Before my time but as I have never seen a trailer over 3500kg with over run brakes I would say it was a long standing UK rule that predates EU stuff.You seem to have missed my point. I understand that now any trailer over 3.5t requires coupled brakes due to EU law but I was questioning when that rule got introduced.
I have a recollection of reading somewhere in some official documents relating to the Sandringham that it did not require coupled brakes to achieve maximum towing capacity hence why I'm asking when the 3.5t limit got introduced.
Is the Sandringham plated over 3500kg MAM?
What does the GTW say?