I now exactly what you are saying having, more or less, worked right down the hall from you or, in reality, across the state. And I know exactly what "specification" you refer to. I had this very same conversation at different times with different engineers over 37 years. I guess that's what you get when you apply the literal word to the interpretation and in some cases it must be. The "Pipeline Construction Specification" does say at least two welders are required for 12" and above. Having said that, I don't see a lot of SAW welding going on in cross country construction. What was always needed was a "Fabricated Piping and Assembly Specification" but then you can write several more specifications to go along with that too. There was one written for shop fabricated assemblies but it was decided after many years without being updated it wasn't needed any more. It was an engineering document not a construction document. Back then we had a Construction Section but the documents were all engineering documents. I guess that we should have felt privileged, we, as just field minions were allowed to comment on them.
What you will continue to learn, and you are wise already, is that you are not an engineer therefore you are not well enough educated to make those kinds of decisions. Unfortunately people who are not experienced do get to make those decisions. As you know I fought the battle many years. It's hard and frustrating and sometimes you just have to walk away shaking your head and be content with the fact that these people can waste money any way they want to.
You can bet that the other contractors were and probably are using SAW procedures they just didn't reference or ask the question about using one welder for SAW welding. Let's face it, in fabrication, as you know, many of the fit-ups are made by one or two welders or a welder and fitter and tacked in place then at some time put on a manipulator and the root bead and HP is put in by one welder, sometimes two, but not often. I guess the thing to do is find that particular job, if it went to another contractor, and see if the welds were finished with SAW, probably a good indication that only one welder was used for F & C and then reject all the welds because the procedure using two welder were not used. Most likely for F&C on the mainline only one welder was used. Maybe the specification has a statement that "...for all root beads and hot passes two welders shall be used for pipe diameters twelve inches and above".... Remember "Common sense isn't all that common any more". With all their education it doesn't necessary mean they are smart. You will get like I was, you know you are right and you will fight the battle every time but then you learn that beating your head against the wall time after time hurts. Remember the discussion about the frequency of the multiple qualification test? There were five people there, I knew I couldn't win. After two breaks to privately discuss the issue a compromise of every other year was agreed upon. So much for the corporate code of ethics. I had bled enough already and I could live with the slow drip for a few more years.
By the way, getting better, but that's what I thought the other two times too.