Is a Forklift a Safe Substitute for an Aerial Platform?
Regulatory
groups and manufacturers have developed, what they refer to as, “safe” methods
for lifting personnel with a forklift (ref. OSHA 1926.602) – or if you will, “licensing”
forklift owners and operators to use their forklifts as “crossover” vehicles,
i.e. in addition to transporting cargo, they can be used as “aerial platforms.”
These
experts did however make a few stipulations, some of which are extremely vague:
- The work platform must be equipped with
standard guardrails or equivalent means, and must be firmly secured to the
lifting carriage or forks.
- The hydraulic system must be designed such
that the lift mechanism will not drop faster than 135 feet per minute in the
event of a failure in any part of the system.
- The operator must be in the driving seat
while workers are on the platform.
- The operator must be in the driving seat
while raising or lowering the platform.
- The forklift must not travel from point to
point with the work platform elevated at a height greater than 4 feet while the
platform is occupied. When
necessary, an occupied platform can be moved as long as the forklift is
“inched” at a very low speed.
- The area between the personnel on the
platform and the mast must be guarded to prevent contact with chains or other
pinch points.
The
preceding stipulations are well-founded. However, could the regulatory groups
and manufacturers have overlooked a number of critical elements associated with
forklift design and ownership, which could either cause, or contribute to, the
uncontrolled descent of a forklift’s lift or tilt mechanisms while the mast is
elevated and thus cause a person to suffer severe injury or death?
1. From a
design point of view comparing a forklift to an aerial platform is akin to
comparing apples and basketballs.
A forklift (also
referred to as a lift truck, fork truck, or a forklift truck is a powered
industrial truck used to lift and transport goods short distances.
In stark
contrast to a forklift, an aerial work platform (AWP), also known as an aerial
device, elevating work platform (EWP), or mobile
elevating work platform (MEWP) is a mechanical device used to provide workers
temporary access to inaccessible areas, which are usually at an elevation
higher than ground level.
Both
forklifts and aerial platforms share similar hydraulic components from an
operational point of view. However, an aerial platform designer has an
additional design responsibility, i.e., to insure the “platform” is fail-safe
from every point of view while it is being used within the operating guidelines
defined by the respective aerial platform manufacturer.
Needless to
say, an aerial platform has a number of hydraulic “safety valves,” which are
not usually incorporated in a conventional forklift’s hydraulic system design.
Without these critical safety devices, any vehicle, forklift or otherwise, is
inherently unsafe for purpose of elevating and/or transporting personnel.
Moreover, forklift manufacturers aren’t shy about warning of the consequences
of using their products for this purpose.
There are
always inherent risks associated with riding “outside the confines of a mobile
vehicle’s frame.”
Forklifts do
not have redundant safety components and/or systems for the specific purpose of
protecting the “rider” in the event of the unexpected failure of a critical
hydraulic or mechanical component.
On the other
hand, aerial platform designers focus very heavily on platform reliability and
machine stability, which makes safety the nucleus of aerial platform design.
Accordingly,
aerial platforms do have redundant safety components/systems for the specific
purpose of protecting the “rider” in the event of the unexpected failure of a
critical hydraulic component.
What the
regulatory groups and manufacturers have apparently done is to give industry
permission to use a forklift as a “crossover” vehicle, i.e., in addition to using it to move goods around the warehouse, it can also double as an aerial platform.
Unfortunately,
due to conventional forklift design objectives, a forklift without substantial
modifications to the hydraulic system, cannot perform the latter with any
guarantee of safety, and thus, there are, and always will be, inherent risks
associated with using a forklift for any purpose other than what it was
specifically designed to do, i.e., transport goods.
2. Education
and training – arguably the weakest link! -
The issue of
forklift safety extends beyond the boundaries of forklift design. It relies
heavily on the qualifications and training of forklift maintenance personnel.
The most
powerful argument against using a forklift as an aerial platform has to do with
the education and training – or the lack thereof – of maintenance personnel.
Equally as
critical is the poor state of maintenance, in general, in the forklift
industry. These issues will be addressed separately.
