Automation in 8Ž. 1999 643±649 www.elsevier.comrlocaterautcon

Addressing construction worker safety in the phase Designing for construction worker safety

J. Gambatese ),1, J. Hinze UniÕersity of Washington, Seattle, WA, USA

Accepted 29 October 1998

Abstract

Facility designers can positively influence by integrating safety considerations into the design process. Although their potential influence on safety has been documented, designers typically lack knowledge of and limit their involvement in construction worker safety. This research effort involved the accumulation of suggestions for improving construction worker safety while in the design phase. Using these design suggestions, a design tool has been developed to assist designers in identifying project-specific safety hazards and to provide best practices to eliminate the hazards. Although use of the design tool is voluntary in the United States, it is one resource which can be used by designers to fulfill their obligations required by the ConstructionŽ. Design and Management Regulations in UK. q 1999 Elsevier Science B.V. All rights reserved.

Keywords: Construction worker; Design; Hazards; Injuries; Safety

1. Introduction conditions. While many construction parties might ultimately bear a portion of these costs, the responsi- In the past decade, construction worker safety has bility has primarily been placed on the employer, become a major concern of the United States con- typically the . struction industry. This is due in part to the high Through the highly litigious nature of the U.S. costs associated with construction worker injuries, construction industry, many parties have been including the costs of workers' compensation insur- brought into litigation regarding worker injuries. This ance, the indirect costs of injuries, the increased is especially true of owners, a party to the construc- chance of liability suits, and also the rise in criminal tion project which is often viewed as possessing the prosecutions of employers who allow work in unsafe most resources. As a result, many owners have be- come more concerned about safety performance on their projects. Increased concern is evident in con- ) Corresponding author 1 Present address: Department of Civil and Environmental En- tract language which has tended to become more gineering, University of Nevada, 4505 Maryland Pkwy, Las Ve- proactive on safety. It is also evidenced through the gas, NV, USA. increased role that owners now play in monitoring

