[Chapter 1] Section 2 Scaffolding Material, Structure, and Assembly Drawing③

3 Single-pipe scaffolding

(1) Single-pipe scaffolding are temporary scaffolding consisting of a 48.6 mm-diameter single-pipe, a clamp that serves as a tensioning metal fitting, a single-pipe base, wall ties, and scaffold boards.
It is the oldest temporary scaffolding in history. In the past, they used “wooden logs” and “strings” as scaffolding components, which are now replaced by single-pipes and clamps.
In terms of strength and safety, it is inferior to prefabricated scaffolding in some respects, and is used for distances of 31 m or less. When the design load acting on the bottom edge of the standards does not exceed the maximum working load, reinforcement such as two sets of steel pipes is not necessary.

・Useful as scaffolding in narrow spaces or complex structures where prefabricated scaffolding cannot be installed

・Fewer components are required than prefabricated scaffolding.

・Can be configured to suit the work and site, from double-pole scaffolding to bracketed scaffolding, etc.

・Difficult to assemble and disassemble

(2) Maximum loading capacity
The maximum loading capacity of single-pipe scaffold (scaffold) shall be 400 kg or less for one span and shall not be carried over a continuous span.

(3) Used materials, etc.
The materials used for single-pipe scaffolds are compliant with JIS and Ministry of Health, Labor and Welfare standards.

 

Steel pipes for scaffolds (JIS) and tensioning metal fittings (orthogonal clamps, universal clamps)

Single pipe joint and single pipe base metal fitting

(4)Keypoints of single-pipe scaffold

1.Use single-pipe base fittings for footings, and provide sill plates, sill angles, root rails, etc.

2.Wall joints shall be 5 m or less in the vertical direction and 5.5 m or less in the horizontal direction.

3.Spacing between standards shall be 1.85m or less in the girder direction and 1.5m or less in the beam direction.

4.The first ledger above the ground shall be 2 m or less.

5.In case the height of the standards exceeds 31 m from the highest point of the standards, steel pipes shall be installed in pairs, except when the design load acting on the lower end of the standards does not exceed the maximum service load of the standards.

6.Joints and intersections of steel pipes shall be securely joined and tightened using suitable fittings.

 

Single-pipe bracket scaffold (Left) and tying scaffold (Right)

*In the past two years, 12 fatal accidents have occurred. Of these, five cases involved falls through gaps between scaffolding and the frame, and four cases involved falls from outside the scaffolding.

*The single-row scaffold is exempted from Article 563 (working floor) of the Ordinance on Industrial Safety and Health, which does not specify the width of the work floor or fall prevention equipment for scaffolding such as handrails and middle rails. However, it should be provided as much as possible.