Curly leaf on Tomatoes

Well our tomato plants have taken a turn for the worse since last week, they have now got curly leaves. I looked up on the internet for the reason and its because they have been over-watered.
Actually it is probably as I suspected the trough they are in is too small.
So we moved them all.
These are the plants on 11th May, really healthy looking.

...and on 10th June 1 month later....

Sad they are looking rather unwell... we will be keeping a sharp eye on them now they are in 'hospital'.

We put one of them in the frame to keep the Cabbage and Beetroot company!