Comments received for TSAC Preliminary NOSAC Towing SC … · 2017. 10. 11. · • IMO MSC Circ. 884 "Guidelines for Safe Ocean Towing" December 1998 -Section 9. • MatthewsDaniel

Exhibit A Final NOSAC Subcommittee Report re Towage of MODUs, MOUs & FOIs on the U.S. OCS

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NVIC 11-91 Encl (1) Section

Comments received for NVIC updating

TSAC Preliminary NOSAC Towing SC Recommendations / Reference Document

Ocean Tow of Jackup Drilling Units

NVIC should address all MODU, MOU, and FOIs, not just Jackup MODUS.

NVIC overall areas for improvement due to lack of existing guidance are tow planning, tow gear arrangements, and emergency towing arrangements.

TSAC was tasked with providing Review of and recommendations based on the Report of Investigation Into the Grounding of the Mobile Offshore Drilling Unit (MODU) KULLUK. TSAC was guided by relevant CFR and broke down the report as follows:

a. Tow Plans, Voyage Plans, Towing Configurations

b. Tow Gear – Identification, selection, testing, utilization, monitoring and logging

c. Towing Master and Tow Master competencies and responsibilities

d. Competencies and conduct of Marine Warranty Surveyor Work

• IMO MSC Circ. 884 "Guidelines for Safe Ocean Towing" December 1998 is a good general guidance along with several Marine Warranty Survey firms such as Matthews Daniel (BV group) and DNV GL (ex Noble Denton)

• MatthewDaniel 9105 "Guidelines for MODU Field Moves & Ocean Towage" October 2015

• Noble Denton 0030/ND Rev 4. Technical Policy Board "Guidelines for Marine Transportation" March 2010

• Noble Denton 0021/ND Rev 10. Technical Standards Committee "Guidelines for the approval of Towing Vessels" December 2015

• IMO MSC.1 - MSC.1/Circ.1255 "Guidelines for Owners/Operators on preparing emergency towing procedures" May 2008


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Manning

1. Manning should comply with U.S. Coast Guard regulations or other national regulatory rules. The number of crew will be dependent on the length of the voyage and be limited to essential personnel only and should not exceed 50% of lifeboat capacity.

TSAC does not specifically address this point. They did "Examine and make recommendations regarding the competencies and conduct of the towing vessel master, and the tow master (if separate) for ocean towing of MODU’s or other vessels of a similar nature.” The Code of Federal Regulations specifically name the Master of the Towing Vessel as the individual responsible for planning for hazards prior to sailing. “The master must check the planned route for proximity to hazards before the voyage begins.” The document “IMO Guidelines for Safe Ocean Towing” reference two Masters; “Tug Master – The Master of the Towing Vessel and Towing Master The manager responsible for the towage. A Tug master may be designated as Towing Master.”

Also, under Towing Vessel Review by MWS, this involves three separate and distinct areas of review. The first is the condition and capability of the hull for the voyage. The second is the skill level of the crew for such a move. The third is the capability of the vessel with the towed vessel to make the voyage given the seas state and weather condition.

• IMO MSC Circ. 884 "Guidelines for Safe Ocean Towing" December 1998 -Section 5;

• A towing master should be clearly designated and identified prior to any towing operation taking place and that the towing master be experienced and competent in respect of towing the type vessel to be towed.

• That the master(s) and crew(s) of the towing vessel have experience and competency in towing operations of the vessel to be towed and in the weather/ sea conditions that could be encountered during the towing operation.

• That the riding crew of the towed vessel have experience and competency in towing operations for the vessel that is begin towed and in weather/ sea conditions that could be encountered during the towing operation.

NOTE: Supporting documents here should be used cautiously as there is


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difference in nomenclature that can be confusing.

• Noble Denton 0030/ND Rev 4. Technical Policy Board "Guidelines for Marine Transportation" March 2010 Section 17 [updated document from DNV-GL as owner of Noble Denton) may now be available.

• Noble Denton 0021/ND Rev 10. Technical Standards Committee "Guidelines for the approval of Towing Vessels" December 2015 Section 10.

• MatthewsDaniel "Guidelines for MODU Field Moves & Ocean Towages" October 2015, Section 14.1 [requirement for warranty surveyor attendance is underwriter dependent for their commercial protection, not needed for operational safety and execution of the towage].

• Per MODU Code 79, lifeboat capacity is 100% allowable POB. A POB maximum of 50% Lifeboat capacity for MODU Code 79 vessels may have considerable commercial impacts and not increase overall safety due to duration, location, and expected environment during the tow.


