530 likes | 1.17k Views
Discover various types of cranes and lifting equipment used in construction, steps for proper planning and execution, safety precautions, and legal requirements. Ensure competence of personnel involved to avoid accidents.
E N D
Lifting Operations on Construction Sites A presentation to Merseyside & Cheshire Construction Safety Group on 12th March 2018 by: John Ellis BSc(Eng),CMIOSH,CMaPS
Most common ways of lifting: • Mobile Cranes • Telehandler • Excavator • Hiab
Types of Mobile Crane • Truck-mounted crane • All-terrain crane • “City” crane • Self-erecting tower crane
Summary of suitability • Truck mounted-long wheelbase, large turning circle • All terrain-more compact, all wheel steer, highly manoeuvrable • City crane-compact, able to operate in limited headroom areas • Tower crane-large working radius directly adjacent to structures
What factors determine the size of crane needed ? • Maximum weight of load to be lifted (e.g. 3.7 tonnes @ 15m radius) • Maximum working radius (e.g.37m lifting 1.2 tonnes) • Angle of jib in restricted headroom locations
Imposed Loadings • Must be clearly shown on lifting plan as both point load and pressure(e.g. point load=25KN,pressure of 25KN/m2) • Should indicate size of pads being used(typically 1m diameter pads have an area of 0.7m2) • Tables can be used to get approx. loads, or crane hire company will be able to provide more precise detail
Ensure ground bearing pressures acceptable • Provided details of imposed loadings to the site (in writing) • Obtain written confirmation from the site that the ground is capable of withstanding the loads • May need CBR tests to be undertaken • May need additional measures to reduce pressures to an acceptable level e.g. steel plates,sleepers,mats
Lift plan should indicate: • Crane access and locations • Crane size and lifting equipment • Berthing study (rigger spread) • Imposed loadings • Position of delivery wagons • Directions of slew • Positions of new/existing buildings • Location of any specific hazards
Planning must be done by a competent person (appointedperson)
Supervision • Supervision done by the appointed person • Or, if not, then by a qualified crane supervisor • Directing the crane is done by a qualified banksman who agrees a means of communication with the crane driver • Slinging is undertaken by trained slingers • Crane driven by suitably competent operator
Summary • Select suitable type of crane • Select right size of crane for the job • Understand how a crane works • Ensure all involved in the planning and operation are competent
Don’t have the required Skills,Knowledge,Experience ? • You must arrange for a “Contract Lift” • A reputable crane hire company will visit the site and do all the necessary planning • They will provide relevant documentation for the lift including a lift plan • On the day they will provide crane driver and crane supervisor/banksman • They will also provide appropriate lifting tackle(chains,slings,etc.)
What can go wrong? • Crane exceeds safe working capacity • SWL of lifting accessories exceeded • Imposed rigger loadings exceed ground bearing capacity • Structural failure of crane and/or lifting accessories (due to lack of maintenance) • Operation in adverse weather conditions • Communication failures
Requirements • Driver must have appropriate skills, knowledge & experience(e.g. CPCS for type & size of telehandler) • Operate on firm & level ground when placing/removing loads (e.g. designated stoned up area) • Suitable reversing mirrors & cameras • Use of stabilizers when required
Types of excavator • Back-hoe excavator • Mini excavator • Tracked excavator
Requirements • Driver to have necessary skills, knowledge & experience for type & size of excavator • Driver to have suitable knowledge & training in attachments (e.g. manual quick hitch, semi-automatic quick hitch, automatic quick hitch • Suitable reversing mirrors and cameras to enable driver to see persons at rear
Requirements • Driver with suitable skills, knowledge & experience • Set up on firm & level ground capable of withstanding rigger loadings • All riggers to be fully extended
Statutory Requirements for Lifting Plant LOLER Regulations require that all plant used for lifting has undergone thorough examination & inspection by a competent person within previous 12 months …..but if being used for lifting persons (e.g. man-rider cage attached to forklift) then must be within previous 6 months
Lifting tackle • Chains (e.g. 2 legged 10mm chains,SWL 4.25 tonnes) • Web slings or wire slings • Grabs of lifting booms • Lifting clutches (e.g. modform lifters) All must be maintained in good condition and should be visually inspected each day before lifting operations commence
Requirements • Capacity of the choked chains must be downrated by 20% • i.e. 2 legged Chains with SWL of 4.25 tonnes can only be used to lift a maximum load of 3.4 tonnes
Statutory Requirements • All lifting accessories to have undergone thorough examination and inspection by competent person within the previous 6 months (as per LOLER Regulations)
Guidance • BS7121 Part 3:Code of Practice for Safe use of Cranes
HSE Guidance • L113 :Safe Use of Lifting Equipment ACOP • L22:Safe Use of Work Equipment • INDG290:Lifting Equipment at Work-a Brief Guide • INDG422:Thorough Examination of Lifting Equipment • HSG144:Safe Use of Vehicles on Construction Sites • HSG150:Health & Safety in Construction