Semi-truck...

[Doubleclutch]

I've always wondered why the largest vehicles on the road were called... semi trucks. I know there's a reason, but I sure can't figure it out.

 

[Peter Campbell]

I may be wrong but- a full trailer is like a hay wagon. A pull bar, some steering stuff on a front trailer axle and a rear axle. A half trailer "semi" trailer only has rear axle sets. The front axle sets are from the tractor. Hence the trailer is only half held up by its own axles.

 

[M Barnett]

A truck is what our Dodges are, capable of hauling a load by themselves and/or with a trailer. A semi truck has no provisions for carrying a load, other than weight transfer through the fifth wheel, and only pulls a trailer.

Michael

 

[illflem]

Both Peter and Michael are correct. The prefix word semi just means partial. Using the word semi by itself is slang.

 

[Doubleclutch]

Perfectly logical. Thank you!