A discipline new to many attorneys is finding its way into the courtroom more and more. We will discuss the human factors, what is it and how can this discipline prevent accidents or help resolve the cause when an accident does occur.
Daniel A. Johnson, PhD, one of MEC's Associates, defines human factors in his recent article "Warning and Human Factors";
Human factors is an area of study dealing with the problems of how to design both the products which humans use, and the environments in which they live [and work]. The producers of human factors data are researchers in psychology, medicine, physiology, biology and anthropology.
In examining warning signs, Dr. Johnson would look at the following areas:
1. Is the warning perceived?
2. Is the warning understood?
3. Will the person heed the warning?
4. Does the person have the knowledge and ability to heed a warning?
Take, for instance, a passenger vessel on which there are a significant number of elderly passengers. The vessel is constructed with special doors necessary to insure weather and water tight integrity. All of them have high sills inherent in their design which are not present in shoreside doorways. Some older people do not lift their feet as much as younger people do because of a number of medical reasons. Thus the design of the vessel has placed an obstacle in their way which, unless they recognize it and are careful, may cause them to trip with resulting injury.
How then should this situation be handled. The operators of the vessel should have knowledge of the potential problem and if not, should hire a human factor's specialist to examine the environment in which the passengers will temporarily live to identify potential problem areas such as sills.
Several approaches to reducing the risk of the high door sill can be identified.
Redesign it! But that is not as simple as it may sound. The Coast Guard sets the regulatory requirements for the watertight integrity of American vessels. Foreign vessels also come under requirements set by international bodies such as the International Maritime Organization (IMO) and various classification agencies that set design standards for construction of vessels.
Perhaps an inclined decking or short ramp leading up to the sill from each side would reduce the likelihood of tripping. That may or may not be a good solution.
Gary Sloan, PhD, another MEC Associate, addressed a similar situation in a recent article he wrote "Human Factor Design Violations."
All to often, the design and construction of stairways, [and] . . . ramps are unsafe from the perspective of both human static form (anthropometry), and human dynamic form (biomechanics). Slips and falls are particularly likely among the elderly as skeletal involution shifts the center of gravity forward, making it more difficult to maintain balance (biomechanics). Ramps, for those who do not require ambulatory aids, require more energy to negotiate (work physiology) than stairs and generally present a greater opportunity for slips and falls. . .
Another solution might be to provide special lighting for the sills, particularly those leading from the open deck which may not be as visible at night. Dr. Sloan commented on lighting thus:
Providing adequate light for safe and efficient task performance is another concern of the human factors specialist. "Was the light level of illumination sufficient for the driver to see the pedestrian?" Actually the question is somewhat misleading. We don't see illumination, we see differences in luminance. Luminance is the product of light striking a surface, i.e., the illumination level, and the surface's reflectance or transmittance.
Place warning signs! But merely a sign may not do the trick. As noted above, there are a number of considerations to be evaluated if the sign is to be effective. A human factors expert can evaluate existing signs, or recommend new ones. The location, size, color and content are judgments which he is trained to make. However, vessel owners don't want an atmosphere for their passengers that would be cluttered by signs. They perceive the signs adversely effect the aesthetic atmosphere of the vessel, and they may unwittingly suggest that the vessel is unsafe when instead, the intent of the signs is to make it safer.
A type of warning commonly used in industry is to mark the obstruction with highly visible colors so that it stands out, for instance, yellow and black diagonal stripes so that the sill stands out from its surroundings.
We have not tried to provide a solution to an existing problem in this article. The example of the door sill is but one of many structural aspects of ships and boats which may warrant the services of a human factors expert, hopefully during the design phase so as to avoid accidents, but also after an accident to evaluate whether an unsafe condition existed or caused the accident. We know many falls do occur when people trip over door sills on vessels with resultant injuries.
Again, MEC values a number of human factors experts amongst its many Associates who are ready to assist the marine industry or attorneys.
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