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19 Cards in this Set
- Front
- Back
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(a) Outline a range of hazards associated with the use of mobile elevating work platforms (MEWPs).
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*Falls from height of persons/materials
*Instability of vehicle e.g uneven ground *Being struck by other vehicles *Trapping & impact hazards *Mechanical failure *Contact with overhead power lines *Exposure of workers to adverse weather conditions |
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(b) Outline the general requirements for the safe use of MEWPs.
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*Selection of trained competent operators
*Prevent falls from the platform by the use of handrails or harnesses *Toe boards installed/use of tool wrist straps *Barriers installed to protect area MEWP used in *Provide head protection where appropriate *Correct positioning e.g. level firm ground, not close to overhead services, *Maintain stability by the use of fully extended and locked outriggers on firm ground *Prevent of use in adverse weather conditions *Not exceeding SWL *Regular inspection and servicing of the equipment *Guard scissor mechanisms to prevent trapping *Control working areas by the use of barriers *Prohibit transfer of people/materials whilst in raised position |
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Outline the process that must be followed before a machine can be supplied under the Supply of Machinery (Safety) Regulations 1992.
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The machine must satisfy Essential Health and Safety Requirements (EHSRs) and be safe:
*Safe and reliable control devices including normal operation and emergency controls *Stable *Protection against mechanical hazards e.g. moving parts guarded *Protection from other hazards e.g. vibration, electricity & noise *Maintenance activities *Adequate indicators e.g. alarms and warning light etc The need for responsible person to prepare technical file: (containing information such as *full detailed drawings *Calculations, test reports *Description of methods used to eliminate hazards *Machinery RA *Instruction draw up in accordance with provision of information) The need for responsible person who might be the manufacturer of the machine or appointed representative in the Community to carry out appropriate conformity assessment procedure to ensure that the machine complies with the requirements of other relevant EC directives To issue a declaration of conformance and Fix the CE mark in a distinct, visible, legible and obvious manner |
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State the main factors to be considered when devising a scheme for the systematic examination and testing of portable electrical appliances.
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*Produce an inventory of the equipment to be examined and tested
*Ensure that each item was provided with a unique means of identification. Determine appropriate type and frequency of inspection for each item based on factors affecting the level of risk: *Type of appliance *Any protective systems provided such as earthing or double insulation *Age and usage of the appliance, *Environment in which it was used and the experience and competence of the user. *Historical data and manufacturer’s recommendations Criteria for each type of examination and test would have to be laid down – *Competence of the tester *Calibration and maintenance of test equipment *Format of records to be kept on the results of the tests and examinations *Systems to identify and take out of use equipment that was found to be faulty |
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(a) Identify the sources of ignition from a typical diesel-engined fork-lift truck.
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*Flames/sparks from exhaust/inlet systems
*Sparks from vehicle electrical system *Static build up from over speeding/loading the engine *Hot parts e.g. exhaust |
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(b) Outline the protection that should be provided on such a truck in order to minimise the risk of explosion when it is required to work in a potentially flammable atmosphere.
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*Fit spark/flame arrestors preventing flashback to atmosphere if vapour was drawn into inlet system and to prevent any sparks from escaping system
*Engine and exhaust system design to ensure surface temps are below ignition temp of the flammable substance *Use of water jacket around hot parts e.g. exhausts system *Electrical equipment on vehicle suitable for zones 1 or 2 and mechanical alternatives (eg fuel gauge) should be fitted where possible *Speed limiters to prevent speed at which static could build up *Use of electrically conductive materials for parts e.g.. tyres to reduce static build up. |
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With the aid of a fully labelled diagram, identify the key safety features of a building to be used as a facility for the storage of highly flammable solvents in 200 litre drums.
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*Bunding to contain spills, including a facility to collect and dispose of spillages
*Building to be constructed of fire resistant materials with lightweight roof or blast panels, *Building to be erected on an impermeable base, with an adequate separation distance from other buildings *Facility for the segregation of materials *Adequate access and egress including a ramp to facilitate the handling of drums *Provision of high/low ventilation and of sprinklers/fire extinguishers to be used in the event of an emergency and *Security features such as the provision of locks and warning signs. |
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The owners of a large distribution warehouse business have secured a contract from a stationery manufacturer. Their insurers have recommended that the proposed storage facility is sprinkler protected. Outline the design factors to be considered in providing an adequate sprinkler system for the facility.
