Shipping container standards 1

[ChrisatEastAg]

I am designing a trailer to carry a standard 20' shipping container. The trailer must be able to be dismantled and packed inside the container (preferably by one man) along with the towing vehicle. I anticipate a trailer GVM of around 4000kg.
I gather that the weight of these containers is normally carried on the corner posts, the positioning of which is governed by standards (I have these). The trailer could be much cheaper and lighter however if it supported the container floor joists and only used the corners for location/securing points. So...
Are there standards for the positioning and upward force capabilities of shipping container floor joists?
Is there a standard depth difference between the base of the corner post fitting and the base of the container floor joists?

Thanks in advance guys,

Chris Eastaugh
Eastaugh Agricultural
Australia

 

[ornerynorsk]

Containers are standardized, I would talk to a manufacturer about getting the dimensions.

 

[JimSteinmeyer]

Chris;
I am interested in your idea that it would be cheaper and lighter to build the chassis using the stringers as supports. The concern I would have is that the corner locks would still have to support/remain attached in a roll over situation.
Also it has been my observation that the corner castings are not always in the same plane, or same relative distance from the bottom of the stringers. This could create problems with supporting the container with chassis beams on the stringers.
Jim
Reinke Mfg
Reinke.com

 

[ChrisatEastAg]

Thanks Jim, that's exactly what I didn't want to hear!
What I have in mind is a 'pig' trailer, with two closely spaced axles slightly to the rear of the load center, and towed via a drawbar. The weight of the (empty) container could then be supported on the 3 metres in the middle, and the forward and rear sections of the trailer chassis could be relatively light-duty.
I recently discovered Australian Standard AS 3711.10-2000, which says that the weight of the container must be supported *only* on the corners, or *only* on the "intermediate load bearing areas in the base structure". As I read it, if I carry on the stringers, the corner fixings must be non-load bearing; perhaps corner blocks to locate and chain dogs to hold down. I was thinking of using twist locks, but if the stringer height is inconsistent then that would be difficult. The front corner mounts would be part of the drawbar sub-assembly, which would be quite substantial.
What started me off was the idea that I could use the strength of the container (which is a fair lump of steel after all) as a structural part of the trailer. It was a lot simpler when it was just an idea...
When you say the corners are 'not in the same plane', I gather you mean that the container is twisted. If I tie down with chains then this won't be a problem for mounting, but a bad twist would create an uneven load. I'm only looking at carting useable, in-spec containers. Who's job is it to reject them, is there an Authority or is it up to the freight handlers?
I had a look at reinke.com . Nice floors mate.

Chris

 

[dbh06]

Chris, I would suggest you take a look at ISO 1496-5. Containers IAW to this spec have a base support frame capable of supporting the load in two long zones and specified support spacing (sect 5.4).

D. Hanna