
I've tracked down the running gear,tow hitches, electric brakes, brake away brakes etc to rate the trailer at 4.5tonne GVM and I hope to keep the trailer at about 1 tonne.
The front of the trailer will have some basic spares, set up to cook and sleep in and there will be a tool box or 2 either side of the axles for the basic tools etc. The whole trailer will be fully enclosed with canvas or something else very light. We are still looking at options here.
The wiring is all covered and the tow vehicle is sorted. This should give you a bit of an idea on what I'm planing.
Now my design plans are this.
It will be a drive over wheel arch design.
The total length of the trailer including draw bar will be 10.4 metres. (max allowed 12.5 metres)
The total width will be 2.4 metres. (max width allowed 2.5 metres)
The total length of the trailer without draw bar will be 8.4 metres.
The total length of the draw bar will be 6.4 metres from centre of axle assembly to the tow hitch. (max allowed 8.5 metres for a pig trailer which I'm assuming this is)

The total over hand will be 3 to 3.1 metres max (3.7 metres max allowed)
The axles will be put from the centre of spring hangers 4 metres from rear.
I think I've just about covered everything. The main thing that has me confused is your not allowed to weld your safety chains on once your over the 3.5 tonne GVM. It's says in the ADRs that you must attach the chains using a suitable pin lock coupling. What the hell are these???
If anyone has any useful advice or thinks I've missed something could you please let me know?

Cheers Mick.