IntroductionThe safety-through-design concept that engineering design can impact the safety of equipment, vehicles, buildings, as well as manufacturing and construction processes. This approach for protecting workers and the public has been around since the early 1900s and before then. Many people in current safety practice are familiar with the emphasis on safety through design that re-emerged in the last 15 years or so as an important area of practice. Engineers have an ethical responsibility to protect the safety, health, and welfare of the public in their professional practice. The primary focus of this is the prevention of accidents, injuries, and illness related to their designs. Many others often help engineers to understand their role and apply effective designs.
Prevention Through Design and Safety Through Design – A Recent EffortIn 2007 the National Institute for Occupational Safety And Health (NIOSH) conducted a workshop on Prevention Through Design. According to John Howard, the NIOSH Director, “one of the best ways to prevent and control occupational injuries, illness, and fatalities is to ‘design out’ or minimize hazards and risks early in the design process.” In order to respond to the need to increase prevention through design efforts, NIOSH developed the Prevention Through Design (PtD) National Initiative. The workshop brought interested organizations, industries and individuals together to help organize that effort. The NIOSH PtD National Initiative led to efforts to increase education of engineers about the importance of preventing injuries, illnesses and death through design and efforts of other organizations to promote PtD in construction and other industries. Prior to that in the late 1990s, the National Safety Council organized a similar activity at a smaller scale. It had the title Safety Through Design. That led to the publication of a book that captures many of the practices one can apply in design to prevent accidents and incidents and related injuries, illnesses and deaths. Those involved in this recent effort deserve much credit for the revival of the importance of preventing accidents and incidents by identifying hazards and risks and eliminating or reducing them through design. However, this concept is not new. It has been around for a long, long time. The focus of design efforts varied over time depending on where the greatest risks and losses occurred.
Mid-20th Century Safety Through DesignSafety through design also got attention in the mid-20th century. For example, the 1955 Edition (5th Edition) of the National Safety Council’s longstanding Accident Prevention Manual stated:
Company policies should be such that safety can be designed and built into the job, rather than added after the job has been put into operation. The design engineer should be conscious of the fact that the safety department is most anxious to help in discovering job hazards and removing them. Each level of engineering should be given the responsibility for building safety into the job, right through the production phase. Such responsibility should extend to product design, machine design, plant layout and condition of premises, selection and specification of materials, production planning, time study, methods, duties of production foreman, and work of employees assigned to the job. When safety is properly inculcated in the planning of new operations or processes, there will be little need to secure management’s backing for incorporating safety features before operations are started.The 5th Edition of the Accident Prevention Manual also devoted a whole chapter to “Removing the Hazard from the Job.” Much of the emphasis was on the need for safe design. In addition, the chapter offered an early version of the concept known today as the “Hierarchy of Controls.” The 4th Edition of Industrial Accident Prevention by H. W. Heinrich stated the following:
The best opportunity to prevent accidents on machines lies with the machine manufacturer and his staff of designers and draftsmen. If accident prevention receives the consideration that it so well deserves in the creative stages of machine manufacture, the finished product will need relatively little alteration to be reasonably safe.
Early Safety Through Design ConceptsThe purpose of this paper is to identify how some from the past pressed for safety through design long before any recent focus on the concept.
An Ancient ConceptOne cannot discuss safety through design and early emphasis for it without some quotes from ancient documents. In the Bible, Moses pointed to safety through design in his admonition:
When you build a new house, you shall make a parapet for your roof, that you many not bring the guilt or blood upon your house, if anyone fall from it.A safety through design concept also links to liability and indemnification. Hammurabi’s Code contains several provisions. One of them reads as follows:
If a builder builds a house for a man and does not make its construction firm, and the house which he has built collapses and causes the death of the owner of the house, that builder shall be put to death. If it destroys property, he shall restore whatever it destroyed, and because he did not make the house which he built firm and it collapsed, he shall rebuild the house which collapsed at his own expense.
