Below is the uncorrected machine-read text of this chapter, intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text of each book. Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.
1 1. INTRODUCTION AND OVERVIEW The U.S. Coast Guard (USCG) has safety regulatory oversight over vessels registered in the United States. One of its oldest regulatory functions is ensuring that these U.S. Flag vessels comply with minimum standards for stability. Vessel stability is simply the ability of a floating body to stay upright when the body is disturbed by an external force. Stability standards have been improved in response to accidents and advances in technical understanding and computational technology. USCG has made major changes to its stability regulations over the last 30 years, most notably by consolidating most of the regulations in a single subchapter [see Subchapter S, Chapter I of Title 46 of the Code of Federal Regulations (46 CFR)] and by acceptance of the International Maritime Organization (IMO) Stability Codes and SOLAS (International Convention for the Safety of Life at Sea) Damage Stability regulations for ships with international certification. Despite these consolidations, USCG believes there may be opportunities to make further improvements to the vessel stability regulations, particularly with regard to their accuracy, clarity, consistency, and usability by vessel designers, classification societies, operators, and inspectors. USCG remains keenly interested in ensuring that the regulations are kept updated based on the latest technical knowledge, well aligned with international standards, and organized and presented in a manner that facilitates compliance. This interest extends to the regulations that pertain to vessel stability in other parts and subparts of 46 CFR Chapter I and the many policy documents that USCG has issued that interpret and elaborate on stability requirements, such as in policy letters, circulars, and safety manuals. Per the request of the Naval Architecture Division, Office of Design and Engineering Standards (CG-ENG-2), which maintains and updates USCG vessel stability regulations, this
2 report reviews the state of USCGâs stability regulations and identifies options for making the regulatory improvements USCG desires. The Statement of Task for the study, which appears in Box 1, also calls for the committee to identify candidate sources of data that USCG can explore to inform its assessment of whether all inspected passenger vessels or some classes of passenger vessels should undergo periodic stability verifications or lightweight surveys. Although the committee did not locate any data sources, it does suggest several potential sources for USCG to consult and also suggests ways that USCG can verify lightship weight over time in a practical manner. Background To evaluate U.S. stability regulations requires an understanding of the various types of vessels regulated by 46 CFR and the services they provide. The vast majority of vessels regulated by USCG serve only domestic routes, such as traveling on rivers, inland waterways, bays, and sounds, and near protected coastal areas. Table 1 shows the number of USCG-inspected vessels by length and type. Of the 11,630 total vessels in the fleet as of April 2018, slightly more than Box 1 Statement of Task: Committee to Revise and Update U.S. Coast Guard Ship Stability Regulations The study committee will review the set of United States Coast Guard (USCG) regulations and policy documents that establish stability requirements for U.S. Flag vessels in order to identify, and recommend as appropriate, options to make and keep the requirements current, align them better with international standards, improve their consistency and clarity, and organize them in a manner that facilitates their use and compliance. In addition, the committee will identify candidate sources of data that USCG can explore further to inform its assessments of the advantages and disadvantages of requiring all inspected passenger vessels to undergo periodic stability verifications, or lightweight surveys.
3 half are passenger type while the remainders are cargo vessels.1 The vast majority of the vessels described in Table 1 are smaller (shorter length) ships, barges, and boats operating in coastwise, protected-water, or inland service. The traditional, longer, ocean-going ship is a small part of the U.S. vessel fleet, accounting for fewer than 10% of vessels. It merits noting that of the more than 5,600 cargo vessels, only 617 are self-propelled, with the balance being barges and other non- self-propelled vessels. Appendix B contains a more detailed breakout of vessels subject to 46 CFR, and in particular, Tables B-1 and B-2 describe the fleet by inspection category, domestic versus international service, and route type. The total number of vessels has remained rather constant over the past 4 years. Table 1 Number of U.S.-Inspected Vessels by Type and Length Length (feet) Number Passenger Vessels under 65' 4,411 65' to 79' 470 79' to 328' 1,066 greater than 328' 21 Passenger Vessel Total 5,968 Cargo Vessels under 79' 79 79' to 262' 2,766 262' to 328' 2,242 328' to 492' 248 greater than 492' 327 Cargo Vessel Total 5,662 SOURCE: USCG, Marine Information for Safety and Law Enforcement (MISLE) database (data as of April 10, 2018). The stability regulations as they apply to the vessels in Table 1 are the focus of this study. In addition to the USCG-inspected vessels listed in Table 1, the domestic fleet contains 1 The fleet is fairly constant over time. Similar statistics from January 2014 from the same MISLE source indicate 12,263 total vessels, including 6,274 passenger vessels and 5,989 cargo vessels (USCG Passenger Vessel Association Partnership National Meeting, Summary Statistics on Small Passenger Vessels (Subchapter T&K) by Captain Dave Fish, USCG, Jan. 2014, slide 2).
