By Adrian Morrall
The structural steel fabricator has developed into a lean, mean machine, but automation in this industry has a long and interesting
history. Most structural fabrication operations of
the past were labor-intensive. Layout, drilling, cutting, and welding were performed manually. In
structural fabrication today, nearly every process
can be automated. Few if any other metal manufacturing sectors could make such a claim.
The ’70s and ’80s
Structural fabricators stepped into beam line automation with machines like the Beatty punch, followed by the three- and five-press beam punch
lines. The beam punch lines of the 1970s were the
first step. They reduced the manual labor required to
process main structural members by punching the
holes in all surfaces in one pass. A saw could be added on the same system to cut members to length.
The next progression was the “pop mark,” an
early way for a beam punch line to make layout
marks on a beam. Using the tip of the punch, a machine could mark the centerpoint of the piece and
the intersection for weldments, plate, and angle
Dealing with mill tolerances was the next challenge to overcome for machines of the late 1970s
and early 1980s. Machines had to be designed to detect all the conditions of the piece to be processed.
This included toed-in or -out flanges, o;-center
webs, twist, and camber.
The structural drilling and sawing line was the
next development, and in the early 1980s drills were
quickly replacing the beam punch lines of the past.
The weight and thickness restrictions of material diminished, paving the way forward.
In some cases, though, the beam punch line was
even faster on lighter material. There was a saying
at one time: Punch for profit, drill for oil. The saying
was true; the cost per punched hole was considerably cheaper than the cost per drilled hole, although
this did not o;set the total benefits of drilling. The
punching system was not as flexible as the drill, and
the punch had restrictions based on the punching
Early automated coping machines of the mid-
1980s were simple systems with no linear measuring that could prepare basic end-connection detail
using three oxyfuel torches.
The next generation of coping machines could
produce far more complex cuts such as copes,
notches, rat holes, weld preparation, slots, web
penetrations, split tees, and castellated beams, to
name a few.
By the late 1980s, downloading of data from 3-D
CAD systems became a reality. The basic cut-to-length, hole position, pop marks for part location,
piece number, and cope information was held in the
DSTV file format, which was developed in Germany
and became a global standard. Many versions later,
this format is still used today, but the file holds far
In the 1990s the cold saw was phased out at many
plants and replaced with more cost-e;ective methods, such as band sawing. Typically, the band saws
were placed in tandem with the drill; this saved
space and required only one operator. The CNC positioned both the saw and the drill before transferring the beam to a coping machine.
The industry soon witnessed the evolution of
plate processing. Structural fabricators moved from
the traditional burn table with multiple oxyfuel
torches to a pass-through-style system in which the
material moved and the machine remained fixed.
Such combination systems could either punch and
plasma cut or punch, drill, and plasma cut. The oxyfuel torch was retained on certain models for thick
The pass-through systems used nesting programs
to minimize scrap. They also dropped o; the finished part rather than requiring an operator to remove it from a table or shake it from a skeleton. The
The road to full
How structural fabrication
evolved from the 1970s to now
A material handling system picks up the workpiece
a;er it exits the beam line and positions it for
Multisystem integration (MSI) integrates multiple metal fabrication machines with material handling systems. The
links allow the entire structural fabrication system to operate as a single, automated unit.