supported scaffolds with height to width ratios greater than

[ back to text ], 2Agency's October 13, 1983, letter from John B. Your inquiry concerns the adequacy of outrigger designs for your "lock-pin" mobile scaffolds used in construction. Temecula, CA 92591 Supported scaffolds with a height to base width ratio of more than 4:1 must be restrained by guying, tying, bracing, or an equivalent means. Scaffold components cannot be mixed if they are from different manufac… First, please note that OSHA neither approves nor endorses products. (1) You must make sure supported scaffolds with a height to least base di-mension ratio of greater than four to one are prevented from tipping by one or more of the following: (a) Guying; (b) Tying; (c) Bracing; (d) Other equivalent means. Or, it could be 1920 x 1080, 1280 x 720, or any other width/height combinations that can be calculated to equal 16:9. Prevention of supported scaffolding platform from tipping . • The scaffold poles, legs, posts, frames and uprights should be plumb, braced to prevent swaying and displacement and rest on base plates or other firm foundation. In each of those illustrations, there are identical captions that read, "First tie closest frame header or bearer above 4 times the minimum base dimension." Alternatively, guardrail systems, canopies, or catch platforms may be installed to retain materials. Are supported scaffolds with a height to base width ratio of more than 4 to 1 restrained from tipping by guying, tying, bracing, or equivalents? Scaffolds with a height to base width ratio of more than 3:1 must be restrained from tipping over by guying, tying, or bracing. Question 1(a): Section 1926.451(c)(1)(ii) contains criteria establishing tie-in requirements for supported scaffolds with a height to base width ratio of more than four to one. Are supported scaffolds with a height to base width ratio of more than four to one (4:1) restrained from tipping by guying, tying, bracing, or equivalents? For a scaffold with a narrow base width of less than 1.2 m, the height of Supported scaffolds with a height to base width ratio of more than 4:1 must be restrained by guying, tying, bracing, or … If you need additional information, please contact us by fax (202-693-1689) at: U.S. Department of Labor, OSHA, Office of Construction Standards and Guidance. Guys, ties, and braces must be installed according to the scaffold manufacturer’s recommendations or at the closest horizontal member to the 4:1 height and be repeated vertically at locations of horizontal membe… This letter constitutes OSHA's interpretation of the requirements discussed. Mobile (Rolling) Scaffold Height must not exceed four times the . With prescribed post spacing the scaffold height in this case can be up to 125 feet. Each plank must extend over its support at least 6 inches. Note that our enforcement guidance may be affected by changes to OSHA rules. Height to smallest base dimension — Supported scaffolds with a height-to-smallest-base-width ratio of more ... every 26 feet if the scaffold is greater than 3 feet wide. (w: 1920, h: 1080 preview size. You have submitted nine letters to the Occupational Safety and Health Administration (OSHA) containing a number of questions on the construction scaffold standard (29 CFR Part 1926 Subpart L).1 We will be responding in a series of separate letters in response; this is the first in that series. Outrigger frames, when used, [must be] installed. Supported scaffolds' poles, legs, posts, frames, and uprights must bear on base plates and mud sills, or other adequate firm foundation. In addition, the variable working conditions at jobsites and possible alterations or misapplications of an otherwise safe product could easily create a hazardous condition beyond the control of the manufacturer. In the United States, the OSHA requires such bracing when a scaffold's height to width ratio 4 to 1 or greater. Supported scaffolds platform with a height to base width ratio of more than 4:1 must be restrained by guying, tying, bracing, or an equivalent means. When the length is shorter than the height, bracing should be installed from the base of end posts upward to the opposite end posts and then in alternating directions until the top of the scaffold is reached. Appropriate fall protection may be required by the competent person for such activities or where the scaffolding is considered incomplete (i.e. Supported scaffolds with a height to base width ratio of more than 4:1 must be restrained by guying, tying, bracing, or an equivalent means. When that criteria is applied to a narrow scaffold (scaffolds with a height to base width ratio of more than 4:1) — for example, a supported scaffold that is 2 feet wide and 40 feet high — the employer would be required to tie, guy, or brace the scaffold at approximately the 8-foot level and then not again until every 20-foot increment. 