A mobile ladder stand is a movable, fixed height, self-supporting ladder consisting of wide flat treads in the form of steps which give access to a top step. The assembly may include handrails and is intended for use by one person.
A mobile ladder stand platform is a movable, fixed height, self-supporting unit having one or more standing levels and is provided with a means of access or egress to the platform or platforms. The assembly may include handrails and/or guardrails and may be designed to accommodate one or more persons. See
Requirements for all Mobile Ladder Stands and Platforms:
The structural safety factor for this class of products is 4. In other words, the units must be capable of supporting 4 times their rated load.
All threaded fasteners used in the construction of mobile ladder stands and platforms must be of a self-locking type.
All exposed surfaces must be free of sharp edges and burrs.
Design Features - Mobile Ladder Stands:
The rated load for a mobile ladder stand must be at least 300 pounds. This rating is based upon the combined weight of one worker, materials, and equipment.
The steps must be at least 16-inches wide and be provided with a durable slip-resistant surface. The slip-resistant feature may be an integral part of the surface, or may be provided by dimpling, knurling, shot blasting, coating, metal spraying, or slip-resistant tapes.
Steps must be uniformly spaced and arranged with a rise (vertical spacing) of not more than 10 inches, and a depth of not less than 7 inches. The slope (angle) of the step stringer to which the steps are attached is limited to not more than 60-degrees from the horizontal.
Handrails, when used, must have a vertical height in the range of 29 1/2 to 37-inches, measured vertically (90 degrees) from the front edge of a step.
All of the standing areas of the mobile ladder stand must be located within the perimeter of the base frame to reduce the overturning hazard.
Ladder stands with a top step height of 4 feet to 10 feet must be provided with handrails. The use of movable gates or non-rigid members, such as chains, is permitted for special use applications.
Ladder stands with a top step over 10 feet high must have the top step protected on three sides by a handrail with a vertical height of at least 36 inches. Top steps that are 20 inches or more, from front to back, must be provided with a midrail and toeboard. On special use applications, the use of removable gates or non-rigid members, such as chains, is permitted.
On mobile ladder stands provided with wheels or casters, the wheels or casters supporting the unit are required to support four times their proportional share of the unit’s rated load plus their proportional share of the unit’s weight. In addition, the size, number, and type of casters must provide maneuverability of the unoccupied unit. The wheel/caster system must also be equipped with a system that impedes horizontal movement of the unit.
Design Features - Mobile Ladder Stand Platforms:
The rated load for a mobile ladder stand platform must be at least "x” times 300 pounds based upon the anticipated number of workers (x), each having a combined weight, including materials and equipment of 300 pounds.
The steps must be at least 16-inches wide and the platform at least 18-inches wide. The steps, standing levels and/or platform(s) must be provided with a durable slip-resistant surface. The slip-resistant feature may be an integral part of the surface, or may be provided by dimpling, knurling, shot blasting, coating, metal spraying, or slip-resistant tapes.
Steps must be uniformly spaced and arranged with a rise (vertical spacing) of not more than 10 inches, and a depth of not less than 7 inches. The preferred slope (angle) of the step stringer to which the steps are attached is limited to not more than 60-degrees from the horizontal. In the event this is not practical, a steeper slope (up to 70-degrees) or a vertical rung ladder(s) may be used. In this case, stability of the unit against overturning when the user accesses the unit must be considered by the designer.
Handrails, when used, must have a vertical height in the range of 29 1/2 to 37-inches, measured vertically (90 degrees) from the front edge of a step.
All of the standing areas of the mobile ladder stand must be located within the perimeter of the base frame to reduce the overturning hazard.
Ladder stand platforms with a top step height of 4 feet to 10-feet must be provided with handrails. The use of movable gates or non-rigid members, such as chains, is permitted for special use applications. Handrails in the platform area above the flat surface must have a height of at least 36-inches and include a midrail.
Ladder stand platforms with a platform over 10-feet high must have guardrails and toeboards on the exposed sides and ends of the platform. The guardrail must have a height of 42-inches 3 inches including a midrail approximately midway between the top rail and the working surface. On special use applications, the use of removable gates or non-rigid members, such as chains, is permitted.
