Review of U.S. Coast Guard Vessel Stability Regulations (2018)

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144 APPENDIX I OTHER AVAILABLE STANDARDS Flag and Regional Standards In Europe, there have been some efforts to harmonize and mutually recognize different standards, as the different national waterways are sufficiently connected to allow significant international trade. Some of these standards could be good references for the U.S. Coast Guard (USCG) for standards to apply to similar U.S. vessels. ES-TRIN (European Standard laying down Technical Requirements for Inland Navigation Vessels, Edition 2017/1) is a set of technical standards that is applicable on inland waterways of the European Community. It is to a large extent a duplication of the Rhine Vessel Inspection Regulations (RVIR), issued by the Central Commission for Navigation on the Rhine. Existing European Union (EU) stability regulations for inland vessels comprise basic criteria, valid for all vessels within the scope of the application of rules, and specific requirements for particular ship types: container vessels, tugs, passenger vessels, river-sea ships, etc. Safety requirements depend on the vessel type and the navigation zone. All regulations divide vessels into three main types: vessels with hatch covers (Type A), tankers (Type B), and open-hold vessels (Type C). European inland waterways are divided into navigation zones 1, 2, and 3, usually related to wave heights of up to 2 m, 1.2 m and 0.6 m respectively. The EU Directive 2006/87/EC distinguishes between Zones 1, 2, 3, and 4, as well as Zone R (the Rhine), but does not link navigation zones to wave heights. Freeboard assignment is a common safety provision in all regulations. In addition to freeboard, regulations for inland vessels also define “safety clearance” or “safety distance” as a vertical distance between the water level at maximal draft and the lowest point of water ingress. Required freeboard and safety clearances are also determined by the vessel type and the navigation zone. Minimal safety distance and freeboard of

145 Type A and B vessels typically depend on the vessel’s length. For Type C vessels, these parameters are prescribed regardless of length. Vessels shall have at least three pairs of draught marks (two for vessels under 40 m). For vessels operating on zones of inland waterways other than Zone 3 (Zones 1, 2, or 4) the bow and stern pairs of draught marks provided for in paragraph 4 shall be supplemented by adding a vertical line to which one or more additional draught lines are added. For passenger vessels, sufficient intact stability for the standard load conditions is given if the maximum righting lever occurs at a heeling angle ≥ 15 degrees and is not less than 0.20 m. The minimum area under the lever arm curve would require 0.07 m-rad to angle 15 degrees or 0.055 m-rad to angle 30 degrees if the maximum lever is at an angle over 30 degrees with a minimum initial metacentric height of 0.15 m. The heeling angle shall not exceed 12 degrees in application of the heeling moment due to passengers and wind, or in application of the heeling moment due to passengers and turning. The residual freeboard shall not be less than 200 mm resulting from moments due to passengers, wind, and turning. For vessels with windows or other openings in the hull located below the bulkhead decks and not closed watertight, the residual safety clearance shall be at least 100 mm on the application of the three heeling moments. In addition to requirements for intermediate stages of flooding, during the final stage of flooding a maximum angle of heel of 10 degrees is required, including watertight integrity requirements and a positive range of the righting lever curve beyond the position of equilibrium of 0.05 m in association with an area under the curve of 0.0065 m-rad up to an angle of heel of 25 degrees. ADN European Agreement concerning the International Carriage of Dangerous Goods by Inland Waterways (2015) classifies vessels into gas tankers (Type G), chemical tankers (Type

146 C), and others (Type N). Proof of sufficient intact stability shall be furnished for all stages of loading and unloading and for the final loading condition. Transport operations shall remain subject to the local, regional, or international requirements. The responsible master shall be in possession of a certificate of special knowledge obtained in an eight-lesson stability training. Vessels that are required to conform to the conditions of damage control (lower openings) are required to have a damage-control plan; documents concerning intact stability as well as all conditions of intact stability, taking into account the damaged stability calculation, in a form the master understands; and a stability booklet and loading instrument that are approved by a recognized classification society. Damage stability requirements include a maximum angle of heel of 12 degrees, including watertight integrity requirements, and a positive range of the righting lever curve beyond the position of equilibrium of 0.05 m in association with an area under the curve of 0.0065 m-rad up to an angle of heel of 27 degrees. Loading instrument: A loading instrument consists of a computer (hardware) and a program (software) and offers the possibility of checking and confirming acceptability of stability in every ballast or loading case. In 2011 the MV Waldhof capsized in intact condition due to lack of stability in the River Rhine, obstructing the river for about 2 weeks. After the incident, requirements for documentation such as stability booklets and safety plans have been updated. As the vessel’s stability properties were too complicated due to free surfaces and not safeguarded by design or simple application, requirements for computer programs dedicated to the assessment of stability, freeboard, and strength have been introduced on a larger scale. The United Nations Economic Commission for Europe (UNECE) Resolution 61 is a set of recommendations, not mandatory regulations. However, the value of the document is in fact

