Specialty Scaffolds

1. Specialty Scaffolds

2. Pole Scaffold • Type of scaffold in which all structural components are made from wood • 29 CFR.1926.452 (a) • Braces, bearers, and runners shall not be spliced between poles • Diagonal bracing in both directions shall be installed across the entire outside face • Scaffold must be designed by a registered professional engineer if over 60 feet • Rarely used and Considered old fashioned because built from scratch and cannot easily be reused http://www.osha.gov/dte/library/scaffolds/scaffolding/handout.html

3. Tube and coupler scaffold • Tube and coupler scaffolds are built from tubing connected by coupling devices. • 29 CFR.1926.452 (b) • Couplers shall be of structural metal; the use of gray cast iron is prohibited • Runners shall be installed along the length of the scaffold, located on both the inside and outside posts at level heights • Bearers must be installed transversely between posts • Bracing must extend upward diagonally to opposite sides of the scaffold • If over 125 feet in height, must be designed by a registered professional engineer • due to its strength, these scaffolds are used where heavy loads need to be carried, or where multiple platforms must reach several stories high • hard to build correctly. http://www.osha.gov/dte/library/scaffolds/scaffolding/handout.html

4. Fabricated frame scaffold • scaffold consisting of platform(s) supported on fabricated end frames with integral posts, horizontal bearers, and intermediate members. • Also called tubular welded frame scaffold • 29 CFR.1926.452 (c) • Frames and panels shall be braced by cross, horizontal or diagonal braces which secure vertical members together laterally. • Frames and panels shall be joined together vertically by coupling or equivalent means • If over 125 feet in height, must be designed by a registered professional engineer • Most common type of scaffold because it is versatile, economical, and easy to use http://www.osha.gov/SLTC/etools/scaffolding/supported/frame/frame.html

5. Plasters’, decorators’, and large-area scaffold • Scaffold that is erected over the entire floor area of a room • 29 CFR.1926.452 (d) • Scaffold should be constructed in accordance of the following: • (a) Pole scaffolds • (b) Tube and coupler scaffolds • (c) Fabricated frame scaffolds http://www.osha.gov/dte/library/scaffolds/scaffolding/handout.html

6. Bricklayers’ square scaffold • supported scaffold composed of framed squares which support a platform. • 29 CFR.1926.452 (e) • Scaffolds made of wood must be reinforced with gussets on both sides of each corner • Diagonal braces shall be installed on all sides of each square and between squares on the rear and front sides of scaffold. • Scaffold shall not exceed three tiers in height http://www.osha.gov/dte/library/scaffolds/scaffolding/handout.html

7. Horse scaffold • supported scaffold consisting of a platform supported by construction horses • 29 CFR.1926.452 (f) • Scaffolds shall not be constructed or arranged more than two tiers or 10 feet in height • The legs of each horse must be nailed down or otherwise secured to prevent displacement • Each tier must be crossbraced http://www.osha.gov/SLTC/etools/scaffolding/supported/specialty.html#Bricklayers'%20Square%20Scaffolds

8. Form scaffold & carpenters’ bracket scaffold • A supported scaffold consisting of a platform supported by brackets attached to formwork, building or structural walls. • 29 CFR.1926.452 (g) • Each bracket, except those for wooden bracket form scaffolds, shall be attached to supporting formwork or structure by the following: • Nails • Metal stud attachment device • Welding • Hooking over secured structural supporting member • And/or bolts For both images: http://www.osha.gov/dte/library/scaffolds/scaffolding/handout.html

9. Roof bracket scaffold • rooftop supported scaffold consisting of a platform resting on angular-shaped supports • 29 CFR.1926.452 (h) • Brackets must be constructed to fit the pitch of the roof and provide a level of support for the platform • Brackets must be anchored in place by nails unless impractical • brackets must be secured with first-grade manila rope of at least 3/4-inch diameter when nails are not used http://www.osha.gov/SLTC/etools/scaffolding/supported/specialty.html

