scaffold and aerial lift safety stan liang, cih, csp, cet kta-tator, inc

Scaffold and Aerial Lift Safety

• Stan Liang, CIH, CSP, CET

• KTA-Tator, Inc.

Webinar Objectives

Brief overview of the following: OSHA Scaffold Standard Safe work practices for the use of

scaffolds, aerial lifts, and scissor lifts

Resources for additional information

Scaffolds/Aerial lifts

• Hazards– Falls– Falling objects– Structural instability– Electrocution– Overloading

Scaffolds29 CFR 1926 – Subpart L

• 1926.450 – Scope, application, and definitions

• 1926.451 – General requirements

• 1926.452 – Requirements applicable to specific types of scaffolds

• 1926.453 – Aerial lifts

• 1926.454 – Training requirements

29 CFR 1926 – Subpart L Appendices

• Appendix A – Scaffold specifications

• Appendix B – Fall protection for scaffold erectors and dismantlers

• Appendix C – National consensus standards

• Appendix D – Training topics for scaffold erectors and dismantlers

• Appendix E – Drawings and illustrations

Competent Person

• One who is capable of identifying existing and predictable hazards in the surroundings or working conditions which are unsanitary, hazardous or dangerous to employees and has authorization to take prompt corrective measures to eliminate them.

Qualified Person

• One who by possession of a recognized degree, certificate, or professional standing, or who by extensive knowledge, training, and experience has successfully demonstrated his or her ability to solve or resolve problems related to the subject matter, work, or the project.

General Requirements

– Support its own weight and 4 times the maximum intended load

– Suspension rope and connecting hardware support 6 times the maximum intended load

General Requirements

– Stall load of scaffold hoist not to exceed 3 times the rated load

– Designed by a qualified person and loaded according to design

General Requirements Scaffold Platform Construction

• Platforms must be fully decked and planked

• Platform must be at least 18 inches wide

• Planks must be in good condition

General Requirements Scaffold Platform Construction

• Each abutted end shall rest on a separate support surface

• Platforms overlap not less than 12” and only over supports

• Platforms that rest on a bearer at an angle other than a right angle must be laid first

General Requirements Scaffold Platform Construction

• The end of the platform must extend at least 6 inches beyond the support; or

• Restrained by hooks, cleats or other means

General Requirements Scaffold Platform Construction

• Platforms 10 feet long or less extend no more than 12 inches past the support

• Platforms more than 10 feet long extend no more than 18 inches

General Requirements Scaffold Construction

• Scaffold components manufactured by different manufacturers shall not be used together unless:– Components fit together without force– Scaffold's structural integrity is maintained by

the user– Competent person determines the resulting

scaffold is structurally sound

General Requirements Scaffolds Construction

• Components of dissimilar metals can not be intermixed

General RequirementsSupported Scaffolds

• Fully planked• Bear on adequate

foundations• Plumbed and braced• Unstable objects not

used as work platforms

General Requirements Suspended Scaffolds

• Support devices must support 4 times the imposed load

• Direct connection evaluated by a competent person

General Requirements Suspended Scaffolds

• Counterweights made of non-flowable material

• Counterweights secured and not removed until scaffold is disassembled

• Tiebacks secured to sound anchorage

• Single tiebacks installed at an angle prohibited

General RequirementsSuspended Scaffolds

• Minimum lengths for suspension ropes on hoists

• No repaired wire rope

• Ropes inspected by a competent person prior to each shift

General RequirementsSuspended Scaffolds

• No gasoline powered equipment or hoist

• Automatic brakes on powered and manual hoists

• Positive crank force required for descent

• Tied to prevent swaying

• Safety devices not used as platforms

Scaffold Access

• Access must be provided when platforms are more than 2 feet below or above a point of access

• Cross braces can not be used as a point of access

Scaffold Access

• Hook on attachable ladders:– Specifically designed

for the type of scaffold

– Rest platforms at 35 foot intervals when more than 35 feet high

Scaffold Use

• Do not overload scaffold

• Platform can not deflect more than 1/60 of the span when loaded

• Inspect scaffolds prior to each shift or after an event which may have damaged the scaffold

• Do not move the scaffold when occupied unless designed for such use

• Shore or lean-to scaffolds can not be used.

