Guide to Special Duty Scaffolds

Special duty scaffolds are those with a specific design load for that particular scaffold.

Special duty scaffolds differ from other scaffold working platforms that are typically rated as medium, light, or heavy duty and have standardised minimum dimensions and a maximum load rating.

Here are some common examples of special duty scaffolds:

Cantilever Scaffold

This is a scaffold that’s supported by cantilevered load-bearing members. You should implement the risk control measures below for a cantilevered scaffold:

– Make sure that the supporting structure is certified by a competent person as being capable of supporting the cantilevered scaffold.

– Design and position the cantilever beams according to the scaffolding plan and the requirements of the engineer.

– Use the following methods to fix the cantilevered beam’s inboard length to the structure:

  • Using counterweights on the beam

  • Using a positive fixing such as a U-bold fitted over the beam and through the concrete floor slab to fix the beam to the floor.
  • Installing props to the beam’s top as well as the underside of the floor above, making sure that props are fixed to avoid dislodgement.

Hanging Bracket Scaffold

The hanging bracket scaffold is a system that’s supported by a frame on a building or another structure.

It is sometimes in the shape of an upside down L, whereby one arm is fixed to a vertical surface while the other protrudes horizontally to support the scaffold planks.

Other hanging bracket scaffold systems may include horizontal members that are supported by building floors or other structures.

It is important to implement the risk control measures below for hanging bracket scaffolds:

– Use an engineer for designing hanging bracket scaffolds along with their means of support – load testing or calculations can provide engineering verification.

– Providing a safe way for those that install the hanging brackets to enter.

– Planks can overlap planks on straight runs on the hanging bracket scaffolds where it’s impossible to achieve butting of the planks as long as the overlap is not less than 3m.

– The supporting structure should be capable of supporting live and dead loads that the hanging brackets supply.

– Using connectors if two or more scaffolds are sagging unevenly and causing a tripping hazard.

– Ensuring that the spacing of brackets does not exceed the maximum plank spans specified by the manufacturer.

Note: This doesn’t refer to the overlap of planks on putlogs.

Spur Scaffold

This is a scaffold that’s supported by inclined load-bearing members.

The following control measures should be implemented for a spur scaffold:

– Make sure that the propping systems are tied together securely and braced

– Provide suitable headstocks at the top of every propping system for distributing the imposed loads

– Fixing propping systems between the ceiling and floor at intervals to suit the spacing of standards within the scaffold

– Bracing spurs that exceed 1.8m in length in either direction at the centre unless otherwise designed

Tube and Coupler Scaffolding

Tube and coupler scaffolding is built from tubing and fixing or joining components that are fixed together to create the desired scaffold design.

The scaffolding is often used on structures with unusual shape, design, or function.

The versatility of this type of scaffolding means that it can be assembled in various different configurations.

It also means that erecting the scaffolds can be more complex than erecting prefabricated scaffolds.

The load that tube and coupler scaffolding can carry is determined by the diameter and strength of the tube as well as the components used.

If a scaffold incorporates plain steel tube, the analysis and design must consider the most adverse combination of tubes by strength of tube material, wall thickness or both.

Aluminium and steel tubes must never be mixed in one scaffold.

Tubes of different wall thickness must never be interconnected using internal-type end-to-end couplers or spigots unless additional measures are taken for positively securing the joint.

For instance, a short tube that has swivel couplers can be fixed over and parallel to the joint. Alternatively, you can fix a bridle that has right-angled couplers to adjacent members.

Metal tube and coupler components must be inspected regularly for damage and special attention given to cracks, deformation, crushing, splitting, and corrosion.

Prefabricated Scaffolding

Prefabricated scaffolding is best defined as an integrated system of prefabricated components with a pre-determined geometry of assembled scaffolds.

This form of scaffolding may include suspended (swing-stage), cantilever, tower, modular, and hung scaffolds.

Prefabricated scaffolding has to be design registered as required under the WHS regulations Part 1 of Schedule 5.

Additional Information

– AS/NZS 4576: Guidelines for Scaffolding

– AS 1576 (Series): Scaffolding

– AS 1577: Scaffold Decking Components

You can find guidance material, codes of practice, and other resources on the Safe Work Australia website.

For more information on professional scaffolding services, Skelskaff Scaffolding is here to provide you the scaffolding management service you need.

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