Usually, heavy-lift ships are used for moving damaged ships, or oil platforms and other non-ship marine loads. Here’s the USS Fitzgerald being loaded onto a heavy-lift ship after a collision. The USS Cole on a heavy-lift ship after a bombing. The USS McCain on a heavy lift ship after a collision.
All this is to replace four bearings in the Carnival Vista’s azipods, the steerable propulsion units. The ship is only three years old, and if they have to replace all the bearings, there must be some design or manufacturing problem.
This is costing $50 million. The azipods were built by ASEA Brown Boveri. Is this covered under warranty? This looks bad for ABB.
Here’s what an azipod looks like during manufacture. Bearing replacement is clearly a major job.
 https://www.youtube.com/watch?v=AalbxJtlLBE  https://www.youtube.com/watch?v=ixHPB8rGX9E  https://www.youtube.com/watch?v=abjqBV3cdAo  https://new.abb.com/marine/systems-and-solutions/azipod  https://www.youtube.com/watch?v=lvHb4XTkC0A