Presentation on theme: "Construction Health and Safety Management"— Presentation transcript:
1Construction Health and Safety Management By Dr Simon Smith – licensed under the Creative Commons Attribution – Non-Commercial – Share Alike License
2Part 8: Working at Height Construction Health & Safety ManagementSimon Smith (University of Edinburgh)& Philip Matyear (Balfour Beatty)Part 8: Working at Height
3Overview General Access from height Legislation Protection measures HSE viewWorking at height examplesHierarchy of controlEliminate work at heightPlanning for working at heightAssess to heightAccess from heightProtection measuresEdge ProtectionLift shafts - Safety AlertSafety harnessesInspection and MaintenanceSummaryFurther reading
4General Source - HSE Statistics of fatal Injuries 2002 / 03 From HSE statistics – figures are out of date but the trends are still valid
5Legislation - Principle Requirements Health and Safety at Work Act etc 1974Management of Health and Safety at Work Regs 1999Construction, Design and management Regs 1995Construction (Health, safety and welfare) Regs 1996Provision and use of work equipment Regs 1998All of these sets of legislation make reference to working at height
6HSE view HSE LOOKING AT SAFE WORK AT HEIGHT HSC press release C044: September 2003HSE LOOKING AT SAFE WORK AT HEIGHTAll work at height has been identifiedWork at height has been eliminated where possibleWhere elimination is not possible, the correct equipment has been selectedWork platforms have been installed with adequate accessIf using mobile elevated work platforms (MEWPs), they are used correctlyIf using tower scaffolds, they are correctly erected with edge protection and toeboards as necessary
7HSE viewLadders or step ladders are only being used for short duration work, that they are the correct type for that work and are secured to prevent slippingIf using safety harnesses, they have suitable anchorages and adequate fall distances and are inspected, andAll work at height equipment, including ladders and step-ladders, havebeen inspected, examined and maintained as necessary.In addition, inspectors will look to ensure that only competent contractors are used for work at height and that all jobs have been properly planned and thought through.
9Working at Height Structural Steel Roofwork Cladding & Glazing At some stage during most construction and maintenance projects there are some tasks that involve working at height - here are some examples.Structural SteelRoofworkCladding & GlazingDeep ExcavationsScaffoldFalsework
10The best way of controlling any hazard is to remove it ! The hierarchy of controlEliminate working at heightThe best way of controlling any hazard is to remove it !Measures that designers can consider include;Use of prefabrication to limit the risks arising from working at heightDetail early access requirements to permit their early construction.Detail slabs or hardstandings to suit scaffolding and mobile access equipmentDesign the structure for scaffold, safety nets, running lines or safety harnesses.Design permanent access facilities to ease access for maintenance of the structure over its life.Select materials that will reduce the risks during maintenance e.g specifying non -fragile roofing materials.
11The hierarchy of control Planning for work at heightIn reality there will always be elements of work at height in the life cycle of any building - Construction, Maintenance and Demolition.Architects and designers are constantly pushing construction boundaries driven by the clients brief for unique and unusual buildings / structures. Its because of this, and the very nature of buildings that working at height will never be completely designed out and so the need to plan and execute the work in a controlled manner remains.Urbis - ManchesterNew Lowry Gallery - Manchester
12The hierarchy of control Planning for work at height4 Ws & 1 HWho - What trades, How many, How many need work positions?What - Type of work - demolition / construction, Quantities of materials, Tools required?Where - At what height will people be working, Is the job built in-situ or by prefabrication? Is access from the ground available, Environmental hazards that could limit access options.When - Can a particular task be scheduled to make use of permanent access arrangements or by adopting existing temporary access, Will a particular order of doing the work make the access needed for carrying out the task easier or more difficult.How - How long is access required, Will continuous access be required for months, Will access be required later in the programme for following trades, testing and inspection etc.
13Access to height - Static Work Platforms Having established the need for a working platform your next decision is what type, here is a list of current options including their common uses and limitationsIndependent Tied ScaffoldFor - Provides a good working platform for a variety of trades - very adaptable.Limitations - Restricts access at ground level, relies on structure for its stability.Preston PrisonCrawshaw School, Pudsey
14Access to height - Static Work Platforms Birdcage ScaffoldFor - Provides access and a working platform below ceilings and soffits, for M & E installation and finishing trades.Limitations - Restricts access in the space below, normally have one working deck fully boarded and are suitable for light work only.
15Access to height - Static Work Platforms Truss - Out and Cantilever ScaffoldFor - Where an independent scaffold cannot be erected from ground level.Limitations - Needs a specific design, potentially hazardous to erect, inspect and dismantle.Simple truss outs and cantilevers areintended for very light work only andshould not be loaded with materialsunless designed accordingly.Its good practise to mark safeworking load on these two types ofscaffoldTruss-out scaffoldCantilever Scaffold
16Access to height - Static Work Platforms Tower ScaffoldsFor M & E installation and other finishing trades such as painters - typically short duration work in many locations.Limitations - Needs a firm level surface and is restricted in height by base dimensions.Types include;-Prefabricated Aluminum AlloySystem ScaffoldTraditional Tube and FittingsGlass Reinforced Plastic (GRP)Height to Base RatioOutside Use : : 1Inside use : : 1! Towers must be erected by acompetent person !
