Surely 23Kgs for hand luggage has to be a typo. None of the internal comms mention 23Kgs but it does specify 23Kgs on ba.com as long as you can lift it yourself. Who would be able to do that in a crowded aisle? There may be space for 5 wheelie bags in a locker but I really doubt it could support 115kgs. Would you want that over your head?