Unauthorized modifications to material handling equipment can be trouble

July 20, 2011
In this edition of In the Trenches, Acme learns that unsafe production processes prove expensive.

Years ago, Awnuld Faiblesse vowed he'd never be scrawny. Ever since then he pumped iron. He lifted weights before he went to work in the morning, he sat on a weight bench in the back of the maintenance shop and did curls while eating sandwiches at lunchtime, and after work he went to his health club. No doubt about it, Awnuld worked out and it showed — he was in shape. He seemed almost comical to the folks in the plant because they could tell when he was coming their way from the rhythmic squeaks of his hand grip strengtheners.

On the business side, as a member of the mechanical gang at Acme, Awnuld prided himself on his ability to screw things together tighter than anyone else. You see, Awnuld believed that if he got things tight enough, they just couldn't break. He really didn't concern himself with disassembly. After all, what were cutting torches for?

About a month ago, Acme's production manager Luther Quick requested that maintenance modify a forklift for use under a mezzanine. The mezzanine was installed next to a loading dock to double storage space and so parts could be transferred directly to the appropriate workstation with the least amount of material handling. The only problem was that no one verified the overall height of the forklift trucks and now none would fit under the mezzanine. Thus came a quiet request from Luther for maintenance to modify at least one forklift to accommodate the less-than-adequate height of the mezzanine.

Maintenance engineer Titus Flint understood the situation all too well. He had backed Luther in the cost reduction and productivity improvement plan that called for the mezzanine, and now he couldn't let that project go sour. So he assigned Awnuld the task of modifying the forklift by installing smaller wheels and making the overhead guard lower and removable so the lift truck could travel under the mezzanine.

Late in the day, Titus called Awnuld to his office and told him that he needed a special job done that evening and asked if Awnuld wanted the overtime. After a moment of thought about getting to the gym later than usual, Awnuld agreed.

Titus then laid out the job of modifying the lift truck — replacing the 14-in. wheels with 10-in. wheels, sawing four inches off the overhead guard cage supports and drilling holes to accommodate push-button type locking pins. Titus explained this would make the overhead guard cage easy to remove by simply depressing the spring button on the shaft of the locking pins.

Awnuld told Titus that he understood what was needed and would take care of the job before he left for the day. This put Titus' mind at ease — a minor modification on a forklift truck to avoid a major material handling faux pas.

Awnuld went to work on the lift truck. The job didn't take nearly as long as he expected. Within a couple of hours, the overhead guard cage was four inches lower than it had been. Unless somebody looked closely, there was no way they could tell that any modifications had been made. Changing the wheels was a snap for Awnuld. He felt proud of himself as he stepped back and reviewed his work. The material handling guys would be able to use the lift truck starting on the midnight shift. Then it occurred to him that he ought to make sure that those wheels didn't come loose. So Awnuld got a persuader — a two-foot long piece of pipe to go on the wrench handle — to be certain the nuts were really tight. As he gave the nuts one last healthy turn, he noticed how easily they began to turn. "A persuader sure makes nuts turn easy," he chuckled to himself.

On his way out of the plant, Awnuld stopped by the production office and told one of the clerks to let the material handling foreman know that a forklift truck located in the maintenance area was ready if they needed it. The modified lift truck went back into service immediately. Ely Kroy arrived to pick up the lift truck at the maintenance area almost before Awnuld was out the door.

As Ely drove toward the mezzanine, it occurred to him that there is a better way. If someone would ride on the truck's forks, they could direct him to the right pallet instead of him having to do it by walking down dimly lit, narrow aisles under the mezzanine then walking back or trying to squeeze himself between the lift and the pallets once he drove down the aisles. Ely saw his opportunity in Phil Krate, an inventory cycle counter, who didn't appear to be busy with anything at the time. Phil gladly accepted Ely's offer to soften the boredom of the midnight shift.

Ely's scheme of having a guide on the front of his fork lift seemed to be working. He was actually ahead of production — not much, but ahead. However, every time he backed the lift out from under the mezzanine the truck shook when it hit a broken section of the plant floor. After as many as 15 trips, something went wrong. One of the back wheels broke off the axle, the truck spun out of control and flipped over. The overhead guard cage that was supposed to protect the operator went flying and Ely lay unconscious under the truck. A few feet away, Phil lay half under a pallet of subassemblies.

By 3 A.M., Titus Flint and Luther Quick were back at work. The ambulances that carried Ely and Phil to hospitals had left. Now, Titus and Luther had to figure out what happened and what they would tell Acme management. Titus sat in his chair looking at the broken parts. The heads on the wheel lug nuts had clearly failed — they looked as though they'd been twisted off. But that didn't seem to make much sense since a wheel hitting a hole in the floor would likely put a shear load, not a torsion load, on the bolt, wouldn't it? The easy release push button locking pins apparently released too easily. Only one of four could be found and it was bent.

Titus and Luther agreed on one thing: this was not going to be pretty. And pretty it was not. Ely was rendered a quadriplegic and Acme paid out $12,650,000 in settlements. Phil was able to recuperate after a period of convalescence but Titus and Luther didn’t.

A plant engineer says:

Here is how to avoid the situation Acme finds itself in now. Train your people and expect them to adhere to your training.

Maintenance Engineer Titus Flint should have known better than to modify the forklift. If he didn’t, Acme should have considered some OHSA training for him. OHSA states in 1910.178(q)(6), “Industrial trucks shall not be altered so that the relative positions of the various parts are different from what they were when originally received from the manufacturer, nor shall they be altered either by the addition of extra parts not provided by the manufacturer or by the elimination of any parts.”

By changing the wheels, and cutting the overhead guard, along with the addition of the “pins,” Titus Flint has done a great disservice to his company. The money spent in settlements, not to mention the pain of an employee becoming a quadriplegic, would have been better spent to correct the situation up front and not risk the safety of company associates. How hard it is to see this on the front side of a bad decision. I guess that’s why there’s a saying that claims “hindsight is 20/20.”

Assuming Titus is over the maintenance department in this Acme plant, it would seem that he should have known about Awnuld’s belief about excessive torque on fasteners. It would seem that this deficiency in understanding torque as it applies to fasteners should have been addressed long ago. So training for the maintenance staff might have helped the situation, but only in that there might not have been an accident so soon after the modifications.

Who trains the forklift operators in this Acme plant? It seems that their training isn’t adequate. OSHA also requires forklift training for everyone who operates a forklift. Ely should have known better, if properly trained, than to place an employee on the forks while moving or any other time.

Training would have gone a long way in not ruining the lives of those involved in this accident.

Jeffrey L. Strasser, Bacova Guild
(540) 863-2656, [email protected]

An academician says:

A couple of problems here could have been prevented easily. First, with respect to the forklift, the better option would be to ask the manufacturer to modify the lift and, having done that, have the OEM attest to its safety. That would have been easiest and would have taken the responsibility off of Acme’s shoulders. However, if Acme really wanted to modify the lift itself, which is not a good idea, it could have done so, but need to have the written approval of the manufacturer that the modifications are safe. Alternatively, Acme could have received a verification of safety for the modifications from a registered professional engineer. These are OSHA requirements that the courts can use as a basis for making a decision in an accident case.

Acme did none of the above, and, thus, it’s not surprising that it was hit hard in the settlement. They also might have been fined by OSHA, although the case doesn’t mention that.

The second issue is having someone riding the forks on the forklift. Not a good idea. I’d assume that the manufacturer’s manual clearly points out that this is a definite safety hazard, and not to be done.

The third issue is not having someone who could step in and make sure the safety issues cited above were, and are, enforced. Acme needs to get its act together on this critical problem.

Professor Homer H. Johnson, Ph.D., Loyola University Chicago
(312) 915-6682, [email protected]

A maintenance consultant says:

Production manager Quick didn’t want to admit his mistake in miscalculating mezzanine height. His attempt to remedy the oversight set this tragedy in motion. Maintenance engineer Flint should have consulted with the forklift manufacturer before making any modifications. The manufacturer could have supplied Acme with a lift truck that would do the job, or come to the plant site and done a factory approved retrofit. By modifying the lift truck on their own, Quick and Flint compromised the unit’s safety and exposed Acme to the liability that occurred.

Flint was under pressure from Quick to modify the lift truck, but his responsibility as a maintenance professional is to evaluate factors such as cost, timing and risk. Flint compounded his error by assigning a mechanic with marginal skills to the modification.

Considering management’s disregard for safety, it’s no surprise that the hourly workers acted as they did. Ely and Krate were asking for trouble by riding through the warehouse in the manner they were. Under normal conditions, discipline for violating safety practices would be warranted. However, Acme could decide their extensive injuries and suffering were sufficient.

In summary, I recommend that, in cases like this, the company should consult the manufacturer before making any modifications to its equipment. This ensures that operational efficiencies, cost and safety have been considered and that the company minimizes its liability if an incident occurs.

Dean Wallace, CPE, Applied Facility Solutions
(610) 630-7414, [email protected]

Reader responses:

There were so many 'safety checkpoints' that could have prevented such a tragedy. The first instance of things going awry was when no one verified the clearance under the mezzanine for the forklifts. At that point, the mezzanine was still new and possibly under warranty. It could have been replaced or modified by the mezzanine company and eliminated the desire to modify the forklift. From there, things got worse when the request to modify a forklift was made 'quietly', so not everyone knew that it was happening. Then no one inspected Awnuld's work or even took it for a test drive. Not that he is untrustworty, but all maintenance modifications should be inspected by someone before being released back into service. And the finishing touch of riding on the forks to 'save time'. Is the time saved really worth the injuries? I think not...

Sarah Olson

I think it is the torsional stress that was applied to the bolt by the nut as it continuously going through.  There is much tension in the bolt and when the wheel hitting the hole in repeated times with a load causing it to break. 

Too much force applied when tightening the nut as it is multiplied by the persuader that makes awnuld turns the nuts easily without thinking that he is strong enough plus the wrench and the 2 ft pipe that worsen the condition of the bolts.

Using push button lock pins is a bad option for safety devices as it easily pop-out with a sudden shock.  Overhead guards should be secured by welding to insure safety of the person operating the lift truck.

It is therefore safety first in every actions and should not be compromised in any way.

Bayani Abasol, Jr.