Safety Philosophy

"Philosophical Aspects of Dangerous Safety Systems"
Triodyne Safety Bulletin v. 5 # 3 (June 1997)

Ralph L. Barnett and Beth A. Hamilton

One of the unfortunate trends developing in the product liability movement is the promotion of dangerous safeguarding devices. Such devices arise principally from insufficient research, judicial coercion, and liability proofing. The safety literature presents an unequivocal mandate against the use of safeguarding systems that sometimes present hazardous themselves.


"Dependency Hypothesis Part 1"
Triodyne Safety Brief v. 2 #3 (November 1983)

Ralph L. Barnett, Gene D. Litwin, and Peter J. Barroso, Jr.

This article discusses the types of changes in the man/machine interface which accompany the incorporation of safety systems into a machine. Safety systems introduced to meet narrowly defined safety objectives may give rise to broad secondary effects that subtly or profoundly influence the machine's overall safety and function. Some new criteria are described to aid in the evaluation of proposed safeguards.


"On Safety Codes and Standards"
Triodyne Safety Brief v. 2 #1 (July 1983)

Ralph L. Barnett

This article posits that 1) compliance or non-compliance with safety codes is presently the only rational way to judge whether a design is safe or defective, and 2) safety codes cannot properly protect the public interest unless they define both the lower and upper bounds, or limits, on the conduct of designers. Engineers are introduced to the doctrine of "rebuttable presumption" relative to safety standards, and a semantic problem concerning the use of the term "minimum safety standards" is addressed.


"Dependency Hypothesis Part 2: Expected Use"
Triodyne Safety Brief v. 2 #4 (September 1984)

Ralph L. Barnett, Gene D. Litwin, and Peter Barroso, Jr.

Safeguarding systems may be introduced to perform specific safety tasks, to comply with some code or standard, or to liability-proof a machine. Whatever the case, the device itself may be perceived to define a safety function and users will expect the device to perform that function.


"Safety Hierarchy"
Triodyne Safety Brief v. 3 #2 (June 1985)

Ralph L. Barnett and Dennis B. Brickman

A popular litany heard in product liability trials is "the safety hierarchy." It is associated with a number of misconceptions which are explored in this paper.


"Principles of Human Safety"
Triodyne Safety Brief v. 5 #1 (February 1988)

Ralph L. Barnett and William G. Switalski

This paper describes selected concepts from safety and human factors engineering. Important philosophical tools that affect designs are summarized.


"Role of Safety Standards in the Design Process"
ASME 89-DE-3
. New York, American Society of Mechanical Engineers, 1989

S. Carl Uzgiris and J. J. Hebert

This discussion addresses concepts which assist the designer in generating a safe design. The concept of what is safe is frequently misunderstood. Some definitions from the safety literature are given, and the notion of safety as an acceptable level of risk is discussed. A safe design is an embodiment of good engineering practice, but there can be different opinions as to what good practice is. To resolve such difficulties a designer can turn to safety standards for guidance.


"Selected Principles of Human Safety in the Workplace"
International Journal of Materials and Product Technology
v. 4 #2 (1989): 125-144

Ralph L. Barnett, Beth A. Hamilton, and Gene D. Litwin

Two pertinent safety philosophies, the Dependency Hypothesis and the Intrinsic Classification of Safeguarding Systems, are discussed.


"Standards Identification and Retrieval for the Design Engineer"
ASME 89-DE-2
. New York, American Society of Mechanical Engineers, 1989

Michael A. Dilich, J. J. Hebert, and Cheryl M. Hansen

Searching for safety standards when one does not know whether or not they exist can be very frustrating. This paper identifies organizations active in promulgating safety-related standards, and explains manual and on-line search techniques.


"Doctrine of Manifest Danger"
Triodyne Safety Brief
v. 8 #1 (September 1992)

Ralph L. Barnett

The Doctrine of Manifest Danger is a design concept using direct cues or indicator devices to communicate to the community of users that the safety of a system has been compromised before injuries occur. The paper addresses a related legal issue by distinguishing between proximate cause and cause of action.


"Strongest Link Principle"
ASME 94-WA-DE-2
. New York, American Society of Mechanical Engineers, 1992

Dennis B. Brickman and Ralph L. Barnett

To prevail in a products liability action it is necessary to establish that the challenged design contains a defect that is a proximate cause of the accident. Using the example of an auger elevator injury, this paper focuses on whether an alleged defect was proximately related to the injury.


"Principle of Uniform Safety"
Triodyne Safety Brief v.10 #1 (August 1994)

Ralph L. Barnett

The expression of the principle of uniformity is generalized and focused on safety issues. Product designs which do not treat dangers uniformly often cause human errors which arise from inductive inference and generalization of experience.


"Active versus Retroactive Regulations"
Triodyne Safety Abstract v. 1 #3 (October 1995)

Gary M. Hutter

Criteria for setting effective dates for safety standards and regulations are reviewed.


"The Drunk, the Child, and the Soldier: My, How They Fall"
Triodyne Safety Bulletin v. 2 #2 (September 1995)

Ralph L. Barnett

It's better to collapse than to topple over, it's better to be short than tall, and it's best not to fall at all. The head strikes the ground at "killer" speeds. Toppling produces greater impact speeds than free fall and for certain limiting shaped objects, infinite speeds are attained.


"Quantification versus Go/No-Go Criteria"
Triodyne Safety Brief v. 10 #4 (April 1995)

Barnett, Ralph L. and Dennis B. Brickman

Compliance or noncompliance with a sound safety code or standard is currently the most rational way of judging whether a product or system is sufficiently safe. Many such codes specify minimum numerical criteria such as loading, tile angle, and judgments based on quantitative test data as opposed to meeting minimum criteria. This paper illustrates the richness of quantification for a number of different products.


"Safeguard Evaluation Protocol: A Decision Tree..."
Triodyne Safety Brief v. 11 #2 (May 1995)

Ralph L. Barnett and Steven R. Schmid

A decision protocol is presented for assessing whether a candidate safeguard should be offered as standard or optional equipment or whether it should be enhanced, prohibited, ignored, or just characterized. Satisfaction of the protocol is sufficient condition for satisfying the Code of Ethics for Engineers, extant codes and standards, the Intrinsic Classification of Safeguards, and the Dangerous Safeguard Consensus. Decisions that do not satisfy the protocol violate one or more of these safety philosophies. The protocol transforms the decision making process into an engineering discipline.


"Safeguard Evaluation Protocol: A Decision Tree: Summary"
Triodyne Safety Bulletin v. 1 #1 (May 1995)

Ralph L. Barnett and Steven R. Schmid

Summarized version of the preceding paper.


"Risk Analysis"
Triodyne Safety Bulletinv. 1 #2 (June 1995)

Peter J. Poczynok and Ralph L. Barnett

Accident frequency rates in all industries and for machinery are calculated and graphed.


"Strongest Link Principle"
Triodyne Safety Bulletin v. 1 #3 (August 1995)

Dennis B. Brickman and Ralph L. Barnett

Summarized version of the paper written for ASME in 1992 (see above).


"Safety Rules of Thumb"
Triodyne Safety Bulletin v. 2 #4 (February 1996)

Ralph L. Barnett

Since rules of thumb presently represent the foundation of safety engineering, it is important to develop a perspective on their strengths and limitations. This bulletin presents a definition and history of rules of thumb, together with related concepts, the Exception Principle and Newton's Fourth Rule.


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