Thanks for the clarification, binsleepen.
Those layovers [justified, of course] certainly add to the manpower requirements, and financial cost, of operating LH. It seems to represent 4 days work and 10 days off - with BA paying salary and expenses for a lot of 'unproductive' time whilst effectively getting a 2-day working week in return. No wonder CC manpower savings are high on WW's agenda.