Safe and
predictable forklift operation (Ref. OSHA 29CFR1910.178O) can only be achieved
if a forklift is expertly maintained.
The safe and
efficient operation of any machine can only be realized through the
implementation and execution of a world-class proactive maintenance program,
which is only effective if executed by well-trained technicians; one cannot exist
without the other!
It is
virtually impossible to meet these requirements if the people who are
responsible for performing the maintenance services are untrained - especially
on critical systems like hydraulics.
Ironically,
over 98% of the people in the U.S. who maintain, service, and, repair hydraulic
systems and components are not properly trained.
OSHA has
passed a law (ref. OSHA 29CFR1910.1780) that makes it mandatory for a forklift
operator to be certified in the safe operation of a forklift. Moreover, the law
requires them to receive both hands-on and formal classroom training.
Ironically,
the people who have the lion’s share of responsibility for the safe and proper
operation of a forklift - the mechanics - are completely ignored by all
regulatory groups, including the owners and operators of forklifts.
So, why
aren’t mechanics held to the same standard as operators? Moreover, why do the
regulatory groups and manufacturers “look the other way” with respect to the
training and certification of mechanics?
“Flying” is
a relative term! -
An airplane
and an aerial platform share a fundamental similarity – they both “fly” people!
To avoid an
unimaginable toll on human life due to crashes born of poor repair and
maintenance practices brought about by untrained personnel, the federal
government – the Federal Aviation Administration (FAA) – passed into law a bill
that made it a federal crime for untrained/unauthorized personnel to perform
any service or repair work on an airplane. The “flying public” feels safe thanks
to “Uncle Sam.”
Unfortunately,
the same cannot be said for the aerial platform industry – it’s a veritable
“free-for-all.” Literally anyone, regardless of training or experience, is
permitted to service and repair all types of personnel lifting mechanisms –
including forklifts, cranes, basket trucks, amusement park rides, etc.
When a
person is elevated by means of a forklift, basket-truck, or an aerial platform,
that person is, for all intents and purposes, “flying.” Ironically, the life
and limb of these “pilots” is generally in the hands of people who have little
or no training!
Needless to
say there has to be a reason why the regulatory groups and manufacturers – the
people whom never in the course of their work have to risk their lives “flying”
these unreliable and unsafe machines – cow-towed to corporate America and
allowed them to make a forklift a “crossover” vehicle. Could the reason be
green in nature – money?
The vast
majority of people who maintain, service, and repair forklifts, and especially
forklift hydraulic systems, have absolutely no formal training. This leaves the
majority of forklifts, regardless of how much training the operator receives,
highly susceptible to accidents, which could result in severe injury, death, or
substantial property damage.
In my
opinion, the regulatory organizations and manufacturers made a very serious
oversight when they ignored a critical aspect of safe and reliable forklift
operation – the mechanic.
3. Forklifts
are generally “maintained” on the basis of “if it ain’t broke don’t fix it.” -
Needless to
say, the quality and consistency of any maintenance program cannot rise above
the level of competence of the maintenance workforce, or maintenance
management, for that matter.
Another
compelling reason why a forklift should never be used to elevate personnel –
the maintenance is less than adequate!
Here are
just a few of the problems:
- The vast majority of forklifts operate on
the basis of “if it ain’t broke don’t fix it!” In a nutshell, forklift
maintenance is generally performed on the basis of “crisis management!” They
are typically “run into the ground” and only then do they get the attention
they need – maybe! Repairs are seldom properly done because maintenance
personnel are generally not empowered to make decisions on the quality of their
work. Supervisors usually dictate how repairs are executed with the main
objectives being cost and time rather than quality and reliability!
- Less than 1% of the hydraulic components on
a forklift are removed on a proactive maintenance basis. The forklift industry
operates on the basis of “run-to-fail (RTF).
NOTE: This problem is not unique to the
forklift industry. The vast majority of hydraulic systems operating in plants
and on mobile machines operate on the basis of “run-to-fail.”
- When a forklift is “sidelined” due to an
unexpected problem, production is usually unaffected. Besides, most plants have
a “fleet” of forklifts – there is usually a backup. If all else fails a
telephone call to the local rental facility solves the problem.
Maintenance
and production supervisors and managers are usually well aware of their options
so their attention is focused on the “squeaky wheel” syndrome.
Maintenance
supervisors and mechanics are usually so busy “putting out fires” on production
machines that little time is left to schedule service on the “non-critical
production machines” such as forklifts!
4. Forklifts
are generally very badly abused. -
A visit to
most truck loading facilities is tantamount to visiting a forklift proving
ground. Forklift operators routinely “spin the tires,” select reverse (or
forward) while the vehicle is traveling in the opposite direction, overload,
etc.
Most
forklifts exhibit severe body damage from constant collisions with whatever is
in their respective paths. In short, a forklift is arguably one of the most
neglected and abused machines in a plant.
The term
“unreliable” is synonymous with neglect. Neglected machinery will inevitably
break down unexpectedly. These aren’t the types of machines electricians,
painters, pipe fitters, etc., should be “flying” in the course of doing their
respective jobs.
5. OSHA’s
“135 feet per minute” descent rate rule for failure to “any part of the system”
is, in my opinion, preposterous. –
“Weaknesses” in forklift design,
makes them relatively safe for transporting cargo, but inherently unsafe as
“work platforms.”
According to OSHA regulation (ref. 29CFR1910.178) a forklift may be used to
lift personnel on condition that the user follows a number of guidelines. One
of those guidelines being, “the lift mechanism will not drop faster than 135
feet per minute in the event of a failure in any part of the system.”
This rule is baseless because it is impossible to control the descent rate of
the lift mechanism “in the event of a failure in any part of the system.”
Here a few examples (Figure 1) of failures which could lead to the
“unrestricted” descent of a forklift’s lift mechanism:
1. Lift chain failure
2. Cylinder retaining pin failure
3. Cylinder internal seal failure
4. Cylinder rod failure
5. Mast guide wear-plate wear.
6. Hose failure.
There are also additional factors that could cause an accident, such as brake
failure, inattentive operator, etc.
NOTE: The vast majority of these types of failures are caused by
poor/inadequate maintenance training, substandard/non-existent service and
repair, and/or forklift abuse.
6. Rider’s
life is in forklift driver's hands! -
Another
distinct disadvantage of using a forklift as an aerial platform is the fact that
the “rider’s” life is in the hands of the forklift driver. An inattentive
driver can cause the rider to "suffer" numerous types of accidents,
which could lead to severe injury or death.
A
conventional aerial platform is designed to permit the “rider” to control all
vehicle functions including wheel drive and steering.
CASE HISTORY:
An electrician asked the forklift driver to hoist him to the ceiling to attend
to a defective light, which was at an elevation of approximately 20 feet from
the factory floor. He used a pallet as a work platform.
The driver was sitting in the forklift receiving instructions from the
electrician. While the electrician was busy attending to the light, the
forklift driver apparently struck up a conversation with a colleague.
A short while later, the electrician shouted to the forklift driver to lower
him to the ground. The driver, without looking up, responded by activating the
lever to lower the platform. However, he continued with the conversation.
A minute or so went by and the electrician repeated his request for the driver
to lower him to the ground.
This prompted the driver to glance forward. To his horror, the lift mechanism’s
cylinder rod was completely lowered while the platform remained aloft.
The forklift driver, realizing the gravity of the situation, (the slightest
movement could cause the platform to come crashing down) immediately activated
the control valve hoping to raise the cylinder rod to meet the platform.
Unfortunately, the electrician became impatient and turned around to see why
the operator was not responding to his commands. His moving caused the mast
sections to realign. The driver watched in horror as the platform came crashing
down to the concrete floor below (Figure 2).
As a result of the fall the electrician suffered severe back injury and
multiple bruises.
