I thought I'd relay a story from my coworker about his son. This man
came within inches of losing his life thru a sequence of very logical
and extremely reasonable steps.
A 4" thick piece of mahogany was being machined for tenons. The piece
was part of a huge 20' door and, as an oversized, required special
cautions, including that the safeties be removed from the machine.
Since mahogany is carcinogenic, they took the trouble to increase the
airflow to prevent the workers from being exposed to the dust. The
guides that were normally in place were too small to accommodate the
large piece of wood.
Apparently the door stile would be cut in two parts- once would make
the horizontal parts of the tenon and then it would be hand sawn to
make the verticals. The piece was so large that it was bigger than
even what the CNC machine could handle.
The gentleman's son had already completed this task on several other
pieces. While removing the this piece, however, he clipped the edge of
the rubber shield that was protecting him from the carcinogenic dust.
The 14" cutter head was instantly wrapped in a thick blanket of rubber
and, under the force of a 20hp motor, shattered.
The sensation, as described, was little more than a small 'kick' to the
stomach and chest. For a moment he looked down and tried to understand
what exactly had happened- obviously the 20' piece of mahogany hadn't
kicked back otherwise he wouldn't have been standing. In seconds,
however, he began to 'spurt blood'- rapidly, too. Three pieces of the
carbide cutterhead had punched thru his stomach and chest. At the
speed of 7200 rpm they left at over 400 fps and the equivelent energy
of being shot with a .357.
Surgery was touch and go for several days- multiple surgeries were
required to repair all the damage and stop the bleeding. At least for
two of the days the doctors kept repeating they had no odds to provide
on whether or not he would live.
Even the most reasonable intentions and safety analysis can show
drastic flaws in hindsight. I quipped that another machine should be
bought. Another coworker pointed out that a simple kevlar vest would
have prevented the torso shots. You can imagine the suggestions and
ideas to prevent this disaster that were all offered up... in
hindsight. Machines are expensive. Bullet resistant vests are
expensive and (considered) by all to be overkill. A lexan face shield
scratches and is expensive to replace.
While I (obviously) don't have all of the details right (and I wasn't
going to push for much more) it just amazed me that this happeend in a
professional woodworking business that knew how to perform these tasks
safely (and has an outstanding record of this). The entire logical
arrangment was completely safe, up until they added the protection from
the carcinogenic dust generated by the mahogany wood.
Hope everyone stays safe and has a sane and productive year.