Scaffolds

Scaffolds

اسلاید 1: OSHA Office of Training & Education1Scaffolds

اسلاید 2: OSHA Office of Training & Education2What Is A Scaffold?An elevated, temporary work platformThree basic types:Supported scaffolds -- platforms supported by rigid, load bearing members, such as poles, legs, frames, & outriggersSuspended scaffolds -- platforms suspended by ropes or other non-rigid, overhead supportAerial Lifts -- such as “cherry pickers” or “boom trucks”

اسلاید 3: OSHA Office of Training & Education3Hazards Falls from elevation – caused by slipping, unsafe access, and the lack of fall protection Struck by falling tools / debris Electrocution – from overhead power lines Scaffold collapse - caused by instability or overloading Bad planking giving wayEmployees working on scaffolds are exposed to these hazards:

اسلاید 4: OSHA Office of Training & Education4Fall Hazards While climbing on or off the scaffold Working on unguarded scaffold platforms When scaffold platforms or planks failFalls may occur:

اسلاید 5: OSHA Office of Training & Education5Protecting Workers from Falls Guardrails, and/or Personal Fall Arrest Systems (PFAS)If a worker on a scaffold can fall more than 10 feet, protect them by:

اسلاید 6: OSHA Office of Training & Education6Install along open sides & ends Front edge of platforms not more than 14 inches from the work, unless using guardrails and/or PFASTop rails - 38 to 45 inches tall Midrails halfway between toprail and platformToeboards at least 3-1/2 inches high Guardrails

اسلاید 7: OSHA Office of Training & Education7Personal Fall Arrest Systems (PFAS)You must be trained how to properly use PFASPFAS include anchorage, lifeline and body harness.

اسلاید 8: OSHA Office of Training & Education8Can use PFAS instead of guardrails on some scaffoldsUse PFAS & guardrails on suspension scaffoldsUse PFAS on erectors and dismantlers where feasible Fall Protection RequirementsThe ends of this scaffold are not properly guarded

اسلاید 9: OSHA Office of Training & Education9Falling Object ProtectionWear hardhatsBarricade area below scaffold to forbid entry into that areaUse panels or screens if material is stacked higher than the toeboardBuild a canopy or erect a net below the scaffold that will contain or deflect falling objects

اسلاید 10: OSHA Office of Training & Education10Overhead Power LinesThe possibility of electrocution is a serious consideration when working nearoverhead power linesCheck the clearancedistances listed in thestandard

اسلاید 11: OSHA Office of Training & Education11Scaffold Support Examples Good supportInadequate support – in danger of collapse? Base plateMud sills

اسلاید 12: OSHA Office of Training & Education12Essential Elements of SafeScaffold Construction Use appropriate scaffold construction methods Proper scaffold access Properly use a competent person

اسلاید 13: OSHA Office of Training & Education13Scaffold Platform ConstructionPlatforms must:be fully planked or decked with no more than 1 inch gapsbe able to support its weight & 4 times maximum loadbe at least 18 inches wideThis is not a properly constructed scaffold

اسلاید 14: OSHA Office of Training & Education14No large gaps in front edge of platformsEach abutted end of plank must rest on a separate support surfaceOverlap platforms at least 12 inches over supports, unless restrained to prevent movementScaffold Platform ConstructionPlanks not properly overlapped

اسلاید 15: OSHA Office of Training & Education15Scaffold Platform Construction No paint on wood platforms Use scaffold grade wood Fully planked between front upright and guardrail support Component pieces used must match and be of the same type Erect on stable and level ground Lock wheels and braces

اسلاید 16: OSHA Office of Training & Education16Scaffold HeightThe height of the scaffold should not be more than four times its minimum base dimension unless guys, ties, or braces are used20’5’

اسلاید 17: OSHA Office of Training & Education17Platform EndsEach end of a platform, unless cleated or otherwise restrained by hooks, must extend over its support by at least 6 inchesNo Cleats

اسلاید 18: OSHA Office of Training & Education18Supported ScaffoldsPlatforms supported by legs, outrigger beams, brackets, poles, uprights, posts, & framesRestrain from tipping by guys, ties, or bracesScaffold poles, legs, posts, frames, and uprights must be on base plates and mud sills or other firm foundationThis support is not adequate!