NOTE:
|
On certain forklift models mast wear guides can
wear out and cause the mast section(s) to temporarily seize while the
lift-mechanism is at maximum elevation. This situation can leave the “rider”
vulnerable to a serious “free-fall” accident because the lift-mechanism’s
lift cylinder(s) can lower independently of the lift-mechanism.
|
The OSHA “descent-rate” rule appears to apply to all forklifts regardless of
type, age, or condition. Most forklifts do not have hydraulic safety valves
(velocity fuses) integrated in the lower port of the mast cylinder(s).
Consequently a hose failure, for whatever reason, can cause the lift mechanism
to “free-fall,” leaving the rider susceptible to severe injury or death.
The regulatory groups and manufacturers appear to have overlooked problems
associated with an unexpected failure of a forklift’s mast tilt mechanism,
which also operates with hydraulic cylinders.
A forklift’s tilt angle averages 3º forward and 3º backwards from center. The
distance of lateral travel at the top of a fully raised mast is approximately
six feet (varies according to maximum lift-mechanism height and maximum tilt
angle)
An unexpected failure of a tilt cylinder hose or mechanical part could result
in a very serious accident. For example, a forklift is being used to elevate a
person to a height in a building to replace a broken light bulb. While the
person is working overhead one of the hydraulic hoses in the tilt cylinder
circuit unexpectedly fails causing the mast assembly to lurch forward
uncontrollably throwing the lift mechanism against the structure. The person
cannot be thrown from the device because, according to OSHA regulation, he/she
is securely harnessed. However, his/her body is thrown against the side of an
adjacent structure violently, which could cause severe injury or death.
7. Don’t be
fooled by dual cylinders! –
People who
don’t fully understand how a forklift’s hydraulic system works might be led to
believe that two cylinders provide a “safety net” i.e., in the event of a
transmission line failure and certain types of mechanical failures in one
cylinder, the “good” cylinder will keep the platform upright.
Not true!
The transmission lines, which supply oil to the cylinders, are connected in
parallel (Figure 3). This simply means that the failure of ANY transmission
line which transports oil between the control valve and the cylinders will
result in a total loss of that systems motion control leaving the rider’s fate
up to the laws of gravity!
The same
applies to certain types of unexpected mechanical failures.
CONCLUSION -
Based on the fact that every facet of the fluid power industry is unregulated, i.e., component repair and overhaul, flexible hose construction, mechanic’s
training, forklift maintenance standards, etc., I cannot agree with the
regulatory group’s and manufacturer’s decision to permit forklifts to be used
as “substitutions” for aerial platforms, and thus offer the following warning:
"Using a forklift as a 'work platform' is inherently dangerous and can lead to accidents,
which could result in severe injury, death, and/or substantial property damage."
The regulatory groups and manufacturers appear to have ignored critical safety
elements in their haste to cow-tow to industry. There are, and will always be,
inherent risks associated with using a forklift for any other purpose than what
it’s designers intended it to be – a cargo carrying vehicle - unless, of
course, it undergoes an extensive design change and incorporates all the “bells
and whistles” needed to make it “fail-safe.”
Moreover, it is high time the regulatory groups and manufacturers focused on
the pathetic state of forklift, crane, and aerial lift maintenance training –
to mention just a few areas that need urgent attention!
It doesn’t take a “rocket scientist” to figure out that regardless of how well
a vehicle driver is trained, his/her safety, and the safety of those who work
around the equipment, lies squarely on the shoulders of the maintenance
mechanic.
A forklift is as safe and reliable as the people who service and repair it,
regardless of how well the operator is trained!
I invited (via e-mail) two major forklift manufacturers to participate in this
safety alert, specifically on the issue of descent rates in the event of an
unexpected failure. To-date, they have ignored my attempt to open dialogue on
these critical issues:
Toyota - no comment (e-mail sent 10/18/07)
Hyster - no comment (e-mail sent 10/18/07)
NOTE: Since writing this blog I
learned about an incident in which a worker was using an aerial platform in the
course of doing his work. While performing the work, one of the tilt cylinder’s
flexible transmission lines unexpectedly failed causing the mast assembly to
surge forward several feet, and stop abruptly causing the worker to be thrown
“overboard.” Fortunately, he was wearing a harness, which from all accounts,
saved his life.
Copyright Rory S. McLaren