40106 Roshani Drive In short, in light of this and in view of the limited amount of information submitted, we are able to comment only on the applicable requirements for the base width-to-height ratio. It should never be used as a work platform while it is "on rubber." the output size list always return values which have width>height despite the fact that screen's width When I use getResources().getDisplayMetrics() (or any similar method) to check width/height it's always return width And based on the value I see that in 2 cases the width/height are likely swap their value. Using outriggers Supported scaffolds with height to base width ratio of more than four to one (4:1) shall be restrained from tipping by guying, tying, bracing, or equivalent means. You can also contact us by mail at the above office, Room N3468, 200 Constitution Avenue, N.W., Washington, D.C. 20210, although there will be a delay in our receiving correspondence by mail. Figure 21-4: Farm Wagon-Type Rolling Scaffold Working Out Height Capacity of Scaffolding The load capacity of scaffolding is determined by a height to base ratio of 4:1, Meaning the scaffold can be up to four times the minimal base width. . When scaffold planks are abutted, each abutted end is required to rest on a separate support surface. Height to smallest base dimension — Supported scaffolds with a height -to smallest base width ratio of more than 4-to-1 (including outrigger supports) must be restrained from tipping by ties, guys, braces, or equivalent means. I believe that this criteria is insufficient and allows for an unsafe condition. We will refer to them respectively as the 4-foot, 6-foot and 7-foot models. The 4-foot scaffold becomes 4 ft. by 6.167 ft.; the 6-foot scaffold becomes 6 ft. by 6.417 ft.; the 7-foot scaffold becomes 7 ft. by 7.333 ft. Supported scaffolds with a height to base width ratio of more than 4:1 must be restrained by guy-ing, tying, bracing, or an equivalent means. Supported Scaffolds (cont.) Guy wires and ties prevent scaffolding from tipping away from the building or structure, and braces are rigid supports that prevent the scaffolding from tipping into the building or structure. Directorate of Construction, 1 When we originally received these questions from you in April 2003, it was unclear to us if you were requesting a response to each or if they were submitted only to call our attention to these issues in the event that OSHA were to do further rulemaking on the standard. Note also that, under §1926.452(w)(6)(iii), when a worker rides on a scaffold, If you need additional information, please contact us by fax (202-693-1689) at: U.S. Department of Labor, OSHA, Office of Construction Standards and Guidance. OSHA continues to use the relationship between total height and least base dimension to calculate height-to-base width ratio. This is in response to your December 30, 2002, letter to the Occupational Safety and Health Administration (OSHA), as well as several conversations with members of my staff. Tie-in requirements for supported scaffolds; errors in Non-Mandatory Appendix E. loaded scaffold Scaffold uprights must be plumb and braced to prevent swaying Install guys, ties, and braces to prevent tipping Supported scaffolds with a height-to-base width ratio greater than 4:1 must be tied to the structure Business & Legal Reports, Inc. (1) Supported scaffolds with a height to base width (including outrigger supports, if used) ratio of more than four to one (4:1) shall be restrained from tipping by guying, tying, bracing, or equivalent means, as follows: This letter constitutes OSHA's interpretation of the requirements discussed. Either the manufacturers’ recommendation or the following placements must be used for guys, ties, and braces: The table below shows at what height OSHA's restraint provision (§1926.451(c)(1)) would require the indicated scaffold model, when used without outriggers, to be restrained (by guying, tying, bracing, or equivalent means) to prevent tipping. Height to base width ratio. vertical ties repeat every 26 feet or less for scaffolds that are greater than 3 feet in width; and scaffolds with a height-to-base ratio of greater than 4:1 are restrained from tipping by guying, tying or bracing. Supported scaffolds may reach four times the base width