The Accurate Reloading Forums THE ACCURATE RELOADING.COM FORUMS Other Topics Miscellaneous Topics Why are American semis 18 wheelers and Australian ones 22 wheelersGo | New | Find | Notify | Tools | Reply | |
| One of Us |
Not talking road trains here. But any Mack, Kenworth running around Australia have the 3 axles at the rear but American ones have only 2 axles. Note: I am not a trucking person. Could the reason be that such a huge percentage of Australia is dead flat and thus the semis carry heavier loads than the American semis? | ||
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| one of us |
Jeeez you bring up bad memories. I don't know what is worse, trying to pass an Australian road train, a cane hauler, or a cotton wagon. | |||
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Or a bunch of Amish buggys just letting out of church!  NRA Benefactor. Life is tough... It's even tougher when you're stupid... John Wayne | |||
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| One of Us |
when they hit eighteen, the government said "Enough". That said, they now can, and do, run up to 22 wheels. We regulated them, OZ does not, to the extent we do. And, OZ is flatter than Kansas for most of the terrain and imposes no speed limit, iirc. Canada is similar. That's about the max a driver can control at speed. Rich In two hours I expect someone to bash me over this. | |||
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| One of Us |
The only ones I have seen in Australia with only two axles at the rear of the trailer also have only single axle on the prime mover. They are doing deliveries to our biggest supermarkets and my guess is they are carting corn flakes, tissue boxes etc. All volume and no weight. | |||
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| One of Us |
 legal GVM is limited by the axle & tyre loads. an extra axle & tyres increases the GVM (everything else being capable). Govt levies Rego+roadtax etc on GVM. 3rd axle on the trailer does more road damage on corners than a dual.& you pay for it. Not much is not speed limited in OZ. hilly country just requires more HP & torque to negotiate at adequate transit times for a given payload size. There are no profits in being overpowered for the payload. The truck for the mainstream job is matched to whether you are carting elephants or antelope,just as in hunting the gun is largely matched to the game. | |||
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In another life I was a Department of Transportation Safety Investigator. The trucking and bus companies have about 1500 pages of Federal laws to follow. Most of the smaller companies 1-5 trucks have a hard time with this. Most of the big trucking companies will have as much technology in safety as an airline. HEB the Grocery chain in Texas was the most sophisticated company I ever walked into. Hazmat and Explosives mean more regulation. Agriculture means less. Beekeepers and people hauling livestock feed or livestock can pretty much do whatever they want. Nuculear powerplants have the most regulation. The majority of the time the problem stems from the drivers not the companies. The drivers either don't know the regulations or are out to make money and do whatever they can do to userp the company and the regulations. I have a thousand stories on things I have seen as a DOT investigator. The most common goes something like this: The driver picks up a load for his company Brand-X and while staying under his 11/14 hour rules delivers it. Opens another book and starts dispatching his own load using company fuel for Brand-Y. Drives all night, breaks the regulations on hours and then picks up another load for Brand-X in the morning. Resulting in the death of 5 motorist while he falls asleep at the wheel 800 miles from where he is supposed to be. The biggest problem is that this is an all too often reality. | |||
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| One of Us |
But does Australia being so flat mean that a given HP/Torque allows for a heavier load and hence the 3 axles instead of 2 axles. Actually I have often meant to ask about this but never get round to it. But I was watching a movie that had trucking/semis as its basis/background and here are these people at the cafes etc. talking about being kings of the roads with their 18 wheelers. It first really puzzled me when I watched the movie Convoy. | |||
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| One of Us |
They run three axle trailers in Maine in the logging areas and unlimited weight. I think the bridges would be a concern for the rest of the country. | |||
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| One of Us |
Does America have the B Double. They are very common in Australia. Some of the bridges they cross in Australia are primitive to say the least. However, the vast majority of these bridges are low due to the flat country. I would imagine a higher bridge would require a lot more strength/engineering etc. | |||
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| One of Us |
There is no limit on the number of tires/wheels in the US. What limits you is the amount of weight to be hauled and the overall length, of the rig, that will be hauling it. Based on the spacing of the axles and the number of axles is how you determine how much weight a truck can haul. It is referred to as bridging the weight. Basically how you spread the weight out over the road. Over a certain weight or overall length requires special permits. The most "wheels" I ever worked with, as the designer, was 34. The rig had tandem steering axles, tandem (2 axles/8 wheels) drivers, tandems on the first trailer and two sets of tandems on the back trailer. They used them to haul grain, on the freeway from Montana down to Utah to make into flour. That was a long time ago, the early 80's. Maybe the rules have changed but I doubt it. I see rigs hauling huge loads ,like construction or road working equipment with so many wheels, to bridge the weight, that it is difficult to count them all! Last year they were hauling these huge blades for wind turbines in our area. Again to many to count! | |||
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| One of Us |
Yep...but that does not explain to me why America has the "18 wheelers" whereas in Australia 99% of semi trailers seen, including the capital cities like Sydney and Melbourne are the 3 axles at the rear. A semi like the American semis is a rare sight in Australia. As I said above the movie Convoy looks ridiculous from the Australian perspective. As a side note, don't get me wrong....I wish my great grand parents on both sides had jumped on the boat to America instead of Australia. | |||
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| One of Us |
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| One of Us |
Engine power doesn't give any right to load. its all in the axles & tyres & their configuration. | |||
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one of us |
Off subject, but not, look at the tires/axles on the rigs built to carry M1 Abrams tank. Don't limit your challenges . . . Challenge your limits | |||
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| one of us |
It also has to do with the roadbed design when a 80000 lb trk was big the engineers. Decided that what they would design for and that became standard. In Maine those really big loads are driven on private roads. In Michigan the logging industry can run up to 13 axles. In Wis they can run six and haul 98000lb. The standard is 34000lb per two axle set. In a former life I use to enforce the size and weight limits for the state of Wis along with the other DOT requirements. As Wyoming said one could tell all kinds of interesting stories. | |||
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The Accurate Reloading Forums THE ACCURATE RELOADING.COM FORUMS Other Topics Miscellaneous Topics Why are American semis 18 wheelers and Australian ones 22 wheelers
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