Mobile Crane Accidents Prevented With Trained, Qualified Operators Operator error is usually only a "symptom" of the cause of crane accidents

M obile cranes are potentially dan· gerous and in most cases harbor higher accident potential than

any other equipment in construction and industry.

"There is still no other piece of equipment that has the potential of causing so much damage or harming so many people as does a crane in an acci· dent,' ' Donald Dickie, internationally· known crane expert, said. For example:

• Cranes are involved in more seri-ous accidents than other construction equipment.

• Crane accidents cost most in in· surance claims.

• More construction fatalities result from cranes and hoisting equip-ment than any other cause.1

FORCE DANGERS. Tocomprehend this better, it is important to under-stand why such potential danger ex-ists.

Mobile cranes are capable of pro-ducing tremendous amounts of force. This force is created by crane functions such as hoisting, booming and swing· ing. The velocity at which these func-tions occur determines the amount of force exerted.

The important thing to remember, however, is that force has virtually the same effect on a crane and its compo-nents as does load weight. For exam-ple, if a load were lifted or swung fast enough, the force created from these movements could be enough to exceed the crane's ratings and result in a turn-over or structural damage.

The problem does not occur from moving loads-that is the purpose of the crane-but instead when the force from these movements exceeds the crane's capacity.

It is essential, therefore, that force be kept within manufacturer's parame-ters and guidelines.

How is this done? Normally it is left up to the operator's perception and judgment. This is one of the many rea-sons why he plays such an important role in crane safety.

CHANGE FACTORS. Because mo-bile cranes are so versatile and mobile, they are constantly in the process of change. Amplified by the many config-urations that mobile cranes can un-

By James Headley, BS, Director; Crane Institute of America, Altamonte Springs, Fla.

26

dergo, this produces a multitude of variables necessary to ensure safe op-eration. When these variables combine with human factors, predicting acci-dents is difficult.2

To illustrate this, consider a hydrau· lie crane prepared to lift a 10,000-pound load with 60 feet of boom at a 30·foot radius. According to the manu-facturer's load chart, this lift is possi-ble since the load to be lifted is within the crane's maximum rated capacity of 11 ,600 pounds.

But there are many other things that must be taken into consideration. For example, there is the lattice exten-sion and jib attached to the main boom, the headache ball, the load block and rigging-all of which when com·

Cranes are complex machines, not tools

all can operate.

bined add several thousand pounds to actual load weight and must be consid· ered before the lift is attempted.

A failure to do so would result in an overload condition and possibly an ac· cident.

Other questions also must be asked: Are there adequate parts of line? Does the list require that outriggers be fully extended? Which capacity chart is to be used? When placing the load will the radius be reduced and how much? In which "quadrant" is the load to be lifted? When the load is swung will it be to an area of less capacity?

SOUND EVALUATION. In addition, there are other factors that come into play, such as wind, terrain and crane set-up on different surfaces. These are only a few of the many variables that can be created through the configura· tion and operation of mobile cranes-each one of which often required pre-cise calculations and sound judgment.

Mobile cranes today differ some-what from the past. Industry demands and increased technology have re· suited in crane manufacturers building sophisticated ' ' state-of-the-art" ma-chines specifically designed to maxi-mize capability.

Pound-for-pound, mobile cranes have more capacity. In the past, for a mobile crane to life 100 tons, its actual weight would have to exceed this capa-

bility. It is possible today, however, to purchase cranes having twice the ca-pacity for their total weight. For the consumer, this translates into the crane being smaller, lighter and more manueverable and cost-effective.

STABILITY PROBLEMS. However, these changes have resulted in the crane's capacities being based more on structural competence rather than sta-bility. The crane could break before it tips-so the raising of outriggers should never be relied upon to indicate an overload. Even though this has never been advised as an alternative to precise load chart interpretations, older cranes do have a tendency to be more forgiving since their capacities are derived more from tipping weight.

