The desire to increase welding productivity is especially important in today's competitive world economy.  In addition, the significant welder shortage makes automatic welding attractive as productivity can be increased significantly. 

The desire to weld in joints with minimum gaps has existed since I entered the industry in the mid 1960's.  However it is even more important today to increase weld completion time and reduce the amount of welding consumables needed.  My early career was in one of the most prestigious Research and Development Laboratories in the USA.  We had over 100 professionals in an era where TIG welding was gaining popularity and MIG welding was just being introduced.  Stick welding represented over 75% of the weld metal being deposited.  I initially worked in the Submerged Arc field optimizing processes and developing new ones like a 3 wire all AC system that controlled arc deflection in a way that allowed welding speeds to be increased over 50% for the manufacture of gas and oil transmission pipe.  Speeds over 125 ipm were achieved in production where previously 60 to 75 ipm was considered the limit. These systems were used in four pipemills in the USA (those willing to invest in the material handling needed.)  It was also installed in pipemills in Japan, Italy, the UK, Middle East and Mexico.

The above photo shows two of the few weld samples kept over the years because of their uniqueness.  The Submerged Arc weld cross section, right, was made with a 3/4 inch root gap, very low angle sidewall  and utilized a two pass per layer split bead technique.  Weld metal deposition rate was up to 75 lbs/hr.  A report was recently prepared for a client with these "relatively narrow gap procedures"  for welding 11 inch thick HY-80.  The resulting weld joint required 75% less welding materials than  conventional procedures with mush less distortion.  This approach also produced crack free deposits without stress relive heat treatment.  A past experience welding 12 inch thick HY-100 was also used to provide these recommended procedures, welding flux/wire recommendations, expected weld properties and special welding nozzle design.

The weld section, left in the picture above, is even more unique.  This cross section is from a MIG weld made in 2 inch thick plate with a 1/2 inch gap and  straight sidewalls.  These are some details: 

_* The weld beads were placed one above the other. 

_* Weld deposition rate was 25 lbs/hr! 

_* How was that deposition rate achieved with solid wire? 

_* How was uniform side wall wetting achieved? 

We are offering a similar proposal for Narrow Gap Welding.  It is particularly useful for the very creative MIG narrow gap system which can have broad appeal.  The Report consists of over 20 pages of information about the original development process effort. 

It also discuses the field trials made in production and although partially successful, the seam tracking systems available at the time, the low labor cost and other economic considerations for both for the fabricator and the supplier prevented their future development.