10. Ladder, Scaffold, and Mobile Work Platform Safety Flashcards
Discuss standards for portable ladders in the workplace.
WorkSafeBC requires that ladders be manufactured in accordance with an acceptable standard, or meet the requirements of a professional engineer.
There is a long list of acceptable standards in the WorkSafeBC guidelines.
Most commercial ladders in Canada meet CSA Z11
- establishes grades of portable ladders
- sets performance requirements
- classifies types of design
- sets safety marking requirements
Describe the 6 common types of portable ladder.
Telescopic
- steps collapse into a stack, and sides telescope. As ladder extends, the steps extend one at a time.
Extension
- Fixed ladder sections, slide over each other to extend.
Step
- Simple a-frame, typically with tool platform at top.
Sectional
- Multiple separate sections of ladder that stack/lock together to desired length.
Articulating
- A ladder with hinges/joints
Combo
- A ladder that can be used as a single ladder, extension ladder, or stepladder.
What four key areas are established in CSA Z11?
- Establishes grades of portable ladders
- Sets performance requirements
- Classifies types of design
- Sets safety marking requirements
List pre-use inspection items for ladders.
- Presence/condition of latches & locking mechanisms
- Rope condition
- Footpad presence/condition
- Rung conditions
- Cracks, splits, corrosion, sharp edges
- Labelling & safety markings
What should be done if people, vehicles, or mobile equipment may pass near a ladder in use?
- Warning signs
- Pylons
- Barricade tape
- Blocking doors
- Adjustment of work schedule
What are the CSA Z11 ladder grades?
Grades: 3, 2, 1, 1A, 1AA.
3 = light/household = 200lb 2 = medium = 225lb 1 = heavy = 250lb 1A = Extra heavy = 300lb 1AA = Special = 375lb
(test loads are 4x rated limits)
What are the ANSI ladder grades?
Grades: 111, 11, 1, 1A.
111 = lightest 1A = heaviest
Discuss job-built ladders.
Ladders can be built on-site.
There are no national/international standards for job-built ladders.
There are local (WorkSafeBC) standards.
What are the minimum contents of a ladder safety program?
- Selection of ladder type/grade
- Pre-use inspections
- Damaged ladders
- Storage & care
- Ladder use
- Ascending and descending safely
- Footing and top support
- Electrical hazards
What inspection findings would be cause to remove a ladder from service?
- Damage/defects to working parts (feet, hinges, joints, locking devices)
- Damage to rung or step connections
- Wear of rope
- Broken/bent ladders
- No markings/concealed markings
Why should a latter extend at least 1 meter above a roofline/support?
- Permits a secure, 3-point contact for workers at top of ladder
- Permits the ladder to be tied off/secured
- Margin of safety in event that ladder slips laterally
- Visible signal to location of ladder
How far away from a wall should a ladder base be?
4:1 rule = for every 4 feet of height, the ladder base should be 1 foot away from the wall.
Steeper angles risk the ladder falling back and creates a steep climb for the worker.
Shallower angles risk the ladder sliding out under weight.
What should be done if work conditions do not permit a 4:1 ladder angle?
Use another means of access, such as a work platform.
What are the 7 best practices for ladder climbing?
1, Face ladder and avoid distractions. Reduces risk of missing a step or shifting body weight.
2, Keep weight between supports. Maintains ladder stability.
3, Maintain 3-point contact. Secures worker to ladder.
4, Transport heavy/bulky items separately to worker. Avoids putting worker off balance.
5, Clean, dry footwear. Reduces slip risk.
6, Avoid carrying tools (use toolbelt or hoist). Keeps hands free to permit 3-point contact.
7, Avoid working at top 2 ladder steps. Reduces risk of tipping and permits 3-point contact.
Discuss ladders near electricity.
Avoid work near electricity when possible.
When necessary, avoid aluminium ladders. Use fiberglass/non-conductive ladders.
Good non-conductive ladders have voltage ratings for conductivity.
List 3 basic types of access scaffolding.
- Non-mobile
- Mobile (rolling)
- Suspended
Describe the 8 types of scaffolding.