Early 20th Century ContextIn the early 20th century, the concept of safety through design got significant attention among organizations focused on accident prevention and reduction in high rates of injuries and death among workers. During the early 20th century, manufacturing created opportunities for safety through design as processes and machines continued to expand the industrial revolution. There was a growing need for skilled workers as society continued to shift from an agricultural economy to a manufacturing economy. In addition, low worker skills were compounded by communication problems. There was a large influx of immigrants from various countries and each spoke their native language and knew little or no English. Machines used in early manufacturing required power transmission mechanisms, since electrical power was not readily available. Electric motors were not a source of power for most early industrial machines. Power generation and distribution often involved centralized water or steam power. The power moved through line shafts, pulleys, belts, gears and other mechanisms to individual machines. Power transmission systems created many danger points. Many machines had operational elements that also had danger points. As a result, there was a strong focus on guarding as an accident prevention method. Many accident cases illustrate the reason for the focus on machines and guarding. For example, a woman working at a machine dropped something to the floor. When she bent to pick it up from under the machine, her hair caught in an unprotected belt and pulley. The machine pulled the hair from her scalp. Another example is a press without an automatic braking device for the end of a cycle. An operator might reach into the point of operation at just the wrong time and lose a finger or hand. See also the story of Lorenzo Coffin (page 13) and the railroad hazards he fought to improve through legislation and design changes. An early 20th century focus on safety through design also involved training for those responsible for factory and construction safety and worker protection. They had to learn how to incorporate safety in their design while employed by manufacturing or construction companies. Many with safety responsibilities were engineers. Engineering societies also engaged in emphasizing safety through design. Machine manufacturers and their designers gave attention to the primary function of the machines and making them safe. There was a high rate of inventions and patents to make more effective, efficient and safe machines. The competition among manufacturers rose rapidly to achieve the best machines. Insurance Company Services. Workers’ compensation also influenced safety through design. The concept of workers’ compensation and workers’ compensation insurance emerged with the first United States worker compensation law in 1911. Many insurance companies selling worker’s compensation insurance hired engineers to focus on reducing accidents and associated insurance claims. The companies trained their engineers in loss prevention. Part of that effort was on safety through design and redesign to help employers and employees. Some companies operated laboratories and special facilities to find better designs and accident prevention methods. Safety Museums. Another approach was the introduction of safety museums. A few were located in major U.S. and European cities. Their purpose was to exhibit effective hazard controls so workers and employers could see some of the available solutions to dangers in their workplaces. The most significant U.S. safety museum was the American Museum of Safety in New York City. It was largely and effort of engineering societies headquartered in New York City. It no longer exists. Early Design Standards. With the introduction of the steam engine and the growth in use of steam power, the frequency of boiler explosions and other failures of steam equipment, there was a need to develop better designs and to standardize many design features. Boiler explosions were quite common. However, one explosion that gained broad attention was the incident at the Grover Show Factory in Brockton, MA on March 10, 1905. The event killed 58 people and injured 117 others and leveled the factory. In 1911 the American Society of Mechanical Engineers (ASME) recognized the challenge and worked to produce the first boiler and pressure vessel design standards. ASME published the first ASME Boiler and Pressure Vessel Code in 1914. Promoting Safety Through Design in the Engineering Community. In September 1915, Frederick Remsen Hutton, Sc.D., a past president of ASME made a presentation at the International Engineering Congress in San Francisco, CA. He was also Vice President of the American Museum of Safety. In Paper No. 129, he addressed the topic of Safety Engineering as an important approach for engineers to achieve safety. He gave many examples of improvements through design for manufacturing and other machines. His examples included a full enclosure for a source of power, an engine. The design included specific openings for an operator to lubricate and assess the machine’s performance. He illustrated an electric motor enclosure with an interlock that requires shutting off the motor. He illustrated safeguards to prevent racing of power supplies and associated flywheels. He offered several examples of safeguards for power transmission involving shafts, belts, and gears. The examples addressed various worker conditions, such as long hair for a woman. He explained how to provide protection for maintenance workers, such as oilers. He addressed the problem of protruding set screws and bolt heads on rotating shafts and couplings. He discussed proper ladder design and protective features for individuals who oiled and serviced machines. He explained the importance of procedures that we know today as lockout-tagout procedures for energized equipment. He discussed hazards associated with overhead cranes, falling objects and falls of operators. He addressed hazards associated with elevators as vertical transportation devices. Included was an explanation for the importance of interlocking the protective gate with the elevator car’s starting mechanism. He illustrated safeguards for a variety of machining tools, woodworking tools and other powered tools. He explained the principles involved in hood design for capturing particles and other contaminants during manufacturing operations. Overall, the presentation was a comprehensive review of hazards during a wide range of manufacturing operations and design solutions for equipment and operations. His goal was to provide a lot of examples of what engineering design can do to minimize workplace injuries. What is noteworthy also is that many of the details preceded any published standards that safety practitioners and engineers rely on today.
