Thanks for the reply,
So if over 400Kg, then internals straps alone are insufficient. Where would this be documented? I could really do with downloading an official document that states this!
I am being told by my transport office that they’re fine, I say they’re not. I had a 450Kg pallet of paint with a 185Kg pallet stacked on top retained only by an internal strap and my curtain. After exiting a roundabout I noticed a bulge in my curtain. The lower pallet had partially collapsed causing the top pallet to slide into the curtain. Luckily the strap & curtain held, but it could have been much worse.
Cheers, Nez