ASME A120.1-2006 pdf – Safety Requirements for Powered Platforms and Traveling Ladders and Gantries for Building Maintenance
ASME A120.1-2006 pdf – Safety Requirements for Powered Platforms and Traveling Ladders and Gantries for Building Maintenance.
3.3.9 TroLley System. A track-mounted trolley system, supported from an overhead structure, may be used as a means of suspension, tinder the definition of a carriage, provided that the installation complies with the requirements of this Standard and with the following specific requirements:
(a) Each installation shall be provided with a means for safe egress of personnel in the event of a loss of power to the equipment.
(b) A maintenance area shall be provided to permit safe access to the trolley(s).
(c) Means shall be provided to prevent the equipment from unintentionally traversing in a horizontal direction.
(d) Manually propelled trolleys shall require a maximum of 40 lb of pull to move the trolley along its track.
3.4 Outriggers (Beam Type)
Outriggers may be used on buildings to support ground-rigged self-powered platforms where the point of suspension does not exceed 130 ft (39.6 m) above a safe surface unless a continuous means of engagement is provided on the face of the building where the maximum rise of the platform shall be limited to 300 ft (92 m).
The initial installation shall be designed by, or under the direction of, a registered professional engineer to comply with the following safety requirements:
(a) Platforms shall be required to be disengaged from the outriggers after each day’s use or the platforms shall be secured and stored at grade with the power supply disconnected. All suspension wire ropes shall be attached to their outriggers with forged double-locking snap hooks or equivalent devices.
(b) All outriggers shall be secured to a certified anchorage on the building during the entire period of use. The anchorages shall provide a stability factor of 4 against overturning or upsetting. Each outrigger, when installed on buildings erected prior to the effective date of this Standard, may be stabilized by rigid counterweights secured to its inboard ends. It shall also be tied back to a certified anchorage on the building with a minimum of 16 in. (8.0 mm) wire rope. The counterweights shall provide a stability factor of 4 against overturning or upsetting of the outrigger. Each counterweight shall be permanently identified as to its weight.
(c) Access and egress shall be from a safe surface such as grade or a roof surface below the elevation of suspension. The installation shall be designed to prevent access to or egress from the platform at the elevation of suspension.
(d) Each outrigger shall be designed for lateral stability to prevent rollover.
(e) Each outrigger shall be designed to support an ultimate load of four times the rated capacity of the hoist to be used with the outrigger.
(b) Rotatable Outrigger Installation. The scaffold platform cannot be raised above the building face being serviced for storage, rigging, and access to or egress from the working platform. For this type of installation
(1) the point of suspension shall not be more than
130 ft (40 m) above a safe surface unless a continuous
means of engagement is provided. In the latter case, the
maximum rise of the platform shall be limited to 300 ft
(2) access and egress shall only be from an area such as grade floor or a roof surface below the point of suspension and shall preclude persons climbing over a building’s parapet or guard railing for access to or egress from a scaffold.
(c) Davit and Rotatable Outrigger Installations Requiring Re! ocation of Davits or Outriggers to Other Work Locations on Same Elevation. For this type of installation
(1) the davits or outriggers shall be inserted into sockets secured and rigged with the suspension ropes before being raised to their vertical position
(2) the davit and outrigger sockets shall he positioned to prevent their being raised at less than 7 deg in respect to the facade being serviced
(3) davits shall be provided with wheels or a cart to assist in traversing
(d) For all davit and rotatable outrigger installations
(1) the sockets shall be made from structural steel hot-dipped galvanized or other corrosion-resistant material
(2) all bolts, nuts, and pins shall be made from stainless steel.