NVIC 08-93: Equivalent alternatives for wide passenger vessel escape

NAVIGATION AND VESSEL INSPECTION CIRCULAR 08-93, CHANGE 1 Subj: CH-1, EQUIVALENT ALTERNATIVES TO 46 CFR SUBCHAPTER H REQUIREMENTS RELATED TO MEANS OF ESCAPE, SAFE REFUGE AREAS, AND MAIN VERTICAL ZONE LENGTH. Ref: (a) COMDTPUB P16700.4, NVIC 8-93

Equivalent Alternatives to 46 CFR Subchapter H Requirements Related to Means of Escape, Safe Refuge Areas and Main Vertical Zone Length — PURPOSE. This document revises reference (a) by adding a new enclosure (4) to provide a

methodology for the acceptance of equivalent alternatives to the 46 CFR Subchapter H requirements for means of escape and safe refuge areas onboard passenger vessels with a maximum enclosed width in excess of 40 m (131 ft.). 46 CFR 72.05 and 72.10 provide the design criteria for the onboard means of escape on traditional passenger vessels. However, these regulations were developed for vessel designs having a maximum enclosed width of 40 m (131 ft.). The alternatives in this enclosure are limited to vessels that: a. Do not operate on international voyages subject to SOLAS; b. Have no overnight passenger accommodations; c. Are primarily comprised of large public spaces; d. Operate on limited protected routes accepted by the cognizant Officer in Charge, Marine Inspection; and e. Do not carry cargo or vehicles. DISTRIBUTION SDL No. 143 a b c d e f g h i j k l m n o p q r s t u v w x y z A B I I 1 C I I I I D * E I I F G H NON-STANDARD DISTRIBUTION: B:a G-MOC (1), G-MO (1) NAVIGATION AND VESSEL INSPECTION CIRCULAR NO. 08-93, CH-1

Equivalent Alternatives to 46 CFR Subchapter H Requirements Related to Means of Escape, Safe Refuge Areas and Main Vertical Zone Length — ACTION. Officers in Charge, Marine Inspection are encouraged to bring this NVIC to the

attention of appropriate individuals in the marine industry within their zones. Vessel owners electing to employ the alternatives outlined in this NVIC must do so in all areas. The Coast Guard will also consider other design alternatives which are shown to provide an equivalent level of protection. This NVIC is available on the World Wide Web at www.uscg.mil/hq/g- m/nvic/. Within the Coast Guard, it will be distributed by electronic means only.

Equivalent Alternatives to 46 CFR Subchapter H Requirements Related to Means of Escape, Safe Refuge Areas and Main Vertical Zone Length — DIRECTIVES AFFECTED. "Equivalent Alternatives to 46 CFR Subchapter H

Requirements Related to Means of Escape, Safe Refuge Areas, and Main Vertical Zones," COMDTPUB P16700.4, NVIC 8-93, is amended by inserting the enclosure of this document as a new enclosure (4).

Equivalent Alternatives to 46 CFR Subchapter H Requirements Related to Means of Escape, Safe Refuge Areas and Main Vertical Zone Length — BACKGROUND.

a. The provisions for onboard means of escape and structural fire protection in Subchapter H and NVIC 8-93 are based on vessel designs with a maximum enclosed width of 40 meters (131 ft.). This enclosure has been prepared to supplement the existing guidance by providing a means to evaluate fire protection and life safety issues on vessels of greater enclosed width, and includes consideration of dockside evacuations. b. Both NVIC 8-93 and Subchapter H are based on the premise that main vertical zone bulkheads are provided every 40 meters (131 ft.) to subdivide the vessel into discrete fire areas. The main vertical zone bulkheads are required to extend for the entire enclosed width of the vessel. In response to industry requests, enclosures (1) and (2) of NVIC 8- 93 were developed to provide a method for evaluating equivalent life safety arrangements for vessels designed with main vertical zone bulkheads spaced more than 40 meters (131 ft.) apart longitudinally. However, the alternative provisions in enclosures (1) and (2) were not intended to apply to vessels with an enclosed width in excess of 40 m (131 ft.). c. Vessels with an enclosed width in excess of 40 m (131 ft.) could have very large public spaces with a significantly higher passenger capacity than vessels previously envisioned during the development of Subchapter H or NVIC 8-93. If these vessels periodically carry passengers while dockside as well as underway, the means of escape provisions must be arranged to ensure an orderly, prompt evacuation in either configuration. The prescriptive means of escape provisions in Subchapter H and NVIC 8-93 do not account for this. The alternatives in enclosure (4) have been selected to ensure that a comprehensive evaluation of the evacuation system is performed at the design stage to eliminate localized congestion and to ensure that the means of escape are adequate to allow efficient movement of all of the occupants from the public spaces to dedicated areas of refuge or to protected dockside exits before untenable conditions occur, assuming worst case fire scenarios. d. Enclosure (4) recognizes performance-based fire protection engineering methods using computer fire models as evaluation tools for this purpose.

Equivalent Alternatives to 46 CFR Subchapter H Requirements Related to Means of Escape, Safe Refuge Areas and Main Vertical Zone Length — DISCLAIMER. While the guidance contained in this document may assist the industry, the

public, the Coast Guard, and other federal and state regulators in applying statutory and NAVIGATION AND VESSEL INSPECTION CIRCULAR NO. 08-93, CH-1 regulatory requirements, this guidance is not a substitute for applicable legal requirements, nor is it in itself a rule. Thus, it is not intended to nor does it impose legally binding requirements on any party, including the Coast Guard, other federal agencies, the states, or the regulated community. T.H. GILMOUR Rear Admiral, U.S. Coast Guard Assistant Commandant for Marine Safety, Security and Environmental Protection Encl: (1) Equivalent Alternatives to 46 CFR 72.05 for Wide Main Vertical Zones NAVIGATION AND VESSEL INSPECTION CIRCULAR NO. 08-93, CH-1