This shot is doubly fascinating. Not only is the lead truck a rare International M-42-CAE yard jockey, but I see it’s got super single tires on the back. Which makes me wonder when these first came out? Good luck trying to find a good answer via Google.
I remember clearly that the concrete mixers at one company in Iowa City in about 1972 or so had them, at least on the front, for additional flotation. And I suppose they may have been used in special off-road applications going way back. But does anyone know when they were more commonly offered on on-the-road trucks?
I did a post on the wide flotation tires available on light trucks back in 2014, but I’ve never seen a good history of wide tires for big trucks. Food for thought.
Just looked up super single tires, seems like a much better idea than duallies. Kahoots with the tires industry?
From what I understand, super singles have lots of advantages over duals, but one *big* disadvantage. If you have a blowout on a super single tire, you’re done. If you have a blowout on a tire on a dually axle (and you’re not heavily loaded) you might be able to gently make your way to a shop for repairs. Tires are much less prone to blowouts nowadays, which weakens the one disadvantage super singles have.
I am amazed at seeing a yard jockey/terminal tractor on what appears to be an interstate highway.
That looks like a Scout on the back. I wonder if this photo was taken anywhere near the old Fort Wayne plant that also built larger trucks. US 30 and the US 30 By Pass were both not far from that factory and were 4 lane roads by the early 60s.
It looks like this photo was taken in the same location as others featured in a recent post by Paul. I believe the photographer stood on the side of US Route 22 somewhere between Harrisburg and Allentown, PA. This was in the 1960s or 70s before the road was upgraded to I-78, IIRC.
I remember building a plastic model Mack cement mixer in the early 1970s (truck models became a thing with the rise of CB culture, and I built a ton of ’em) that had the super-wide tires… on the front.
I assumed they were a new thing then… but what did (or do) I know? 😉
I don’t have much first-hand knowledge, which never stops me, so I’ll make some guesses aided by a bit of Internet research. When I worked at Peterbilt from 1976 to1982 I don’t recall seeing or hearing of super-singles, as a rear fitment instead of duals. This was borne out by a tire dealer site I found that credits Michelin with introducing the first super-singles, the XOne, in the year 2000. What was an occasional fitment at the Peterbilt plant, mostly for mixers and construction vehicles, were front flotation tires, often Michelin Pilote radials but occasionally other brands, all bias-ply. I still remember that everyone pronounced the name with three syllables: pill-oh-tay.
So my guess is that this yard hauler was fitted with flotation tires for its normal duties, presumably on an unpaved equipment site, and not true super-singles designed as duals alternatives. Or perhaps it was a trend-setter ahead of its time.
One other disadvantage of using super singles/floaters on the drive and trailer axles is axle width. You either use a wider or longer axle to maintain tire track width or you use special offset wheels with “standard” width axles. The special offset wheels put an offset load on the wheel bearings so this option is rarely used.
Super single advantages, lighter then two tires, no need to match tire height on trailers. Less tires to check air pressure on. Less rolling resistance? Better fuel economy?
Another side effect was getting the proper equipment to handle tire removal, installation and tire changing. Prior to this a lot of shops still did a lot of manual labor handling tires, Super singles and floaters put an end to that.
The inner tires of a dual wheel set-up wear and tear faster than the outer tires. Not when rolling down the road in a straight line, but when cornering (a lot).
Super singles on rear drive axles are still utterly rare. For the rest everything goes: on heavy-duty steering axle(s), tag axles, pusher axles and above all (the norm): on trailer and semi-trailer axles.
Speaking of drive axles: below a Tatra Phoenix 10×10 with super singles all around. The undisputed, non-military on-/off-road king.
A search of “International one-man cabs” took me to ATHS Forums where I found scans of M series brochures from 1963. Looks like all were gas powered, and all, even 6X4 models, had the single floatation tires at all wheel positions.
I really like the line about the tires.
Specially designed tires (not aircraft retreads) with lug treads on driving wheels.
The right hand outside mirror appears mounted on a post. Neat.
Photo’s taken from exact same spot?