OSHA requirements are set by statute, standards and regulations. Our interpretation letters explain these requirements and how they apply to particular circumstances, but they cannot create additional employer obligations. This letter constitutes OSHA's interpretation of the requirements discussed. Note that our enforcement guidance may be affected by changes to OSHA rules. Also, from time to time we update our guidance in response to new information. To keep apprised of such developments, you can consult OSHA's website at https://www.osha.gov.

April 27, 2015

Jennifer Coon
7740 West New York Street
Indianapolis, Indiana 46214

Dear Ms. Coon:

Thank you for your letter to the Occupational Safety and Health Administration (OSHA), Directorate of Construction. This is in response to your letter, dated October 13, 2014. This letter constitutes OSHA's interpretation of only the requirements discussed and may not be applicable to any question not delineated in your original correspondence.

We have paraphrased your question as follows:

Scenario: When abrasive blast cleaning and painting, the inner surfaces of a water storage tank are accessed by personnel using a ladder boom. The ladder boom is constructed of a ladder attached to a lug near the floor of the tank with a system of pulleys and cables which adjust to rise and lower the height and pitch of the ladder. These ladder booms are constructed on site without the approval from the ladder manufacturer or certified by a safety professional.

Question 1: You asked if the proposed support system described above, and as pictured in the photos you submitted, would comply with OSHA standards.

Answer: No. While OSHA does not have a specific standard covering personal ladder boom support systems, the use of the equipment in the manner described would not be compliant with multiple OSHA standards. Such standards would include, but are not limited to, the OSHA construction ladder standard (29 CFR Part 1926, Subpart X), the fall protection standard (29 CFR Part 1926, Subpart M), and the scaffold standard (29 CFR1926, Subpart L). Specific standards applicable to use of this support system would include:

  1. 29 CFR 1926.1053 (b)(4) states that "Ladders shall be used only for the purpose for which they were designed". We know of no ladders designed for use as a means of transporting construction equipment, materials and tools. Thus, the proposed support system is not in compliance with this standard.
  2. 29 CFR 1926.1053(b)(5)(i) states that "Non-self-supporting ladders shall be used at an angle such that the horizontal distance from the top support to the foot of the ladder is approximately one-quarter of the working length of the ladder..." This angle is approximately 76° from the horizontal. The submitted photographs and drawing indicate that the ladder is used as a main structural member with an angle of approximately 15° from the horizontal. To use the ladder in this flatter angle is not in compliance with this standard.
  3. 29 CFR 1926.1053(b)(3) states that "Ladders shall not be loaded beyond the maximum intended load for which they were built, nor beyond their manufacturer's rated capacity." In the same configuration as Item 2 above, the ladder would subject to very high longitudinal and flexural stresses beyond the manufacturer's rated capacity. Thus, the proposed support system is not in compliance with this standard. In addition, based on the information submitted, we are unable to tell if the connection devices at the end of the ladder will not deform or damage the ladder or put any stresses on it beyond those for which it was designed.
  4. 29 CFR 1926.451(a)(6) requires all scaffolds to be designed by a qualified person and constructed and loaded in accordance with that design. Due to the materials and configuration of the system, a complex engineering analysis would be needed to assess the capacity of such a system. The analysis is further complicated by the fact that the capacity may diminish over time due to wear and corrosion of materials or as a result of events during use.
  5. 29 CFR 1926.500(b) walking/working surface states that "Any surface, whether horizontal or vertical on which an employee walks or works, including, but not limited to, floors, roof, ramps, bridges, runways, formwork and concrete reinforcing steel, but not including ladders, vehicles, or trailers,..." Since the ladder is not a walking/working surface for employees to perform their job duties, the proposed support system is not in compliance with this standard.
  6. 1926.451(g)(3)(iv) states that vertical lifelines, independent support lines, and suspension ropes shall not be attached to each other, nor shall they be attached to or use the same point of anchorage, nor shall they be attached to the same point on the scaffold or personal fall arrest system.

Please note that the use of a personal fall arrest system in conjunction with this ladder support system would not abate the hazards addressed by the standards noted above.

Thank you for your interest in occupational safety and health. We hope you find this information helpful. OSHA's requirements are set by statute, standards, and regulations. Our letters of interpretation do not create new or additional requirements, but rather explain these requirements and how they apply to particular circumstances. This letter constitutes OSHA's interpretation of the requirements discussed. From time to time, letters are affected when the Agency updates a standard, a legal decision impacts a standard, or changes in technology affect the interpretation. To assure that you are using the correct information and guidance, please consult OSHA's website at http://www.osha.gov. If you have further questions, please feel free to contact the Directorate of Construction at (202) 693-2020.


James G. Maddux, Director
Directorate of Construction