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Ocean Tow Loading Plan

2. A Loading Plan should be formulated and, if required, submitted to the Underwriter’s Marine Survey company utilized by the Contractor for the tow in time for proper review (See Addendum A enclosed for a sample loading plan )

Delete reference to Addendum A

• IMO MSC Circ. 884 "Guidelines for Safe Ocean Towing" December 1998 - Section 9.

• MatthewsDaniel "Guidelines for MODU Field Moves & Ocean Towages" October 2015 - Sections 6 & 9.

• Noble Denton 0030/ND Rev 4. Technical Policy Board "Guidelines for Marine Transportation" March 2010 - Sections 8, 9 & 10. 3. Cargo is defined as

any material, temporary structure, shipping container, consumable item, machinery, tubular, equipment and items not included in the drill barge lightship weight.

[1] 33 CFR Subchapter P Part 164 Section 80 (c) 3

4. Stowage of on the main weather deck of a Jackup drilling unit while on an ocean tow is not desirable and should be avoided with the exception noted below.

Grammatical edits & removed reference to Jackup rig. "Stowage on the main weather deck of a drilling unit while on an ocean tow is not desirable and should be avoided with the exception noted below."

[2] IMO Guidelines for Safe Ocean Towing, Rev 7, Pg. 2

5. Exceptions to this policy may be permitted if:


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5.a. A permanent structure has been erected for the stowing and securing of an item such as a pipe rack for drill pipe and drill collars, or a mandrel and locking beams for a BOP. The permanent structures should be adequate for their intended purpose, reviewed, and approved by a classification society in accordance with the appropriate rules.

Grammatical edit: "...the main deck by means of a suitable support structure."

5.b. Cargo is elevated or located above the main deck by mans of a suitable support structure.

5.c. Temporary structures are permitted when designed by a registered professional engineer and approved by the underwriter’s marine surveyor.

Add section titled "Preparation of Transit Plan" to supplement or

Voyage planning and executing tows are required by regulation in the Code of Regulations for all towing vessels


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replace some of the legacy verbiage in 11-91:

A tow plan will be developed for every transit.

a. Vessel operations will be conducted in accordance with the vessel specific, class approved, marine operations manual.

b. The following will be identified and addressed for the towage:

(i) Weather conditions and current regimes likely to be encountered during the tow.

(ii) Detailed review of the emergency response services and capabilities available en route and on location.

c. Transit times between technically feasible locations for shelter.

d. Permits or authorizations needed to use the selected shelter locations.

e. Timeline required to achieve a position of safety at the sheltered location.

f. A risk assessment will be performed for removal of

navigating in the navigable waters of United States of America regardless of area of operation with limited exceptions as follows:

Voyage plans are required by 33 CFR Part 164.80 for all Towing vessels except as follows:

a. Used solely for any of the following services or any combination of these services—

(i) Within a limited geographic area, such as a fleeting-area for barges or a commercial facility, and used for restricted service, such as making up or breaking up larger tows;

(ii) For harbor-assist;

(iii) For assistance towing as defined by 46 CFR 10.103;

(iv) For response to emergency or pollution;

b. A public vessel that is both owned, or demise chartered, and operated by the United States Government or by a government of a foreign country; and that is not engaged in commercial service;

c. A foreign vessel engaged in innocent passage; or


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nonessential personnel where the tow can extend beyond a 72 hour duration.

g. Any set-back carried in the derrick will be in conformance with the vessel operations manual and the worst weather forecast conditions for the transit.

h. Decks which can be affected by green water during heavy weather events will either:

(i) Be left clear of cargo, if practicable.

(ii) Have cargo fastened to prevent movement due to inertia forces, green water impact, or floatation, and verified by the Master or OIM and attending MWS, if present.

i. Towing vessel selection and arrangements will be aligned with 0030/ND, section 12, or equivalent industry standard.

d. Exempted by the Captain of the Port (COTP).

The voyage plan must follow company policy and consider the following (related requirements noted in parentheses):

a. Applicable information from nautical charts and publications (also see paragraph (b) of section 164.72), including Coast Pilot, Coast Guard Light List, and Coast Guard Local Notice to Mariners for the port of departure, all ports of call, and the destination;

b. Current and forecast weather, including visibility, wind, and sea state for the port of departure, all ports of call, and the destination (also see paragraphs (a)(7) of section 164.78 and (b) of section 164.82);

c. Data on tides and currents for the port of departure, all ports of call, and the destination, and the river stages and forecast, if appropriate;

d. Forward and after drafts of the barge or barges and under-keel and vertical clearances (air-gaps) for all bridges, ports, and berthing areas;


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e. Pre-departure checklists;

f. Calculated speed and estimated time of arrival at proposed waypoints;

g. Communication contacts at any Vessel Traffic Services, bridges, and facilities, and any port-specific requirements for VHF radio;

h. Any master's or operator's standing orders detailing closest points of approach, special conditions, and critical maneuvers; and

i. Whether the towing vessel has sufficient power to control the tow under all foreseeable circumstances.

