Transcript Scaffolds/Aerial lifts

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
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Falls
Falling objects
Structural instability
Electrocution
Overloading
Scaffolds
29 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 Requirements
Supported 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 Requirements
Suspended Scaffolds
• Minimum lengths for suspension ropes on
hoists
• No repaired wire rope
• Ropes inspected by a competent person
prior to each shift
General Requirements
Suspended 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 Arrest
Vertical 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 Arrest
Horizontal Lifelines
• Can not be attached only to suspension
ropes
• Independent anchorages are mandatory on
all suspended scaffolds, except for twopoint suspension scaffolds
Additional Requirements for
Personal 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 Protection
Guardrails
• 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 Protection
Guardrails
• 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 Protection
Guardrails
• 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 Protection
Guardrails – 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
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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:
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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 Requirements
Training
• 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 Requirements
Training
• 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
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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