Factors That Affect Safety of Tower Crane Installation/Dismantling in Construction Industry

Abstract

This paper is to investigate factors that contribute to accidents during tower crane installation/dismantling. Accident analysis and focus group interviews (FGIs) were conducted with people involved in crane work. Accidents occurring during installation/dismantling of tower cranes accounted for 68.4% of all fatal accidents. Accident analysis identified “Not following work procedures” as one of the main causes of these accidents, followed by “unsafe acts of workers.” The FGIs investigation revealed the following factors that adversely affected the safety of the tower crane installation/dismantling: competence of the workers; roles of stakeholders such as principal contractors in the tasks; deterioration of tower crane components; and working conditions for conducting the tasks. These results may provide regulators as well as practitioners with insights for improving the safety of tower crane installation/dismantling.

Introduction

I. INTRODUCTION

Tower cranes are used on construction sites as lifting equipment for their combination of height and lifting capacity. Tower crane accidents, however, are likely to be fatal because of the weight of the objects and the heights to which they are lifted. United States labour statistics recorded 632 crane-related construction worker deaths from 611 crane incidents and 17 multiple death incidents resulting in 38 deaths from 1992 to 2006. A crane safety analysis and recommendation report carried out in Singapore. Indicates that in 2008, there were 162 crane-related fatalities, injuries and dangerous occurrences, a 27% increase from 128 cases in 2007. While most of the cases involve less serious non-fatal injuries, crane accidents can ultimately result to huge and severe damage to physical properties and human lives.

Indoor posit that construction processes in Nigeria are characterized by unsafe practices leading to accident that leaves severe consequences on both the project and the workers. Accidents in building construction sites, whether minor or fatal could result to injuries, loss of resources, partial or permanent disability and death in case of fatalities.

In his analysis of types of accident that usually occur in construction sites, injury from the use of equipment ranked first among nine. Other types of accident examined.

Accidents frequently occur on Building construction sites, these accidents could be in the form of workers falling from heights, excavation accidents, the risk of falling debris or equipment’s and so forth. Researches have shown that accidents and injuries in developing countries are generally high when compared to other European countries. Effective safety management is to make the environment safe, to make the job safe and to make workers safety conscious.

In recent years, many developed countries have considered safety as one of the important management issues of construction projects, especially, personal safety. He concludes that cranes are machines with high risk and should be operated with safety management and strong communication between crane operator and signalman. Factors that affect construction site safety due to the work of tower cranes have attracted only moderate attention; they are commonly addressed indirectly and partially within the broader treatment of site safety or of crane work in general. Literature addressing crane safety that explicitly suggests tower crane related risk factors or safety hazards is limited. Hence the need to critically examine safety issues regarding the installation/dismantling operation of tower cranes.

The objectives of this research are: i. to determine the probability of occurrence and degree of impact of safety risk factors during installation and dismantling of tower cranes in construction sites. ii.

To evaluate the safety risk factors based on established risk rating scales. Safety risk factors during the operation of tower cranes were not considered for this study only those associated with the process of installation and dismantling of tower cranes were considered.

II. LITERATURE SURVEY

Idoro, G. I. Health and safety management efforts as correlates of performance in the Nigeria construction industry Journal of Civil Engineering and Management, Vol. 14, Number 4, pp 277–285, 2008

 The consequences of building construction accidents are enormous and cannot be easily quantified, though inevitable but could be controlled to prevent minor or serious consequences to safety of workers [4]

Idoro, G.I. Effect of Mechanization on Occupational Health and Safety Performance in the Nigerian Construction Industry, Journal of Construction in Developing Countries, Vol. 16, Number 2, pp 27-45,

Idoro [10] asserted that although there is no reliable construction accident/incident data in Nigeria. However, a study of 40 contractors in 2006 revealed that accident and injury rates were high in the Nigerian construction industry and the best safety ratios were 2 accidents per 100 workers and 5 injuries per 100 workers.

