had no reason to believe the platen would
fall and injure him.
It is foreseeable to designers, manufacturers, constructors and sellers of cardboard balers that a worker will need to
reach into the loading chamber of the baler
under the platen in order to load the baler
and to remove scraps stuck in the baler.
Accident prevention options
The subject baler as sold by the local
metalworking company had no means
to prevent a crushing hazard with an
unreasonably high and intolerable risk
of serious injury or death should the pin
connecting the platen to the cylinder rod
fail and the platen become disconnected
from the hydraulic ram.
The hazard is a heavy platen weighing
851 pounds that is elevated and attached
to a hydraulic cylinder by a single pin that
can fail. If the pin fails, the platen free-falls and will crush anything in its path,
which can cause severe injury.
It was technologically and economically feasible, and very easy and inexpensive, to install a safety cable to prevent the
platen from falling should the pin fail.
Competitors’ balers were equipped with
safety cables. (Figure 2)
Any machine that contains an uncontrolled hazard when a technologically and
economically feasible method to control
the hazard is available is unreasonably
dangerous if the risk is not tolerable. A
user expects a machine, in this case, the
baler, to be reasonably safe. The unreasonably dangerous and defective condition
of the subject baler is a cause of the employee’s injury. But for the pin failing, the
employee would not have been injured.
Had the baler contained a safety cable,
the platen could not have separated from
the hydraulic ram and would not have
fallen on the employee’s arm, causing the
severe crushing injury.
The local metalworking company did
not check the condition of the pin con-
necting the platen to the ram before it sold
the baler. The local metalworking com-
pany knew or should have known about
safety cables for platens on cardboard
balers. At the time of our inspection at
the shop, three balers were observed with
safety cables connecting the platen to the
hydraulic ram. Additionally, the baler in
question had a hole in the ramrod, but no
safety cable installed.
The owner of the metalworking company testified he knew about safety cables
and their relationship to the hole in the
cylinder rod. Shortly after the incident,
the owner of the metalworking company
reconfigured the platen with a safety cable.
Applying industry standards
There is a standard for balers of this
type. ANSI Z245.51-2013 requires that
balers be designed and constructed with
consideration of the reduction of injury to
persons during operation. The standard
also requires that a rotating or moving
part that creates a risk of injury to persons
due to the part becoming disengaged shall
be provided with a means to retain the
part in place under conditions of use.
It was our opinion that the company
that sold the used baler did not comply
with the applicable ANSI standard because they failed to remove and inspect
the pin, and failed to replace the cotter
pins that would have reduced the likelihood of a cotter pin coming out or the
pin breaking. They also failed to install
a safety cable to prevent the platen from
falling and seriously injuring the operator.
This case settled the week before trial.
Jeff Warren, Ph.D., PE, CSP, (jeff@
warrenforensics.com) is founder and
CEO of The Warren Group, a forensic
engineering and consulting firm.
A user expects a machine, in this case
the baler, to be reasonably safe.