before restraints are required. The width is always the first number. Our interpretation letters explain these requirements and how they apply to particular circumstances, but they cannot create additional employer obligations. We appreciate your pointing out that the captions in the Non-mandatory Appendix are in error. Are supported scaffolds with a height to base width ratio of more than 4 to 1 restrained from tipping by guying, tying, bracing, or equivalents? One of those requirements is §1926.452(w)(6)(ii), which states: The materials you submitted do not indicate that you have designed and constructed the "lock-pin" scaffolds to meet or exceed "nationally recognized stability test requirements." Your materials describe three "lock-pin" scaffold models. )Footings must support loaded scaffoldScaffold uprights mustbe plumb and braced toprevent swayingInstall guys, ties, andbraces to prevent tippingSupported scaffolds witha height-to-base widthratio greater than 4:1must be tied to thestructureBusiness & Legal Reports, Inc. Guys, ties, and braces must be installed at locations where horizontal members support both inner and outer legs 2. The height of the scaffold work platform does not exceed the height to base width ratio defined in AS4576. • Horizontally—at each end; at intervals not to Make sure all guys and ties are secure. Scaffolds sometimes require support such as guying, tying, and bracing. Either the manufacturers’ recommendation or the following placements must be used for guys, ties, and braces: They must be placed every 20 feet vertically and every 30 feet horizontally for scaffolds 3 feet wide or less. If meeting the capacity requirement in §:1926.451(a)(1) necessitates installing tie-in/guy ties/braces at closer intervals, the employer would be required to do so. If the ratio is not maintained, ties or guys must be used. An aspect ratio is the relationship between width and height of images. 21-4 Construction Health and Safety Manual SCAFFOLDS 2. We will be responding in a series of separate letters in response; this is the first in that series. So a 2 feet wide scaffold may reach 8 feet in height without using restraints. Our analysis shows the base geometry changes on all three models.  Height to smallest base dimension—Supported scaffolds with a height -to smallest base width ratio of more than 4-to-1 (including outrigger supports) must be restrained from tipping by ties, guys, braces, or equivalent means. Toe boards are required when above 10 feet from the lowest level. b. A supported scaffold with a height-to-base ratio (including outriggers supports, if used) of more than four to one (4:1) shall be restrained from tipping by guying, tying, bracing or equivalent means as follows: . [29 CFR 1926.451(c)(1)] Note: Guys, ties, and braces must be installed at locations where horizontal members support both inner and outer legs. Figure 21-3: Castor-Type Rolling Scaffold Gate Banana clip Castor wheel with brake and swivel lock Brake Horizontal Bracing. The width is always the first number. I. Supported scaffolds must be restrained from tipping by way of tying, bracing or an equivalent means if it has a height-to-base-width ratio of more than 4:1. − The height to base width ratio of the scaffold during movement is greater than 2 to 1, unless the scaffold is designed and constructed to meet or exceed nationally recognized stability test requirements (such as ANSI/SIA A92.5 and A92.6) (1926.452(w)(6)(ii)) Retraining [ back to text ], Occupational Safety & Health Administration. Some common 1:1 ratios are an 8 x 8 inch photo, a 1080 x 1080 pixel image, or typically any profile picture template on social media sites (think Facebook). [29 CFR 1926.451(c)(1)]Note: Install guys, ties, and braces at locations where horizontal members support both inner and outer legs. Supported scaffolds with a height to base width (including outrigger supports, if used) ratio of more than four to one (4:1) shall be restrained from tipping by guying, tying, bracing, or equivalent means as follows: By its terms, §:1926.451(c)(1)(ii), at levels above the initial tie-in and below the top tie-in, establishes. Every 20 feet after for scaffolds less than 3 feet wide, 26 feet for ones wider than 3 feet. However, in light of the width measurements in your materials, we have calculated the maximum permissible scaffold height for use without restraints. March 10, 2004 Supported scaffolds with a height to base width ratio of more than 41 must be restrained from tipping by guying, tying, or bracing. 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