Kadiri, Z.O., Nden, T., Avre, G.K., Oladipo, T.O., Edom, A., Samuel, P.O., & Ananso, G.N. Causes and Effects of Accidents on Construction Sites (A Case Study of Some Selected Construction Firms in Abuja F.C.T Nigeria), IOSR Journal of Mechanical and Civil Engineering, Vol.11, Number 5, pp 66-72, 2014

 Kadiri, et. al [11] stated that as the growth of construction industry blossoms in Nigeria, this also causes an increase in competition of projects to execute between construction firms which are however achieved at the expense of the workers welfare and their safety Therefore identifying the various causes and effect of accidents on construction sites and proposing ways and means of reducing these accidents should be acknowledged. Erection/climbing/dismantling of tower cranes is a potentially hazardous process involving working at heights, awkward postures, lifting and aligning components of significant size and mass and installing temporary support systems.

Safework. Erection, climbing and dismantling tower cranes. Industry plant consultative committee, New South Wales, Australia, October 31, 2016

These are all often performed under significant time pressure due to the need for road closures, suitable daylight hours or short weather windows as the case maybe [12]

Occupational Safety and Health Administration (OSHA). Region 6 News Release: 12-2231- DAL, United States, November 20, 2012

 The most dangerous process that can lead to fatalities at construction sites is the installation/dismantling of tower cranes; for instance, in 2012, the collapse of a tower crane during dismantling at the University of Texas, USA claimed the lives of two workers [13] 

Ting, F. “The promotion strategy of occupational health and safety by government.” Annual meeting of Hong Kong Const 

There have been five fatal accidents relating to tower crane use during 2002–2006 in Hong Kong, with three workers being killed in July 2007 alone. One such accident in July 2007 caused two fatalities and five serious injuries. The accident happened during the dismantling process, with workers on the tower crane as it crashed down [14]

Zhao, Q. Cause analysis of US crane-related accidents, MSc Dissertation, Graduate School of the University of Florida USA, 2011

Also in a related development, out of the 571 incident cases of crane related accidents that happened from 2000 – 2009 in the U.S as examined by [15] 

Shin, I. J. Factors that affect safety of tower crane installation/dismantling in construction industry, Journal of Safety Science, Vol. 72, Number 2015, pp 379-390, 2015  41 cases which amounted to 7.18% occurred during assembly/disassembly. He further went ahead to say that 22 cases (23.40%) of the 94 cases that occurred from 2007-2009 resulted directly from the operations of assembly/disassembly. More recently, is an investigation of tower crane accidents that occurred in Korea from 2001-2011, it was reported that out of the 38 fatal accident cases involving tower cranes, 68.4% of the accidents resulted from the installation/dismantling operation [16 ]

 Chi, S., Sangwon, H., Dae Y.K., & Yoonjung, S. Accident risk identification and its impact analyses for strategic construction safety management, Journal of Civil Engineering and Management, Vol. 21, Number 4, pp 524-538, 2015

Chi, et al. [17] opined that, risk identification and cautioning can improve the safety of workplaces. By organizing high recurrence risk factors to viably control accident occurrence and deal with the probability of lethal injuries on construction sites when an accident is unavoidable, enables/helps safety managers to comprehend the nature of construction accidents and plan for key risk mitigation Jannadi, O.A., & Almishari, S. Risk assessment in construction. Journal of Construction Engineering and Management, Vol. 129, Number 5, pp 492–500, 2003 However, [18] having concerted for the fact that assessment of risk is crucial for improving safety, went ahead to say that precise evaluation is not really necessary and that an estimated predicted level of risks will suffice for the safety managers to take necessary actions

III. RESEARCH METHODOLOGY

The study looks at probability/likelihood of occurrence and impact of safety risk factors with respect to determining their frequency of occurrence and degree of impact respectively. This requires eliciting knowledge from practitioners who are directly involved in the process such as safety managers, equipment managers and team leaders of installation and dismantling workers. Hence, questionnaire survey was adopted. Population size for the research was unknown as no data is available on exact number of these practitioners. The sample size was determined from a table developed by that the minimum sample size for an unknown population for 95% confidence interval with 5% error level is approximately 34. A total of 57 questionnaires were generated and distributed in Chennai, Mumbai, and Delhi using purposive sampling technique. However, only 38(66.7%) questionnaires were analysed using descriptive statistics and results presented in tables.

A.  Respondents Profile

This section presents the personal details of the respondents to include their nature of job, educational qualification and years of experience as presented in Table 2 indicates that all the categories of respondents are adequately represented having at least ≈ 30% representation each with safety managers having a higher representation of 36.8% and equipment managers having the least representation of 28.9%. All the respondents had at least a post-secondary education with 13(34.2%) of them having a bachelors and 6(15.8%) had MSc. Table 4.1 also shows that 34.2% of the respondents had between 0-5 years of experience. A cumulative of 65.8% of the respondents have at least 6years of experience working in tower crane environment and were therefore able to make correct and valid judgement.

Table 1: Respondents profile

B.  Probability Of Occurrence For Safety Risk Factor

The probability of occurrence for each safety risk factor were scored by the respondents based on a five-point Likert scale. Mean values were determined, and standard deviation also determined to help rank the factors that have the same mean value as shown in Table 1 presents the assessment of the probability of occurrence of each factor which shows that the most probable factor is “Abrasion (wear and tear of components such as bolts, nuts or pins)” with a mean value of 3.63 and the least probable factor is “Incompatibility of components” with a mean value of 2.16. However, the first six (6) factors as seen in Table 2 had mean values ≥ 3.0 which means these factors have a possibility of occurring and may recur occasionally. The factors from 8th position to 21st had mean values ≥ 2.0 which means these factors are unlikely to recur but, have the possibility of occurring. We can conclusively say that these results implies that all the identified factors have the possibility of occurring on our construction sites.

Researchers that previously looked at safety issues associated with tower crane installation and dismantling concluded that failure to follow work procedure is the most likely factor that can result to accidents on construction sites as stated by [13, 16]. However, the results presented in Table 2 proved otherwise by ranking “not following work procedure in manuals” as 12th position with a mean value of 2.89. This could imply that there have been an increased awareness and recognition of safety issues during installation and dismantling of tower cranes over the years which has made the users more safety conscious by implementing work procedures as stated in the manuals.

 The most probable factor being “abrasion (wear and tear of components such as bolts, nuts, or pins)” has affirmed previous research finding that maintenance management is a highly affecting factor on safety when using tower cranes as stated by [9]. This implies that this factor yet plays a great influence on safety during installation and dismantling and/or during operation.

It is also interesting to note that operator proficiency or experience of the tower crane operator which has been widely accepted as the major safety determinant on site as cited by [1, 9, 22] was ranked 4th with a mean value of 3.18. This implies that although it remains a probable factor according to this study however, it has a greater influence on safety during the operation of tower crane. Another likely reason for this factor been ranked 4th could be that operators had gained experience over the years thereby reducing its influence on safety as tower cranes are now widely used and becoming a culture in every construction environment. Incompatibility of components ranked the least amongst all other factors assessed which implies that tower crane manufacturers have continuously improved on the compatibility of their tower crane components. More efforts is still required to completely eliminate this factor as it is still a probable factor although not recurring frequently.

Table 2: Probability of occurrence

C.  Degree Of Impact For Safety Risk Factors

The impact of each factor were assessed using a five point Likert scale so as to establish their various levels of severity/degree of impact if they eventually occur on construction sites. The mean values were then calculated as shown in Table 3. fracture of a wire rope during dismantling had the highest degree of impact with a mean value of 4.63 which implies that the resultant effect of this safety risk factor if it occur is fatality, major injury/injuries, permanent impairment, critical process loss and critical property damage. The factor “workers (erectors, dismantlers) are leaving the work often due to hard working condition” had the lowest degree of impact with a mean value of 2.34 which therefore implies that it’s resultant effect if it occur can only lead to minor injury. All the factors however had degree of impact that range from minor injury to fatality as shown in Table 4. There is a need to pay serious attention on the first six factors as they have mean values ≥ 4.0 which means if they occur, their resultant impact would lead to fatality on site.