- Tube and Clamp
Tubes connected together & to building with clamps. Can be adjusted to any configuration to work around shapes. - Systems Scaffold
Frame connected with special joints. Can be configured to work around most shapes. - Farm Wagon Rolling Scaffold
Mounted on a wagon with big wheels. Must have outriggers. Still requires a stable rolling surface. - Standard Frame Scaffold
Basic fixed-frame scaffold with platform. Usually with ladders built-in. - Rolling Scaffold
Fixed scaffold with caster wheels that require smooth/flat rolling surfaces. - Mast-climbing Work Platform
Center mast with a motorized platform that can move up/down. - Walk-through Scaffold
A scaffold with a raised base permitting persons to walk through. - Fold-up Scaffold
Simple, light scaffold that can be folded & transported.
Discuss scaffold standards in Canada.
Most commercial scaffold meets CAS S269.2 although it is not a required standard.
OHS regulators (WorkSafeBC) have local standards for job-built scaffold.
List factors that increase fall risk associated with workers climbing the rungs on scaffold end-frames.
- There is no fall protection, and the use of fall restraint/arrest systems can be impractical.
- Workers climbing on the outside of the rungs that fall will be in free-fall without anything to grab onto.
When are scaffold platforms exempt from standard guardrail requirements?
When the side of a structure adjacent to the platform acts as equivalent protection and is 30cm or less away from the platform.
Describe sills and mudsills.
A sill is a platform (such as a timer sill) placed under a base plate to provide support and distribute the weight of the scaffold.
A mudsill is a small excavation to level ground for scaffold baseplates. (mudsills should never be backfilled).
Discuss cross braces, gooser bars, and deck planks in relation to scaffold stability.
Cross braces form diagnal connections/support to increase lateral stability.
Gooser bars corm horizontal connections/support to increase lateral stability.
Deck planks create work platfoms, and create connections to surrounding vertical scaffold improving lateral stability.
Why shouldn’t cross-braces be used in scaffolding in place of a guardrail?
Crossbraces are not designed to withstand the impact of a fall against their sides, and they likely have gaps that fail to meet guardrail requirements.
WorkSafeBC guidelines explicitly state that cross-bracing does not provide equal protection to a guardrail.
When and how is scaffolding required to be given added stability?
If scaffold height causes inherent instability, if the height is 3 or more lifts, or if the height is 3 or more times the base, then additional support is required.
Support may be provided by outriggers at scaffold corners, placed on film surfaces or sils.
Guy wires may also be used to secure the scaffold to the structure at various intervals.
What safety features should rolling scaffold wheels have?
- Made of durable/strong material
- Wheels in good condition
- Wheels large enough for stability
- Wheels properly inflated when applicable
- Locking brakes built into wheel design
- All wheels equal and appropriate sizes
What are the 5 most important controls in a scaffold safety program?
1, Purchase approved scaffold components.
2, Regular inspection and maintenance.
3, Prevent overloading
4, Educate, train, and supervise set-up and operation.
5, Safe movement of rolling scaffolds.
What are the three basic classes of mobile work platform?
Elevating rolling work platforms.
Self-propelled elevating work platforms.
Self-propelled boom-type work platforms.
What are the three required CSA standards for mobile work platforms?
CSA B354.1 - Portable Elevating Work Platforms
CSA B354.2 - Self-propelled Elevating Work Platforms
CSA B354.3 - Self-Propelled Boom-Supported Work Platforms
After purchasing a new mobile work platform, what 8 steps should be taken to ensure machine safety?
- Confirm machine in working order (inspection by qualified person if not new)
- Ensure OHS & key supervisors know manual contents and inspection requirements
- Determine scope of work and MWP intended for the work
- Training/education for workers and supervisors
- Review regulations
- Written safe work procedures
- OHS on-site for first few operations
- Formal inspection process of equipment
What are best safety practices for selection of portable ladders for use in the workplace
Identify the scope of work
Purchase ladders based on CSA performance criteria
What is the end frame in scaffolding?
The majority of the scaffolding frame. The sides that are held together by the other components.
What support methods are commonly used if the height of the scaffold exceeds three times its minimum base dimension?
outriggers
tying the scaffold to the structure at regular vertical intervals
guy wires
List any features found on a standard mobile work platform that are designed to prevent a worker from falling from the platform.
Guardrails
Adequate platform structure to prevent worker from falling through
Attachment point for fall-restraint system
