Construction of Multi-Story Car Park - Case Study Example

Risk Assessment Construction of Multi-Story Car Park at The University of Central Lancashire 1. Introduction Due to the shortage of car parking spaces in recent months, the management of the University of Central Lancashire decided to construct a multi-story car park in front of Foster building. During the construction phase, the entrance to Foster Building will be through Maudland Building. The construction company hired a luffing tower crane to service the lifting requirements of the construction project. In view of the health and safety requirements of such operation, an assessment should be developed to assist the construction company and the university’s management to maintain a hazard free environment. 2. Statutory Requirements The most commonly used piece of handling equipment is the crane, which is over the years has been developed to meet highly specialized applications. As a result of accidents in the past, a body of legislation has grown up which covers the construction and use of crane. The requirements to be met for the safe use of lifting equipment are contained in Provision and Use of Work Equipment Regulations 1998 or PUWER 2 supplemented by the Lifting Operations and Lifting Equipment Regulations 1998 or LOLER and a supporting Approved Code of Practice. These regulations cover all work equipment for lifting loads including accessories that connect the load to the crane and they revoke the Hoists Exemption Order 1962. Theses Regulations are proscriptive and risk based and requires the carrying out of risk assessments of lifting operations. Under LOLER, lifting equipment provided for use at work should be strong and safe enough for its use. It should be marked with its safe working load and should be installed and positioned to minimise risks. It should be use safely and thoroughly examined and, where appropriate, inspected by competent person on an ongoing basis. All equipment used at work for lifting and lowering loads, including attachments and accessories, but with the exception of escalators, is covered by the regulations. Regulation 6 of PUWER requires that all work equipment shall be maintained in an efficient state, in efficient working order and in good repair. Compliance with this absolute duty implies the operation of planned maintenance programmes1. Lifting equipment must be suitable for its purpose and constructed of materials of adequate strength with a suitable factor of safety taking account of any hostile working environment. It should be stable when used for its intended purpose and this particularly pertinent for mobile lifting equipment, which should be provided with outriggers. Access to operating positions and where necessary, other parts should be safe and precautions should be taken to prevent slips, trips, and falls whether on the equipment itself or when moving in the work area during a lifting operation. Protection must be provided for the operator especially where he is likely to be exposed to adverse weather. Instruments should be provided to detect dangerous weather conditions such a high winds so precautions can be taken and, if necessary, the equipment taken out of use. Additional measures have to be taken for lifts that carry people including enhance strength of lifting ropes, means to prevent crushing or trapping, falling from a carrier and to allow escape from a carrier in an emergency. The lifting equipment should be 1 J. Stranks. The Manager's Guide to Health & Safety at Work. Kogan Page Publishers, 2005, p. 231 positioned to minimise the risk of equipment or load striking someone, loads should not be carried over people and hooks should have safety catches. All lifting operations should be properly planned and supervised and measures taken to ensure that no loads pass over places where people are working and that people do not work under suspended loads. The operator should have a clear view of the load or be directed by a 'banksman' using signs or signals clearly understood by himself and the operator2. Lifting equipment should not be used for operations likely to cause it to overturn, for dragging loads or used in excess of its safe working load. Lifting accessories should be used within their safe working loads and stored where they will not deteriorate or be damage. All lifting equipment must be regularly inspected to program either laid down because of an assessment of its use or based on experience. Someone competent and knowledgeable in the equipment such as an insurance surveyor should carry out the inspection and a report containing the prescribed particulars prepared for the employer. Any faults affecting the safe operation must be reported to the enforcing authority. Reports of inspection and documents accompanying new equipment must be kept available for inspection3 2 J. Ridley and J. Channing. Safety at Work. Butterworth-Heinemann, 2003, p.758 3 ibid 3. Risk Assessment INITIAL RISK ASSESSMENT Use of Lifting Equipment SIGNIFICANT HAZARDS Unintentional release of load High Unplanned movement of load Low Damage to equipment Low Crush injuries to personnel Medium ACTIONS TO BE TAKEN TO REDUCE RISKS: Operation should be in compliance with: Lifting Operations and Lifting Equipment Regulations (LOLER) Safety Signs and Signals Regulatory (SSSR) Provision and Use of Work Equipment Regulations (PUWER) British Standard – Specification for flat woven webbing slings BS- Guide to selection and use of lifting slings for multipurpose Planning: Copies of statutory thorough examinations of lifting equipment will be kept on site. Before selection of lifting equipment, the above standards will be considered as well as the weight, size, shape, and centre of gravity of the load. Lifting equipment is subject to the planned maintenance programme. Physical: All items of lifting equipment will be identified individually and stored to prevent physical damage or deterioration. Safe working of load lifting equipment will establish before use. Packing will be used to protect slings from sharp edges on the load. All items of lifting equipment will be visually examined for signs of damage before use. Ensuring the eyes of strops are directly below the appliance hook and that tail ropes are lifted to larger loads will check swinging of the load. Banksmen will be used where the lifting equipment operator’s vision is obstructed. Approved hand signals will be used Managerial/Supervisory: Only lifting equipment that is in date for statutory examination will be used. Manufacturer’s instructions will be checked to ensure that methods of sling attachment and slinging arrangements general are correct. Training: Personnel involved in the slinging of loads and use of lifting equipment will be required to be trained to CITB or equivalent standard. Supervisors will be trained in the supervision of lifting operations. Source: Hughes and Ferrett (2005) 4. Suitable Safe Systems of Work for Daily Operation A safe system of work is a formal procedure that should result to a systematic examination task in order to identify all the hazards and assess the risks, and which identifies safe methods of work to ensure that the hazards are eliminated or the remaining risks are minimized4. On daily operation of the crane, the following should be taken5: a. The operator must undertake a brief inspection of the crane and associated lifting tackle each time before it is used. b. He must ensure that loads are not left suspended when the crane is not in use. c. Ensure that crane or the load would no strike anybody before a lift is made. d. He must ensure that loads are never carried over people. e. Hen muse ensure good visibility and communications. f. Lift loads vertically since cranes must not be used to drag a load. g. Travel with the load as close to the ground as possible. h. Switch off power to the crane when it is left unattended. 5. Hazards and Control to Minimize Hazards The principal reasons for crane failure, including loss of load are overloading, poor sling of load, insecure or unbalanced load, loss of load, and overturning, collision with another structure or overhead power lines, foundation failure, structural failure, operator error, and lack of maintenance and or regular inspections. 4 A. Holt. Principles of Construction Safety. Blackwell Publishing, 2001, p.76 5 P. Hughes and E. Ferrett. Introduction to Health and Safety at Work: The Handbook for the NEBOSH National General Certificate. Butterworth-Heinemann, 2005, p.116 Six of the most frequent life-taking hazards are two-blocking, crane upset, jib-boom stowage on hydraulic telescoping booms, latticework boom disassembly, crane operator protection, and power line contact6. The hazard of two-blocking is dormant when the crane is not in use. The hazard becomes armed when the operator is using the crane, as use may allow the headache ball to approach the vicinity of the tip of the crane boom. The hazard is active when two-blocking occurs and the load hook assembly or lower load block contacts the sheave on the boom tip or upper load block, causing the hoist line to part and break, or pull the headache ball and hook up over the top of the sheave at the tip of the boom. The load straps become disconnected, and the load is lost, becoming a failing object and imperilling the lives of those working below. To avoid two-blocking, a crane should be equipped with functioning anti-two-blocking devices. These devices are now generally standard on all new cranes. Similarly, safety latches are necessary on every crane hook used on a construction site. A safe lifting hook is critical component in lifting a load, as a hook that has no latch to secure load straps or chains within the throat of the hook can kill. Many hooks have thin sheet metal latches that are easily damaged or bent and are worthless for securing the straps safely within the hook. Before a crane or other lifting equipment, using hooks is allowed to operate on the job site, make sure that the hook has a double-locking safety latch7. 6 D. MacCollum. Construction Safety Engineering Principles: Designing and Managing Safer Job Sites. McGraw-Hill Professional, 2006, p.157 7 D. MacCollum. Construction Safety Planning. John Wiley and Sons, 1995, p.83 A crane can upset from overloading. Any crane without a load-moment indicator or LMI presents a dormant hazard that can become armed at any time when the weight of the load on a crane exceed its rate capacity and causes it to destabilize. Analysis shows that over half of the incidents involving this hazard occur when the crane operators is either sluing the crane cab, or extending or lowering the boom with the outriggers retracted. Both these actions can activate the hazard to upset by increasing the lifting radius. The significant consequences of crane upset are mixed bag or either one or a combination of the following. Fatalities, lost-time injuries, lost-production time, damage to the crane, serious damage to other property. OSHA Subpart N, 1926.550(a)(9) requires ‘Accessible areas within the swing radius of the rear of the rotating superstructure of the crane, either permanently or temporarily mounted, shall be barricaded in such a manner as to prevent an employee from being struck by the crane. To assume a crane is overloaded when it starts to become light and raises off its outriggers is very dangerous, as some newer cranes carry extra heavy counterweights that increase the tipping load far beyond the designed structural strength of the boom. The use of a load-moment indicator or LMI is necessary to limit the cranes’ lifting capacity to within its rated capacity, which is based upon both the structural strength of the boom and the stability of the crane8. Hazards can be reduced by clear design of control panels, providing a chart at the operator’s fingertips that specifies load configuration, handrails, non-glare windows, windows that extend to the cab floor, comfortable seats and both noise and thermal insulation. Crane owners are responsible for keeping their machines in good condition by ensuring regular inspection and proper maintenance. The crane assigned to the project must have the capacity to handle heaviest load it must carry. A competent person should inspect it with a maintenance record kept. Ventilation should be provided to remove or dilute engine exhaust from cranes working in enclosed areas. 8 D. MacCollum. Construction Safety Planning. John Wiley and Sons, 1995, p.82 Hearing protection, when necessary should be provided. Signaller should be used to aid the operator near the limit of approach around power lines. The ground, including access in and around the site, must have the ability to bear the weight of the crane and the load it is lifting. The crane operating area should be roped off to prevent injuries from overhead lifting. A signaller must be used when the operator cannot see the load clearly and both should be trained and competent in all aspects of the job (Stellman 1998, p.93). 9 J. Stellman. Encyclopaedia of Occupational Health and Safety. International Labour Organization, 1998, p.93 6. Bibliography HOLT, Allan. Principles of Construction Safety. Blackwell Publishing, 2001 HUGHES, Phil and FERRETT Ed. Introduction to Health and Safety at Work: The Handbook for the NEBOSH National General Certificate. Butterworth-Heinemann, 2005 MacCOLLUM, David. Construction Safety Planning. John Wiley and Sons, 1995 MacCOLLUM, David. Construction Safety Engineering Principles: Designing and Managing Safer Job Sites. McGraw-Hill Professional, 2006 RIDLEY, John and CHANNING, John. Safety at Work. Butterworth-Heinemann, 2003 STELLMAN, Jeanne Mager. Encyclopaedia of Occupational Health and Safety. International Labour Organization, 1998 STRANKS, Jeremy. The Manager's Guide to Health & Safety at Work. Kogan Page Publishers, 2005 Read More