To Jeff, Jura and anyone else interested:
The hangar on the T23 was designed from the start to take a folded Merlin, I had a wander round one at Portsmouth's Navy Days a few years back and those hangars are truly cavernous on the inside! (designed like the TARDIS). They, like the T45s can embark (and stow folded in the hangar) two Lynx/Wildcats or a single Merlin. The flight decks of the T45s go one step further, being sized and strengthened to handle a Chinook.
The previous class, the Type 22 had a double hangar to accommodate two Lynx helos, but from HMS Brave onwards, with a view to eventual embarkation of Merlins they were fitted with enlarged flight decks and taller hangars, embarking a single Sea King each or two Lynx as required for their current deployment. The Merlin takes up as much deck space as a Sea King and also folds down to a very manageable size:
