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Safety guides and audits to make your job as a safety professional easier

Supported and Suspended Access

Supported scaffold.

Supported Access

Portable ladders, supported scaffolds, and aerial lifts let you get to a work area and support you while you work. They make getting to a work area easy, but they can cause falls when they're not used properly.

Portable Ladders

Portable ladders are versatile, economical, and easy to use. However, workers sometimes use them without thinking safety. The Bureau of Labor and Statistics reports that most injuries from falls occur from a height that is less than 10 feet, 20 percent of fatal falls at work occur from heights less than 15 feet (4.5 m), and 50 percent of fatal falls are from a height less than 35 feet (10.6 m).

ladder parts
Ladder Types
(Click to enlarge)

Step Ladders

Common Stepladder Hazards include the following:

  • Damaged stepladder
  • Ladders on slippery or unstable surface
  • Unlocked ladder spreaders
  • Standing on the top step or top cap
  • Loading ladder beyond rated load
  • Ladders in high-traffic location
  • Reaching outside ladder side rails
  • Ladders in close proximity to electrical wiring/equipment

1. Each year, most workers are injured when they fall from ladders from a height that is _____.

a. more than 10 feet
b. less than 10 feet
c. less than 2 feet
d. more than 15 feet

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Portable Ladders (Continued)

Straight or Single Ladders

ladder parts
This image shows a straight or single ladder.

The most common type of portable ladder is a straight or single ladder. It is a non-self-supporting portable ladder that is non-adjustable in length, consisting of one section. Unlike a stepladder that requires level support for all four of its side rails, the Single Ladder requires only two level ground support points in addition to a top support. Ladder levelers may be used to achieve equal rail support on uneven surfaces. (American Ladder Institute)

  • It is intended for use by one person.
  • The length cannot exceed 30 feet.
  • It is available in wood, metal and reinforced fiberglass.
  • It supports only one worker.
  • The top support allows tie off the top of the ladder to increase stability.
ladder parts
Ladder is extended 3 feet above landing.

Extension Ladders

We use ladders to do all sorts of tasks, so it's not surprising that many types of ladders are available. Let's look at the most common types. Characteristics of extension ladders include:

  • They offer the most length in a general-purpose ladder.
  • They have two or more adjustable sections.
  • The sliding upper section must be on top of the lower section.
  • They are made of wood, metal, or fiberglass.
  • The maximum length of extension depends on material
  • They support only one worker.

It's important to choose the right ladder for the right job. Using a ladder for a task that it was not designed for may increase the risk of falling.

2. How many workers will a standard straight ladder support?

a. 1
b. 2
c. 3
d. 4

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Preventing Falls from Ladders

Most workers fall from unstable ladders that shift or tilt when the workers climb too high or reach too far beyond the side rails. Workers also fall when they slip on rungs while they're climbing or descending and when vehicles strike the ladders. Workers can reduce their risk of falling by doing the following:

Stand at the base of the ladder with your toes touching the rails. Extend your arms straight out in front of you.
                        If the tips of your finger just touch the rung nearest your shoulder level, the angle of your ladder has a 4:1 ratio.
Always use the 1 to 4 rule. Click to expand.
  • Read and follow all labels/markings on the ladder.
  • Avoid electrical hazards! – Look for overhead power lines before handling a ladder. Avoid using a metal ladder near power lines or exposed energized electrical equipment.
  • Always inspect the ladder prior to using it. If the ladder is damaged, it must be removed from service and tagged until repaired or discarded.
  • Always maintain a 3-point (two hands and a foot, or two feet and a hand) contact on the ladder when climbing. Keep your body near the middle of the step and always face the ladder while climbing (see diagram).
  • Only use ladders and appropriate accessories (ladder levelers, jacks or hooks) for their designed purposes.
  • Ladders must be free of any slippery material on the rungs, steps or feet.
  • Do not use a self-supporting ladder (e.g., step ladder) as a single ladder or in a partially closed position.
  • Do not use the top step/rung of a ladder as a step/rung unless it was designed for that purpose.
  • Use a ladder only on a stable and level surface, unless it has been secured (top or bottom) to prevent displacement.
  • Do not place a ladder on boxes, barrels or other unstable bases to obtain additional height.
  • Do not move or shift a ladder while a person or equipment is on the ladder.
  • An extension or straight ladder used to access an elevated surface must extend at least 3 feet above the point of support (see diagram). Do not stand on the three top rungs of a straight, single or extension ladder.
  • The proper angle for setting up a ladder is to place its base a quarter of the working length of the ladder from the wall or other vertical surface (see diagram).
  • A ladder placed in any location where it can be displaced by other work activities must be secured to prevent displacement or a barricade must be erected to keep traffic away from the ladder.
  • Be sure that all locks on an extension ladder are properly engaged.
  • Do not exceed the maximum load rating of a ladder. Be aware of the ladder’s load rating and of the weight it is supporting, including the weight of any tools or equipment.

3. Most workers fall from ladders when _____.

a. the ladders become unstable and shift or tilt
b. the ladders sink into unstable ground
c. the ladders are placed on uneven ground
d. the ladders are not inspected by workers before use

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Supported Scaffolds


Of the many types of supported scaffolds, fabricated frame scaffolds are the most common. Like portable ladders, they're versatile, economical, and easy to use. You'll see them on construction sites as single supported platforms and multiple platforms stacked several stories high on modular frames.

How Falls From Scaffolds Occur

Workers fall from scaffolds when components fail, planks break, handrails give way, and scaffold supports collapse. However, most scaffold accidents can be traced to untrained or improperly trained workers.

When fall-protection systems are required. If you work on a supported scaffold more than 10 feet above a lower level, you must be protected from falling. Guardrails at least 42 plus or minus 3 inches high are appropriate for most scaffold platforms. If you can't use a guardrail system, then you must use a personal fall-arrest system or restraint system. We'll discuss personal fall-arrest systems later in the course.

4. At what height above a lower level must workers be protected from falling when working on a supported scaffold?

a. Four feet
b. Six feet
c. Ten feet
d. Twelve feet

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Preventing Falls on Scaffolds

Safety Memo - Three Point Contact.
  • Use ladders or stairs to reach platforms that are more than 2 feet above or below the access point.
  • Don't climb cross-braces to reach a scaffold platform.
  • Scaffolds must be able to support their own weight and at least four times the maximum intended load. The maximum intended load includes workers, equipment, and supplies.
  • Platforms must not deflect more than 1/60 of the span when they are loaded.
  • Platforms must be fully decked or planked between the front uprights and the guardrail supports.
  • Don't use damaged scaffold components; repair or replace them immediately.
  • Make sure a competent person inspects the components before each workshift.
  • Don't modify components.
  • Scaffold components made by different manufacturers may be mixed, provided they fit together without force and maintain structural integrity.
  • Watch for slippery surfaces. Don't work on platforms covered with snow and ice.
  • Stay off scaffolds during storms and strong winds unless a competent person determines that it's safe.
  • Keep a safe distance from power lines and any other conductive source.
  • Minimum clearance distances:

    • Uninsulated electrical lines: 10 feet
    • Insulated lines more than 300 volts: 10 feet
    • Insulated lines less than 300 volts: 3 feet
  • Scaffolds must be erected, dismantled, or moved only under the supervision of a competent person. The competent person must be on site to direct and supervise the work.

5. How much weight must supported scaffolds be able to support?

a. At least five times its own weight
b. Their own weight and at least four times the maximum intended load
c. The combined weight of the scaffold and 4 workers
d. The scaffold's own weight plus total weight of workers and materials

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Aerial lifts


Types of Aerial Lifts

Most aerial lifts have extensible or articulating mechanisms that can position workers up, down, or sideways. ANSI defines and sets operating standards for four different types of aerial lifts:

  • Vehicle-mounted elevating and rotating lifts (ANSI A92.2 devices).
  • Manually propelled elevating work platforms (ANSI A92.3 devices).
  • Boom-supported elevating work platforms (ANSI A92.5 devices).
  • Self-propelled elevating work platforms and scissor lifts (ANSI A92.6 devices).
Click to play video

How Aerial Lift Falls Occur

Most accidents involving aerial lifts can be traced to untrained or improperly trained workers. Reasons for falls:

  • A hydraulic cylinder fails and causes the boom to drop.
  • Outriggers are not used or improperly placed and the lift vehicle overturns.
  • Workers are not tied off while they are in the bucket.
  • Workers fall or are pulled off the platform when the lift vehicle is struck by another vehicle or moves unexpectedly.

6. What are most aerial lift accidents caused by?

a. Inadequate training
b. Defective equipment
c. Lack of common sense
d. Engaging in horseplay

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Aerial Lifts (Continued)

Example of articulating aerial lift. (click to enlarge)

Appropriate Fall Protection

If you work from an aerial lift, you must be protected from falling. The type of fall protection you need depends on the type of lift you use. Most platforms must have a guardrail and each worker may be required to use a personal fall-arrest system: a full-body harness and lanyard attached to the boom or the platform.

Safe Practices On Aerial Lifts

Keep in mind the following when you use an aerial lift:

  • Use the lift only for its intended purpose and follow the manufacturer's instructions. Keep the operating manual with the lift.
  • Multiple platforms.
    Multiple lifts. Source: Lab Padre YouTube Twitter
  • Keep the lift level and stable; use outriggers and intermediate stabilizers.
  • Never move the lift when the boom is up and workers are on the platform.
  • Stand on the platform floor. Don't sit or climb on the edge of the basket, guardrail, or midrail.
  • Be sure to close the access gate while you're working from the platform.
  • Inspect the lift before using it to make sure that it's working properly and is in good condition.
  • Know the lift's rated load capacity and don't exceed it.
  • Stay at least 10 feet away from electrical power lines.
  • Never use the lift during severe weather.
  • Use warning signs or barricades to keep others out of the work area.
  • Never tie off to equipment or to a structure next to the platform.

Portable ladders, supported scaffolds, and aerial lifts provide easy access to most elevated work areas. When they're not feasible or safe, however, the alternative is a suspended platform.

7. How far must aerial lifts stay away from overhead powerlines?

a. At least three feet
b. Five feet
c. Ten feet or more
d. At least 13 feet

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Suspended Access

Example of suspended scaffold. (click to enlarge)

In some cases, however, even adjustable-suspension scaffolds may not be feasible or safe. When there is no other safe way to reach the work area, a crane or a derrick can provide suspended access by hoisting a personnel platform to reach the work area.

Adjustable-Suspension Scaffolds

A suspension scaffold is a temporary elevated platform that hangs by wire rope. Add a hoist to move the platform up or down, and you have an adjustable-suspension scaffold - but not necessarily a safe one. Suspension ropes, lifelines, platforms, hoists, overhead support devices, and tieback systems are critical to the safety of adjustable-suspension scaffolds.

How Suspended Scaffold Accidents Occur

Most accidents involving adjustable-suspension scaffolds happen when a primary suspension rope breaks. Workers die because they don't use personal fall-arrest systems or they use them incorrectly. Steel suspension ropes rarely break if they're correctly rigged, maintained, and inspected regularly. When the ropes aren't maintained, they weaken. If an ascending platform snags, an electric hoist that continues to operate can easily snap a weak rope. Pressure from the two steel discs that clamp to the support rope in sheave-type hoist motors can also break a weak rope.

Failing anchors also cause serious accidents. Too often, untrained workers attach lifelines and suspension ropes to "secure-looking" rooftop fixtures for convenience. These anchors fail because they aren't designed to support suspended loads.

Lifelines fail because workers hang them over unpadded edges, don't inspect them, or use ropes not designed for personal fall-arrest systems.

