7th Wheel

laknox wrote:
AFAIK, the term "fifth wheel" goes back to horse-drawn days. A wagon with a straight axle needed some way to steer it and, I imagine, some inventor in the dawn of wheeled vehicles, took an old wheel, mounted it horizontal on a straight axle, attached an old spindle to the bottom of the wagon box, dropped it into the old wheel on the axle to allow the axle to pivot.

Lyle

this ^^^ is correct

Somebody got left out in the cold.

AFAIK, the term "fifth wheel" goes back to horse-drawn days. A wagon with a straight axle needed some way to steer it and, I imagine, some inventor in the dawn of wheeled vehicles, took an old wheel, mounted it horizontal on a straight axle, attached an old spindle to the bottom of the wagon box, dropped it into the old wheel on the axle to allow the axle to pivot.

Lyle

The fifth-wheel coupling provides the link between a semi-trailer and the towing truck, tractor unit, leading trailer or dolly. Some camper trailers use a fifth-wheel configuration, requiring the coupling to be installed in the bed of a pickup truck as a towing vehicle, and "fifth wheel" is therefore sometimes used as a synonym for such campers in North America. The coupling consists of a kingpin, a 2-or-3 1/2-inch-diameter (50.8 or 88.9 mm) vertical steel pin protruding from the bottom of the front of the semi-trailer, and a horseshoe-shaped coupling device called a fifth wheel on the rear of the towing vehicle.

So actually it doesn't matter how many wheels your tow vehicle has! :)

There's no logic in the term "fifth wheel" anyway. The hitch is not a wheel, and the ones used in pickups aren't even close to round! So, seventh, eleventh, or 23rd wheel makes just as much sense as fifth!

All I could afford wrote:
Thank god “Charlie” from “18 wheels and a dozen roses” didn’t run on Super Singles”...
10 wheels and s dozen roses just doesn’t sound right

That's a good one !!!! LOL

Thank god “Charlie” from “18 wheels and a dozen roses” didn’t run on Super Singles”...
10 wheels and s dozen roses just doesn’t sound right

I've got 22 wheels on my semi. Boy am I confused now! LOL

What do you call semi trucks with the super singles ?

MarkTwain wrote:
Sounds like some one is suffering from "cabin fever" otherwise know as boredom:):)

True. But, the OP has a good point.