On Oct 25, 6:51*am, wrote:
On Sun, 24 Oct 2010 17:42:31 -0700 (PDT), Cross-Slide

wrote:
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

Thanks for the post. That was way cool. Here is the link to part two
of the vid:

http://www.youtube.com/watch?v=Dc2i06331qQ

As to your question: Those pipe sections look about one flatbed rail
road car in length. Start at pipe manufacturing plant....load to
flatbed rail car.....rail trip to port....port loads pipe sections to
transport barge......transport barge to assembly ship. The rail car is
the limiting factor in pipe length.

They weld two short lengths together in one pass using the submerged
arc method. As far as work flow, this one pass welding is quicker (and
probably cheaper) then the multi-pass welds done further down the
line. This assures a ready supply of pipe into the final product line
even accounting for whatever down time may happen to occur in the
initial preparation area (bringing pipe up from the hold and welding
the two sections together).

It looks like the engineers that designed this whole process pretty
well knew what they were doing. I am impressed with the ingenuity of
them damn humans sometimes.
Dave

I was impressed because for once, there is a video that explains what
is happening, and shows the processes involved, the work flow and the
support to make it possible.

Thanks for the explanation about the two types of welding processes.
The first stage, they can rotate the pipes as they weld them. The
submerged arc never has to be inverted.
The main line welding, that does not appear to be an option.