0926-5805r99r$ - see front matter q 1999 Elsevier Science B.V. All rights reserved. PII: S0926-5805Ž. 98 00109-5 644 J. Gambatese, J. HinzerAutomation in Construction 8() 1999 643±649 project safety during construction. In addition, own- struction of the project. By working together in the ers commonly award contracts to firms who have same firm, they begin to appreciate each other's demonstrated the ability to deliver projects safely. concerns. For example, the construction personnel Despite the changes that have taken place in past might alert the designer of how a particular connec- years, there remains one party that has not been tion could hinder worker safety. Good ideas will be involved in safety. This party is the designer. Safety remembered and used on subsequent projects. It is has been a topic which, all too often, is overlooked unfortunate that this design knowledge is not accu- until the start of the construction phase. This practice mulated and stored in a central location for all ignores the effect that designers have on construction designers to access. The development of a central safety. Perhaps no one has previously considered the body of knowledge is an important first step in role that designers play in influencing construction improving the way that safety is addressed by de- safety. signers. This body of knowledge must then be shared Designers play a very real role in influencing by some means with the design community. construction worker safety. It is the design that dictates how a project will appear and how a particu- lar project or its components will be assembled. The 2. Literature search methods of assembly are often not recognized as being dictated by the designers. In reality, designers Ideas on how to design for construction worker influence many decisions about how construction safety have not been well-publicized in the past. tasks are undertaken. Unfortunately, designers have Literature discussing the subject is sparse. Research not been cognizant of their influence and, as a and publications on construction worker safety has profession, they have not acknowledged the impor- mainly focused on the constructor's role because tance or relevance of their role in safety. Some Occupational Safety and Health Administration designers have stated that, in order to minimize their Ž.OSHA places the responsibility for safety on the liability exposure, they deliberately avoid addressing employer's shoulders. The importance of the de- construction safety. signer's role in safety has only been briefly men- In the United States, designers are being encour- tioned. There is evidence of a need to educate and aged by some owners to specifically address con- involve the design communitywx 2 , and to eliminate struction worker safety in their . Designer the `hands off' attitude designers often express to- involvement in the U.S. has largely been a voluntary wards construction worker safetywx 3 . effort. A clear shift from this is occurring in Great A recent study on the role of designers in con- Britain where recently enacted legislation, titled struction worker safety provides the most relevant ConstructionŽ. Design and Management Regulations information about design decisions concerning safety wx1 , has imposed an obligation on designers to ad- wx4 . The study consisted of surveying design firms dress safety during the construction phase. and firms conducting constructability reviews regard- A common problem designers mention when their ing their involvement in safety. Conclusions from the influence on safety is intimated is that they lack the study indicate that ``for safety of construction work- skills and training to address construction worker ers to be addressed by designers on a regular basis or safety. While they might admit that their designs as an integral design function on all projects, a impact safety performance, they contend that they do dramatic change must occur in the mindset of the not know how to change their designs to improve or design profession.'' The authors recommend that ensure safety. This brings up the need for a central ``one of the means by which designers can become body of knowledge available for designers to address more responsive to the safety needs of construction safety in their designs. workers is through education. Designers must be Some designers, especially those in design±build made aware of the various means by which their firms, already address construction worker safety in design decisions impact the jobsite safety conditions their designs. These designers, of course, work with for construction workers. Such an educational pro- their fellow colleagues who are responsible for con- cess could begin with a compilation of the various J. Gambatese, J. HinzerAutomation in Construction 8() 1999 643±649 645 design approaches that have successfully addressed In addition to the search for existing best practices construction worker safety on past projects.'' to improve construction site safety, the research ef- fort included the development of additional design suggestions. Three resources were accessed for de- 3. Research methodology veloping additional design suggestions: worker safety The main objective of this research was to search manuals, safety design manuals and checklists, and for and develop design suggestions or `best prac- the research team's personal knowledge and experi- tices' which could be implemented in the design ence. phase in order to improve safety during construction. It was felt that additional design suggestions could The accumulated design suggestions would form the be developed from a review of typical construction database of knowledge for a design tool to facilitate site hazards and the safety measures prescribed to their implementation. eliminate or reduce those hazards. The first source To fulfill the objective of compiling design sug- utilized to develop design suggestions was worker gestions, the research effort focused on the construc- safety manuals, such as the OSHA, Army Corps of tion community itself. The goal of this effort was to Engineers, and other state construction safety manu- compile as many design suggestions as possible. All als. These manuals were created to provide guidance safety suggestions applicable to the design phase of for safety practices and conditions on construction any type and size of project were recorded. No sites, and to direct and regulate construction site design suggestions were discarded based on cost, safety. In reviewing these manuals, an attempt was schedule, relative risk reduction, or other design or made to develop design suggestions which would construction performance criteria. eliminate the need to apply the safety measures or Although designing for construction worker safety the dangers experienced during implementation of has only recently been publicized, it was anticipated the safety measures. that some ideas have been developed and are cur- Another source of suggestions was safety design rently in use. Existing design suggestions were sought manuals and checklists. Many large companies, as from two resources: construction industry literature well as state and national agencies, use safety design and personnel. As part of the literature search de- manuals or checklists to address safety in terms of scribed above, academic research and industry work the `end-user', such as the office worker, motorist, or presented in various publications were reviewed for plant operator. A review of these manuals and check- applicable design suggestions. All design suggestions lists by the researchers focused on applying the found were extracted and noted. techniques used for enhancing end-user safety to In addition to the literature search, construction safety during construction. industry personnel were contacted to solicit existing design suggestions. In-person and telephone inter- views were conducted to directly access their knowl- 4. Research results edge and gain from their past experiences. Major public and private parties involved in construction To date, the research effort to collect design projects, including owners, designers, constructors, suggestions has been very successful. Since the start design-builders, and construction managers, were in- of the research in early 1994, over 400 design sug- terviewed. In order to reflect the entire breadth of the gestions have been accumulated. All of the design construction industry, firms of various design and suggestions are included in the final working version construction disciplines were targeted. So that haz- of the design tool. ards of all types would be addressed, the interviews All of the targeted resources proved to be valu- focused on firms of various sizes and on personnel able sources of design suggestions. Table 1 reveals involved in a diversity of projects. Personnel em- that the majority of suggestions came from safety ployed at a variety of levels within a firm were design manuals and checklists. A good proportion interviewed to gain information which reflected vari- also came directly from the researchers and research ous levels of work experience. team members and through interviews with industry 646 J. Gambatese, J. HinzerAutomation in Construction 8() 1999 643±649

