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Suspended access
Portable ladders, supported scaffolds, and aerial lifts provide easy access to most elevated work areas. When they are not feasible or safe, however, the alternative is a suspended platform.
Suspended access is a means of getting to difficult-to-reach work areas on a suspended platform. Usually the platform is an adjustable suspension scaffold. The scaffold, typically suspended by wire rope from a rooftop anchor, has a hoist that workers use to reach the work area.
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 derrick can provide suspended access by hoisting a personnel platform to reach the work area.
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Tieback system
and anchorage
Counterweight
Secure anchorage
Primary suspension rope
Personal fall arrest system
Key components
of an adjustable
suspension
scaffold.
Primary suspension rope
Anchor 2
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. Basic types of adjustable-suspension scaffolds:
Single-point adjustable scaffolds. A single-point suspension scaffold is suspended by a single wire rope from an overhead support device such as a davit or outrigger beam. The platform is usually ground rigged.
A boatswain’s chair, the most common single-point suspension scaffold, supports only one worker in a sitting position. The chair is lightweight, easy to rig, and favored by window cleaners. Most chairs are equipped with descent-control devices.
Two-point adjustable-suspension scaffolds. Also known as swing-stage scaffolds, these scaffolds are suspended by two independent ropes from an overhead support device such as a davit or outrigger beam. They’re used by window cleaners on skyscrapers and by construction workers on high-rise projects.
Multipoint adjustable-suspension scaffolds. As the name suggests, these scaffolds are suspended by more than two
independent ropes. They are often used for chimney cleaning and are called chimney hoists.
How falls occur from adjustable-suspension scaffolds. Most accidents involving adjustable-suspension scaffolds happen
when a primary suspension rope breaks. Workers can die during such events if they don’t use personal fall-arrest systems
or they incorrectly use them. Steel suspension ropes rarely break if they are 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 are not designed to support suspended loads.
Lifelines can fail when workers hang them over unpadded edges, don’t inspect them, or use ropes not designed for personal
fall-arrest systems.
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.
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.
Newer buildings and renovated buildings usually have some form of support system for suspension scaffolds. However, older
buildings, buildings with large cornices, and tiered buildings often lack adequate support for suspended platforms. If you are
not sure, have a qualified person determine whether it is safe to use an adjustable-suspension scaffold on these buildings.
When fall protection systems are required. If you work on an adjustable-suspension scaffold more than 10 feet above a
lower level, you must be protected from falling with an appropriate fall protection system.
• 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.)
Required training. Those who work from adjustable-suspension scaffolds must be trained to recognize fall hazards and to
control or minimize the hazards. Training must cover the following topics:
• Scaffold load capacity and the types of loads appropriate for the scaffold
• When fall protection is required, the appropriate protection to use, and how to use it
• How to use scaffold components
• How to reach access areas
• How to protect those below the scaffold from falling objects
• How to avoid electrical hazards
Training for scaffold erectors and dismantlers. If you erect or dismantle scaffolds, you must have additional training by a competent person that covers scaffold hazards, erecting and dismantling procedures, design criteria, and load capacities.
Safe practices: adjustable-suspension scaffolds. Table 4 highlights safe practices.
What you should know about 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 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.
How falls occur. Most falls happen when the primary support rope or a supporting anchor fails – not the descent device.
Support ropes fail because workers don’t regularly inspect them 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.
Oregon OSHA requirements. Oregon OSHA does not have specific requirements for descent-control devices. However, you should follow the manufacturer’s instructions and be trained by a competent person.
Safe practices for descent-control devices:
• Know how to use the equipment.
• Inspect the equipment daily.
• Rig suspension ropes and support devices properly.
• Use an independently anchored personal fall-arrest system.
• Ensure that primary support ropes and lifelines will support at least 5,000 pounds.
• Don’t use primary support ropes and lifelines that are worn or damaged.
• Protect primary support ropes and lifelines that contact surface edges.
• Protect primary support ropes and lifelines from extreme temperatures and corrosive chemicals.
• Understand self-rescue procedures and techniques.
• Don’t use descent-control devices in strong winds.
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Anchor 3
Crane and derrick suspended personal platforms
Sometimes, workers may not be able to reach the work area with stairways, ladders, scaffolds, or aerial lifts. When there is no
other safe way to reach the area, you can use a crane or a derrick and a personnel platform to lift workers to the area.
Employee safety must be the basis for your decision to use this method. [See Subdivision CC, Cranes and Derricks in Construction, 1926.1431 (Hoisting Personnel) for more information.]
How injuries occur. Workers rarely fall from suspended personnel platforms. Most incidents occur when the boom or another part of the crane contacts an energized power line.
Other causes of serious incidents 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 for riding personnel platforms to the work area:
• Conduct a pre-lift meeting to review the applicable requirements of 1926.1431 and the procedures that will be followed.
• Conduct a trial lift with the unoccupied platform loaded at least to the anticipated lift weight from where employees will enter the platform to each location at which the platform is to be hoisted and positioned.
• Conduct a visual inspection of the equipment, base support or ground, and personnel platform to determine if the trial lift has exposed any problem or produced any adverse effect.
• Stay within the platform while it is moving and use a fall arrest system with the lanyard connected to a structural member of the platform.
• Stay in view of the crane operator or signal person while you are on the platform.
• Before leaving the platform for the work area, secure it to the structure.
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