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*Capacity of water required
*Existence of an adequate *Assured water supply and the availability of an alternative if this was to fail for any reason Design of pumping system: *With diesel back up if the decision was taken to install electrically operated pumps *Means of activating the system (frangible bulbs or detector activated) *Linkage of the system to alarms *Spray pattern required *Area to be covered and *Presence of other combustibles apart from the stationery *Height of storage racks and their distance from the sprinkler heads with a decision to be taken on the need for in-rack sprinkling *Provision of fire stopping for sprinklers passing through compartmentalisation *Provision of fire water run off *Procedure put in place for testing the equipment and *Issues concerned with the protection of the sprinkler heads and the electrical system. |
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A rectangular warehouse building (40m x 100m ground area & 18m high) was constructed on a structural steel framework, with a flat roof and coated steel walls. During a storm, the warehouse suffered a catastrophic failure of one of its long walls which in turn caused collapse of the roof and buckling of the other walls. (a) Describe the possible mechanisms of structural failure that investigators would need to consider as potential causes of the incident.
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*Adverse weather conditions exceeding designed wind loading capacity of structure
*Excess weight on roof caused by rain water or snow *Weakening of steel structure by corrosion through roof leaks *Inoperation of rainwater drains *Alterations to structural members which have invalidated original design calculations *Subsidence or nearby tunnels/excavation leading to foundation instability *Vibration caused by traffic etc leading to structural fatigue *Inadequate design and/or construction of structure |
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A rectangular warehouse building (40m x 100m ground area & 18m high) was constructed on a structural steel framework, with a flat roof and coated steel walls. During a storm, the warehouse suffered a catastrophic failure of one of its long walls which in turn caused collapse of the roof and buckling of the other walls. (b) Outline the health and safety issues to be considered when planning the subsequent demolition of the damaged warehouse.
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*Notification of HSE under CDM 2007 regs
*Identification of competent demolition contractors *If building partially collapsed already devise method for demolishing to avoid premature collapse of the remainder *Protection of nearby buildings/business/properties *Protection of public e.g.. barriers, signs, security *Precautions to prevent people or objects falling e.g.. scaffolds, edge protection *Identification of buried and/or overhead services e.g.. power cables, gas pipelines *Selection of and Inspection, maintenance of plant and equipment to be used *Identification of hazardous materials, control of dust and safe removal of waste from site – use of licensed carrier etc *Control of noise *Welfare facilities provision e.g.. toilets, wash and rest facility plus maybe lay down area for contaminated clothing *PPE required for workers e.g.. hard hats, ear protections safety boots, protective clothing, eye protection etc *Site traffic management if required |
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(a) Describe the factors that may cause instability of a mobile crane.
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Causes of instability
*Incorrect selection of crane e.g.. SWL to low for lift *Incorrect sling of load *Unstable ground incapable of bearing weight of crane and load *Uneven/sloping ground *Obstructions being struck by crane of things striking crane e.g.. other plant of site *Exceeding SWL of crane of lift tackle *Inoperation of crane e.g.. incompetent, inexperienced operator, not using out riggers *Poor lift control by AP/banksman. *Unsuitable lifting plan *Mechanical failure *Adverse weather condition e.g.. wind *Lack of maintenance of crane e.g.. incorrect tyre pressures, rope not inspected etc. |
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(b) Outline the measures that should be taken to reduce the likelihood of overturning during a lifting operation.