 Overloading tower cranes with objects exceeding its load limit is the 20th probable factor to occur on site as seen from Table 3. However, results for degree of impact in Table 4. Showed that it has a high degree of impact if its accident does happen on site as it was ranked 3rd position amongst other factors with a mean value of 4.18. The latter is in line with previous findings that exceeding tower crane load limit results to accident on site that could be very fatal involving multiple injuries in most cases. From a careful observation of this factor, one would notice a sharp distinction between its probability of occurrence and degree of impact. The reason for this could be linked to the

previous assertion that there has been a significant improvement in the level of safety awareness on site as a result of continuous research on safety challenges associated with tower crane working environment thereby, reducing the probability of occurrence which is a function of the probability of occurrence and the degree of impact. The result of this was then measured against a standard risk rating developed by [23] so as to come up with their risk levels as shown in Table 4.

Σα (probability risk score), Σβ (degree of impact risk score), ΣRS (combined risk score), N (population), RSIS (relative significance index score).

From Table 5, fracture of a wire rope during dismantling had the highest RSIS of 15.6 and implies a high risk factor which requires a high level of control put in place to forestall danger and make the working environment safer. The factors ranked from 2nd to 15th as shown in Table 5 had RSIS of 13.2 - 9.0 respectively, and as such implies that they are moderate risk factors that is acceptable but, requires suitable controls to maintain a safe working environment. Those ranked from 16th to 21st had RSIS of 7.9 – 6.4 respectively, which implies low risk factors that are acceptable with no further action required. The factor “workers (erectors, dismantler) are leaving the work often due to hard working condition” had the lowest RSIS of 6.4 and does not really pose any treat to safety.

This could be attributed to the high rate of unemployment in the country as reported by [24] thereby making the assertion in the factor false because, those who managed to be gainfully employed instead of leaving would rather do everything possible to keep their jobs so as to continue sustaining themselves. The fear that losing their job might make them become unemployed for the rest of their lives makes people

Table 3: Degree of impact

Table 4: Safety risk evaluation

Stick to the ones they have irrespective of the working condition. It is widely recognised that poor maintenance culture is lacking in both private and public sectors in Nigeria as stated by [25]. This could therefore be the reason why “fracture of a wire rope during dismantling” closely followed by “Abrasion (wear and tear of components such as bolts, nuts or pins) had high RSIS of 15.6 and 13.2 respectively. Routine maintenance of the tower cranes could help to minimize the risk level.

D.  Safety Risk Factors During Installation And Dismantling Of Tower Cranes

Various factors affecting safety during installation and dismantling operation of tower cranes on construction sites are rarely reported nor documented for use as contractors are simply making maximum profit. Erection, dismantling and operations failure to follow a list of safety risk factors as shown in Table 5.

Table 5: Safety risk factors, [Reference 21]

Conclusion

The study concludes that abrasion (wear and tear of components such as bolts, nuts, or pins) was the most probable factor and fracture of a wire rope during dismantling had the highest degree of impact. In evaluating the safety risk factors, “fracture of a wire rope during dismantling and abrasion (wear and tear of components such as bolts, nuts, or pins) which could both be seen as a maintenance management issue as looked at by previous research is a highly affecting factor on safety during installation and dismantling. Adoption of a preventive maintenance strategy or routine check on the tower crane parts and components could help minimize the probability of occurrence and impact of the safety risk factors on site during installation and dismantling of tower cranes.

