Ships are lengthened by inserting a new midbody

How and where are ships lengthened by adding a middle section?

The cut-and-insert operation is normally done in a dry dock, sometimes a floating dock, and remains common on large commercial vessels as well as historic warship rebuilds.

The work requires dock support so the separated hull sections can be aligned and joined safely. The method is no exotic historical trick: modern cruise ships still receive major capacity increases through comparable midbody insertions.