, we only see em up north in indiana, otherwise theyre just doubles down here.
I cant imagine trying to back up a triple or a rocky mountain setup.
I used to drive a Ford LCF cab over when I was a late teen/early 20s. The sense of speed is so strange at first. I was terrified to exceed 25mph because you almost feel like you’ll fell forward onto the road when you brake. Freeway speeds were always a little weird but the ability to maneuver and forward viability was great. I definitely miss it sometimes over the F550s we have but the bounciness of the front suspension regardless of load was crazy since there was no suspension for the seat itself.
Mmm… that’s some good cabover content Torch. I’ll never forget seeing one of those open up for the first time. I must been about seven or so, hanging out with The Old Man down at the fire station and they flipped open the big yellow cab on their ’74 Ford fire truck. I just stood there stunned thinking something along the lines of “Holy trucker’s mother, the hood is actually the cab!”.
This was my first experience with a cabover opening as well. The fire department was doing some sort of career day at my elementary school and tilted forward the cab with a couple dozen of us kids all going “OOOOOHHHHHHH” in unison to it. Knowing what I was like as a kid, I bet that’s all I talked about to anyone who would listen for at least the next week.
I really hope the salesman asks people to select body styles by giving them choices like Ritz Crackers, Pop Tarts or Saltines.
Yet another profound article by Jason “The Torch” Torchinski
The Autopian is having a stellar week. This article, Tracy’s “This is everything wrong with the old 4×4 I bought” one, and the fantastic car sounds article, and it is only Thursday.
This kind of content is awesome. You answer the questions I never knew I had. I just find it exciting and amazing to learn about how these things work and why they exist. Even though I’m in my 50s, I’ve never lost that part of me that fills with wonder and excitement when I see big machinery, trucks, farm implements etc. Thanks!
This is the reason why at the MN State fair ever year I go I have to visit “machinery hill” which is where you’ll find a sizable section of old farm tractors, hit or miss engines, steam tractors, as well as dealers for new usually smaller sized tractors and various ice fishing and small travel (rv) trailers + some construction equipment, usually mini-skidsteers, ride on lawn equipment, full size dump trucks (w/dump bed up bc it catches eyeballs), etc…
Great opportunity to get up close and ask ‘how’s this/that work?’.questions
https://youtu.be/mgTOz6cTuJ4 THIS Is Why America Stopped Making Cab-over Trucks
The steering mechanism/linkage of cab-overs intrigues me. It is impressive that it works at all at those angles and then also stays connected when tipping the cab forward for repairs.
There is a YouTuber named Bruce Wilson that has been documenting his journey to getting a Scania cabover federalized for use in the USA. It’s fascinating. Y’all need to check out his vids.
I’m enamored by cabovers.. The packaging marvels that they are make me wonder why we don’t see more of them on the roads here. What’s not to love about sitting above, if not slightly forward of the front axle. Turning radii on these are nice and tight compared to your typical Mack or Volvo truck and it makes operating these seem like childs play compared to their full-length brethren.
https://www.carscoops.com/2023/04/this-is-why-america-stopped-building-european-style-cab-over-trucks/
The safety aspect is a bit of a null argument. Modern cabovers meet or exceed crash safety guidelines, and Bruce’s Scania even has automatic emergency braking like a modern sedan or SUV.
I did not write the article. I also know that perception of safety is more important to people than actual safety or safety data. (see big SUV buyers)
That’s a weird article. I’ve never heard safety as a reason for the phaseout of cabover semis in the US – I’ve always heard that old cabovers ‘rode hard’ before air seats were introduced, since the driver had to sit over the front axle, so they weren’t popular with drivers, and the whole cab-tip-up thing made them unpopular with mechanics, so when regulations on overall truck length were loosened in the early 80s (I wanna say 83?) they more or less fell off the market.
I did not write it but I think that safety was not the primary objective.
I live in Europe and I’d never realised Volvo (trucks) made anything except cab-overs. I’m surprised that it’s worth it for them to go to the trouble of making a US style truck when they already have a cabover design.
The modern cabover as built in Europe in the 21st century is a very different beast from old US-style cabovers shown here. Complete air suspension for the whole cab, not just the driver’s seat. Safety cell construction for the cab. Very modern sound insulation and either a minimal “doghouse” over the engine, or an entirely flat floor.
