Full title reads: "Hamburg. Ship 'Surgery'. Four Hamburg-America liners are being 'operated' on to increase length by 50 feet."
Shots of liner ship Hamburg sailing along.
Shots of liner in dry dock / ship yard.
Various shots of lots of work being done to liner. They appear to be cutting of the front or back of the ship and fitting and extended piece to make the ship longer. The extension is slowly moved into place.