4 thousands of additional uninspected vessels, including towing, fishing, work, and recreational boats. Other than the larger fishing vessels, USCG generally does not directly regulate the stability of the uninspected vessels. However, certain vessels obtaining a Load Line are subject to the same intact stability criteria as inspected vessels of the same type,2 and over the next few years, more of these uninspected vessels, primarily towing vessels, will need to comply with Subchapter M of Title 46 CFR.3 Study Emphasis and Scope In light of the studyâs short time frame, the committee decided to focus its efforts on providing a high-level review of USCGâs vessel stability regulations, intent on identifying options for improving their clarity, harmony, and accuracy. Consideration was first given to options that can be pursued quickly because they do not require formal regulatory changes. The committee then turned its attention to those options that are likely to take more time because of the restrictions and limitations of the federal rulemaking process. Although that rulemaking process is highly structured and time consuming to effect change, some potential improvements warrant this concerted effort. The committee observes that USCGâs policy of consolidating stability regulations in one place, Subchapter S, has made it easier for users and regulators to find and understand the requirements. Nevertheless, some of the provisions in the subchapter can be problematic for users because they are difficult to understand, refer to standards that have been superseded by comparable international standards, have not incorporated the widely used capabilities of modern 2 See https://media.defense.gov/2017/Mar/29/2001723819/-1/-1/0/CIM_16000_9.PDF. 3 When briefing the committee at its first meeting, USCG estimated that approximately 5000 vessels could be affected by Subchapter M. More information on Subchapter M is provided at the following link: https://www.dco.uscg.mil/Our-Organization/Assistant-Commandant-for-Prevention-Policy-CG-5P/Traveling- Inspector-Staff-CG-5P-TI/Towing-Vessel-National-Center-of-Expertise/SubIRegulations-Copy.
5 computational technology, and do not use consistent definitions of terms. The report provides examples of each of these issues and suggests candidate changes to address them. It also recommends a potential reorganization and an update of some regulations in Subchapter S, which are summarized in Section 3 and discussed in more detail in Appendixes F and G. The intent of the proposed reorganization is to make it easier for users to find the stability requirements for a specific vessel type and to reduce the number of places where similar terms are defined through a consolidation of definitions. In summary, the options considered in this report pertain to: ï· 46 CFR Subchapter Sâstability regulations applicable to most cargo vessels and larger passenger vessels. ï· 46 CFR Subchapter Tâstability regulations applicable to most small passenger vessels. ï· Periodic review and update in stability regulations over time. ï· Applicability of IMO stability-related codes to U.S. vessels. ï· Passenger vessel lightweight change and monitoring. Other stability-related issues that are considered include: ï· The importance of tracking vessel casualty statistics as an effective tool for evaluation of stability regulations, ï· New methods of evaluating stability using the increasing capability of computers, particularly for assessing the stability of vessels in dynamic conditions, ï· Stability regulations in other countries as an important reference for U.S stability regulations, and
6 ï· The importance of providing useful stability information on board vessels to assist operators in evaluating their stability risks in extreme conditions, which was highlighted in the investigation reports related to the 2015 loss of the El Faro. It merits noting that in addition to the regulations contained in the CFR, USCG maintains many additional documents that contain information relevant to stability policy, guidance, and requirements. These documents include Navigation and Vessel Inspection Circulars (NVICs), Marine Safety Center (MSC) Plan Review Guidelines, Policy File Memorandums (PFMs), the Marine Safety Manual, and MSC Technical Notes (MTNs), among others. The committee realizes that, individually and collectively, these documents are an important resource for the U.S. maritime community, but they could be made more easily available and searchable by consolidating them into one website. This is an example of an improvement that could be made without initiating the rulemaking process. In the next section, the main findings of the report are summarized. They are intended to meet the study charge, but not exceed it. Accordingly, the report does not address numerous issues that were deemed outside the study scope, including the: ï· Current state of the IMO stability regulations and whether changes and improvements are needed in them. ï· Accuracy of data used in stability calculations, such as weight data and measurement data. (Although the accuracy of weight data is key to accurate stability calculations, this complex topic would require a significant amount of analysis of data confidence levels and would influence the data uncertainty of overall calculation predictions.) ï· Stability of vessels not covered under the CFR regulations addressed in this report, such as recreational boats, military and government vessels, and most uninspected
7 vessels (including fishing vessels). Regulations for these vessels are found in 46 CFR Subchapter C. Although related to the study topic, these complex issues would have been impractical to address given the studyâs short time frame and limited resources. Summary of Main Findings and Recommendations Finding 1: International stability regulations for ocean-going vessels may not be appropriate for a majority of vessels regulated by USCG. USCG regulates stability for more than 11,600 passenger and cargo vessels. Of that number, approximately 8,400 vessels (more than 70%) are nonâocean-going and operate only in bays, rivers, lakes, and other protected or partially protected waters (see Appendix B for a more detailed breakout of U.S.-regulated vessels). IMO stability regulations, and those of many coastal nations, are focused on ocean-going vessels and the wind, wave, and weather conditions that they encounter in the open sea. In light of these differences in conditions, the current USCG policy of developing separate stability regulations for domestic vessels appears sensible. However, when the domestic vessel regulations apply the same or similar requirements as international stability regulations (primarily in various codes), this could allow USCG to accept compliance with the international regulation as equivalent to the CFR requirement. Such acceptance could allow vessels to comply with the latest versions of international regulations without having to wait for the USCG rulemaking process to update the comparable CFR regulation. Inasmuch as USCG is a major contributor to the development of international stability regulations, it is reasonable to expect that USCG would concur with the latest version of the international regulation.