CFR Voyage plan considerations include but not limited as follows:33 CFR Navigation and Navigable Waters, Chapter I, Subchapter P (Ports and Waterway Safety) Subchapter I (Anchorages), Subchapter J (Bridges)

In the IMO Guidelines for Safe Ocean Towing it states that all aspects of towage should be planned in advance including as follows:

1. Maximum anticipated environmental conditions

2. Tides/Currents

3. Water Depths


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4. Tow (size, windage, displacement, cargo storage, and draft)

5. Weather routing advice with careful consideration bollard pull of the towing vessel

6. Towing arrangements and procedures

7. Contingency Plan for Points of refuge (a copy should also be carried aboard the barge if manned)

8. Manuals for routine towing operations

9. Manuals for special towage requirements

The IMO Guidelines for Safe Ocean Towing is largely consistent with already existing United States Voyage Planning requirements.

Tow procedures may include (or reference), but not be limited to, the following subjects:

1. General

a. Go –No Go departure criteria and associated decision-making process.

b. Contact details and responsibilities.

c. Reporting requirements: who to, how often and content.

d. Arrival details, contacts, field plan (scaled chart of the oil field clearly


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displaying the location of all surface and subsea assets), etc.

e. Contingency planning

2. Description of the towed asset.

a. Any limiting criteria and motions (roll, pitch and period, etc.) for the transport or tow, weather forecasting arrangements (2 independent sources).

b. Motions and strength - detailed supporting calculations for the motions and accelerations, longitudinal strength and strength of the seafastening and cribbing/grillage.

c. Drawings to include, where applicable, cargo, GA and other key drawings of vessel and cargo, stowage plan, towing arrangement, cribbing /grillage arrangement, load-out /discharge plan, seafastening arrangement, guidepost details etc.

3. Description of the towing vessel(s)

a. Reference documents, including applicable standard operating procedures of each operator.

b. Towing vessel bollard pull calculation (if applicable).

c. Towing vessel specification.

d. Tow configurations and drawings.


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Towage

Believe an area for improvement to this NVIC surrounds developing a prudent tow plan. When you review the Kulluk Investigation report one of the key (and recurring) findings from both the USCG and NTSB was the planning for the tow could have been better. This section should be an area of focus to improve guidance to industry.Possibly create new subsection titled “Tow Plan?”

Operators should pay particular attention to selection of ports of refuge to ensure the tug and tow can safely make entry, have necessary charts and publications of the areas, and any other applicable local data required.

One concept not addressed in the past was put forth as follows: Critical Tows - Critical tows are those tows having a Risk Factor >15, according to the following:

a. Risk is defined as the product of the probability of occurrence and potential severity of consequences, each on a respectively scale of 1 to 5, 5 being highest probability and highest severity.

b. Risk is the combination of the probability of some event occurring during a time period of interest and the consequences, (generally negative) associated with the event. In mathematical terms, Risk can be calculated by the equation: Risk = Consequence x Probability

c. There are components, equipment, and machinery aboard a towing vessel whose failure could lead to catastrophic consequences.

Highest Risk

In terms of Consequence severity, those failures that can result in allisions, collisions, or loss of tug and/or tow have the highest ranking, where those failures (non-critical systems, for

• IMO MSC Circ. 884 "Guidelines for Safe Ocean Towing" December 1998 - Sections 6, 7, 8, 9 & 10.

• Noble Denton 0030/ND Rev 4. Technical Policy Board "Guidelines for Marine Transportation" March 2010 - Section 14.


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example) that are not likely to result in injury or catastrophic loss, carry the lowest ranking. The highest consequences are sub-graded such that failures that could endanger other vessels, or people and property ashore, are considered the most severe. Generally, these are failures that result in loss of control, loss of tug and/or and loss of tow.

Critical tows, would, by definition, carry a “4” or “5” Consequence Rating.

Determining Consequence of Failure (COF)

In order to determine Risk, it is necessary to determine a Consequence of Failure (COF). Traditionally, this is a 5-point numerical scale where 1 represents negligible consequence and 5 represents a potentially catastrophic impact.

