This is a pretty cool video of a pipe laying ship.
That's a LOT of machinery and work going on there.

I don't understand is it seems as though half of the ship is dedicated
to processing short sections of pipe into longer sections, which are
then sent to yet another separate welding station to be welded into
the actual string.
Wouldn't it be so much cheaper to have a shop on shore to weld the
short sections together, rathern than having two separate welding
operations on the ship?

http://www.youtube.com/watch?v=EyrdjqEiTZc