اسلاید 19: OSHA Office of Training & Education19Proper Scaffold AccessProvide access when scaffold platforms are more than 2 feet above or below a point of accessPermitted types of access: Ladders, such as portable, hook-on, attachable, stairway type, and built-ins Stair towers Ramps and walkwaysMay use building stairs and come out window

اسلاید 20: OSHA Office of Training & Education20Scaffold AccessNo access by crossbracesWhen using ladders, bottom rung no more than 24 inches highCan use some end framesCan access from another scaffold, structure or hoistEnd FrameDo not access by crossbraces

اسلاید 21: OSHA Office of Training & Education21Suspension ScaffoldsTrain employees to recognize hazardsSecure/tie to prevent swayingSupport devices must rest on surfaces that can support four times the loadCompetent person: evaluate connections to ensure the supporting surfaces can support load inspect ropes for defects before shiftPFAS must have anchors independent of the scaffold support systemPlatforms suspended by ropes or wires. Rope must be capable of supporting 6 times the load

اسلاید 22: OSHA Office of Training & Education22Moving ScaffoldsEmployees can’t be on a moving scaffold unless:Surface is levelHeight to base ratio is 2 to 1Outriggers are installed on both sides of scaffoldsEmployees can’t be on scaffold part beyond the wheelsCompetent person must be on site to supervise

اسلاید 23: OSHA Office of Training & Education23Fatal Fact – Moving a LiftEmployee was operating an aerial lift, with an extendable boom rotating work platformThe boom was fully extended and the machine apparently ran over some bricks, causing the boom to flex or spring, throwing the employee from the basketThe employee fell 37 feet to a concrete surface

اسلاید 24: OSHA Office of Training & Education24Don’t use Shore or Lean-to ScaffoldsShore scaffold supported scaffold which is placed against a building or structure and held in place with propsLean-to scaffold supported scaffold which is kept erect by tilting it toward and resting it against a building or structure

اسلاید 25: OSHA Office of Training & Education25 Using ScaffoldsDon’t work on snow or ice covered platforms or during storms or high windsUse tag lines on swinging loadsProtect suspension ropes from heat & acidA covered scaffold has special wind load considerations

اسلاید 26: OSHA Office of Training & Education26Fatal Fact – Ice & No GuardrailsLaborer was working on the third level of a tubular welded frame scaffold which was covered with ice and snowThe scaffold was not fully decked, there was no guardrail and no access ladderThe worker slipped and fell head first 20 feet to the pavement below

اسلاید 27: OSHA Office of Training & Education27Overhand Bricklaying from Supported ScaffoldsA guardrail or personal fall arrest system is required on all sides except the side where the work is being done

اسلاید 28: OSHA Office of Training & Education28Competent PersonPerson capable of identifying and promptly correcting hazardsDetermines if it’s safe to work on a scaffold during storms or high windsTrains workers to recognize hazardsSelects qualified workers to conduct work

اسلاید 29: OSHA Office of Training & Education29Scaffold InspectionCompetent person inspects scaffolds for visible defects before each shift and after any alterationsDefective parts must be immediately repairedDeformed bearer

اسلاید 30: OSHA Office of Training & Education30Scaffold ErectionScaffolds can only be erected, moved, dismantled or altered under the supervision of a competent personCompetent person selects & directs these workers and determines the feasibility of fall protection

اسلاید 31: OSHA Office of Training & Education31Training RequirementsTrain employees on scaffold hazards and procedures to control the hazardsThe training must include: Nature of electrical, fall, and falling object hazards How to deal with electrical hazards and fall protection systems Proper use of the scaffold Scaffold load capacities Retrain as necessary

اسلاید 32: OSHA Office of Training & Education32Training ErectorsTrain employees involved in erecting, disassembling, moving, operating, repairing, maintaining, or inspecting a scaffold to recognize its hazards and the correct procedures to use

اسلاید 33: OSHA Office of Training & Education33Avoid the Main Hazards of ScaffoldsFalls from elevationBad plankingScaffold collapseGetting struck by falling tools or debrisElectrocution

اسلاید 34: OSHA Office of Training & Education34SummaryUse appropriate scaffold construction methods Erect, move, or alter scaffold properly Protect from falling objects or toolsEnsure stable accessUse a competent person Train on scaffold construction and the hazards involved with scaffolds Inspect scaffold before each shift and after alterations Determine fall protection requirementsRemember to: