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.

January 4, 1980

Mr. Marvin Wood, P.E.
Manager, Design Engineering
Ecodyne, Smith and Loveless
Division 14040
Santa Fe Trail Drive
Lenexa, Kansas 66215

Dear Mr. Wood:

This is in response to the meeting with you, Tom Fowler and myself, in our Regional Office on December 20, 1979. In the meeting, we discussed your designs and the OSHA standards on fixed ladders and landing platforms to be used in underground chambers for pumping stations.

According to your design drawings of the 30-foot maximum underground chamber, the fixed ladder can be installed without cages or landing platforms. The chamber wall inside dimensions around the fixed ladder are the same as OSHA requires for a basket guard hoop; therefore, the chamber wall will serve as a cage and will be acceptable to OSHA. The 30-foot maximum depth of the fixed ladder does not require a landing platform when cages are provided (see 29 CFR 1910.27(d)(2) attached).

When the underground chambers extend beyond the 30-foot depth, a landing platform is required for each 30 feet of fixed ladder with cages. From your design drawings of the semi-circular landing platform at the 30-foot level, we feel this landing platform satisfies the OSHA requirements, even though the ladder section is not offset. The employee using this ladder must stop at this level, because of the landing floor, and step around the landing which will change his direction of travel 180 degrees on the ladder to get below the 30-foot level. Here again the chamber walls around the ladder, below the 30-foot level, serve as cages for the employee.

We understand from our meeting that all other OSHA standards concerning fixed ladder requirements will be met, such as:

1. Seven inch (7") minimum clearance in back of ladder.

2. Metal ladder rungs will be 1-1/8" diameter and painted or treated to resist corrosion.

3. A minimum clearance length of metal rungs between metal side rails of 16 inches.

4. Distance between metal rungs shall not exceed 12 inches and shall be uniform throughout the length of the ladder.

5. Fastenings shall be an integral part of fixed ladder design.

6. Welding shall be in accordance with the "Code for Welding in Building Construction," (AWSD 1.0-1966)(see 29 CFR 1910.27 attached).

We are sending a copy of this letter and copies of your design drawings to our National Office requesting their review and concurrence, correction and/or additions, as applicable. Upon receipt of a reply, we will give you a final answer.

We appreciate your concern for occupational safety and health, and if we can be of any further assistance, please let us know.


Charles E. Adkins
Assistant Regional Administrator
Office of Technical Support