Once the total combination length restrictions in the US were largely harmonized and cabovers were no longer essential, truckers quickly abandoned them for safety (no longer wanting to be “the first at the scene of an accident”) and interior room of a conventional cab and sleeper with a flat floor. European safety regulations and the resulting packaging changes to cabover designs have made them reportedly as safe or safer in a crash than modern American conventional cab designs.
And interestingly, due to the considerably higher weight limits allowed and expected for European trucks, available engine horsepower is often higher than what’s typically found in US trucks. Although seemingly small due to very compact designs, the European cabovers are very competitive for power and efficiency. Other than typical payload capacity, the major difference in operation for European trucks is that their speeds are limited to the equivalent of 45 MPH in many countries, and in a few, up to the equivalent of 55 MPH. They have very advanced anti-lock brakes and traction control, and many trailers have passive or even active self-steering rear wheels or sets of wheels (Some of which can be remote-controlled from the cab.) Oh, and much stronger under-run protection at the sides and rear of semi-trailers. They’re far in advance of how trucks are equipped in the US.
They really are very different markets. European trucks operate at lower speeds in a very dense environment, and have more terrain and elevation changes. US trucks generally cover much more mileage per year, but most of it is on open highways where simplicity for reliability is valued over the latest tech, and things like trailer steering are unnecessary. That said, ABS and traction control are the norm for current US trucks.
A decade back I did engineering work for a class 8 OEM, and one thing that always surprised me was the enormous fuel tanks some European trucks would spec. They would put a tank anywhere frame space was available, sometimes carrying as much as 500 gallons. My understanding is that they were filling up in countries with cheap diesel, then trying to make their whole trip through Europe before refilling, a scheme that might work if you were hauling a lot of something fairly light.
Drivers running on the US East Coast would probably appreciate European cabovers’ maneuverability and the steerable trailer axles. Lots of tight spots to get in and out of there.
Seems like a cab-over would be a good solution for those Alaskan ice-road truckers. Sitting on top of a heat generating diesel seems a good bit cozier than letting all the heat dissipate in front of your eyes.
That’s what heater cores are for. In principle for extremely cold climates you could make the radiator the heater core.
True, but there is still a lot of heat in the engine compartment that isn’t captured by the cooling system. I would imagine having the floorboards soak up a chuck of that extra heat would be welcomed.
I remember one episode in which a driver had multiple socks on his feet and additional towels wrapped over his boots due to a poorly working heater. In a cab-over, I would think you’d still get a measurable amount of heating even with a busted heater. I’m sure it wouldn’t be enough to forego the heater, but every little bit helps.
Floorboard heat of the transmission is how I warmed my hands in my TR3 which had no factory heater.
A few months ago I was going back and forth with another Autopian who worked for his city’s transit org regarding this topic. I had made the point auxiliary heaters were not needed for diesel powered transit busses in cold climates, that waste heat would be plenty. This claim which did not go unchallenged. I did some maths and yeah, the coolant heat and a portion of the exhaust heat was roughly the output of the auxiliary heater his busses used.
So I’m pretty confident coolant waste heat in a truck cab is plenty. At least if the heater is working like it should which in your example it was not. At which point I might cut a hole in the transmission tunnel, CO poisoning be damned.
In my ’64 F100 coach-built crewcab, due to the addition of the rearhalf cab, the muffler was repositioned to directly under the rear seat area. I remember way back when I occupied the rear seat that occasionally the floor got really hot, especially in the summer. Great in winter though.
They are marvels of packaging. I loved cab-over trucks as a kid. I knew they were special somehow, like “why does the other kind need such a long hood while this one has no hood?”
Working in the heavy equipment industry, most people don’t realize that the design of heavy trucks are dictated heavily by regulation and use case.
For the example of the cabover above, this was because prior to the Motor Carrier Act (MCA) of 1980, commercial vehicles were limited by overall total size. After the act, the length restrictions were lifted, allowing larger tractors to come into play.
Tractor length in itself a function of utility as well, as the motors for these vehicles are very large, dictating a large hood and equally large opening for serviceability. There are also concerns around weight distribution, i.e. “The Bridge Formula” that allows only so much weight on each axle of the vehicle, with large fines for carriers and drivers for being over limit.
All this leads to some very esoteric design choices, which, unlike passenger cars, puts function and total cost of ownership over style.