Table 1 architectural features of work. Suggestions may re- Design suggestion sources late to more than one design discipline. Source Number ofŽ. % The accumulated design suggestions can also be suggestions sorted according to what project component is af- Safety design manuals and checklists 140 35.4 fected. Table 3 reveals that piping was addressed Researchers and research team members 98 24.8 most often, followed by electricalrinstrumentation InterviewsŽ. in-person, telephone 80 20.3 r OSHAŽ. CFR, publications, data 34 8.6 and mechanical HVAC components. Similar to the Journal articles and periodicals 29 7.4 design disciplines described above, each suggestion Other 14 3.5 may apply to more than one project component. Total 395 100 Components typically designed by the structural engineerŽ foundation, structural framing, slab-on- grade, floor, roof, stairs, ladders, ramps, walkways, platforms. were addressed a total of 145 times personnel. Safety design manuals and checklists typi- Ž.36.7% . Similarly, components typically within the cally address hazards during the startup, operation, 's scope of workŽ furnishings, finishes, pro- and maintenance phases of a project. This resource ject layout, structure planrelevation, doors, win- was particularly fertile due to the close relationship dows, handrails, guardrails. , together with the work between the construction and startup phases, and the schedulersequence, were addressed a total of 120 construction and maintenance phases. As a result, the timesŽ. 30.4% . These percentages are echoed in the design tool will also be useful for improving safety significant number of suggestions which relate to the in the startup and maintenance phases. structural and architectural disciplines shown in Table The relative success of the interview process can 2. be attributed to the construction industry's interest All types of construction site hazards are ad- and willingness to improve safety. This process re- dressed by the design suggestions. The majority of vealed that personnel in construction and design± the suggestions, as shown in Table 4, relate to build firms were able to contribute a substantial hazards that may result in falls, followed by electri- amount of information. These types of firms are cal shocks, cave-ins, and explosions. Many falls on directly affected by construction worker accidents construction sites occur due to the structural and and injuries, and their personnel know the inherent architectural scope of workÐthe design of beams, hazards in specific designs. Personnel in architectural columns, walls, stairways, ladders, etc. Thus, the and consulting engineering firms were not as knowl- edgeable concerning design suggestions, possibly re- sulting from a lack of formal education about con- struction worker safety and their minimal involve- Table 2 ment in overseeing jobsite safety. Design disciplines addressed by design suggestions On-site personnel and others who frequently visit Design discipline Number of Percentage of jobsites provided the most design suggestions. These times addressed recorded suggestionsa individuals are involved in day-to-day construction Structural 131 33.2 activities and regularly address jobsite hazards. Simi- Architectural 120 30.4 lar design suggestions were offered by personnel Pipingrplumbing 76 19.2 r who are involved in the design and construction of Mechanical HVAC 68 17.2 Electricalrinstrumentation 67 17.0 similar types of facilities. Civilrtransportation 64 16.2 The great diversity of the construction industry 56 14.2 led to the accumulation of design suggestions which Other 23 5.8 reflect all types of design disciplines, project compo- Total 605 nents, and jobsite hazards. With respect to design a Since design suggestions may address more than one design disciplines, as shown in Table 2, the most significant discipline, these numbersŽ expressed as a percentage of the 395 number of suggestions address the structural and recorded suggestions. exceed 100%. J. Gambatese, J. HinzerAutomation in Construction 8() 1999 643±649 647