10. Outrigger scaffold • supported scaffold consisting of a platform resting on outrigger beams projecting beyond the wall or face of the structure • 29 CFR.1926.452 (i) • Must be designed by a registered professional engineer • Platform units must be nailed, bolted or otherwise secured to outriggers • Entire supporting structure must be securely braced • Inboard ends of outrigger beams shall be securely anchored by braced struts and/or tension members http://www.osha.gov/Publications/OSHA3150/images/3150_10.jpg

11. Pump Jack scaffold • supported scaffold consisting of a platform supported by vertical poles and movable support brackets • 29 CFR.1926.452 (j) • Pump jack brackets, braces and accessories shall be fabricated from metal plates and angles • Poles shall be secured to the structure by rigid triangular bracing or equivalent at the bottom, top, and other points necessary • Work benches shall not be used as scaffold platforms http://www.osha.gov/SLTC/etools/scaffolding/supported/pumpjack.html

12. Ladder Jack Scaffold • supported scaffold consisting of a platform resting on brackets attached to ladders • 29 CFR.1926.452 (k) • Platforms shall not exceed a height of 20 feet • All ladders used shall meet requirements of subpart X and shall be placed, fastened, or equipped with devices to prevent slipping • Platforms shall not be bridged together http://www.dir.ca.gov/Images/t8img/1938-29.gif

13. Window jack scaffold • platform resting on a bracket or jack which projects through a window opening. • 29 CFR.1926.452 (l) • Scaffold should be securely attached to window opening and used only for the purpose of working at the window opening through which the jack is placed • Window jacks shall not be used to support planks or other elements of scaffolding placed between one window jack and another. http://www.osha.gov/SLTC/etools/scaffolding/supported/specialty.html#Window%20Jack%20Scaffolds

14. Crawling boards • supported scaffold consisting of a plank with cleats spaced and secured to provide footing, for use on sloped surfaces such as roofs • Also called chicken ladder • 29 CFR.1926.452 (m) • Shall extend from roof peak to eaves when used in connection with roof construction, repair, or maintenance • Shall be secured to roof by ridge hooks or means that meet equivalent criteria http://www.osha.gov/SLTC/etools/scaffolding/images/chicken4.jpg

15. Step, platform, and trestle ladder scaffolds • platform resting directly on the rungs of step ladders or trestle ladders • 29 CFR.1926.452 (n) • Scaffold platforms shall be placed no higher than the second-highest rung or step of the ladder supporting the platform • Scaffolds must not be bridged one to another • All ladders used shall meet requirements of subpart X and shall be placed, fastened, or equipped with devices to prevent slipping http://www.osha.gov/SLTC/etools/scaffolding/supported/specialty.html#Window%20Jack%20Scaffolds

16. Single-point adjustable suspension scaffold • suspension scaffold consisting of a platform suspended from an overhead support by one rope, equipped with means to move the platform • most common called boatswain's chair (used by window washers) • 29 CFR.1926.452 (o) • supporting rope between the scaffold and the suspension device must be kept vertical unless • Rigging designed by qualified person • Scaffold is accessible to rescuers • support rope is protected from chaffing during direction changes • scaffold is positioned so swinging cannot bring it into contact with other surfaces http://www.osha.gov/SLTC/etools/scaffolding/images/single01.jpg

17. Two-point adjustable suspension scaffold • A suspension scaffold consisting of a platform supported by hangers and suspended by two ropes from overhead supports • 29 CFR.1926.452 (p) • Platforms shall be more than 36 inches wide • Platforms shall be securely fastened to hangers by U-bolts • Scaffolds shall not be bridged or connected to each other while being raised or lowered. • Passage from one platform to another may only be made when : • Platforms are the same height or abutting • Walk-through stirrups are used http://www.osha.gov/SLTC/etools/scaffolding/images/voltage5.jpg

18. Multi-point adjustable suspension scaffold • A suspension scaffold consisting of one or more platforms suspended by more than two ropes from overhead supports • 29 CFR.1926.452 (q) • Scaffolds shall be suspended from metal outriggers, brackets, wire rope slings, hooks or by equivalent means • Passage may be made from one platform to another only when bridges are not used and platforms are the same height or abutting • When two or more scaffolds are used they shall not be bridged to each other unless: • They are designed to be bridged • Bridge connections are articulated • Hoists are properly sized http://www.osha.gov/SLTC/etools/scaffolding/suspended/multipoint.html