References

[1] Beavers, J.E., Moore, J.R., Rinehart, R., and Schriver, W.R. Crane-related fatalities in construction industry, Journal of Construction Engineering and Management, Vol. 132, Number 9, pp 901–910, 2006. [2] Bureau of Labour Statistics (BLS). Crane-Related Occupational Fatalities, United States, Fact Sheet BLS, 2008 [3] Annex, B. Crane safety analysis and recommendation report. Workplace Safety and Health Council, the Ministry of Manpower and the National Crane Safety Taskforce, Singapore, 2009 [4] Idoro, G. I. Health and safety management efforts as correlates of performance in the Nigeria construction industry, Journal of Civil Engineering and Management, Vol. 14, Number 4, pp 277–285, 2008 [5] Orji, S.E., Enebe, E.C., & Onoh, F.E. Accidents in building construction sites in Nigeria; a case of Enugu state, International journal of innovative research and development, Vol. 5, Number 4, pp 244-248, 2016 [6] Chen, W.T., Lu, C.S., & Huang, Y. Investigating the safety cognition of Taiwan’s construction personnel, Journal of Marine Science and Technology, Vol. 19, Number 4, pp 398-408, 2011 [7] Ali, M.K.A.M., & Muhamad, M.I. Crane Failure and Accident in Construction. Faculty of Civil Engineering, University Teknologi Malaysia, Malaysia, 2016 [8] Nunnally, S.W. Managing construction equipment, (2nd ed.). Upper Saddle River, New Jersey, Prentice-Hall, 2000 [9] Shapira, A., & Lyachin, B. Identification and analysis of factors affecting safety on construction sites with tower cranes. Journal of Construction Engineering and Management, Vol. 135, Number 1, pp 24–33, 2009 [10] Idoro, G.I. Effect of Mechanization on Occupational Health and Safety Performance in the Nigerian Construction Industry, Journal of Construction in Developing Countries, Vol. 16, Number 2, pp 27-45, , 2011 [11] Kadiri, Z.O., Nden, T., Avre, G.K., Oladipo, T.O., Edom, A., Samuel, P.O., & Ananso, G.N. Causes and Effects of Accidents on Construction Sites (A Case Study of Some Selected Construction Firms in Abuja F.C.T Nigeria), IOSR Journal of Mechanical and Civil Engineering, Vol.11, Number 5, pp 66-72, 2014. [12] Safework. Erection, climbing and dismantling tower cranes. Industry plant consultative committee, New South Wales, Australia, October 31, 2016 [13] Occupational Safety and Health Administration (OSHA). Region 6 News Release: 12-2231- DAL, United States, November 20, 2012 [14] Ting, F. “The promotion strategy of occupational health and safety by government.” Annual meeting of Hong Kong Construction Association Limited, Hong Kong, 2007 [15] Zhao, Q. Cause analysis of US crane-related accidents, MSc Dissertation, Graduate School of the University of Florida USA, 2011 [16] Shin, I. J. Factors that affect safety of tower crane installation/dismantling in construction industry, Journal of Safety Science, Vol. 72, Number 2015, pp 379-390, 2015 [17] Chi, S., Sangwon, H., Dae Y.K., & Yoonjung, S. Accident risk identification and its impact analyses for strategic construction safety management, Journal of Civil Engineering and Management, Vol. 21, Number 4, pp 524-538, 2015 [18] Jannadi, O.A., & Almishari, S. Risk assessment in construction. Journal of Construction Engineering and Management, Vol. 129, Number 5, pp 492–500, 2003 [19] Odeyinka, H.A., and Dada J.O. Risk assessment and allocation in budgeting. A paper delivered at the Nigerian Institute of Quantity Surveyors (NIQS) Workshop at Precious Conference Centre Makurdi, Benue State, July 27-28, 2016. [20] Salihu, A.A., Aliyu, S.S., & Abubakar, M. An assessment of safety risk factors during installation and dismantling of tower cranes in construction sites, MSc Dissertation, Building Department, Ahmadu Bello University Zaria, Kaduna State, 2018. [21] Louangrath, P.T.I. Sample Size Determination for Non-Finite Population. International Conference on Discrete Mathematics and Applied Sciences (ICDMAS), University of Thai Chamber of Commerce Conference Proceedings, Applied Science Section, 2014, Article No. 2. [22] Shapiro, H., Shapiro, J., & Shapiro, K. Cranes and Derricks, McGraw-Hill, New York, 2000. [23] Construction Plant Hire Association (CPA). The climbing of tower cranes CPA Best practice guide, Published by tower crane interest group (TCIG), London, United Kingdom, 2011 [24] National Bureau of Statistics (NBS). Labour Force Statistics Vol:1 Unemployment and Underemployment Report. Q1 – Q3, 5. Nigeria, 2017 [25] Mbamali, I. The impact of accumulation of deferred maintenance on selected buildings of two federal universities in the northwest zone of Nigeria. Journal of Environmental Sciences. Vol. 5, Number 1, pp 77-83, 2003

Copyright

Copyright © 2022 Thanu Lingam C, Barathkumar R. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.