Everytime I see a movie etc. the American semis have two axles at rear of trailer and Australian are three axles. The prime movers look the same.

Some have 3 axles most have two goes way back to early trucking regulations and highway design.

My guess would be load weight limits are less in the U.S. We don't have Road Trains like Y'all do either!

Wow, you learn something new every day. . . . .

Now if you REALLY want to find out something historically interesting, look up why the current railroad rails are the distance they are from each other. It will surprise you unless you already know.

Never even thought of something so simple as weight limit laws.

quote:

Originally posted by Mike McGuire:
Never even thought of something so simple as weight limit laws.

Frost heave in much of the country affects our roads. There are places where there are five seasons. The fifth season is called 'mud season'.

We don't use no steenking chariots no more!

Mike - In the US we have these things called railroads. Pretty much negates the need for road trains.

quote:

Originally posted by Opus1:
Mike - In the US we have these things called railroads. Pretty much negates the need for road trains.

Not much rail in outback Australia. A train goes from east cost across to Perth (capital of Western Australia) and another goes from Adelaide (capital of South Australia) to the top end.

Once you move well inland heaps of the roads that appear as "highways" are dirt roads.

A place where I shoot is all dirt for about 80 miles to very small town. Bills' properties are north west New South Wales so not real outback. Below are some of his semis. Click the photos tab to show more pictures of trucks.

https://www.trucksales.com.au/...harvest-fleet-59932/

I've passed a lot of those road trains. They'll give you a thrill.

quote:

Originally posted by Kensco:
I've passed a lot of those road trains. They'll give you a thrill.

We have semis with a trailer behind, called a B train. Is that the same thing ? Only allowed on certain multi lane roads.

Grizz

Well, Lee, you might be the only one here who knows the answer.

quote:

Originally posted by Grizzly Adams1:

quote:

Originally posted by Kensco:
I've passed a lot of those road trains. They'll give you a thrill.

We have semis with a trailer behind, called a B train. Is that the same thing ? Only allowed on certain multi lane roads.

Grizz

The are called B Doubles in Australia. Seem to see them everywhere. Not sure but might not be able to use roads with a weight limit.

The road train is normally thought of as having 2 trailers or more in addition to the trailer hooked to the prime mover. Some are very big, a lot more than 2 trailers hooked to the trailer that is hooked to the prime mover.

Raod trains in Australia on a youtube

https://www.youtube.com/watch?v=0iFkKRh5kcM

quote:

Originally posted by Mike McGuire:
Everytime I see a movie etc. the American semis have two axles at rear of trailer and Australian are three axles. The prime movers look the same.

Well in the US it would depend on which state your in. I see plenty of three axle trailers where I live but two axle ones are still common too. So it would also effect how much weight you can carry.

105,000 gross where I live.

quote:

So it would also effect how much weight you can carry.

The federal limit is 34000 per standard two axle spread 80000 gross.

But the states often have special regulations that allow trucks to carry more.

I'm interested because I do a lot of insurance coverage work in the trucking venue. Stop it with railroad. Two thirds of the goods in the US are transported by truck. Sounds like a GVW issue and I suspect the GVW in Australia must be higher than 80,000 lbs, necessitating an additional axle.

quote:

Originally posted by NormanConquest:
Now if you REALLY want to find out something historically interesting, look up why the current railroad rails are the distance they are from each other. It will surprise you unless you already know.

I will look that up. I’ve noticed the narrow tracks in Africa and Argentina and wondered why.

quote:

Originally posted by NormanConquest:
Well, Lee, you might be the only one here who knows the answer.

Well the myth is Roman chariots but the right answer is what the English gentleman that first built rail lines there just decided on.

https://www.truthorfiction.com/railwidth/

Well, maybe so, maybe no. I'm sure there will be contestation about HWY I-35 that runs through Texas + beyond. It was built upon the wagon train tracks that separated East + West Texas + that trail, that in turn, was established by the buffalo herds in their migration.