8. Most fatalities involving adjustable-suspension scaffolds happen because _____.

a. platforms snag on building structures
b. of failure to use fall protection
c. primary suspension ropes break
d. failure of hoist motors

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Using Adjustable-Suspension Scaffolds

Before you use an adjustable-suspension scaffold, you need to know the engineering principles for anchoring and suspending the scaffold, how to rig the scaffold, how to operate the hoist, how to work safely from the scaffold, and what to do in an emergency.

In addition, a competent person must examine all direct connections that are part of the system and confirm that the connections will support the platform loads. You must also wear a personal fall-arrest system to protect yourself if a connection fails. Most fatal falls from suspended platforms result when a support rope fails and workers aren't wearing personal fall-arrest gear.

Requiring Fall-Protection Systems

If you work on an adjustable-suspension scaffold more than 10 feet above a lower level, you must be protected from falling.

  • Single-point and two-point adjustable-suspension scaffolds: Personal fall-arrest systems and guardrail systems are required on single-point or two-point adjustable-suspension scaffolds. The top edge of guardrail must be between 36 inches and 45 inches above the platform surface. (The top edge can exceed 45 inches when necessary.)
  • Boatswain's chairs: Personal fall-arrest systems are required for workers who use boatswain's chairs.
  • Multipoint adjustable-suspension scaffolds: Personal fall-arrest systems and guardrail systems are required on multipoint adjustable-suspension scaffolds. The top edge of the guardrail must be between 36 inches and 45 inches above the platform surface. (The top edge can exceed 45 inches, when necessary.)

Descent-Control Devices

A descent-control device lets you descend a primary support rope - typically from a boatswain's chair - then lock the device when you reach the work area. The device works by friction, engaging the support rope and controlling the descent speed. Most workers start from the roof and work down the face of the building. When they reach the ground, they remove the descent equipment from the support rope and return to the roof for another drop.

Why Falls Occur

Most adjustable-suspension scaffold malfunctions that cause falls result from failure of the primary support rope or a supporting anchor, not the descent device. Support ropes fail because workers don't inspect them regularly or they misuse them. Anchors fail when workers simply assume they are secure. Descent devices, support ropes, and anchors rarely fail when workers know how to use them.

9. Most suspended scaffold falls result from _____.

a. a failure of friction stops
b. a failure of the descent device
c. a failure of the support rope or anchor
d. a failure of fall protection systems

Next Section

Crane- and Derrick-Suspended Personnel Platforms

Crane-suspended platform.

How Injuries Occur

Workers rarely fall from suspended personnel platforms. Rather, most crane-related fatalities happen when the boom or another part of the crane contacts an energized power line. Other causes of serious accidents include:

  • Instability. Unstable ground or support surface causes the crane to tip over.
  • Lack of communication. The crane operator can't see the suspended platform while it is moving.
  • Rigging failure. Platform loads are not properly rigged.
  • Boom failure. The weight of the loaded platform exceeds the boom's load limit.

Safe practices

Safe practices for riding personnel platforms to the work area:

  • Stay within the platform while it's moving.
  • Wear a body belt or harness and use a lanyard; attach the lanyard to the lower load block or overhaul ball or to a structural member of the platform.
  • Stay in view of the crane operator or signal person while you're on the platform.
  • Before leaving the platform for the work area, secure it to the structure.

10. Most crane-related fatalities happen when _____.

a. the boom fails due to an excessive load
b. platform loads are not properly rigged
c. the crane is located on unstable ground
d. the crane boom or another part contacts a power line

Check your Work

Read the material in each section to find the correct answer to each quiz question. After answering all the questions, click on the "Check Quiz Answers" button to grade your quiz and see your score. You will receive a message if you forgot to answer one of the questions. After clicking the button, the questions you missed will be listed below. You can correct any missed questions and check your answers again.


Window Washer Rescue

In this Associated Press video, two window washers in California have been rescued after dangling from a high-rise building after their work platform tilted. Officials say the metal scaffolding slipped but the workers didn't fall because they were wearing safety harnesses


Next Video

Scaffolds for Compliance Officers

This is a Department of Labor video designed for presentation to OSHA Compliance Officers.

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