Consequence Rating Used to Calculate Risk.

5 Collision/Allision/Loss of Tug/Loss of Tow resulting in fire or explosion, and/or toxic chemical release, and/or damage to critical infrastructure.


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4 Fire, explosion, sinking affecting the vessel itself and pollution limited to that caused by the vessel itself.

3 Collision/Allision/Loss of Tug/Loss of Tow resulting in fire and/or environmental release not immediately harmful to people and/or damage to non-critical infrastructure.

2 Mechanical, thermal or chemical energy release affecting one or more of the vessel’s crew and without harm to the environment.

1 Failure of non-critical system affecting part of the vessel itself without harm to the crew or the environment.Table 1

Determining Probability of Failure (POF)

In order to determine Risk, it is necessary to determine Probability of Failure (POF). Traditionally this is a 5-point numerical scale where 1 represents a remote possibility and 5 represents a frequent possibility.

A critical point is that single point failures are more likely to yield a high consequence failure than an equivalent failure in a redundant system.

The probability of any failure is greatly reduced when the system being


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evaluated for failure is 100 percent redundant.

Probability of Failure Rating Used to Calculate Risk

5 Single point Failure in Extreme Weather

4 Redundant Failure in Extreme Weather

3 Single Point Failure in Moderate Weather

2 Redundant Failure in Moderate Weather

1 Benign Weather

Critical tows would, by definition, carry a “4” or “5” Probability of Failure Rating.

6. One set of up-to-date navigation charts and pilot books for the tow course and alternate courses should be available for the voyage aboard the rig including detailed charts of ports of refuge.

What constitutes a safe haven – and what you need to do - i.e. carry charts, determine bottom, think about if there is surf and how it affects your rig.

7. Tow routing should be determined in advance including ports of refuge and the required entry data.

What constitutes a safe haven – and what you need to do - i.e. carry charts, determine bottom, think about if there is surf and how it affects your rig.


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8. A weather service should be selected with a back ground in ocean tow forecasting. Weather updates should be sent every 12 hours with at least 72 hour advance forecasts. Direct communication with a marine weather forecaster is recommended.

Replace with the following:

Weather and environmental criteria

a. The maximum operational MetOcean parameters for under tow conditions will be identified in the approved marine operations manual for the MODU.

b. Wind, seas, and current forces and directions affecting the tow will be identified by the person in charge of the rig move in consultation with the Master of the towing vessel.

c. A weather service should be selected with a background in ocean tow forecasting. Weather updates should be sent every 12 hours with at least 72 hour advance forecasts.

Direct communication with a marine weather forecaster is recommended.

Grammatical edit: "...with a background in ocean tow…"

9. The Towing vessel(s), and towing gear, should

Suitable shape of Boats for Ocean Towing in very rough


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be designed and equipped for towing in ocean service with full crew aboard. Towing gear should be inspected and approved by the attending marine and the O.I.M. prior to departure.

weather, i.e. motion of back end and its impact on the stern roller– Jones act issues, Spare Towline able to be reeved onto the winch at sea.Competence (or perhaps Experience) of towing crew - as a minimum for major ocean tows in potentially bad weather - not the same as towing shorter distances.

How might you write down a minimum requirement for crew?

How many vessels do you need to tow?

Checking Certification of all towing equipment – how why and what is acceptable and what is not.

Marine warranty surveyor (MWS) approvals:The MODU operator will obtained towage approval from a MWS approved by the vessels hull and machinery underwriters.

Grammatical edit "The towing vessel(s), and…"clarifying edit "...attending marine

Existing regulation clearly identifies monitoring and logging of towlines and terminal gear as follows:

The condition of each towline must be monitored through the—( This Tow Gear Log should cover all towing gear, visual inspections during and post tows, NDT inspections periodically, and SWL proof tests periodically which would be in lieu of renewing any towing gear for each critical tow.)

(i) Keeping on board the towing vessel or in company files of a record of the towline's initial minimum breaking strength as determined by the manufacturer, by a classification (“class”) society authorized in §157.04 of this chapter, or by a tensile test that meets API Specification 9A, Specification for Wire Rope, Section 3; ASTM D 4268 (incorporated by reference, see §164.03), Standard Test Method for Testing Fiber Ropes; or Cordage Institute CIA 3, Standard Test Methods for Fiber Rope Including Standard Terminations;

(ii) If the towline is purchased from another owner, master, or operator of a vessel with the intent to use it as a towline or if it is retested for any reason, keeping on board the towing vessel or in company files of a record of each retest

• IMO MSC Circ. 884 "Guidelines for Safe Ocean Towing" December 1998 - Sections 11 & 12.

