AN OWNER'S GUIDE TO MAINTAINING, SERVICE AND REDUCE THE OPERATING COST OF A FORKLIFT FLEET.
Lift truck tip-overs are avoidable
Understanding the concept of a lift truck's "Stability Pyramid" is
the key to keeping a truck upright and operating safely. As long as the machine's center of gravity is kept inside
its imaginary Stability Pyramid, there is reduced risk of tip-over. You can find the Stability Pyramid for any
lift truck by drawing an imaginary line from front wheel to front wheel, then back to the pivot point for the rear
steer axle. The resulting triangle is the base of the machine's Stability Pyramid.
At first glance it would seem that a four-wheeled lift truck would have a rectangular base instead of a triangle,
but that is not the case. The steer axle pivots on its center pin, and that pivot pin becomes the third point forming
the triangular base of each machine's Stability Pyramid. The top point, or peak, of a lift truck's Stability Pyramid
is located near the back of the machine's mast, somewhere just above the operator's head. Its height depends on
the height of the load, and its fore and aft location is determined by the tilt of the mast.
The Stability Pyramid grows taller or shrinks, skews or becomes more vertical as the operator raises and lowers
loads and tilts the machine's mast. When a lift truck's forks are kept low, its Stability Pyramid is short and
squat, making it relatively stable. Raising the forks elongates a truck's Stability Pyramid, making it tall, skinny,
and much easier to tip over.
The center of gravity rises as the load rises, and now needs only to shift a short distance to get outside the
narrow top of the imaginary pyramid and cause a tip-over, especially if the machine is moving. Momentum multiplies
the torque caused by turning or operating on sloping or rough surfaces, dramatically increasing the potential for
tip-overs.
Lift truck operators who understand the principles and limits of their truck's Stability Pyramid understand that
keeping loads low, close to load backrests, and the mast vertical or tilted back slightly cuts tip-over chances.
Carrying a load at the tips of forks, with the mast tilted far forward, or carrying high loads on a tilted mast
may move the center of gravity near or into the danger zone. Well-trained drivers always wear a seat belt and keep
the operator's platform clean.
Despite break room tales of drivers who brag of having leaped to safety when their sit-down lift truck rolled off
a loading dock, the best place for a driver during a tip-over is strapped securely in the seat.
The overhead guard is what seems to get people who try to jump clear of a machine when it tips over. The guard
extends enough that it?s hard to jump far enough to get clear of it before it hits the ground.
Safety films of staged forklift tip-overs, using live volunteers, (who wore crash helmets and protective padding)
show the volunteers getting a rough, but survivable ride when strapped into safety seats with seat belts. Unbelted
crash test dummies in staged tip-overs invariably ended up under the forklift or pinned beneath the forklift's
overhead guard.
The only exception to the rule of"stay with the
machine" is for those who operate stand-up rider forklifts. Rioux notes that stand-up rider operators usually
have opportunity to step off and away from the machine in a tip-over or off-the-dock accident, and recommends abandoning
the machine when this type of accident is unavoidable.
Keeping operators' platforms clean can also reduce injuries in case of a tip-over.
Some drivers carry Thermos jugs, wrenches, chains, and other job accessories on their machines. While there have
been no reports of deaths due to getting bonked in the head by a flying Thermos full of coffee during a roll-over,
it can be an unnecessary headache that could have been prevented by keeping the operator's platform clear of loose
items. Also keep the platform clear of materials to prevent objects from getting caught underneath foot controls
such as brake pedals.
Safety surveys show that the single most important factor in minimizing lift truck tip-overs is operator training.
All the restraint systems in the world are worthless if a lift truck operator is not trained in the safe operation
of a machine and encouraged to follow safe operating procedures. Unfortunately, few companies aggressively train
their lift truck operators.
Between 65 and 70 percent of
lift truck operators have inadequate training. Companies have the perception that driving a forklift is a "low
skill" job, and that's far from the truth. Driving a forklift efficiently and safely around all the obstacles
in factories and warehouses requires skill and expertise. Compound this with dodging pedestrians and other forklift
traffic, and a forklift operator has a very difficult job.
OSHA regulations currently require only that all workers be trained in the safe operation of any lift
truck they operate in the course of their job. New regulations will be implemented, specifying exactly what sort,
and how much, training is mandatory to operate each type of lift truck.
The days of watching a 20-minute video and being 'certified' to drive a forklift
are coming to an end. A good training program requires a minimum of four hours of classroom training and at least
an hour or more of supervised driving. That's the direction the OSHA regulations seem to be headed in.
All lift truck drivers should be trained in safe operations, especially young drivers. Youthful exuberance and
lack of practical experience can be a deadly combination. Superior Safety Training reports that workers under the
age of 25 account for approximately 12 percent of all work fatalities but nearly 20 percent of all forklift-related
fatalities.
'Occasional' lift truck operators should not be overlooked when training personnel. Many small manufacturers and
warehouses do not have full-time lift truck drivers, and those who operate the trucks are often more interested
in accomplishing their tasks (such as changing light bulbs) than operating equipment safely. Because they are relatively
unfamiliar with controls and lift capacity, the potential for accidents increases.
Many companies are reluctant to spend time and money on training programs for their lift truck drivers. That may
change with the new OSHA regulations. In the end, the new training regulations will actually save money for companies,
because well-trained drivers will cost less in accidents, repairs and downtime.
Productivity magazine
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