Thanks.
We've got a fairly crazy set-up. After a year of looking for land we had to buy somewhere to live and then buy the field. As a result we finished up owning land about 20 miles from the house. Not ideal. However, we only want to grow stuff - no animals - so being that far way isn't a show stopper.
BUT
We can't leave machinery in the field as it would be gone 10 minutes after leaving it there. Hence the trailer.
The trailer is also a small caravan (front 6 feet) so it gives us temporary accommodation when we need to spend more than one day working there. The back half of the trailer has a drop down ramp and the tractor, topper, transporter box, etc. can all go in the back. The tractor is a 20hp alpine one with an air cooled engine so it only weight 600kg - about half a ton. So its weight isn't a problem as the trailer can carry about 1.5 tons and still be legal.

NN