Essay Elevated Working Platform Case Study – ABC Site Worx – Management Assignment Help

Assignment Task:

Case Studies

1) Site Works Case Study 

ABC Site Worx provides for the installation of underground services such as sewerage, drainage, water and gas lines. This requires excavation and earthworks to install such services. ABC Site Worx employs an excavator operator. 

ABC Site Worx was contracted to install sewerage and water services and perform sub-soil drainage works for a residential project. This required excavation to be performed under and near 2 sets of overhead power lines. One set carried 22 000 kv and the other 132 000 kv of electricity. Recognising the risk working near power lines presented, ABC Site Worx had consulted with the power authority in an effort to isolate or insulate these power lines so works could be performed safely underneath them. However, given the nature of the power lines and the duration these would be required to be isolated for the power authority determined it was impracticable to isolate or insulate these power lines. 

The power authority proposed alternate mechanisms to prevent plant under ABC Site Worx control entering the danger zone of these powerlines. These measures included a visible marked barrier delineating the safe working limits under the power lines, the provision of spotters where works were required to be performed in the vicinity of the power lines and the use of small or smaller equipment that was likely to enter the danger zone to perform any excavation works under or near these power lines. 

The excavator operator arrived at the workplace and began performing excavation and clearing works along the intended trench line for these services near the power lines using a hydraulic excavator. In the course of performing this work the excavator operator slewed the excavator around causing the boom to make contact with the 22 000 kv power lines. The power lines gave a loud crackle, emitted a burst of light and left scorch marks on the excavator boom. No-one was injured although this contact caused a surrounding area to be blacked out. 

The excavator operator reported the incident to his supervisors. After checking the area and that there was no damage to the excavator or any immediate danger of electrocution the excavator operator was instructed to resume works. The power authority and safety inspectors later attended and the excavator operator was directed to relocate the excavator. 

2) Scaffolding (1) Case Study

Two people were observed erecting an aluminium mobile scaffold located on the northern elevation of a block of units in Straw Street. 

Four lifts of scaffold had been installed; however, the scaffold was not structurally sound in the lower lifts. One person was observed working on the top lift platform when only half the platform had been installed. It was approximately 7 metres above ground level. A second person was observed working on a lower platform also with only half the platform for that level installed. This platform was approximately 4 metres above ground level. 

The first lift had no sole plates under the casters and the casters were bearing on sand and lawn. The first lift also was not fitted with ledgers on both sides of the bottom bay and a diagonal brace was not fitted to the inside panel. 

Records confirmed that the persons erecting the scaffold did not hold relevant certificates of competency to erect the scaffold. 

3) Scaffolding (2) Case Study

PQR Plastering is a plastering company that was engaged to perform plastering work on a two storey office complex. 

A steel scaffold system had been erected in front of the complex that created a work platform that was approximately 3.3 metres above the ground. 

The scaffold had guardrails (including a mid rail and top rail) in place over the majority of the scaffold. However, where the scaffold angled across the front entrance of the complex adjacent to the work platform there was a void that had been covered by an unsecured piece of timber board loosely seated onto the brickwork. The part of the scaffold adjacent to the void did not have a top rail in place. 

As PQR Plastering was finishing off the rendering to the outside of the complex an 18 year old employee of PQR Plastering was on the scaffolds work platform performing work on the rendering of the windows of the complex. As the apprentice tried to reach a window directly above the void adjacent to the scaffold, he stepped onto the piece of timber that gave way causing him to fall through the void a distance of approximately 3.3 metres. 

4) Site Power Case Study

ABC Constructions was constructing a single storey home. A safety inspector visited the site and observed that the building had reached plate height, but no power had been connected to the site. There was no power board nor was there a meter in the meter box. The roof carpenters had completed pitching the roof. 

There was a consumer connection pillar at the front of the site and there was power connected to the house next door, which was under construction. 

5) Edge Protection Case Study

Big Commercial Builders (BCB) was managing the construction of a building complex. BCB had contracted with a roofing contractor to construct the roof over the complex. The roof was being constructed out of metal roof sheets, which were screwed to the metal purlins underneath them. 