147 that UNECE gathers all European countries (unlike the EU) and proposes some interesting blends of different rules. Rules of the Russian River Register (RRR) are applicable in the Russian Federation, which has a very large fleet. They have a different take on ship stability, taking into account some level of ship dynamics, etc. RRR defines O, R, and L navigation areas corresponding to Zones 1, 2, and 3, respectively. The most distinctive feature of the rules of RRR and the Yugoslav Register of Shipping is an effort to take into account the dynamic effects, both by dynamic stability calculations and by introducing safety margins in static stability analysis. Stability of a ship is generally considered to be sufficient when it withstands dynamically applied wind pressure on still water or in waves (depending on the ship’s class) and the resulting heel angle is less than the permissible value. For passenger ships a more dynamic criterion is applied, including gusting and roll angles, similar to the IMO weather criterion. In addition, different ship types have additional stability criteria. Several other national requirements were reviewed, but the requirements often reflected how the nature of the stability could be suitable to the range of service. USCG Stability Regulations in Comparison with ES-TRIN Regulations It is of interest to compare USCG stability requirements with those of the ES-TRIN. Intact Stability USCG 170.170 and 170.173 requirements are basically comparable to the ES-TRIN stability requirements. The primary difference is that the ES-TRIN requirements also include a heeling moment due to centrifugal force caused by the turning of the vessel. Subdivision and Damage Stability

148 USCG 171.070–171.073 require one compartment subdivision for vessels > 100 gross registered tons (GRT) or length (L) > 19.8 m (65 ft) or number of passengers > 150. The ES-TRIN requires passenger vessels to comply with the one compartment or two compartment standard of flooding, depending on the size of the vessel. In general, USCG damage stability calculation requirements (171.080) and ES-TRIN requirements are comparable. Class Standards Classification societies are independent and are generally organized as nonprofit self-regulating organizations that establish and apply technical standards or class rules in relation to the design, construction, and survey of marine-related facilities, including ships and offshore structures. These rules are issued and published by the classification society. Flag administrations can delegate the inspection and survey of ships to class societies to provide statutory certification on their behalf. Class rules are published for a type of vessel or offshore unit (e.g., tanker, bulk carrier, container ship, passenger ship, mobile offshore drilling unit, barge, etc.) or specific service or geographic service areas (e.g., rivers, oceans, etc.) and include intact and damage stability classification requirements. For vessels in ocean service, the class stability requirements follow the International Maritime Organization regulations (International Convention for the Safety of Life at Sea [SOLAS], International Convention for the Prevention of Pollution from Ships, Intact Stability [IS] Code, etc.). These regulations also incorporate Subchapter S by reference for U.S. Flag SOLAS-certified vessels in ocean service. The American Bureau of Shipping Rules for Rivers and Intercoastal Waterways contain stability requirements for passenger vessels and crane barges. For passenger vessels over 100 gross tons, greater than 20 m (65 ft) in length, or carrying 50 or more passengers, the metacentric

