What Is A Scaffold?
Three basic types:
ØSupported scaffolds -- platforms supported by rigid, load bearing members, such as poles, legs, frames, & outriggers
ØSuspended scaffolds -- platforms suspended by ropes or other non-rigid, overhead support
ØAerial Lifts -- such as “cherry pickers” or “boom trucks”
Some Supported Scaffolds
Aerial Lifts
Hazards
Types of Scaffolds - Load
light duty scaffold: A scaffold designed and constructed to carry a working load not to exceed 25 pounds per square foot.
Medium duty scaffold: A scaffold designed and constructed to carry a working load not to exceed 50 pounds per square foot.
Heavy duty scaffold: A scaffold designed and constructed to carry a working load not to exceed 75 pounds per square foot.
Rated Load Capacity
Maximum Capacity
To determine the maximum weight that can be applied to the scaffold, determine the square footage and multiply it by the manufacturer’s rated load capacity.
Example: scaffold size is 7’ x 5’ = 35sq. ft.
35 x 25 psf (light-duty) = 875 pounds
Types of Scaffolding
A- Frame Scaffolding
The primary steel scaffolding system.
It is primarily for rectangular jobs.
It is relatively simple and fast to erect, provided the surface is level, and the access is not restricted.
Frame Scaffold
OSHA refers to frame scaffolds as sectional steel scaffold.
There are two basic parts to a frame scaffolds – The frame and the cross brace.
Frame Selection
Scaffold frames are available in two basic configurations – the end frame and the walk-through frame.
Access Onto Scaffold
OSHA requires that adequate means of access is given to the scaffold platform.
Stairways or demountable ladders.
In addition Waco has a walk-through and an end frame with built-in ladders.
Scaffold Access
No access by crossbraces
When using ladders, bottom rung no more than 24 inches high
Can use some end frames
Can access from another scaffold, structure or hoist
B- Tube and Clamp
To accommodate jobs too difficult for frame scaffolding, because of the obstruction, limited access.
Tube and clamp requires much greater expertise to erect.
Oil Refineries
C- Modular System Scaffolds
The advantage that modular systems have over tube and clamp is that they do not require the high degree of expertise .
Once the base is set, the erector does not have to worry about the location of connections
D- Rolling Scaffolds
When height to minimum base width ratio of the scaffold exceeds 4:1, stabilizers are required.
Casters (brakes)
Adjustable screws with base plates.
E- Suspended Scaffolds
Title :
Types of Scaffolding
Description : What Is A Scaffold? Three basic types: Ø Supported scaffolds -- platforms supported by rigid, load bearing members, such as p...
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