Engineering RevisionEarly emphasis on safety through design adopted a new term for the part of the concept. The new term was engineering revision. Discussion around 1910 involved two main points of application for engineering when applied to design. The first occurred when a company manufactured a new product or created a new process. The engineering role for safety was to eliminate hazards that could lead to accidents. In many cases, employers had existing machines and processes that produced accidents. The engineering role was to make changes to add safeguards or to “revise” the machine or process. The role gained the common use of the term engineering revision for two to three decades. The role of engineers in eliminating hazards and reducing the frequency and severity of accidents became one of two main approaches for safety. To understand the context, one must understand the other focus, education. As noted earlier, the lack of skilled workers, the dangers of machines and processes and the complexities of communication produced a strong need to train workers for completing their tasks safely. This was something that engineering alone could not solve. Many involved in the safety movement realized that educating workers to do their jobs safely was not sufficient. In a 1925 pamphlet by the College Committee of the National Safety Council, the report also recognized “safeguards” as temporary while a more fundamental means of eliminating hazards was needed–engineering revision. Safeguards included such devices as enclosures for power transmission equipment and guards for various points of operation. The publication defined engineering revision as a more fundamental change in machine or operation. It noted that engineering revision requires more expert knowledge of operations and entire processes. It stated that engineering revision often involves the installation of new equipment, improving and refining present equipment, and re-designing various processes. A National Safety Council publication on safe practices stated that the term engineering revision was coined by Dr. L. W. Chaney of the U.S. Bureau of Labor Statistics. He said:
Engineering revision is safety engineering in the truest sense of the term. It includes the widest possible application of engineering skill to the safety of industrial plants. It includes the design and location of buildings with special reference to the necessary connection with transportation facilities, ready and safe access to every point where workers must go, the provision of adequate and properly arranged lighting, the provision of machines designed from the safety standpoint, the guarding of such machines of faulty design at the plant is unfortunate enough to have, the proper attention to all dangerous conditions.The publication also explains that “engineering revision is the most fundamental method of actually preventing accidental injuries. Through safety education and supervision, workers are influenced to avoid accident hazards; safeguards cover up these hazards; but engineering revision removes or reduces the hazards right at their source.” The publication also discusses “Safety Through Design” and states:
The engineer cannot only correct many existing hazards, but he can also eliminate many hazards before they are created. When called upon to design new buildings, equipment and processes, he can make sure that safety is built into each project as an integral part of the design and construction.In a paper presented by Dr. L.W. Chaney he gave examples of engineering revision from the steel industry. He explained that the Bessemer and open hearth processes started out with relatively small production batches. The processes had serious hazards. However, with the growing demand for steel, the companies increased the size of batches several times, typically from 6-ton to 12 and 15-ton vessels. That increased the rate of serious injury and death. Manipulation of hot steel involved manual labor by large crews who manipulated larger and larger ladels and pouring operations. It involved large crews to move hot ingots into rolling machines. One engineering revision introduced placing moulds on small cars to move them. Another major change was the introduction of electrical power. Prior to 1890 steel production consumed no electric power. By 1909 the industry consumed nearly 20 percent of manufacturing electric power. One application was movement of ingots to the rolls. With electricity, the ingots were moved from a soaking pit to electrically operated cars which dumped them onto motor driven rolls. With process changes, there were major increases in productivity and reductions in crew sizes and reduced rates of injury and death. In commenting on the importance of both education and engineering to reduce accidents, the author concluded: “I can but insist that application of engineering skills are far and away the most important factor.” In an article published in the late 1930s, D. D. Fennell, the National Safety Council President, noted that there are two important factors in safety engineering: environment and human behavior. He concluded that “engineering for safety is aimed primarily at the environment, although the phrase “intelligently operated” implies that part of the work must be aimed at human behavior. Much later, the human behavior part became ergonomics, a specialty in engineering and safety engineering that designs workplaces to fit the capabilities of workers.
SummaryThe idea of safety through design or prevention through design emerged along with the general need to help protect people from hazards and prevent unneeded injuries, illness and death at work or for the public. The primary responsibility for design of products, machines, buildings, workplaces and processes rests with engineers. They have an obligation to eliminate and reduce hazards and to prevent harm to people in their designs. This responsibility has extended throughout human history and remains today.
1. John Howard, Prevention Through Design – Introduction, (http://www.cdc.gov/niosh/
2. Atila Ertas, Prevention Through Design – Transdisciplinary Process.(http://ciret-
3. Prevention Through Design – Design for Construction Safety. (http://www.
9. The History of ASME’s Boiler and Pressure Vessel Code (https://www.asme.org/
13. Lucian W. Chaney, “Three Periods of Engineering Revision”, from Proceedings of the American Society of Safety Engineers and published in Safety Engineering, Vol. 39, No. 1, pages 1-3, January 1920.