Drawing upon years of experience in safety consulting, Triodyne's engineers and scientists have published research papers which appear in the Triodyne Safety Briefs. These publications cover a variety of topics of interest to academics, manufacturers, and safety professionals.

To request copies of those Triodyne Safety Briefs not available on-line, please direct a message to Library Services. Please remember to include your name and mailing address as these documents may not be available via email.

Volume 27 No. 4, April 2005
Extreme Value Formulation of Human Slip: A Summary
Ralph L. Barnett and Suzanne A. Glowiak

Conventional "slip and fall" theory establishes a go-no-go criterion that indicates whether or not a given floor has satisfactory slip resistance. Specifically, the theory states that no slip, and hence no fall, will occur whenever the average coefficient of friction between a floor and some "worst case standard footwear material," e.g. leather, is greater than a threshold friction coefficient. This threshold friction is not selected by some rational protocol; it is often established by legislative fiat or consensus. Using extreme value statistics, this paper reformulates classical "slip theory" to explicitly account for the stochastic nature of friction coefficients. By abandoning the traditional deterministic approach to slip in favor of a statistical formulation, fully integrated protocols are able to be developed which predict the number of pedestrians who will slip or, alternatively, who will violate a threshold slip criterion. A new theory emerges that embraces everything from a simple floor with a single walker to very complicated real floors traversed by a throng of pedestrians with multiple ambulation styles and wearing a variety of footwear. It must be emphasized that the new slip protocol merely provides a mathematical framework that enables walkway professionals to make quantitative estimates of slip propensity. Like conventional theory, it also suffers from the "garbage in-garbage out" syndrome. Accu- rate tribometers, for example, are still required for precise predictions. On the other hand, the concept of threshold criterion and worst case footwear surrogates are replaced by force-plate data obtained by gait laboratories using various communities of walkers. Reliability determination for real floors requires the introduction of floor duty cycles.

Volume 27 No. 3, April 2005
Back-Up Alarm System Design Using Smart Technology
Christopher W. Ferrone and Charles Sinkovits

Accidents occurring from trucks and equipment backing up and contacting workers and pedestrians remain a problem even with the use of back-up alarms which beep when trucks and heavy equipment are shifted into reverse. A new method, combining a warning when a vehicle is shifted into reverse with a separate and distinct warning to indicate that the vehicle is actually moving in reverse, has been developed.

Volume 27 No. 2, November 2004
Standards - Impact and Impotence
Ralph L. Barnett and Suzanne A. Glowiak

Most of the technical works of humankind are designed without the guidance of safety codes and standards. Specific safety standards are generally developed when contrivances give rise to numerous accidents and liability actions. The salient features of such standards are briefly outlined in this article.

Volume 27 No. 1, October 2004
Driver Fatigue/Inattention Monitoring Device - An Integrated System for Heavy Trucks
Christopher W. Ferrone and Charles Sinkovits

The National Transportation Safety Board has reported statistics which indicate that 31% of all fatal-to-the-truck driver accidents occur due to fatigue/inattention and 58% of all single-vehicle large truck crashes were also fatigue related. If these numbers can be reduced, many lives can be saved. A Driver Fatigue Monitoring System has been designed and built to monitor whether a driver is sleeping or inattentive. This integrated system monitors the steering input behavior of the driver during a specified period of time. If the number of steering inputs is below the expected predetermined threshold, the system activates an audible alarm and light in the cab, waking the driver. Furthermore, this system can deactivate cruise control as well as activate various other preprogrammed truck systems or components to further aid in the control of the truck and to alert nearby motorists.

Volume 26 No. 4, September 2004
Limited Movement Machinery Rollers
Ralph L. Barnett and Dennis B. Brickman

Ancient Egyptians allegedly moved large stone blocks by placing cylindrical rollers beneath them and manually urging them along. This rolling procedure required that the rollers emerging from the rear of the stone be manually lifted and replaced in front. This roller replacement protocol has been automated in commercially available roller units that allow continuous movement of heavy machinery under the action of pry bars, come-a-longs, winches, or manual push efforts. Unfortunately, when slopes or asperities are encountered these heavy loads may accelerate uncontrollably or steer themselves in unsafe directions when the roller units become reoriented. This paper describes two inventions that cause the locomotion of the machinery to proceed in inchmeal fashion by intermittently braking the system while the roller units are manually reset. 

Volume 26 No. 3, August 2004
Anti-Diving Safety Systems for Swimming Pools
Robert Kaplan and Ralph L. Barnett

This paper addresses new design concepts for the anti-diving system introduced in 2003 by Barnett and Poczynok.

Volume 26 No. 2, June 2004
Slip and Fall Characterization of Floors
Ralph L. Barnett and Peter J. Poczynok

During ambulation, every maneuver causes the feet to impose tangential loading at each contact with the floor. If the frictional resistance at the contact point is less than the associated tangential loading, slipping occurs and sometimes falling. There are five disciplines, some recently developed, that enable one to develop the general theory for predicting the number of walkers who will slip within a given time period on a statistically homogeneous and isotropic floor. These include force-plate studies, floor duty cycles, tribometry, extreme value theory of slipperiness, and floor reliability theory. When used with some additional bookkeeping notions, the general theory will be extended to real floors traversed by walkers with multiple ambulation styles and wearing a variety of footwear.

Volume 26 No. 1, May 2004
Infant Pull Strength - Ability to Dislodge Crib Sheets
Ralph L. Barnett and Dennis B. Brickman

The suffocation of infants caused by crib sheet entanglement appears to be a nonproblem which has nevertheless resulted in a brouhaha that has incited remediation activities by the Good Housekeeping Institute (GHI), American Society for Testing Materials (ASTM), Consumer Product Safety Commission (CPSC), Juvenile Products Manufacturers Association (JPMA), crib sheet manufacturers, and product liability suport professionals of different stripes. To show that the removal of crib sheets by infants is not a safety issue, one may establish that the problem is not reasonably foreseeable. Three approaches for doing this are described in this paper: anecdotal, simulation, and reliability. The reliability of a crib sheet is the probability that it will remain in situ when exposed to the community of infants. Application of the classical "load minus strength" analysis required new information on the pull strength of infants.

Volume 1 No. 2, September 1981
On Classification of Safeguard Devices (Part II).
Ralph L. Barnett and Peter Barroso, Jr.

Part I of this article described an intrinsic classification system focusing on characteristics of individual safeguarding devices. In Part II we are concerned with the relationships among such devices. This requires the introduction of a category which deals with those safety characteristics inherent in a system. These are ranked under Zero Order Systems in the article's functional hierarchy of safety devices and concepts.

Volume 1 No. 1, April 1981
On Classification of Safeguard Devices (Part I).
Ralph L. Barnett and Peter Barroso, Jr.

Engineers cannot change the law but we can provide guidelines to help the courts make more reasonable decisions. The first step is to stop looking at safety devices as a homogeneous lump. Safety devices differ in the amount of safety they provide and the amount of harm they can do. This article presents a classification system that makes it possible to evaluate the efficacy of safeguarding devices, breaking down devices into mutually exclusive and jointly exhaustive categories.