149 height is to be sufficient to withstand wind pressure and passenger heeling moments according to the given formulas. Smaller vessels with a lower number of passengers do not need to apply the wind heel requirement. All vessels over 100 gross tons, greater than 20 m (65 ft) in length, or carrying more than 150 passengers are to comply with a one-compartment standard of flooding (no damage to any main transverse watertight bulkhead), irrespective of the maximum number of passengers carried. Each barge that is equipped to lift is to comply with a requirement that the area under the righting arm curve must be at least 0.053 m-rad (10 ft-degrees) from the equilibrium heel angle (based on the wind heeling moment) up to the smallest of the second intercept, the downflooding angle or 40 degrees. European classification societies primarily apply the comprehensive European stability rules, but some have extra criteria for specialized craft or service. Observations from Comparison of CFR, ES-TRIN, and Class Rules  A stability booklet is mandatory and when a computer for stability calculation is on board a vessel, it is considered a supplement to the stability booklet in all of the stability requirements reviewed. (Class also approves the computer software.)  USCG Subchapters T and K for small passenger vessel maximum size limits based on gross registered tons (GRT) are inconsistent with class rules and national regulations reviewed (including 2008 IS Code), which base vessel size limits on vessel length.  For passenger vessels, USCG intact stability righting arm curve criteria consider only heeling moments due to wind pressure and passengers on one side of the vessel. Class rules and ES-TRIN also include a turning circle moment.

150  It is noted that in all of the reviewed ES-TRIN and class stability requirements for inland waterway vessels, the intact stability standards do not consider severe wind and wave criteria in the 2008 IS Code, which is applicable to vessels in ocean service.  All damage stability standards for inland vessels are deterministic and not probabilistic.  A review of the intact and damage stability calculation requirements for USCG, class, and ES-TRIN show considerable consistency. The differences are primarily in the specification of vessel maximum size limits (GRT, vessel length) for which the requirements apply. Alternatives to the required intact stability, subdivision, and damage stability calculations are also allowed for small passenger vessels that do not exceed specified maximum vessel size limits. Some of the class stability requirements for inland waterways passenger vessels of four class societies—ABS, Bureau Veritas (BV), Det Norske Veritas–Germanischer Lloyd (DNV-GL), Class NK (NK), and ES-TRIN were compared to those of the Code of Federal Regulations (CFR) Subchapters T and K in Table I-1.

151 Table I-1 Comparison of 46 CFR to Other Stability Standards Topic USCG 46 CFR Chapter I ABS Bureau Veritas DNV-GL Class NK ES-TRIN Size Limits T Boat: <100 GRT; no. of pass >6 and <150 Vessel <100 GRT; <20 m (65 ft), or no. of pass >49 and <150 Vessel Length <135 m Passenger vessel carries >12 passengers Vessel Length <135 m Passenger vessel carries >12 passengers Vessel Length >24 m; Vessel >24 GRT Passenger vessel carries >12 passengers Vessel Length > 20 m; LxBxT >100 m3 where T = draft Passenger vessel carries > 12 passengers K Boat: <100 GRT; no. of pass >150, or with overnight accommodation for >49 passengers Vessel >100 GRT; >20 m (65 ft), or no. of pass >150 Intact Stability (Passenger Vessel) T Boat: 170.170 and 170.173: Righting arm curve criteria due to steady wind pressure are to be complied with. Passenger heel moment also included. 178.310(c): For nonsailing vessel L <19.8 m (65 ft) and number of passengers <12 on international voyage, can skip Type II subdivision (171.070– 171.073) and damage stability requirements (171.080) and instead undergo simplified stability proof test. Chap 3, Sec. 1, Sec 5, Para. 3: Righting arm curve criteria due to steady wind pressure are to be complied with. Passenger heel moment also included. Part D, Sec. 6, Para. 9.2: Righting arm curve criteria due to steady wind pressure are to be complied with. Passenger heel moment and turning circle moment also included. Part 5, Chap. 5, Para. 6.2: Righting arm curve criteria due to steady wind pressure are to be complied with. Passenger heel moment and turning circle moment also included. Inland Waterway 2.1.7 Passenger ships defined in 2.1.39 (12 or more passengers) are to comply with the Rules of Survey and Construction of Passenger Ships (IMO/SOLAS). For ships registered for restricted service, the requirements for subdivision and stability may be modified appropriately. Chap. 19, Art. 19.03, Para. 1-6: Righting arm curve criteria due to steady wind pressure are to be complied with. Passenger heel moment and turning circle moment also included.