19. Catenary scaffold • suspension scaffold consisting of a platform supported by two horizontal and parallel ropes attached to structural members of a building or other structure • 29 CFR.1926.452 (r) • Shall not have: • more than one platform between vertical pickups • More than two platforms used • Platforms supported by wire ropes shall have hooked shaped stops on each end • Wire ropes shall not be over tightened to the point of overstress, but shall be continuous without splices between anchors http://www.osha.gov/SLTC/etools/scaffolding/suspended/catenary.html

20. Float (ship) scaffold • suspension scaffold consisting of a braced platform resting on two parallel bearers and hung from overhead supports by ropes of fixed length • 29 CFR.1926.452 (s) • Platform shall be supported by at least two bearers that, each, shall be securely fastened to the platform and that project 6 inches or more beyond the platforms • Rope connections shall be such that the platform cannot shift or slip http://www.osha.gov/SLTC/etools/scaffolding/suspended/float.html

21. Interior hung scaffold • suspension scaffold consisting of a platform suspended from the ceiling or roof structure by fixed-length supports • 29 CFR.1926.452 (t) • Scaffolds shall only be suspended form roof structure or other structural members • Overhead supporting members shall be inspected and checked for strength before erection • Suspension ropes and cables shall be connected by shackles, clips, thimbles or equivalent means http://www.osha.gov/SLTC/etools/scaffolding/suspended/interiorhung.html

22. Needle beam scaffold • scaffold consisting of a platform suspended from needle beams, usually attached on one end to a permanent structural member • 29 CFR.1926.452 (u) • Scaffold support beams shall be installed on edge • Support connection shall be arranges to prevent needle beam from displacing or rolling • Platforms shall be securely attached to needle beams by bolts or equivalent means http://www.osha.gov/SLTC/etools/scaffolding/suspended/needlebeam.html

23. Multi-level suspended scaffold • two-point or multi-point adjustable suspension scaffold with a series of platforms at various levels resting on common stirrups • 29 CFR.1926.452 (v) • Scaffolds shall be equipped with additional independent support lines that are: • Equal in number to the number of points supported • Equivalent strength of suspension ropes • Rigged to support scaffold if suspension ropes fail • Independent support lines and suspension lines shall not be attached to the same points http://www.osha.gov/SLTC/etools/scaffolding/suspended/multilevel.html

24. Mobile scaffold • type of supported scaffold set on wheels or casters and is designed to be easily moved • 29 CFR.1926.452 (w) • Scaffolds shall be braced by cross, horizontal, diagonal braces or a combination thereof • Scaffold casters and wheels shall be locked with positive wheel locks, wheel and swivel locks or equivalent means • Manual force to move the scaffold shall be applied as close to the base as possible, but no more than 5 feet above supporting surfaces • Platforms shall not extend outward beyond the base supports unless outrigger frames or equivalent devices are used http://www.osha.gov/SLTC/etools/scaffolding/supported/manually_propelled.html

25. Repair bracket scaffold • supported scaffold consisting of a platform supported by brackets which are secured in place around the circumference or perimeter of a other supporting structure • 29 CFR.1926.452 (x) • Brackets shall be secured in place by at least one wire rope with a diameter of at least ½ inch • Scaffold erection shall progress in only one direction around any structure • Each turnbuckle shall be connected to the other end of its rope by the use of an eyesplice thimble of appropriate size http://www.scribd.com/doc/9731353/Scaffold-Handbook

26. References Aramco, S. (2001, May). Scaffold Safety Handbook. Retrieved November 17, 2009 from , Web site: http://www.scribd.com/doc/9731353/Scaffold-Handbook OSHA (n.d.). Glossary. Retrieved October 26, 2009 from , Website: http://www.osha.gov/SLTC/etools/scaffolding/glossary.html OSHA (2007). OSHA Standards for the Construction Industry (1st ed. ). Chicago, IL: CCH. OSHA (2007, September 28). Scaffolding. Retrieved October 21, 2009 from , Web site:http://www.osha.gov/SLTC/etools/scaffolding/index.html