Max Wind Speed - spiderstaging.com

1 Max wind Speed Spider Phone: 1-877-774-3370 365 Upland Drive E-mail: Seattle, WA 98188 USA Internet: SafeWorks , LLC 2008 THIS DATA SHEET AND ALL REPRODUCTIONS ARE THE PROPERTY OF SPIDER . ALL DIMENSIONS AND FIGURES ARE SHOWN FOR GENERAL INFORMATION ONLY AND SHOULD BE CONFIRMED BY SPIDER BEFORE BEING USED FOR DESIGN OR CONSTRUCTION PURPOSES. ALL INFORMATION IS SUBJECT TO CHANGE WITHOUT NOTICE. SPIDER IS A DIVISION OF SAFEWORKS, LLC. 1 What is the maximum wind Speed that a suspended scaffold can be safely operated at? The simple answer to this question is that maximum wind Speed a suspended scaffold can be operated at is to be determined by the Competent Person on site and has no defined number within OSHA. DEFINITION: Competent Person 29 CFR Part 1926 Subpart L, (b) 1. A Competent Person must be capable of identifying existing and predictable hazards in the surroundings or working conditions.

2 2. A Competent Person must have authorization to make prompt corrective measures to eliminate the hazards. BACKGROUND Within the OSHA code there are two pertinent sections commonly applied to suspended scaffolding applications. They are commonly referred to as 1926 Construction Industry and 1910 Standards for General Industry. Many persons within the suspended scaffold industry refer to these codes as 1926- Temporary Equipment Platforms like those found in the rental industry especially on construction jobsites, or for single or limited use job platforms; and 1910- Permanent Installation Equipment Platforms like those platforms specifically built for one building or group of buildings for regularly scheduled maintenance as defined by the trade of window washing. Only one of these code sections specifically addresses the wind Speed at which a suspended scaffold can be operated at, and it is Part 1910 normally considered as dealing with permanently installed equipment. (i)(2)(v) The platform shall not be operated in winds in excess of 25 miles per hour ( km/hr) except to move it from an operating to a storage position.

3 wind Speed shall be determined based on the best available information, which includes on-site anemometer readings and local weather forecasts which predict wind velocities for the area. Max wind Speed Spider Phone: 1-877-774-3370 365 Upland Drive E-mail: Seattle, WA 98188 USA Internet: SafeWorks , LLC 2008 THIS DATA SHEET AND ALL REPRODUCTIONS ARE THE PROPERTY OF SPIDER . ALL DIMENSIONS AND FIGURES ARE SHOWN FOR GENERAL INFORMATION ONLY AND SHOULD BE CONFIRMED BY SPIDER BEFORE BEING USED FOR DESIGN OR CONSTRUCTION PURPOSES. ALL INFORMATION IS SUBJECT TO CHANGE WITHOUT NOTICE. SPIDER IS A DIVISION OF SAFEWORKS, LLC. 2 Within the code section normally applied to the construction industry, the answer is less clear. (f)(12) Work on or from scaffolds is prohibited during storms or high winds unless a competent person has determined that it is safe for employees to be on the scaffold and those employees are protected by a personal fall arrest system or wind screens.

4 wind screens shall not be used unless the scaffold is secured against the anticipated wind forces imposed. Common Sense Recommendation A competent person should always assess the conditions while work is being performed. Never use a suspended scaffold in high winds or during storms. At minimum, do not work on the scaffold when winds are in excess of 25 MPH on the wall. Do not operate the suspended scaffold if wind speeds are greater than 25 mph. Consider stopping operation at a lesser wind Speed then 25 mph, if you are carrying any material in the suspended scaffold that would allow the wind to blow against a larger surface causing a sail effect Consider stopping operation at a lesser wind Speed then 25 mph, if you are using a single point unit. Purchase a hand held anemometer from Spider under part number P-00178 to help monitor wind Speed .. (i)(2)(vi) On exterior installations, an anemometer shall be mounted on the platform to provide information of on-site wind velocities prior to and during the use of the platform.

5 The anemometer may be a portable (hand held) unit which is temporarily mounted during platform use. Max wind Speed Spider Phone: 1-877-774-3370 365 Upland Drive E-mail: Seattle, WA 98188 USA Internet: SafeWorks , LLC 2008 THIS DATA SHEET AND ALL REPRODUCTIONS ARE THE PROPERTY OF SPIDER . ALL DIMENSIONS AND FIGURES ARE SHOWN FOR GENERAL INFORMATION ONLY AND SHOULD BE CONFIRMED BY SPIDER BEFORE BEING USED FOR DESIGN OR CONSTRUCTION PURPOSES. ALL INFORMATION IS SUBJECT TO CHANGE WITHOUT NOTICE. SPIDER IS A DIVISION OF SAFEWORKS, LLC. 3 REFERENCE MPH Description - Visible Condition 0 Calm smoke rises vertically 1 - 4 Light air direction of wind shown by smoke but not by wind vanes 4 - 7 Light breeze wind felt on face; leaves rustle; ordinary wind vane moved by wind 8 - 12 Gentle breeze leaves and small twigs in constant motion; wind extends light flag 13 - 18 Moderate breeze raises dust and loose paper; small branches are moved 19 - 24 Fresh breeze small trees in leaf begin to sway; crested wavelets form on inland water 25 - 31 Strong breeze large branches in motion; telephone wires whistle; umbrellas used with difficulty 32 - 38 Moderate gale whole trees in motion; inconvenience in walking against wind 39 - 46 Fresh gale breaks twigs off trees; generally impedes progress 47 - 54 Strong gale slight structural damage occurs; chimney pots and slates removed 55 - 63 Whole gale trees uprooted; considerable structural damage occurs 64 - 72 Storm very rarely experienced.

6 Accompanied by widespread damage 73+ Hurricane devastation occurs Table Sourced at On 8/12/08