152 Table I-1 Comparison of 46 CFR to Other Stability Standards (continued) Topic USCG 46 CFR Chapter I ABS Bureau Veritas DNV-GL Class NK ES-TRIN Subdivision (Passenger Vessel) 171.070–171.073 Type II subdivision: For passenger vessel >100 GRT or L >19.8m (65 ft) or no. of pass >150 One compartment standard of flooding Chap. 3, Sec. 1, Sec. 5, Para. 5: For passenger vessel >100 GRT or Length >19.8 m (65 ft) or number of passengers >150: One compartment standard of flooding Part D, Sec. 6, Para. 9.3: L< 135 m, number of passengers >12: One compartment standard of flooding Part 5, Chap. 5, Para. 6.4.2: For Length <45 m and number of passengers <250: One compartment standard of flooding For ships registered for restricted service, the requirements for subdivision and stability may be modified appropriately. Chap 19, Art. 19.15, Para. 1: For L <25 m and number of passengers <250: One compartment standard of flooding Damage Stability (Passenger Vessel) 179.212: For monohull vessel L >19.8 m (65 ft) or number of passengers >49, can skip Type II subdivision (171.070– 171.073) and damage stability requirements (171.080) and instead undergo simplified stability proof test. 171.080 (Damage Stability): For specified conditions of loading, assumed extents of damage and permeabilities, intermediate and final equilibrium positions of flooding are calculated. Specified minimum damage stability criteria (angles of heel, range of stability, max righting arms and righting arm curve areas) are to be complied with. Chap. 3, Sec. 1, Sec. 5. Para. 5: For vessel >100 GRT or Length >19.8 m (65 ft) or number of passengers >150, Damage stability requirements same as USCG 171.080. Part D, Sec. 6, Para. 9.3.8: For Length <25m and number of passengers <50, symmetrical flooding not to exceed margin line and GM0 >0.10 m. Part D, Sec. 6, Para. 9.3: For Length >25m and number of passengers >50, Damage stability requirements similar to USCG 171.080. Part 5, Chap. 5, Para. 6.4: For Length < 25m and number of passengers < 50, symmetrical flooding not to exceed margin line and GM0 > 0.10 m. Part 5, Chap. 5, Para. 6.3: For Length >25m and number of passengers >50, Damage stability requirements similar to USCG 171.080. For ships registered for restricted service, the requirements for subdivision and stability may be modified appropriately. Chap. 19, Art. 19.15, Para. 1: For Length <25m and number of passengers <50, symmetrical flooding not to exceed margin line and GM0 >0.10 m. Chap. 19, Article 19.03, Para. 7-13: For Length >25 m and number of passengers > 50, Damage stability requirements similar to USCG 171.080.

153 Industry Standards  ISO 12217-1:2015–Small craft—Stability and buoyancy assessment and categorization, Part 1: Nonsailing boats of hull length greater than or equal to 6 m.  ISO 12217-2:2015—small sailing vessels.  Transport Canada refers to these ISO regulations for small vessels.  The European Community (CE) Seaworthiness Rating or Sport Boats Directive (official name is Directive 2013/53/EU of the European Parliament and of the Council) is an EU standard that guarantees uniform standards for the safety of vessels. With the introduction of the CE marking, vessels that are used in sport and leisure shipping within the European Economic Area have also been subject to so- called “harmonized” rules. There are four categories of seaworthiness, A to D. Category A contains the highest standards and must be met by boats that may be in heavy weather; Categories C and D are mainly intended for offshore or inland waterways. The categories are defined by limit values for wind force and wave height.  UK MCA MGN 280 (M)–Small Vessels in Commercial Use for Sport or Pleasure, Workboats and Pilot Boats–Alternative Construction Standards. There are several other standards.  UK MCA MSN 1823 (M) Safety code for passenger ships—Safety code for passenger ships operating solely within UK categorized waters. Other examples of an industry standard are the American Petroleum Institute (API) recommended practice documents. These guides are typically prepared by industry expert panels and one of particular interest is RP-2T, the Recommended Practice for Planning, Designing, and

154 Constructing Tension Leg Platforms (API, 2010). In the wake of the total loss of the tension leg platform (TLP) Typhoon during Hurricane Rita in 2005, the newest version of this guide reflects the unique mechanics of the TLP, which relies on the tendon tension to provide stability. If one or more of these tendons ceases to provide tension, a catastrophic failure may occur.