As above, the only limit as far as I was told was the baggage handlers H&S limits [32kg, I believe]
Not sure what you mean CaptainMainwaring but the cabin baggage limits are listed on the baggage part of the FAQ page [2 clicks from the home page] & seems clear enough to me.
Cabin Baggage Allowance
Each passenger (excluding infants) is permitted to carry one piece of cabin baggage on board (free of charge). Strictly one item of cabin baggage is permitted per passenger (excluding infants). Handbag, briefcase, laptops, etc must be carried within your permitted 1 piece of cabin baggage. It should weigh no more than 10kg and not exceed the maximum dimensions of 55cm x 40cm x 20cm.