Law Department notice on WTC document preservation, Oct 2001

NYC 9/11 Public Portal Document

Standard Operating Procedure Page 8 of 15 Fall Protection

More than 5 feet up to 10 feet 10 feet More than 10 feet 13 feet

Safety nets shall be installed with sufficient clearance under them to prevent contact with the surface or structures below when subjected to an impact force equal to the drop test specified below. Safety nets and their installations shall be capable of absorbing an impact force equal to that produced by the drop test.

Safety nets and safety net installations shall be drop-tested at the jobsite after initial installation and before being used as a fall protection system, whenever relocated, after major repair, and at 6-month intervals if left in rate place. The drop-test shall consist of a 400 pound (180 kg) bag of sand 30 + or - 2 inches (76 + or - 5 cm) in diameter dropped into the net from the highest walking/working surface at which employees are exposed to fall hazards, but not from less than 42 inches (1.1m) above that level.

When it is unreasonable to perform the drop-test a designated competent person shall certify that the net and net installation is in compliance with the above listed specifications by preparing a certification record prior to the net being used as a fall protection system. The certification record must include an identification of the net and net installation for which the certification record is being prepared; the date that it was determined that the identified net and net installation were in compliance and the signature of the person making the determination and certification. The most recent certification record for each net and net installation shall be available at the jobsite for inspection.

Defective nets shall not be used. Safety nets shall be inspected at least once a week for wear, damage, and other deterioration. Defective components shall be removed from service. Safety nets shall also be inspected after any occurrence which could affect the integrity of the safety net system.

Materials, scrap pieces, equipment, and tools which have fallen into the safety net shall be removed as soon as possible fi-om the net and at least before the next work shift.

The maximum size of each safety net mesh opening shall not exceed 36 square inches (230 cm) nor be longer than 6 inches (15 cm) on any side, and the opening, measured center-to-center of mesh ropes or webbing, shall not be longer than 6 inches (15 cm). All mesh crossings shall be secured to prevent enlargement of the mesh opening. Each safety net (or section of it) shall have a border rope for webbing with a minimum breaking strength of5,000 pounds (22.2 kN). Connections between safety net panels shall be as strong as integral net components and shall be spaced not more than 6 inches (15 cm) apart.

5.4 PERSONAL FALL ARREST SYSTEMS

Connectors in a fall arrest system shall be drop forged, pressed or formed steel, or made of equivalent materials. They shall have a corrosion-resistant finish, and all surfaces and edges shall be smooth to prevent damage to interfacing parts of the system.

Dee-rings and snaphooks shall have a minimum tensile strength of 5,000 pounds (22.2 kN). Dee-rings and snaphooks shall be proof-tested to a minimum tensile load of3,600 pounds (16 kN) without cracking, breaking, or taking permanent deformation.

Snaphooks shall be the selfclosing, self locking type.

Unless the snaphook is a locking type and designed for the following connections, snaphooks shall not be engaged:

• Directly to webbing, rope or wire rope; • To each other; • To a dee-ring to which another snaphook or other connector is attached; • To a horizontal lifeline; or

NYC-WTC_000145145