Interesting thread. I was doing a little research on ISO containers on trucks myself and ran across this one.
I think that the question of "can a truck carry an ISO container" has to be qualified. I'm not sure off hand what the tare (empty) weight of a standard 20 ft. container is but that's a starting point. What they call a 5 ton truck in US service could easily handle an EMPTY container, or tow a trailer with an EMPTY container.
Of course, an empty container isn't much use to anyone.
If you run over to the Oshkosh Truck site at
http://www.oshkoshtruckcorporation.com/ and poke around a little bit I think that you will find that their HEMTT trucks (fairly exotic 8x8 vehicles) in the Load Handling configuration (that's with a Tiphook lift for loading and unloading ISO containers) has an empty weight of 36,000 lbs. and a loaded weight of 66,000 lbs., so roughly it can handle a 30,000 lb. (15 US tons) cargo.
That's not a whole lot.
In order to get up to a 20 ton plus cargo weight you need to go to the Oshkosh PLS, which has 5 axles, all of which drive.
Moral of the story: I think that a 5 ton truck in US service is a 3 axle truck. *IF* you could safely overload it a bit you still would have some problems with having too much weight on the front axle to do much in the way of meaningful transportation.
In the States, for commercial trucks, the Feds look at three things: overall weight (usually limited to 40 tons), axle weights (which can vary from state to state as a practical matter), and the Bridge Formula, which is a mathematical formula that basically encourages you to spread the weight out or add axles. This is why you often see multi-axle trucks and trailers with sliding axles - so that you can adjust your Bridge Formula numbers.
And 20 ft. ISO containers are notoriously tricky to get the weights correct on. I noticed on a recent trip to New Orleans that most of the new trailer chassis for 20 ft. containers are actually longer than they used to be. That's so they can spread the weight out and satisfy some law somewhere (Federal, State, local roads - who knows).
In the States trucks with two front axles are very rare. That also makes it tough to legally carry anything that heavy without overloading something on a "straight truck" (non-articulating lorry for you Brits).
All of which being a bit of a moot point if we are talking about strictly military applications. While the US military tries to comply with this stuff in order to humor our various state governements, as a practical matter they haul things like tanks under conditions that would be illegal for a civilian contractor.
So I think that the issue of "can you" haul an ISO container is more along the lines of how heavy is it, do you want to install a couple of tons of unloading equipment on the truck, how tall will it be (a standard container is 8 ft. tall if I remember correctly and on a tall truck you may have trouble staying under the US legal height of 13'6" (a lot fo Europeans can go taller, btw), and so forth.
Comments? Like I said, it's an interesting thread.