The wheels and casters supporting a mobile ladder stand are required to support four times their proportional share of the unit’s rated load plus their proportional share of the unit’s weight. In addition, the size, number, and type of casters must provide maneuverability of the unoccupied unit. The wheel/caster system must also be equipped with a system that impedes horizontal movement of the unit.
Product Performance:
Mobile ladder stands and mobile ladder stand platforms which comply with the governing safety standard, ANSI-ASC A14.7, are required to pass a variety of stability and load tests. In addition, the on-product labels must pass a variety of durability tests with regard to humidity, adhesive strength, water contamination and temperature. Only when the manufacturer’s design has complied with these design verification tests is it permissible to display a compliance label or an indication in the product manual that compliance has been achieved.
Users are advised, however, that compliance with stability test requirements does not mean that a unit is incapable of overturning as is the case when severe misuse of the unit takes place. Similarly, compliance with load test requirements does not mean that structural collapse will not occur in the event severe overload of the unit occurs.
Proper Care and Use:
The mobile ladder stand or ladder stand platform manufacturer is required to provide maintenance instructions with each unit. These instructions must address visual inspection procedures, general maintenance, and proper tightening directions for threaded fasteners. Users are required to read and understand the user instructions before being allowed to use a mobile ladder stand or mobile ladder stand platform. As an alternative, employers must instruct employees in the proper use of the units prior to allowing use.
Upon receipt following shipping, and prior to each period of use, each mobile ladder stand or ladder stand platform unit must be visually inspected for damage, such as unusual wear, deterioration, or corrosion. Any loose bolts, nuts or connections must be tightened. All threaded fasteners must be equipped with locking hardware. It is the owners’ responsibility to comply with the manufacturers’ maintenance instructions to maintain the quality and serviceability of the unit.
Units that are damaged or weakened from any cause are not to be used until repairs are completed. Units that are damaged subsequent to their receipt and/or are worn beyond repair must be removed from service and destroyed.
General maintenance of a mobile ladder stand or platform includes cleaning, lubrication, painting and the replacement of on-product labels and markings as well as wheels, casters, and rubber pads.
Climbing a damaged ladder stand or ladder stand platform is not permitted.
Ladder stands and ladder stand platforms must never be moved while occupied.
Units must not be loaded beyond their rated load capacity.
Materials and/or equipment must not be stored on the steps or platform of a unit.
Additional height must not be gained by the addition of any type of extension or object being placed upon the unit.
Users must remove foreign materials, such as mud or grease, from their shoes prior to climbing or mounting.
Handrails, when provided, should be used while ascending or descending. The user must face the steps while ascending or descending except when the slope of the steps is 50 degrees or less above the horizontal.
When electrical lines are present, proper safety measures to avoid contact with energized conductors, insulated or uninsulated, must be taken to avoid electrical shock or electrocution.
Occupied units must not be placed in front of a door unless the door is secured in an open position, locked, attended, or barricaded.
Overreaching while on a unit can cause instability and result in a fall. Always place the unit in close proximity to the work. Descend from the unit and relocate it to avoid overreaching.
Use ladder stands and ladder stand platforms only on level surfaces. They are not to be used on uneven or sloping surfaces.
Access to or egress from a step or platform from any other elevated surface is prohibited unless the unit has been positively secured against movement.
Users are not permitted to stand on components of the unit other than the steps or platform.
On-Product Labels and Markings:
Each unit must be marked with the manufacturers’ product data information including:
1. Manufacturers or distributors name or logo;
2. Month and year of manufacture;
3. Maximum rated load
In addition, the following safety topics must also be addressed by the labels and markings:
1. Visual inspection
2. Maintenance
3. Overreaching
a.
Example: CAUTION – Overreaching causes a tipping hazard
4. Engagement of the locking mechanism
a. Example: CAUTION – Make sure locking mechanism
is engaged before climbing
5. Holding handrails during ascent and descent;
6. Appropriate standing surfaces
7. User orientation during ascent and descent
a.
Example: CAUTION – Face ladder stand & hold handrails when ascending and descending
Mobile Ladder Safety Standard:
Safety and design requirements for mobile ladder stands and mobile ladder stand platforms can be found in the following standard:
• ANSI-ASC A14.7-2006, American National Standard for Mobile Ladder Stands and Mobile Ladder Stand Platforms