8 Finding 2: Parts of 46 CFR Subchapter S are unclear, outdated, or superseded by similar international stability regulations. The committee encountered examples of content and organization issues, including multiple and conflicting definitions, and a reliance on outdated references to U.S. standards. For example, in its review of Subchapter S, there are conflicting definitions of downflooding, downflooding point, and downflooding angle that appear in multiple sections. Appendix D describes these issues in more detail. Finding 3: Data for weight change on passenger vessels are not readily available but opportunities exist to obtain such data. As part of its remit, USCG asked the committee to identify candidate sources of data that could inform it about periodic lightweight surveys. Obtaining relevant data on weight change is challenging, especially without periodic checks of a vesselâs lightship weight, and the committee was unable to locate a usable data set. The report presents potential data sources that USCG could investigate for possible use in tracking weight changes on passenger vessels (see Section 4 and Appendix H). For example, the report provides a sample sensitivity study on the existing passenger vessel fleet to estimate the potential impact of lightship growth on various types or classes of passenger vessels. Tracking weight changes, even minor changes, is important for passenger vessels, as small weight increases occurring over a period of many years could go unnoticed and potentially have an adverse effect on a vesselâs stability. Recommendation 1: USCG should engage with applicable industry advisory groups prior to any rulemaking initiative on vessel stability requirements. Maintaining clear and current regulations will require USCG to establish a process for continuous review and update of regulations in consultation with internal and external
9 stakeholders. Industry engagement is vital for improving the likelihood that USCG receives relevant input from industry stakeholders concerning any proposed rule change and that industry will ultimately accept any proposed change. The existing USCG industry advisory groups would seem to be a good starting point for such engagement and outreach. Recommendation 2: As part of the nonregulatory effort to update vessel stability information, USCG should consolidate existing USCG stability policy decisions into a single database, which is made available online and searchable. As outlined in Appendix D, stability policy decisions are contained in other documents, such as NVICs, MSC Plan Review Guidelines, PFMs, and MTNs, and often created in response to questions about how to interpret and implement the regulations in Subchapter S. Initial steps for creating a database would include the review of all stability-related policy documents to determine if they are valid, consistent with other policy documentation, require updating, or could be incorporated into a higher-level document. Curating all relevant stability policy decisions in an online database would create an accessible and comprehensive record of all USCG stability policy decisions and provide a firm basis for updating and maintaining the regulations over time. Recommendation 3: As part of a long-term initiative, USCG should commence a regulatory project that proposes fundamental organizational changes to the stability regulations in Subchapter S with the goal of improving the regulationsâ clarity, harmony, and accuracy. As a starting point for USCG, the committee provides a series of suggested options of possible regulation improvements and updates. The committee recognizes that USCG faces challenges in initiating any comprehensive regulatory project and realizes that any ârewriteâ of the stability regulations will be difficult. Appendix F outlines a potential reorganization of Subchapter S and
10 provides a table that lists all Parts from other Subchapters in 46 CFR that refer back to Subchapter S. Appendix G provides a review of relevant Parts of Subchapter S and provides options for potential updates. Appendix H reviews the issue of passenger ship lightship weight change and suggests candidate methods to assess such a potential change. Recommendation 4: USCG should take actions to improve data collection and analysis of casualty and near miss data in the United States to inform stability regulation. Casualty and near miss data and statistics can be a key source of information on where vessel stability problems are occurring and at what level of significance. In the United States, accident and incident data for marine transportation analysis are stored in various systems and managed by different agencies and entities. Much of these data are not stored in a common repository that is accessible to users with requirements for data access, storage, or analysis. Furthermore, data are not stored in a common format to facilitate data validation, reconciliation, analysis, and reporting. Validation, compatibility, integration, and harmonization are increasingly significant challenges in maritime data analysis and risk assessments. The USCG MISLE database does capture marine casualty statistics related to stability. Missing, inaccurate, and underreported maritime accident and incident data remain an issue, however, and with MISLE data, the apparent gaps and a lack of a common safety data ontology and classification scheme can create data inconsistencies. Absent a standard incident and accident coding scheme, common data storage and data transmission formats, and a common data dictionary, marine casualty and stability-related data analysis and data record reconciliation can require extensive, time- consuming steps. Future data requirements to analyze structured and unstructured data such as pictures, video, sound, animation, and drawings will exacerbate the data challenges noted in this