Welder — tasks, one by one

Reading the drawing and choosing the method

Procedure databases, digital drawings and offline robot programming now carry much of what used to be looked up by hand. Deciding how a particular joint on a particular part should be welded — the sequence that keeps it from distorting, what to do when the drawing and the part disagree — stays with the welder.

This rests on what welding software can do, not on a measurement of how much planning welders still do themselves.

Preparing, cutting and fitting the parts

Plate is increasingly cut on CNC plasma and laser lines, and positioners and fixtures hold repeat parts. Fitting up real structures — parts that are slightly out, gaps that vary along a seam — is still done by hand, and a robot can only weld what has been fitted well.

This rests on how fabrication is done and what cutting lines and fixtures can do, not on a count of shops using them.

Welding repeated joints and structural blocks

Robots have welded repeated joints on car bodies and production lines for decades, and shipyards are now bringing them to large structures. Singapore's Sembcorp Marine reported installing a robotics steel fabrication workshop and working with robot makers to develop robots that carry out multi-directional welding of large built-up structural blocks, describing the capability as safer, more efficient and better for quality.

The shipyard's report does not say how much of its welding the robots do or how many welders work alongside them; it shows the work being automated in one yard, not a share of the trade.

Out-of-position, site and repair welding

Robots need the part held still, the joint reachable and the geometry repeatable. A pipe in a plant room, a crack in a crane or a repair inside a hull changes from one job to the next, and the welder adjusts by eye and hand as the weld goes in.

This rests on what welding robots can reach and handle, not on a measurement of how much site and repair work there is.

Setting up and running welding robots

Where robots take the repeated welds, someone who understands welding has to set them up and judge their output. Sembcorp Marine's 2021 report shows a technician in its structural fabrication department operating and controlling an automated robotic welding system that welds complex offshore structures remotely, under a mentor's guidance — the welder's knowledge applied from a control position rather than at the torch.

The report shows one person in that role in one yard; it does not say how many people do this work, or what it replaced.

Inspecting welds and fixing defects

Seam tracking, weld monitoring and camera inspection increasingly flag problems while the weld is being made. Deciding whether a flaw is acceptable, repairing it, and qualified sign-off stay with people, because the standards the work is certified against name people who are responsible for it.

This rests on what monitoring and inspection systems can do, not on a measurement of how many welds are now checked by machine.