Scaffold Use

• Scaffolds must be erected, moved, and dismantled only under the supervision of a competent person

• Erecting, moving, or dismantling scaffolding must be performed by trained employees selected for such work by the competent person

Scaffold Use

• Employees are prohibited from working on scaffolds covered with snow, ice, or slippery materials

• Tag lines or equivalent means must be used to prevent swinging loads from contacting the scaffold

• Work on scaffolds is prohibited in high winds.• Debris can not accumulate on platforms.

Power Line Clearances

Voltages Minimum Distance

Less than 300 volts 3 feet (0.9m)

300 volts to 50kV 10 feet (3.1m)

More than 50kV 10 feet (3.1m) plus 0.4 inches for each kV over 50kV

Power Line Clearances

Voltages Minimum Distance

Less than 50kV 10 feet (3.1m)

More than 50kV 10 feet (3.1m) plus 0.4 inches (1cm) for each 1kV over 50kV

Power Line Clearance Alternatives

• Two times the length of the insulator

• Notify utility company in advance and:– De-energize the power

lines;– Relocate the lines; or– Install protective

covering to prevent accidental contact

Fall Protection

• Fall protection is required when employees are more than 10 feet above a lower level

• Fall protection is required for erection or dismantling of scaffolds, if the competent person determines it is feasible

Fall Protection Methods

• Boatswain’s chair, catenary scaffold – personal fall arrest

• Single or two point adjustable suspension scaffold – personal fall arrest and a guardrail

• All other scaffolds – personal fall arrest or a guardrail

Fall Protection

• Each employee on a walkway within a scaffold must be protected by a guardrail system installed within 9 1/2 inches of and along each walkway

Personal Fall ArrestVertical Life Lines

• Can not be used if overhead components are part of a single point or two point adjustable scaffold

• Attached to an anchorage independent of the scaffold

• Protected from sharp edges and abrasion

Personal Fall ArrestHorizontal Lifelines

• Can not be attached only to suspension ropes

• Independent anchorages are mandatory on all suspended scaffolds, except for two-point suspension scaffolds

Additional Requirements forPersonal Fall Arrest

• If lanyards or lifelines are connected directly to a two-point suspension scaffold, the scaffold must be provided with additional independent support lines

• Vertical lifelines, independent support lines and suspension ropes shall not be tied to each other or share common anchorage points

Fall ProtectionGuardrails

• Guardrails must be installed on all open sides

• Guardrails must be installed prior to use• Top rail height must be between 38 inches

and 45 inches• Where personal fall arrest is also used, top

rail height must be between 36 inches and 45 inches

Fall ProtectionGuardrails

• Intermediate members must be not more than 19 inches apart

• Mid rails, screens, or mesh must be used

• Screens or mesh, if used, must extend along the entire opening between supports and from the top rail to the platform

Fall ProtectionGuardrails

• Top rail must withstand 200 pounds of force (100 pounds for single-point and two-point adjustable suspension scaffolds)

• When maximum force is applied, the top rail must not deflect below minimum permissible height

• Mid rails, screens, mesh, and intermediate members must withstand a force of 150 pounds (75 pounds for single-point and two-point adjustable suspension scaffolds)

Fall ProtectionGuardrails – Cross Bracing

• Can be used in place of a mid rail when the crossing point is between 20 inches and 30 inches above the work platform

• Can be used instead of a top rail when the crossing point is between 38 inches and 48 inches above the work platform

• Upright end points must be more than 48 inches apart

Falling Object Protection Options

• Barricading the work areas below

• Install toe board on scaffold platforms

• Install canopies or debris nets to protect workers below the platform

Requirements for Specific Scaffolds

• Tube and coupler scaffolds

• Mobile scaffolds

• Containment platforms

• Two-point suspension scaffolds

• Singe-point suspension scaffolds

• Pik boards

Tube and Coupler Scaffolds

• Designed by a P.E. if over 125 feet

• Requirements for couplers and bracing

Containment Platforms

• Containment platforms must comply with 1926. Subpart L.