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Measure taken to avoid
*Conduct full assessment of lift required and surrounding areas including establishing the load bearing capacity of the ground that the crane will operate on *Define and implement sufficient lifting plan use of competent appointed person *Selection of appropriate crane for lift *Ensure that maintenance and testing of crane is adequate *Appoint competent person to supervise lift i.e.. appointed person, competent banksman *Engineering controls e.g.. ensure that outriggers are used and fully extended where appropriate, ensure that capacity indicator and alarms are functional *Ensure that the motion and performance limit device are in working condition *Behavioural controls such as competence and training of driver, slinger and banksman |
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Construction work is to take place in a rural area where electrical power for the site is to be gained from an existing 11kV overhead supply that cuts across the site on wooden poles. Outline the control measures to ensure electrical safety in relation to: (a) the over head supply;
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*Explore possibility of re-routing cables or making dead
*Consult with utilities supplier before taking any protective measures *Identification of safe working distance i.e. 9 m if wooden or steel poles 15m if pylons plus length of jib or boom if cranes/excavators are to be used *Use of barriers, marking tape and bunting *Use of goal posts and/or tunnels *Height restrictions on plant *Safe systems of work to be defined and implemented *Supervision and hazard awareness training for workers e.g.. toolbox talk on hazard associated with cable and what measure need to be taken to avoid *Warning signs and protection for public if necessary |
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Construction work is to take place in a rural area where electrical power for the site is to be gained from an existing 11kV overhead supply that cuts across the site on wooden poles. Outline the control measures to ensure electrical safety in relation to: (b) the provision and use of electricity on the site.
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*Planning and assessment for development of electrical supply by a competent person
*Safe positioning of transformers e.g.. protection from plant/vehicle impact, barriers to prevent workers accessing area *Routing, marking and protection for cables *Use of protective devices e.g.. reduced low voltage systems (110), RCD’s and double insulated equipment *Arrangements for inspection and maintenance of the fixed supply to include earth bonding checks *Arrangements for testing and maintenance of portable equipment *Development of safe systems of work *Use of competent persons for installation work of electrical supply |
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A serious accident occurred when a threaded steel rod in the braking mechanism of a hoist broke. An investigation revealed that the cause of the breakage was fatigue failure. (a) Describe the mechanism and characteristics of fatigue failure.
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crack propagation from points of stress concentration, fluctuating stress environments and the characteristic conchoidal fracture pattern. The final failure may be ductile or brittle.
Factors contributing *Surface occlusions/damage *Choice of material *Residual stress imposed through manufacture *Corrosion, temperature |
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A serious accident occurred when a threaded steel rod in the braking mechanism of a hoist broke. An investigation revealed that the cause of the breakage was fatigue failure. (b) List THREE factors which can contribute to such a failure and for each factor describe one circumstance in which it may occur.
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unsure
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A serious accident occurred when a threaded steel rod in the braking mechanism of a hoist broke. An investigation revealed that the cause of the breakage was fatigue failure. (c) Describe the measures that could have been taken to minimise the likelihood of such a failure.
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*Design, manufacture and installation involving the correct specification of materials and components to match service conditions, correct assembly and quality assurance
*Maintenance, inspection and examination (with NDT) particularly of critical components and their replacement at planned intervals *Measures connected with use such as avoiding abuse and remaining within designed operational limits, the provision of training and instruction for those involved in the use and the keeping of service history records |
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The horizontally sliding gate at the bottom of a construction site hoist used for raising and lowering both persons and materials is electrically interlocked.
(a) Illustrate, by means of a schematic diagram, a suitable interlocking arrangement and give reasons for the level of protection shown. |
diagram required
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The horizontally sliding gate at the bottom of a construction site hoist used for raising and lowering both persons and materials is electrically interlocked. (b) Outline the factors that could prevent effective operation of the interlocking mechanism and the measures that would be needed to ensure continued effectiveness.
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Factors that could prevent effective operation include:
*The arduous conditions, *Dirty environment, *Exposure to adverse weather conditions, and *Use of the equipment by a variety of employees some of whom were not trained to do so and some with the desire to defeat the safety measure in the desire to improve efficiency, needed to feature in the discussion of. Measures to ensure continued effectiveness could have included: *Selection of robust components, *Circuit design to minimise the risk of earth faults, *Arrangements for regular inspection and maintenance, *Protection from the environment and effective supervision. |