Table 3 many which might be regarded as subsets of struck Project components addressed by design suggestions by and caught inrbetween. Project component Number of Percentage of The following is a sample of the design for safety a times addressed recorded suggestions suggestions recorded: Piping 69 17.5 Ž.1 Suggestion: design components to facilitate r Electrical instrumentation 56 14.2 pre-fabrication in the shop or on the ground so that MechanicalrHVAC 54 13.7 Structural framing 47 11.9 they may be erected in place as complete assemblies. Stairs, ladder, ramp 43 10.9 Purpose: reduce worker exposure to falls from Work schedulersequence 40 10.1 elevation and being struck by falling objects. Roads, paving, flatwork 32 8.1 Ž.2 Suggestion: design parapets to be 42 in. Ž 1.07 Slab-on-grade, floor, roof 30 7.6 m. tall. General conditionsr 26 6.6 special provisions Purpose: while the Uniform stan- Earthwork, sewer, etc. 24 6.1 dards require parapets to be just 30 in. tallŽ. 0.76 m , Furnishings, finishes 20 5.1 modifying the design to increase the parapet height Structure planrelevation 19 4.8 to 42 in.Ž. 1.07 m would also satisfy OSHA guardrail Door, window 16 4.1 requirements. This modification eliminates the need Project layout 15 3.8 Foundation 14 3.5 to construct guardrails during construction, and also Tank, vessel 14 3.5 during future roof maintenance operations. Technical specifications 13 3.3 Ž.3 Suggestion: design beam-to-column double- Walkway, platform 11 2.8 connections to have continual support for the beams Contract drawings 10 2.5 during the connection process by adding a beam seat, Handrail, guardrail 10 2.5 Total 563 extra bolt hole, or other redundant connection point. Purpose: continual support for beams during erec- a Since design suggestions may address more than one project tion will eliminate falls due to unexpected vibrations, component, these numbersŽ expressed as a percentage of the 395 mis-alignment, and unexpected construction loads. recorded suggestions. exceed 100%. Table 4 Construction site hazards addressed by design suggestions resulting large number of suggestions related to falls is expected based on the large number of suggestions Construction site hazard Number of Percentage of times addressed recorded suggestionsa related to structural and architectural disciplines and components noted in Tables 2 and 3. Falls 133 33.7 Electrical shock 59 14.9 The construction site hazards addressed by the Cave-in 53 13.4 design suggestions are distributed in a manner simi- Explosions 52 13.2 lar to OSHA's fatality statistics. OSHA's analysis of Fire 41 10.4 construction fatalities from 1985 to 1989wx 5 revealed Toxic substances 33 8.4 that the majority of fatalitiesŽ. 33% were due to falls Work area 31 7.8 Environmentrclimate 28 7.1 from elevation. This is comparable to the percentage Vehicular traffic 25 6.3 of suggestions recorded that relate to fall hazards On-line equipment 20 5.1 Ž.33.7% . Similarly, the percentage of suggestions Struck by objects 20 5.1 recorded that relate to electrical shock hazards Worker issues 18 4.6 Ž.14.9% , is close to OSHA's reported electrocutions Obstructions 17 4.3 12 3.0 that amounted to 17% of all fatalities. Although Confined spaces 10 2.5 OSHA statistics show that `struck by' and `caught Caught inrbetween 6 1.5 inrbetween' hazards are responsible for 22% and Lighting 5 1.3 18% of the fatalities, respectively, similar high per- Total 563 centages are not reflected in the distribution of a Since design suggestions may address more than one jobsite recorded suggestions. This is probably due to the hazard, these numbersŽ expressed as a percentage of the 395 additional categories that are reflected in Table 4, recorded suggestions. exceed 100%. 648 J. Gambatese, J. HinzerAutomation in Construction 8() 1999 643±649

