I cannot agree with OSHA’s and manufacturers’ decision to permit forklifts to be used as substitutes for aerial platforms. Thus, the Fluid power safety Institute issues 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 substantial property damage.

The regulatory groups and manufacturers appear to have ignored critical safety elements in their haste to kowtow to industry. There are, and always will be, inherent risks associated with using a forklift for any purpose other than what it’s intended to be — a cargo carrying vehicle — unless it undergoes extensive design changes to incorporate all the features needed to make it fail-safe. Moreover, regulatory groups and manufacturers should focus on the state of forklift, crane, and aerial lift maintenance training.

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.

The Fluid Power Safety Institute invited (via e-mail on October 8, 2007) 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, these manufacturers — Toyota and Hyster — have ignored our attempt to open dialogue on these critical issues.

Rory McLaren is Founder and Director of The Fluid Power Safety Institute, Salt Lake City, which presents safety-based hydraulic workshops. Find a schedule at www.fluidpowersafety.com.

Case history: worker falls when cylinder lowers independent of lift-mechanism

 

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 ft (6 m) 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. Many 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 6 ft (1.83 m). This number varies according to maximum lift-mechanism height and maximum tilt angle.

The 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.