BY
Sreenivasa Hassan Jayaram
Manager-Projects, Jones Lang LaSalle India, Bangalore, Karnataka
Introduction – Ladders are a great resource to help workers access materials or work areas that are out of reach. Additionally, ladder accidents are one of the leading causes of occupational injuries and fatalities.
The proper precautions must always be taken. Employees should be able to recognize potential hazards associated with ladder use. Additionally, they should know how select the right ladder for the task, set up, and use ladders in accordance with manufacturer and site ladder safety requirements.
Fixed ladder – A Fixed Ladder is a ladder permanently attached to a structure, building, or equipment.
1. Inspection and Maintenance – All ladders shall be maintained in a safe condition, they shall be inspected regularly, with the intervals between inspections being determined by use and exposure, manufacturer requirements and/or as prescribed by local regulatory requirements; sites must be able to demonstrate performance to this requirement. At a minimum fixed ladder inspections should include:
i. Assessment of all components for function and wear to include rungs, side rails, supports, fasteners, anchors, backside and front side clearance/obstructions and ladder cages and ladder hatches when present.
ii. If electrical grounding protection has been provided for the ladder, a continuity inspection of the ground connection(s) shall be performed per system requirements.
iii. If a fall protection system has been provided, it shall be inspected and tested according to the manufacturer’s recommendations.
2. Fixed Ladder Design Requirements – Except for where local laws are more stringent,fixed ladders shall be designed in accordance. Below is an overview of some of the basic fixed ladder design requirements.
2.1 Load – The minimum design live load shall be a single concentrated load of 200 pounds (90kg).
2.2 Pitch – preferred pitch of fixed ladders shall be considered to come in the range of 75 degrees and 90 degrees with the horizontal. Ladders with a pitch in excess of 90 degrees with the horizontal are prohibited.
2.3 Clearance – Clearance on the climbing side of the ladder requires that from the centerline of the rungs to the nearest permanent object there shall be 36 inches (91cm) for a pitch of 76 degrees, and 30 inches (76 cm) for a pitch of 90 degrees. Excluded in this requirement are ladders in wells and with cages.
2.4 Rungs/cleats –
i. Rungs will be free of splinters, sharp edges or any projects that may be a hazard
ii. Rungs shall be uniform not exceed a distance between steps of 12 inches (30cm) and
iii. Shall have a minimum diameter of three-fourths inch for metal ladders
2.5 Step across distance – The step-across distance from the nearest edge of ladder to the nearest edge of equipment or structure shall be between 2 .5 – 12 inches (6.3-30cm). Where an employee has to step a distance greater than 12 inches (30cm) from the centerline of the rung of a ladder to the nearest edge of structure or equipment, a landing platform shall be provided.
2.6 Cages – Cages are required for fixed ladders longer than 20 feet (6m) to a maximum unbroken length of 30 feet (9.1m). Cages shall extend down the ladder to a point not less than 7 feet (2.1m) nor greater than 8 feet (2.4m and shall extend a minimum of 42 inches (106cm) above the top of a landing unless other acceptable protection is provided (such as a ladder safety system).
2.7 Landing platforms – “Landing platforms.” When ladders are used to ascend to heights exceeding 20feet (6m) (except on chimneys), landing platforms shall be provided for each 30 feet (9.1m) of height,except where no cage, well, or ladder safety device is provided, landing platforms shall be provided for each20 feet ((6m) of height. Each ladder section shall be offset from adjacent sections. Where installationconditions (even for a short, unbroken length) require that adjacent sections be offset, landing platformsshall be provided at each offset.
i. All landing platforms shall be equipped with standard railings and toeboards, so arranged as to give safe access to the ladder. Platforms shall be not less than 24 inches (60cm) in width and 30 inches (76cm)in length.
ii. Ladder rung shall be even with the landing platform.
2.8 Fixed ladder passageways – For ladders that extent to another working surface or platform the passageways through the railing of all shall be protected by a swinging gate or offset so that a person cannot walk directly into the opening. This applies to floor openings in runways and catwalks.
2.9 Fixed ladder extension – Side rails of through or side-step ladder extensions shall extend 3.5 feet (1m) above parapets and landings.
2.10. Fixed Ladder grab bars – Rug spacing and grab bar diameter shall continue the same pattern as the ladder they are located on.
2.11. Protection from deterioration –
i. Dissimilar metals at risk of electrolytic action shall not be joined.
ii. Metal ladders and appurtenances shall be painted or otherwise treated to resist corrosion and rusting when location demands.
iii. Wood ladders, when used under conditions where decay may occur, shall be treated with a nonirritating preservative, and the details shall be such as to prevent or minimize the accumulation of water on wood parts.
iv. Where different types of materials are used in the construction of a ladder, the materials used shall be so treated as to have no harmful or damaging affect one upon the other.
v. Ladders formed by individual metal rungs imbedded in concrete, which serve as access to pits and to other areas under floors, are frequently located in an atmosphere that causes corrosion and rusting. To increase rung life in such atmosphere, individual metal rungs shall have a minimum diameter of 1 inch (2.5cm) or shall be painted or otherwise treated to resist corrosion and rusting.
Reference and Acknowledgement
[1] Fall Protection Program by OSHA guidelines http://www.oshatrain.org
[2] Working At Height Guidelines, Version II, 21st September 2011 http://www.mic.ul.ie/adminservices/policies.
We at engineeringcivil.com are thankful to Sir Sreenivasa Hassan Jayaram for submitting this paper to us.
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