I confirm that 'tub' is released.. Search back, I myself cant reermber the post but its in this forum somewhere, search for 'Hermes'
All my larger ships will receive this style of construction, the smaller ships of 100m and less will also likely be done as a standard ship with the ability to move, but with the restrictions that also come with it.
Heres an interesting co-incidence...
The Royal Navy's latest carrier is going to be built in the SAME WAY, ie in independant blocks that they will then join together, partlyl because we dont have a single naval yard big enough to build as a whole from the keel.