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© Thornton Tomasetti Inc. 2017
Susta inab i l i t y
St ructura l Eng ineer ing
Const ruct ion Eng ineer ing
Façade Eng ineer ing
Weid l inger Protect ive Des ign
Weid l inger Appl ied Sc ience
Renewal
Proper ty LossConsul t ing
Forens icsWeid l inger
Transpor tat ion
About Thornton Tomasetti - Our Practices
Agenda
Façade Access Components and Types
Overview of Various Design and Testing Regulations
Testing Procedures
Summary
Image Credit: https://www.constructionspecifier.com/designing-and-testing-facade-access-equipment/print/
Activities include: Window Washing, Construction,
Repairs/Renovation, Inspections
OSHA estimates that 202,066 serious injuries and 345
fatalities occur annually among workers directly affected by
the final standard.
What is Façade Access and Why is it Needed?
Façade Access ComponentsPortable Outriggers (i.e., “Beams and Weights”)
https://www.archtoolbox.com/materials-systems/equipment/windowwashsuspension.html Source: New England Scaffolding
Roof-mounted
Façade Access ComponentsRoof-Mounted Tiebacks
https://www.archtoolbox.com/materials-systems/equipment/windowwashsuspension.html
Façade Access ComponentsWall-mounted Tiebacks
https://www.archtoolbox.com/materials-systems/equipment/windowwashsuspension.htmlImage credit: Columbia Building Services, Inc.
Façade Access ComponentsRope Descent Systems (i.e., “bosun’s chairs”)
http://www.highwindowcleaning.com/bosun-chair-window-cleaning.php
Seat Board
Question: Which components do I need to test?
Façade Access Components
Answer: Building-mounted support elements.
Building-mounted Contractor-supplied
Davit Bases and Sleeves/Sockets Portable Outriggers (i.e., “Beams and
Weights”)
Davit Arms Parapet Clamps
Permanent tie-back points Everything else (ropes, cables,
harnesses, hoists, etc.)
Building Maintenance Units*
*BMUs fall underneath a different OSHA guideline
Façade Access Regulations
Codes and Standards
Voluntary Standards
“Rated Load” versus “Stall Load” for hoists
Fall-arrest/lifeline anchorages – 5,000 pound load requirement
OSHA’s “Final rule” states that building owners must affirm in writing
that building anchorages for rope descent have been tested, certified,
and maintained as capable of supporting 5,000 pounds – i.e., field
testing
OSHA Design Requirements
Incorporate design loads consistent with
OSHA strength requirements
Hoist Load requirements (DAVITS):
2.5 x rated load x 1.6 safety factor, OR
1.0 x stall load x 1.6 safety factor
Fall-arrest load requirements (TIEBACKS):
3,100 pounds per person x 1.6 safety
factor ~ 5,000 pounds
ASCE/SEI and IBC Design Requirements
IWCA and ASME Testing Standard
IWCAInternational Window Cleaning Association - Window Cleaning Safety
Published once in 2001
Withdrawn in 2011
Proposed testing to 50% of minimum required strength
ASMEAmerican Society of Mechanical Engineers - Safety Requirements for Powered Platforms and Traveling Ladders and Gantries for Building Maintenance
In 2010 proposed the 50% restriction, similar to IWCA
Voluntary standard which contradicts legally-required codes
Starting November 20, 2017 per OSHA Final Rule:
Written assurance requirement from Building Owner begins
300-foot height limit for rope descent systems
Test loads:
Many davit systems were designed for 1,000 pound motors, but 1,250
pound (or even 1,500 pound motors) are common in restoration work
Test load requirement for personal fall-arrest or safety-line tiebacks is
5,000 pounds
Test loads must reach 100% of intended load
Summary and Main Takeaways