Mobile Scaffolds

•Must be plumb, level, and squared

•Wheels must be able to be locked

•Scaffold must be leveled using screw jacks

• Caster stems and wheel stems shall be pinned or otherwise secured

Mobile Scaffolds

• Manual force to move the scaffold must be applied no more than 5 feet above the supporting surface

• Power systems used to move the scaffolds must be designed for such use

Mobile Scaffolds

• Employees can only ride mobile scaffolds under the following conditions:– Surface is within 3 degrees of level– Height to base width is two to one or less– Outrigger frames, when used, are installed on both

sides– Speed does not exceed one foot per second when power

systems are used– No employee is on any part of the scaffold that extends

outward beyond wheels, casters, or other supports

Two Point Suspension Scaffolds

•Can not be connected together during raising and lowering operations unless the connections are articulated and hoists properly sized

•Can not be more than 36 inches wide unless designed by a qualified person to prevent unstable conditions

Single Point Suspension Scaffolds

•Use of a safety hook (hook with a latch), if a boatswain’s chair is used

•Supporting rope must be kept vertical

Pik Boards

–Safety ropes or clips on stirrups used to suspend the platform from the cables

–Minimum width of the pik boards must be at least 18"

- Pik secured to hangers at both ends

Training

• Employees using scaffolds must receive training from a qualified person that covers:– Nature of electrical, fall, and falling object

hazards– Use of scaffold – Maximum intended load and load carrying

capabilities of the scaffold– Requirements of subpart L

Training

• OSHA has separate training requirements for workers engaged in the following:– Erecting– Disassembling– Moving– Repairing– Maintenance – Inspection

Training

• Employees engaged in activities other than use must receive training from a qualified person that covers:– Nature of electrical, fall, and falling object

hazards– Correct procedures– Design criteria, load capacity, and intended use– Requirements of subpart L

Retraining

• Required if an employee lacks the skill or understanding needed for safe work involving scaffolds

• Retraining is also required when:– Additional or new hazards exist

– Changes occur in the type of scaffold and fall protection

– Where there are inadequacies in an employee’s work practices

OSHA Aerial Lift RequirementsTraining

• Operated only by authorized persons• According to an OSHA letter of interpretation

training is required• Training requirements enforced by OSHA would

be based on industry standards as defined in ANSI Standard A92.2

OSHA Aerial Lift RequirementsTraining

• ANSI Standard A92.2 training requirements include:– Instruction in safe operation including the operator’s manual,

user’s work instruction, and other applicable ANSI standards– Hands on training must also be included

OSHA Aerial Lift Requirements Fall Protection

• Fall protection must be worn when in the basket

• A short lanyard (e.g. 3 to 4 foot lanyard) should be used for restraint

• Employees must always stand firmly on the floor of the basket (not the guardrails)

OSHA Aerial Lift Requirements

• Must be provided with upper and lower controls

• Lower controls to be operated only in emergencies or with permission of workers in the basket

• Test controls daily prior to use

OSHA Aerial Lift Requirements

• Place outriggers on solid surface or pads

• Load limits specified by the manufacturer must not be exceeded

• Boom must not be elevated when lift is moving

OSHA Scissor Lift Requirements

• Requirements for mobile scaffolds apply

• If guard rails are in place, no additional fall protection is required

Additional Information

• www.osha.gov– 29 CFR 1926 Subpart L (Scaffold Standard)– CPL 02-01-023 [CPL 2-1.23] (Compliance Directive)– Scaffolding Construction e-Tool– Letters of interpretation

• www.scaffold.org (Scaffold Industry Association)• http://www.ansi.org (American National

Standard Institute)– A92 (SIA): Scaffolds and other elevating devices

Questions