This can be illustrated by a conver-sation I had recently with a plant man· ager interested in acquiring some training. During our conversation he said his company owned an older lattice-boom crane, but last year had purchased a rough-terrain, hydraulic crane. Even though they had experi· enced several minor accidents with the older crane, it was not until they ac· quired the hydraulic crane that the more serious accidents began. In fact, during the course of a year they had buckled two booms resulting in $60,000 damage and turned the crane over twice. Why did this happen? Pri· marily because those involved with the crane failed to perform the necessary pre-lift ·calculations and comply with the manufacturer's instructions and warnings.

MISPERCEPTIONS. For the benefit of the safety professional, our failure to understand why mobile cranes are so potentially dangerous has not been the only oversight, but rather has led to a more serious problem: the way the crane is viewed.

This inaccurate perception has been perpetuated by the emergence of hy· draulic cranes and the erroneous idea that their operation requires little skill.

Instead of viewing the crane as a complicated and sophisticated rna· chine, it has been viewed as a "tool" to be operated by virtually anyone. Be· cause of this, industry is continuing to pay a tremendous price in terms of ac· cidents.

This information does provide a clue as to why most crane accidents oc·

OCCUPATIONAL HEALTH & SAFETY

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cur and where prevention should begin. Mobile cranes do inherently entail a high degree of danger, but this danger does not exist within the crane itself, as some have mistakenly thought. The problem begins when the crane is put into operation.

It is also interesting to note that statistics place the most blame for ac· cidents on human error with the opera-tor being responsible for the largest percentage. Operator error is not the real cause at all, but only a ''symptom" of the cause. The underlying cause of most crane accidents is our failure to determine and maintain an operator's qualifications.3

PREVENTING ACCIDENTS. The most important step in preventing ac-cidents then, is to allow cranes to be operated only by trained and qualified personnel. Even though these require-ments are published in Occupational Safety and Health Administration standards, the process by which opera-tory competency and qualifications are determined needs clarification.

In the American National Stand· ards Institute B30.5 (1982), a widely referenced National Consensus Stand-ard on Mobile and Locomotive Cranes is the heading "Qualifications For Op· erators." It says that "Operators shall be required by the employer to pass a written or oral examination and a prac-tical operating examination unless able to furnish satisfactory evidence of qualifications and experience. Qualifi· cations shall be limited to the specific type of equipment for which examined. Operators and operator trainees shall meet the following physical qualifica· tions."

In this portion of the standard, an operator's qualifications is a process involving three areas. If failure to dem· onstrate competency in any one area is discovered, the operator must be con· sidered unqualified to operate the crane.

PHYSICAL TRAITS. The operator must meet the following physical qual· ifications:

Vision of at least 20/30 Snellen in one eye and 20/50 in the other, with or without corrective lenses.

Ability to distinguish colors, re· gardless of position, if color differenti· ation is required for operation.

Adequate hearing, with or without hearing aid, for the specific operation.

Sufficient strength, endurance, agil-ity, coordination, and speed of reaction to meet the demands of equipment op-eration.

In addition, evidence of physical de-fects or emotional instability that

JULY 1988

could "render a hazard to the operator or others, or which in the opinion of the examiner could interfere with the oper-ator's performance, may be sufficient cause for disqualification. In such cases, specialized clinical or medical judgments and tests may be required.''

Evidence that an operator is "sub· ject to seizures or loss of physical con· trol shall be sufficient reason for dis-qualification. Specialized medical tests may be required to determine these conditions.

"Operators and operator trainees should have normal depth perception, field of vision, reaction time. manual dexterity, coordination, and no tenden-cies to dizziness or similar undesirable characteristiscs."

The operator also is required to pass a written examination for mental competence to be assured. Even though an oral examination and evi-dence of qualifications and experience are allowed by ANSI as proof of quali-fications, a more verifiable means is the use of written tests.

If these exams are designed prop· erly, they are normally far more objec· tive. Oral examinations tend to be sub· jective: an accurate determination of

the operator's mental abilities depends solely on the personal judgment of the . . examrner.

Written examinations not only will reveal whether operators possess the required knowledge, but they also will reveal if an operator is illiterate.

In fact, according to Jonathan Ko-gel, author of Illiterate America, there are 60 mjllion illiterate adults in A mer· ica. Of these 60 million, 46 million adults are considered functionally illiterate- where they function at a fifth grade level in basic skills. This level is definitely not high enough to comprehend and assimilate the techni· cal information found in operator's manuals and load charts, especially for the mobile hydraulic cranes built to· day.

HARD TO MEASURE. The final area ANSI identifies for examination is the operator's practical competence. This area, compared with the physical and mental, is perhaps the most difficult to determine. Maintaining objectivity is far more difficult.

The person conducting the practical tests must be qualified (with a solid background in use and operation of mobile cranes) to accurately determine

CRANE SAFETY

proper operating speeds, movement, techniques and procedures.

Furthermore, an obstacle course should be designed to cover any and all responsibilities and experiences the op-erator is expected to perform.

When the outcome of these examina· tions are evaluated, they will reveal any deficiencies t.he operator may have.

TRAINING . It is important when de-veloping an in- house program or acquir· ing the services of an outside company to remember to develop the program to meet specific needs and applications.

An obstacle course prepares crane operators.

For operators this would include both classroom and hands-on training. The classroom instruction should include theory of operation, technical data, ap· plicable standards, manufacturers' in· formation and rigging- all with an em· phasis on safety.

Equal time should be devoted to hands-on or practical instruction. This is where the operator is actually taught how to inspect, set up and operate the crane in a lift situation. It is here that the operator can see the relevance of what was taught in the classroom, thus meeting the objective of safe crane oper-ation.

A GOOD TEACHER. Selecting the appropriate instructor also is crucial. Not only should this person possess the technical knowledge associated with your particular equipment, but he should have a thorough understanding of applicable government and industry standards and how they relate to the operator and his job.

Don't select someone who has ac-quired his knowledge only through books. This will only result in the train-ing program being "bookish" thus lack-ing the required depth and practical ap-plication.

Finally, look for an instructor who has the ability to communicate. He does not have to be an orator, but he should be able to make the material relevant and help the operator understand the importance of his training.

References 1. Dickie. D.E. "Mobile Crane Accidents," Con·

struction Safety Association of Ontario, revised September 1986, p. 2.

2. Headley, James. " In Defense of the Operator." Cranes Today, December/January 1988, p. 45.

3 . Headley, Ja~es. " The Employer's Duty." Cranes Today. February 1988, p. 39.

4. IBID p. 39.

ASBESTOS continued from page 22

At the time of my inquiry, there were 33 members sharing this aggregate limit. If one member experiences a $1 million claim, is the policy limit ex· hausted for the 32 other members? How many members will ultimately be· long to this program? I was told 102. Is the aggregate limit per year or for the three-year, non-cancelable term? I learned that the dues were a one-time charge of $100,000 per member.

At first glance, this program has some very attractive coverage and cost features. However, by plugging in the membership fees and the aggregate limits, the overall benefits derived from this plan require close analysis.

The six remaining carriers afford contractor's coverage on a claims-made basis only. Two of these six mar· kets are rated respectively as A+ (su· perior) and A (excellent) by A.M. Best Go. One of these two carriers operates on a licensed, admitted basis through-out the United States. The other trans-acts business on a non-admitted, excess/surplus lines basis in all states except Delaware, its domicile.

Another market out of the six, while ineligible for a Best rating, does oper· ate as a licensed carrier in approxi· mately 28 states. Remember, being li· censed requires the insurance department to approve rates, policy forms and financial data. It also pro· vides for participation in the state in· solvency fund. The three remaining carriers are ineligible for Best rating and they offer their coverages in most states as non-admitted carriers.

Several of these companies can be quite competitive in their rating ap· proaches in relationship to the past premiums that were being charged. This is especially evident in the case of the larger contractors. Coverage has been known to switch from one claims-made carrier to another as several car-riers compete for business in this arena. Most of the carriers want to compete for the larger, more estab· lished asbestos contractors. New con· tractors without established track re· cords or substantial financial statements will have a tougher time getting either acceptance or competi-tive rates. To accommodate the switchfrom one carrier to another, the new carrier obtaining the order for cover· age has been known to offer retroac· tive coverage (coverage for the un· known prior acts back to the date the contractor has had coverage through another carrier). In this way, the con· tractors do not leave themselves with a gap for unknown prior acts that could give rise to future claims.

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