This section includes the discussion of the background for Case Study 3 and the analysis of the incident or accident that occurred, focusing on possible causes for occurrence (National Institute for Occupational Safety and Health, 2012) (Nebraska State Fatality Assessment and Control Evaluation Department , 2005) (Higgins, 2004).
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4.6.1 Background
A construction employee suffered a fatal accident in Nebraska in 2005 when a steel roof truss fell from a forklift’s tines onto him. The company, for which the victim worked, constructs commercial facilities, such as concrete buildings, gymnasiums, auditoriums, etc. At the time of the incident, the company employed twenty employees. However, none of these employees received descent safety training as the company was lacking a written safety program. Employees on site only received “on- the-job” training that included informal conversations between them and their employers. Training with regard to operating forklifts was also lacking at this time. The employee that was operating the forklift at the time of the incident did not have any qualifications or certification.
As presented by Figure 10, the company made use of a CAT 920 loader forklift with each forklift tine possessing a lifting capacity of 5 tons. Each steel roof truss was 25m in length and 1.1m in height in the centre. The steel roof trusses decreased in height towards the ends. The trusses were transported in groups of three with a total weight of 4.96 tons.
The victim, together with two other employees, were responsible to move the steel trusses to an area where the trusses were joined together, using x-bracing, for use in a newly constructed gymnasium. The incident occurred as the forklift operator lowered the steel roof trusses and a single truss slipped off from the forklift’s tines and struck the victim.
Figure 11 shows the position of the victim when he was struck by the end of a steel roof truss. The red circle in Figure 11 (next page) represents the location of the victim and the red arrow points towards two 100mm x 100mm wooden blocks that served as supports for the truss. However, the top wooden block had not been placed correctly in the centre of the bottom block and this forced the victim to move in under the steel trusses to replace the top wooden block.
Maximum raised position of forklift
Figure 10: CAT 920 loader forklift that was used for transportation of the steel roof trusses (Higgins, 2004)
B VERMEULEN 64 It is important to notice that the incident forklift had two burned holes near the tip of each tine (refer to Figure 12). According to Cascade Corporation (2009), holes should be drilled into a forklift’s tine and never be burned. The reason is that the tines of the forklift are heat treated. When a hole is burned, the heat treatment is lost in that specific area. This will result in the loading capacity of the tips to be compromised (Cascade Corporation, 2009).
4.6.2 Case Study 3 analysis
With reference to the construction site subjects of concern mentioned in Chapter 3.3, construction plant and equipment played a role in this case study. According to the JBCC Principal Building Agreement (2000), Clause 19.3, the contractor shall be responsible to provide, maintain and remove Location of the two holes
that was burned into the tines of the forklift
Figure 12: The tines of the forklift with two holes burned near the ends (Higgins, 2004)
B VERMEULEN 65 on completion all plant, equipment and scaffolding. With regard to construction safety that is affected by plant and equipment, the contractor is mainly the responsible party (Department of Labour, 2003). However, the engineer should still play a part during the design phase as it may result in the safety of the construction site to increase.
With reference to construction plant and equipment, the engineer can improve safety and efficiency by allowing for the use of temporary works equipment and scaffolding by monitoring that level surfaces and sufficient room around temporary work and equipment are present on the construction site for easy and safe access (WorkCover NSW, 2009). Furthermore, it would have been beneficial for the safety of this project if the engineer had informed the contractor that plant and equipment should be used that provide the adequate loading strength. The engineer can specify that the latter should be included in the health and safety plan of the contractor.
Certain factors, such as the length, weight and the terrain should always be taken into account when steel trusses are moved to the location where the trusses are joined together. Since holes had been burned into the tines of the forklift, the loading capacity of it was reduced and therefore, it seemed unsafe to use the specific forklift. If any of the factors mentioned above are considered to result in unsafe practice, alternative methods to transport the trusses should be used. In this case, a crane or a larger forklift with a wider span between the tines would have been a safer alternative.
The latter may be an indication why the steel truss slipped from the tines. However, a post incident investigation of this case study resulted in the conclusion that no exact causes can be determined that allowed the steel truss to slip off. However, it is the responsibility of the contractor to ensure that steel trusses are secured to the tines of the forklift by using chains. As for most cases, the engineer can assist the contractor by visiting and monitoring the construction site on a regular basis, communicating regularly with the contractor and enforcing quality standards with regard to construction plant and equipment, i.e. enforcing the use of plant and equipment that are adequate, reliable and which will perform the work safely.
A lack of safety training was also present on this specific construction site. Safety training should be a combination of formal instructions and practical training. Formal instructions include lectures, discussions, interactive computer learning and written material whilst practical training includes demonstrations performed by the safety trainer.
4.6.3 Lessons learned from Case Study 3
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The engineer can allow for the use of temporary works equipment and scaffolding by monitoring that level surfaces and sufficient room are present on the construction site for easy and safe access.
During regular site visits and meetings with the contractor, the engineer can enforce a construction method statement included in the mandatory health and safety plan from the contractor that includes the use of plant and equipment that provide adequate loading strength.
In the construction method statement, the contractor should indicate that the construction terrain, weight and length of the steel trusses are taken into account for transportation of the trusses.
According to the Construction Regulations, Clause 7.4, a contractor should ensure that all employees under his or her control are informed, instructed and trained by a competent person regarding any hazard related to work procedures before any work commences. Therefore, in the health and safety plan, the contractor can be required by the specifications of the engineer to include proof that all employees working on site receive descent safety training. Therefore:
o The engineer can enforce safety training programs with formal instructions that include lectures, discussions, interactive computer learning and written material. o The engineer can also enforce practical training that includes demonstrations
performed by a safety trainer.