Ž.4 Suggestion: allow adequate clearance between cally not involved in the safety watch. Designers the structure and overhead power lines. Bury, dis- typically distance themselves from the responsibility connect, or re-route existing power lines around the for construction worker safety mainly because of project before construction begins. their lack of knowledge of safe designs and the Purpose: overhead power lines which are in ser- possibility of increasing their liability exposure. To- vice during construction are hazardous when operat- day's design codes and regulations in the U.S. reflect ing cranes and other tall equipment. this attitude, and worker safety rests on the construc- Ž.5 Suggestion: design and schedule a permanent tors' shoulders. Currently, no national reference stan- stairway to be constructed at the beginning, or as dards exist to bridge the gap between existing design close as possible to the start, of construction. standards and construction worker safety. Purpose: timely erection of permanent stairways In Great Britain, the CDM Regulations have suc- can help eliminate fall and other hazards associated cessfully addressed the need for designers to focus with temporary stairs and scaffolding. on worker safety, and outline mandatory steps for Included in the research effort was the compila- action. The CDM Regulations direct the designer to tion of the recorded design suggestions into a design participate in the identification and reduction of tool. The main objective of the design tool was to health and safety risks. ``The Regulations are not provide a simple means by which a designer could prescriptive; they avoid setting standards. Emphasis be alerted of project-specific construction safety haz- is placed on identifying hazards and the assessment ards, and be introduced to a variety of design sugges- of riskwx 6 .'' The CDM Regulations require designers tions which would eliminate or reduce the identified to play a role in the identification of risks, with hazards. To fulfill this objective, a computer pro- limited guidance on how this assessment is to be gram, titled Design For Construction Safety Tool- made. ``Many designers currently lack skills in de- Box, was created. signing to avoid or reduce health and safety risk and The program allows the user to access the sugges- they feel uncomfortable and threatened by the tions by focusing on the project in one of three ways wxR egulations wx 7 .'' ``The challenge facing designers or paths: project components, construction site haz- is the ability to seek out and discover or develop ards, or project systems. Regardless of the path other techniques or construction methods to produce taken, the user has complete access to all of the the same or similar results than a more inherently design suggestions. All of the topics within each high risk optionwx 6 .'' ``It is suggested then that the category can be independently addressed. By select- designer develops a methodical approach to record- ing a topicŽ. component, hazard, or system , the ing the design considerations with reasoned out- program narrows its focus to only safety concerns comeswx 6 .'' and design suggestions regarding the topic chosen. Complimenting the British effort, this research After selecting a topic, the program presents ques- takes that next step in addressing construction worker tions about the project. Answers to the questions safety. In an effort to provide designers with the guide the program's search for applicable safety required knowledge and tools, design suggestions concerns and design suggestions. The program then have been accumulated which provide designers presents safety concerns and various design sugges- practical examples of how to design for construction tions to mitigate those concerns. worker safety. A workable software package has been developed which can effectively and efficiently address project-specific hazards on all types and 5. Conclusions sizes of construction projects. The design tool will be useful not only for improving safety in the construc- Although interest in construction worker safety in tion phase of a project, but also during the startup, the United States has expanded to owners of con- maintenance, and de-commissioning phases. struction projects, this interest has not spread While designer involvement in construction throughout the design community. Except for those worker safety in the U.S. is voluntary, the CDM employed in design±build firms, designers are typi- Regulations are mandatory. The Design For Con- J. Gambatese, J. HinzerAutomation in Construction 8() 1999 643±649 649 struction Safety ToolBox is one resource which can when owners, those employing the designers, insist be used by designers to fulfill their obligations re- that designers address construction safety concerns. quired by the CDM Regulations in Great Britain. It Thus, owners must provide the initial impetus, by is interesting that this research seems to have the requesting or requiring through contract terms, that same general objective as the CDM Regulations. designers consider construction worker safety in their There is little overlap in the actual work, and in fact, designs. the efforts are highly complimentary. Distribution and use of the design tool will help foster this change in the construction industry. Ex- tensive use of the tool will generate additional design 6. Recommendations suggestions which can then be cycled back into the software in future versions. Continued use of the tool Consideration of construction worker safety by will also lead to further development of the program's designers can eliminate common safety hazards and functionality to better fit the needs of the design reduce worker injuries. These benefits lead to a community. reduction in project costs and liability potential. Al- though these points are widely understood and ac- cepted, a gap exists between constructors and design- References ers in their knowledge of and commitment to jobsite safety. As a result, information on designing for wx1 The ConstructionŽ. Design and Management Regulations, SI construction site safety must ultimately be drawn 3140 HMSOŽ. 1994 . wx from the construction personnel and transferred to 2 R.E. Raggs, J. Cunningham, Safety and efficiency in steel constructionÐthe Broadgate experience, the designers. Designers must be educated regarding Ž.Ž.London May 1988 35. designing for construction worker safety. It should wx3 S. 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