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.

July 27, 2012

Mr. Ken Knauer
Prock Marine Company
67 Front St.
Rockland, ME 04841

Dear Mr. Knauer:

On June 1, 2012, you sent a letter to Senator Susan Collins of Maine regarding the Occupational Safety and Health Administration's (OSHA) regulations on crane barges.  The Senator has forwarded your letter to OSHA for response, and we appreciate the opportunity to address your concerns.  You have asked specific questions about crane barges under OSHA standard 29 CFR § 1926.1437(n)(7)(ii).  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.  For clarity, we have paraphrased your questions as follows:

Question #1: OSHA standard 29 CFR § 1926.1437(n)(7)(ii) requires that barges on which land cranes/derricks are mounted must have "a subdivided hull with one or more longitudinal watertight bulkheads for reducing the free surface effect."  What are the reasons for this requirement?

Response: The purpose of the longitudinal bulkhead requirement is to improve stability and reduce the risk of the vessel capsizing.  As stated in § 1926.1437(n)(7)(ii), the watertight longitudinal bulkheads "reduce[] the free surface effect."  The free surface effect refers to the movement of water within the barge, or its bilges, which can unbalance the vessel.  OSHA addressed this hazard in §§ 1926.1437(n)(7)(ii) and 1926.1437(m)(5)(ii).  The requirements in 29 § 1926.1437(n)(7) and § 1926.1437(m)(5) are identical.1  As the preamble for § 1926.1437(m)(5) explains, "Paragraph (m)(5)(ii) requires a subdivided hull with at least one longitudinal watertight bulkhead to reduce the free surface effect on the vessel.  Subdividing the hull limits the effects of liquid movement on vessel stability, thereby, reducing the risk of the vessel capsizing."2

OSHA based the requirement for a longitudinal watertight bulkhead on a requirement found in the American Society of Mechanical Engineers (ASME) B30.8-2010 Floating Cranes and Floating Derricks standard.  Section 8-1.3.2 requires "at least one longitudinal watertight bulkhead on the centerline or at last two longitudinal watertight bulkheads at one quarter the breadth of the barge off the centerline to port and starboard."  The same standard notes that, "[t]his configuration limits free surface."

Question #2:  Prock Marine Company believes that its barges are safe because they were designed by marine architects and have been in use for years.  These barges do not have longitudinal bulkheads.  Can alternative, or existing, barge designs be used and still considered safe by OSHA?

Response: Yes.  As noted above, the purpose of 29 CFR § 1926.1437(n)(7)(ii) is to reduce the free surface effect, which can unbalance the vessel.  Crane barges that were designed and constructed prior to the promulgation of the cranes and derricks final rule, that do not meet the rule's requirement to have longitudinal bulkheads, may be used so long as they do not present any reasonably foreseeable risk of capsizing.  For safe functioning of the barge, voids should be sounded daily and visually inspected weekly to ensure that they do not contain water.  If so, then the water must be removed/pumped out.  In addition, if the hull has been breached, the hull must be repaired before further use of the barge.  So long as your marine architect has determined and certified in writing that your barges are structurally safe for crane operations by considering, among other things, the free surface effect, the list angle, the trim angle, the wave action, the wind effect, and the modification of the rated capacity of the land cranes/derricks per 29 CFR § 1926.1437(n)(1), the lack of a longitudinal bulkhead will be considered a de minimis violation, and no citation will be issued.  De minimis conditions are those where an employer has implemented a measure different than one specified in an OSHA standard, that has no direct or immediate relationship to worker safety or health.  One of the criteria OSHA uses to determine if a de minimis condition exists is when an employer complies with the intent of an OSHA standard, yet deviates from its particular requirements in a manner that has no direct or indirect impact on employee safety or health.

Thank you for your interest in occupational safety and health.  We hope you find this information helpful.  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 http://www.osha.gov.  If you have any further questions, please feel free to contact the OSHA Directorate of Construction at (202) 693-2020.

Sincerely,



James G. Maddux, Director
Directorate of Construction

cc:  Office of Senator Susan Collins
      OSHA Boston Regional Office

1  Subsection (n) regulates land cranes and derricks on barges, pontoons, vessels or other means of flotation, while subsection (m) regulates floating cranes/derricks.    [Return to Text]

2  75 FR 48069, Aug. 9, 2010.   [Return to Text]