One morning an employee of the roofing contractor was working on the roof from a height of 6 metres while about 2.5 metres from the edge of the roof and slipped. At about the same time another employee of the roofing contractor was working on the roof from a height of 5 metres while about 500 mm from the edge of the roof. 

The edges from which the employees were working were not protected by edge protection, and a fall injury prevention system was not in operation. 

6) Elevated Working Platform Case Study

A rigger employed by another organisation was operating an elevated work platform (EWP) at full platform height on a construction site. 

The rigger was fitting bridging ties (steel connecting brackets tying the roof purlins together) inside the front building entry. While the rigger was reversing the EWP, to line up with the bridging tie line, the EWP swayed and fell over. The rigger remained in the EWP platform until it hit the concrete, falling approximately 6.2 metres. 

The EWP that was operated by the rigger was being manoeuvred on a concrete slab that had 15 polystyrene foam filled penetrations. A wheel of the EWP had entered one of these penetrations. The rigger suffered a perforated right lung and fractures to his pelvis, femur, ribs and L1 vertebrae. 

7) Trenching Case Study

ABC Site Worx was engaged as a subcontractor for the development of a multi-storey apartment complex. 

ABC Site Worx engaged one employee to carry out the plumbing work and another employee as an excavator driver to dig a trench of about 20 metres alongside a brick retaining wall so that the plumber could lay the sewer pipes. ABC Site Worx employed a site supervisor and a labourer. 

The site plan showed the level to which it was necessary to dig the trench to accommodate the sewer pipes. It was not below the depth of the footing of the brick retaining wall. While the excavator driver used the excavator to dig the trench the plumber and the labourer intermittently worked inside the trench. 

The trench was dug to a depth below the base of the concrete footing of the brick retaining wall, and the sides of the trench were very steep. The steep sides of the trench were not supported in any way. 

When the trench had been excavated to about 2 or 3 metres from the end of the boundary wall and was about 10 metres long the excavator driver thought that the retaining wall was in danger of collapsing, and the labourer told the excavator driver that he could see daylight coming through the concrete footing of the retaining wall because the trench had been dug to below the base of the footings of the brick retaining wall. The plumber then walked to that part of the trench where the labourer was standing. The brick retaining wall then collapsed narrowly missing the labourer but crushing the plumber and pinning him against the side of the trench. 

An ambulance was called and the plumber was taken to Hospital where he was diagnosed as having suffered a broken collarbone, broken ribs, a punctured lung and ruptured spleen. 

8) Demolition Case Study

DEF Demolitions operate a demolition business and purchased an excavator with a quick hitch attachment. Various attachments could be secured to the quick hitch attachment and held in place by hydraulics. The quick hitch was supplied with a safety pin that was secured to it by a short chain so that it could not be fully removed from the quick hitch and it was held in place with a clevis pin. The safety pin was a safety device provided to ensure that the attachments could not fall off the quick hitch if the hydraulics failed. 

DEF Demolitions decided to permanently remove the safety pin from the quick hitch. During a house demolition DEF Demolition was using the excavator without the safety pin in place. The quick hitch and bucket fell off the excavator and hit an employee on the upper back causing injuring including a severed spinal cord. 

The employee was taken to Hospital and after treatment to a Rehabilitation Hospital. The employee suffered serious harm and is now a permanent paraplegic. 

9) Access Case Study

XYZ Building Company was the main contractor for the construction of a two storey residence, and had subcontracted the concrete work. 

XYZ Building Company did not supply any means to access the first storey, therefore the subcontractor used his own extension ladder to access the formwork on the first storey. The subcontractor proceeded with concrete work on the first storey level. When he returned to access the ladder he noticed the ladder had been moved from where he originally put it and stepped onto the first rung of the ladder. The ladder was not secured and it came away from the formwork and fell to the ground. The first floor slab did not have any edge protection or fall protection equipment. The subcontractor fell 3.1 metres to the ground breaking his left arm.