17Access to height - Mobile Work Platforms Mobile Elevated Work Platforms (MEWP’s)For - Used for M & E installation, steelwork connections, finishing, maintenance and inspections.Limitations - Ground conditions,Reach / length of boomRestricted loads in basket.Types include;-Scissor LiftArticulated BoomTrailer Mounted! MEWP’s must be operated by acompetent person !
18Access to height - Mobile Work Platforms Mast Climbing Work Platforms (MCWPs)For - Repetitious work at different levels in one location finishing, cladding and maintenance.Limitations - Need suitable ground conditions, trained operator, requires tying in at height.MCWP’s - consist of three main components:Mast or towers which support the work platformPlatform capable of carrying persons and equipmentChassis supporting tower/mast structure
19Access to height - Other LaddersTo be used for light, short duration work only (That’s Minutes - Not Hours!)To rest on a stable, firm and level surfaceProject at least 1.0m above working platform ( 5 rungs)Set at an angle of 1 : 4 (approximately 75 degrees)When used as part of an access platform tied securely by the stiles.Inspected on a regular basis as part of the scaffold inspectionsRef : - Construction (Health, Safety and Welfare) Regs 1996, Regulation 6, Schedule 5.
20Access to height - Other Step LaddersStepladders provide a free standing means of access.They require more careful use as they are not designed for any degree of side loading and are more easily overturned.Accidents with step ladders occur for similar reasons for those with ladders but with the additional hazard of people standing on the top platform.Work should never be undertaken from the top platform which shouldbe used for tool, bucket and paint storage only.
21Access to height - Other TrestlesA common piece of equipment found on most construction sites and used mainly by finishing trades such as plasters and painters. Easy to set up and often miss used.Common problems with trestles include;Scaffold boards not supported at correct centre’s (commonly 1.2m).Overloaded platforms,No provision for proper access - Ladder etcToo often used instead of a proper scaffold working platform!
22Access from height Man Riding Skips For - Short duration work at high level or below ground typically for steelwork connections, inspections and maintenance.Limitations - Needs a suitable crane.ChecksAll lifting equipment has been testedand holds a valid test certificate within the last6 months.Operative in manrider should wear a harnessthat is attached directly to the crane block
23Access from height Slung Scaffolds For - High level work on ceilings and soffits - work above railways, roads or operating factoriesLimitations - Limited safe working load, attachment points, needs a specific design, potentially hazardous to erect, inspect and dismantle.
24Access from height Cradles, Bosun’s Chairs and Abseiling For - Painting, inspection and maintenance, sometimes used in conjunction with abseiling techniques.Limitations - Limited safe working load, need to train operators and require highly skilled and trained operatives for abseiling, restricted work area.
25Protection Measures Fall Arrest - Safety Nets A passive fall arrest system comprising of a series of safety nets tied and supported on the new structure / scaffold.For - Versatile fall protection for the safe installation of pre- cast sheets.Limitations - Safety nets can be difficult to rig - must be installed by trained personnel , they require suitable anchor points, regular inspections and allowances for sag / falls must be considered.
26Protection Measures Fall Arrest - Air Mats A passive fall arrest system comprising of a series of connected air bags.For - Offers a quick, versatile fall protection for the safe installation of pre-cast concrete floor sections, beam and block floors, and roof trusses.Limitations - Must be installed directly below the floor being laid - to keep potential fall distances to a minimum, can damage new block work if installed to early.
27Crawshaw High School, Pudsey Protection MeasuresEdge ProtectionThe primary means of achieving safety when working at height is to provide adequate access arrangements and working platforms with good edge protection - Schedules 1 & 2 of the Construction (Health, Safety and Welfare) Regs set out the requirements for edge protection and working platforms.Crawshaw High School, Pudsey
28Protection Measures - Lift Shafts The erection of scaffold to an internal shaft as the shaft is to be fully boarded including hop-up brackets and boards where required.Minimum double guard rail and toe board must be installed at all shaft openings as a shaft is constructed.This arrangement will allow any viewing of a shaft interior by personnel to take place at early stages prior to internal fitting.No other protection arrangement is to be accepted and flush ‘boarding up’ is not an acceptable practice.For lifts, as soon as practicable a lift shaft installer shall fit proprietary temporary lift doors at every floor opening. (see Figs 1&2 for examples).Safety AlertFigure 1Figure 2
30Protection MeasuresRemember fall arrest systems do not prevent falls, but can reduce injury once a fall has happened. There are two basic types:Those that give general protection: PassiveSafety nets, Air Mats and Crash Decks once properly installed can protect everyone within the area of protectionThose giving individual protection: ActiveSafety harness attached to suitable anchorage point or running line. Harnesses need to be suitable for the individual, who should be trained to fit and use them.
31Inspection and Maintenance It is vital that access and fall arrest equipment are regularly inspected and maintained so that they remain fit for purpose through out the construction period to ensure:No person or materials can fall from access ways and working platformsthe access equipment remains stable with no danger of collapsefall arrest equipment is undamaged or affected such that it could impair performance.Working platforms, suspension equipment and safety nets must be inspected:before being taken into use for the first time,after any substantial alteration,after an event likely to have affected its strength or stabilityand at regular intervals not exceeding 7 days
32Inspection and Maintenance Example of Inspection & Maintenance report form from AWG Construction
33There is no such thing as a ‘safe height’ - SummaryThere is no such thing as a ‘safe height’ -anyone working off the ground is at risk offalling and being injured.Always consider the hierarchy of work, and ask yourself -Do we need to work at height ?Is there another way ?If there is no alternative then use this presentation as guide to help select the best method of access / protection.