There were a lot of different trucks on the highways in the early ’60s that kept me busy spotting them on our summer vacation trips. One that caught my eye early on was this particular style of Diamond T COE (Cab Over Engine). One of the reasons for that is that it reminded me of certain electric locomotives that I had seen in Europe in the ’50s.
It’s a very handsome truck, with its chrome horizontal bars and curved front end, to improve its aerodynamics. It’s also a bit unusual, in that the front edge of the upper portion of the cab sits slightly behind the leading edge of the lower portion.
Let’s a take a look at some of these:
That detail is clearly visible here. Unfortunately, there’s no ready info on this model on the web, so I’d have to do a bit more research as to when it was first built and its model number.
Here’s the same truck from the front.
Chicago-based Diamond T was a big competitor to Mack, and had its greatest success in the 1930s, when it built exceptionally handsome trucks. We’ll take a look at some of those soon. Here’s another version of this style, presumably a promo shot of a new one. It’s hauling a refrigerated trailer, with a single cylinder gas engine mounted up there, used to blow air over the load of ice inside the trailer to keep the load cool.
Here’s another, this time with a proper refrigeration unit.
And the final one is a long wheelbase unit as was common in the western states.
You would think that with these being built in Chicago that I would have remembered seeing them, but I do not. But my childhood years were the golden age of International Harvester trucks, that were built in Fort Wayne.
I always thought it was hard to make an attractive cabover, but these guys gave it a good shot.
Yes. Definitely the least ugly COE. The locomotive theme hit my eye immediately. It’s like the typical yard engine or doodlebug, with a low rectangular catwalk base and a long hexagon on top.
Not seeing the loco look, but I see more of a Filipino jeepney with the brightwork…
When did refrigerated trailers get their own true systems instead of having to rely on ice? The cold chain is something that marvels me.
I don’t know about this one, looks like another slapped together parts bin special. Reminds me of the 60’s Bedford vans. Looks like it has a bad case of under bite.
The cab doesn’t appear to be a repurposed conventional cab. Its just odd looking, some what aero rounded off cab sitting on top of a rectangular base. Why is the cab set back from the front of the base?
IMHO these two trucks below are THE classic cab overs.
Kenworth Aerodyne K100
“Why is the cab set back from the front of the base?”
Maybe to make room for a bigger engine. The heavy DAF DO-series had a very similar nose job, only to accommodate the Leyland O.680 (11.1 liter) engine. The lighter models (introduced earlier) had the completely “flush” front, yet those never went beyond a 5.75 liter engine.
Johannes, did any of those trucks with the Leyland engine ever use the pneumocyclic gearbox that was installed in many buses? Here in Uruguay they were everywhere in buses, but the engines were not in trucks
Rafael, DAF truck chassis never had a pneumocyclic gearbox, Fuller and ZF manuals only (these days also ZF TraXon, which are automated manuals).
The Leyland diesel engines were initially license-built, but they all evolved into DAF’s own engines (for example, the 11.1 liter Leyland O.680 became the 11.6 liter DAF 1160-series in the late sixties).
DAF bus chassis were available with a Wilson semi-automatic gearbox with a fluid coupling. Isn’t that the gearbox you’re referring to?
Johannes, most post war Leyland buses imported into Uruguay (late 40s up to early 70s) had a preselector gearbox. It’s likely that the coupling was fluid, though I don’t know. However, what always fascinated me was the gearchange. It was a lever installed at the top of a long turret from the floor of the bus, and very at hand for the driver. The gear change took place when pressing the throttle. No clutch pedal was present. The movement was through a gated pad, á la Ferrari. It would emit a loud hiss every time the driver moved it, and the pneumatic system (I think I was told sometime) was fed by the same pumps as the brakes and doors. There was usually a sticker in Spanish saying “Attention – Pneumocyclic gearbox – do not xxx” (I don’t remember….). Every now and then, there would be some kind of pressure problem and the bus would “fail to proceed”, in classic English terms….
Finally, there was a fleet of ACLO buses which had exactly the same procedure, but their gear lever was very small and was installed in a small portrusion under the steering wheel. I suppose that operation was electric, as they didn’t sound the same. Anyway, the last of those buses was decomissioned probably 30 years ago.
I vividly remember that same gated pad from many DAF-based public transport buses I rode in during my younger years (seventies and early eighties). Wilson GB340, that was the semi-automatic transmission.
I looked Wilson GB340 up. It’s clearly a newer version of a similar conceopt. Thanks!
British bus brands often had a preselect gearbox and fluid flywheel probably from Wilson Ive only had a play with one in an old AEC house bus a mate had it still worked ok though the bus hadnt moved for years untill it had to 3 meters but the engine ran well and low gear selected it moved then shut down again.
Air assisted shift, low pressure would stop them working properly those long stroke diesels found their way into lots of buses, Leyland 400 was the top of the range engine in Bedfords too and better than the 466 Bedford diesel though those used a regular manual shift and two speed diff.
The Wilson pre-selector had a ‘gearchange’ pedal to actuate the change.
The Leyland SCG box was slightly more conventional, albeit with a bit of a delay on the actual change due to the length of the air plumbing.
Leyland tried the box in trucks too, but it was viewed with too much suspicion and was dropped.
Maybe to make room for a bigger engine.
There was only this version, and they mostly all came with the big Cummins diesel six, so that’s not the reason.
Yeah, other than the gentle curve of the cab it mostly reminds me of a Dodge L-series trucks with some extra chrome, which is about the bottom of the list of pretty COE trucks. The curved cab looks mismatched with the lower area
Personally I think the Ford and GM COEs that used a blunted and raised up version of their conventional truck noses were the best looking. The dedicated heavy duty designs mostly look too industrial, which can be attractive – talking locomotives I like the looks of a EMD GP7/9 over a E/F series carbody – it’s just a different kind of attractiveness. I have to agree with the ones that are are the peterbilts and kenworths, namely the ones that still used round headlights
I would love to know the story behind the last one depicted. Does the trailer slide forwward to the back of cab? Was another load placed there and the trailer remained where it is shown? Working with load distribution for trucks, this fascinated me. Anyone have information?:
This one intrigued me too. Surely, something must have been done to utilise all that length?
This was common on the West Coast, where the overall length restrictions were much more generous. But some Western states had “bridging” limits, which favored long wheelbases.
I’ve shown a number of these before. Maybe I’ll put a bunch together in a post to show and explain.
I believe these are 923C models, sometimes referred to as ‘China Closets’. The model that replaced the 923C (931C?) was similar, but with a squared-off cab and flat windshield. Probably an attempt to modernize!
Neat – what a unique style – never saw one of these in central Ohio in the 50’s/60’s.
I wonder, given the fact that Diamond T used the International “Comfo-Vision” cab so much on their conventionals, why they didn’t follow I-H and use that cab in a raised position like the LCD-405 and RCD-405 Highbinder Internationals? Just slap a Diamond T grille on and ride!
Yes, but what was really funny was Diamond-T developed their own low cab forward tilt that they shared with International. International eventually modified (raised) that cab on the DCO Emeryvilles:
Diamond T: https://www.ebay.com/itm/194269756363
International DCO: https://commons.wikimedia.org/wiki/File:International_DCO-405_truck_MD2.jpg
Nice old trucks the bottom half of the front has a TJ6 Bedford vibe about it probably the grille bars, but I like it, no I dont want to drive one old trucks are nice to look at only.
Paul, I’m intrigued by which European locomotive it reminded you of. I’m assuming Austrian/German/Swiss, and probably electric. Have to go looking in my library…