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1. Use of the Appendix. Appendix A provides examples of equipment and methods to assist the employer in meeting the requirements of the indicated provision of the standard. Employers may use other equipment or procedures which conform to the requirements of the standard. This appendix neither adds to nor detracts from the mandatory requirements set forth in Article 6.
2. Assurance. Section 3292(c) requires the building owner to inform the employer in writing that the powered platform installation complies with certain requirements of the article, since the employer may not have the necessary information to make these determinations. The employer, however, remains responsible for meeting these requirements which have not been set off in Section 3292(c)(1).
3. Design Requirements. The design requirements for each installation should be based on the limitations (stresses, deflections, etc.), established by nationally recognized standards as promulgated by the following organizations, or to equivalent standards:
AA-The Aluminum Association
818 Connecticut Avenue, N.W.
Washington, DC 20006
Aluminum Construction Manual
Specifications For Aluminum Structures
Aluminum Standards and Data
AGMA-American Gear Manufacturers Association
101 North Fort Meyer Dr., Suite 1000
Arlington, VA 22209
AISC-American Institute of Steel
400 North Michigan Avenue
Chicago, IL 60611
ANSI-American National Standards Institute, Inc.
11 West 42nd Street
New York City, NY 10036
ASCE-American Society of Civil Engineers
345 East 47th Street
New York, NY 10017
ASME-American Society of Mechanical Engineers
345 East 47th Street
New York, NY 10017
ASTM-American Society for Testing and Materials
1916 Race Street
Philadelphia, PA 19103
AWS-American Welding Society, Inc.
Box 351040, 550 NW LeJeunne Road
Miami, FL 33126
JIC-Joint Industrial Council
2139 Wisconsin Avenue, NW
Washington, DC 20007
NEMA-National Electric Manufacturers Association
2101 L Street, NW
Washington, DC 20037
4. Tie-in Guides. Indented mullions, T-rails or other equivalent guides are acceptable as tie-in guides in a building face for a continuous stabilization system. Internal guides are embedded in other building members with only the opening exposed (see Figure 1 of Appendix B). External guides, however, are installed external to the other building members and so are fully exposed. The minimum opening for tie-in guides is three-quarters of an inch, and the minimum inside dimensions are one-inch deep and two inches wide.
Employers should be aware of the hazards associated with tie-in guides in a continuous stabilization system which was not designed properly. For example, joints in these track systems may become extended or discontinuous due to installation, building settlement or flexing. If this problem is not corrected, the system could lam when a guide roller shoe strikes a joint or distorted area and this would cause a hazardous situation. In another instance, faulty design will result in guide rollers being mounted in a line so they will jam in the track at the slightest misalignment.
5. Building Anchors (Intermittent Stabilization System). In the selection of the vertical distance between building anchors, certain factors should be given consideration. These factors include building height and architectural design, platform length and weight, wire rope angulation, and the wind velocities in the building area. Another factor to consider is the material of the building face, since this material may be adversely affected by the building rollers.
External or indented type building anchors are acceptable. Receptacles in the building facade used for the indented type should be kept clear of extraneous materials which will hinder their use. During the inspection or use of the platform system, evidence of a failure or abuse of the anchors should be brought to the attention of the employer.
6. Stabilizer Tie Length. A stabilizer tie should be long enough to provide for the planned angulation of the suspension cables. However, the length of the tie should not be excessive and become a problem by possibly becoming entangled in the building face rollers or parts of the platform machinery.
The attachment length may vary due to material elongation and this should be considered when selecting the material to be used. Consideration should also be given to the use of ties which are easily installed by employees, since this will encourage their use.
7. Intermittent Stabilization System. Intermittent stabilization systems may use different equipment, tie-in devices and methods to restrict the horizontal movement of a powered platform with respect to the face of the building. One acceptable method employs corrosion-resistant building anchors secured in the face of the building in vertical rows every third floor or 50 feet, whichever is less. The anchors are spaced horizontally to allow a stabilization attachment (stabilizer tie) for each of the two platform suspension wire ropes. The stabilizer tie consists of two parts. One part is a quick connect-quick disconnect device which utilizes a corrosion-resistant yoke and retainer spring that is designed to fit over the building anchors. The second part of the stabilizer tie is a lanyard which is used to maintain a fixed distance between the suspension wire rope and the face of the building.
In this method, as the suspended powered platform descends past the elevation of each anchor, the descent is halted and each of the platform occupants secures a stabilizer tie between a suspension wire rope and a building anchor. The procedure is repeated as each elevation of a building anchor is reached during the descent of the powered platform.
As the platform ascends, the procedure is reversed; that is, the stabilizer ties are removed as each elevation of a building anchor is reached. The removal of each stabilizer tie is assured since the platform is provided with stopping devices which will interrupt power to its hoist(s) in the event either stopping device contacts a stabilizer during the ascent of the platform.
Figure 2 of Appendix B illustrates another type of acceptable intermittent stabilization system which utilizes retaining pins as the quick connect-quick disconnect device in the stabilizer tie. Intermittent stabilization anchors shall both be located outboard, in line with, or inboard of suspension ropes. A combination of locations at the same level shall not be allowed.
8. Wire Rope Inspection. The inspection of the suspension wire rope is important since the rope gradually loses strength during its useful life. The purpose of the inspection is to determine whether the wire rope has sufficient integrity to support a platform with the required design factor.
If there is any doubt concerning the condition of a wire rope or its ability to perform the required work, the rope should be replaced. The cost of wire rope replacement is quite small if compared to the cost in terms of human injuries, equipment down time and replacement.
No listing of critical inspection factors, which serve as a basis for wire rope replacement in the standard, can be a substitute for an experienced inspector of wire rope. The listing serves as a user's guide to the accepted standards by which ropes must be judged.
Rope life can be prolonged if preventive maintenance is performed regularly. Cutting off an appropriate length of rope at the end termination before the core degrades and valley breaks appear minimizes degradation at these sections.
9. General Maintenance. In meeting the general maintenance requirement in Section 3297, the employer should undertake the prompt replacement of broken, worn and damaged parts, switch contacts, brushes, and short flexible conductors of electrical devices. The components of the electrical service system and traveling cables should be replaced when damaged or significantly abraded. In addition, gears, shafts, bearings, brakes and hoisting drums should be kept in proper alignment. For a stabilization system to be effective, the building face rollers cannot be dirty or greasy and shall be kept clean.
10. Training. In meeting the training requirement of Section 3298, employers should use both on the job training and formal classroom training. The written work procedures used for this training should be obtained from the manufacturer, if possible, or prepared as necessary for the employee's information and use.
Employees who will operate powered platforms with intermittent stabilization systems should receive instruction in the specific ascent and descent procedures involving the assembly and disassembly of the stabilizer ties.
An acceptable training program should also include employee instruction in basic inspection procedures for the purpose of determining the need for repair and replacement of platform equipment. In addition, the program should cover the inspection, care and use of the personal fall protection equipment required in Section 3299.
In addition, the training program should also include an emergency action plan as specified in Section 3220 of the General Industry Safety Orders.
Following the completion of a training program, the employee should be required to demonstrate competency in operating the equipment safely. Supplemental training of the employee should be provided by the employer, as necessary, if the equipment used or other working conditions should change.
An employee who is required to work with chemical products on a platform should receive training in proper cleaning procedures, and in the hazards, care and handling of these products. In addition, the employee should be supplied with the appropriate personal protective equipment, such as gloves and eye and face protection.
11. Suspension and Securing of Powered Platforms (Equivalency). One acceptable method of demonstrating the equivalency of a method of suspending or securing a powered platform, as required in Sections 3294(b)(3), 3295(c) and (e)(1)(F), is to provide an engineering analysis by a professional engineer currently registered in the State of California. The analysis should demonstrate that the proposed method will provide an equal or greater degree of safety for employees than any one of the methods specified in the standard.
NOTE: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code; and Section 18943(c), Health and Safety Code.