• Noble Denton 0030/ND Rev 4. Technical Policy Board "Guidelines for Marine Transportation" March 2010 - Sections 12 & 13.

• Noble Denton 0021/ND Rev 10. Technical Standards Committee "Guidelines for the approval of Towing Vessels" December 2015 - Sections 6, 7, 8, & Appendix A tug requirements & B for Bollard Pull Test method.


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warranty surveyor and the O.I.M. prior…"

of the towline's minimum breaking strength as determined by a class society authorized in §157.04 of this chapter or by a tensile test that meets API Specification 9A, Section 3; ASTM D 4268 (incorporated by reference, see §164.03) or Cordage Institute CIA 3, Standard Test Methods;

(iii) Conducting visual inspections of the towline in accordance with the manufacturer's recommendations, or at least monthly, and whenever the serviceability of the towline is in doubt (the inspections being conducted by the owner, master, or operator, or by a person on whom the owner, master, or operator confers the responsibility to take corrective measures appropriate for the use of the towline);


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(iv) Evaluating the serviceability of the whole towline or any part of the towline, and removing the whole or part from service either as recommended by the manufacturer or a class society authorized in §157.04 of this chapter or in accordance with a replacement schedule developed by the owner, master, or operator that accounts for at least the—

(A) Nautical miles on, or time in service of, the towline;

(B) Operating conditions experienced by the towline;

(C) History of loading of the towline;

(D) Surface condition, including corrosion and discoloration, of the towline;

(E) Amount of visible damage to the towline;

(F) Amount of material deterioration indicated by measurements of diameter and, if applicable, measurements of lay extension of the towline; and

(G) Point at which a tensile test proves the minimum breaking strength of the towline inadequate by the standards of


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paragraph (a)(1) of this section, if necessary; and(v) Keeping on board the towing vessel or in company files of a record of the material condition of the towline when inspected under paragraphs (a)(3)(iii) and (iv) of this section. Once this record lapses for three months or more, except when a vessel is laid up or out of service or has not deployed its towline, the owner, master, or operator shall retest the towline or remove it from service.

Terminal gear. The owner, master, or operator of each vessel towing astern shall ensure that the gear used to control, protect, and connect each towline meets the following criteria:

(1) The material and size of the terminal gear are appropriate for the strength and anticipated loading of the towline and for the environment;

(2) Each connection is secured by at least one nut with at least one cotter pin or other means of preventing its failure;

(3) The lead of the towline is appropriate to prevent sharp bends in the towline from fairlead blocks, chocks, or tackle;

(4) There is provided a method, whether mechanical or non-mechanical, that


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does not endanger operating personnel but that easily releases the towline;

(5) The towline is protected from abrasion or chafing by chafing gear, lagging, or other means;

(6) Except on board a vessel towing in ice on Western Rivers or one using a towline of synthetic or natural fiber, there is fitted a winch that evenly spools and tightly winds the towline; and

(7) If a winch is fitted, there is attached to the main drum a brake that has holding power appropriate for the horsepower or bollard pull of the vessel and can be operated without power to the winch.

10. The bollard pull of the towing vessel(s) should be of sufficient size for the intended tow.

Factor of safety for towline strength related to bollard pull. As the size of the vessels continues to grow, and the use of multi-purpose vessels [which generally have a higher weight to horsepower ratio] becomes more common, towline strength to bollard pull needs to be calculated prior to each towage of a MODU, MOU and FOI.Requirement for catenary/scope of wire.


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The maintenance of a catenary for tows is essential. There are some rough rules, such a 8:1 ratio (length to depth) that should be mentioned in tow plans to not “tight lining” the tow.

Most [experienced] tow captains will maintain the proper scope/catenary naturally, although usually empirically.

The use of regulated winches and tension meters on the vessel helps manage this issue, but understanding how to best use this equipment is a competency issue. Towmasters.

How best to employ the use of a towmaster needs clarification.

11. Communication means between the rig and towing vessel(s) is of utmost importance. Backup communications should be provided. The vessel should provide a qualified riding crew member to assist the rig crew during tow.

Who is in charge?' Capt, Towmaster or Marine advisor ashore. Used not to be a problem before communications improved.

Ultimate work authority?

The Towmaster is an advisor to the OIM. The Code of Federal Regulations specifically name the Master of the Towing Vessel as the individual responsible for planning for hazards prior to sailing. “The master must check the planned route for proximity to hazards before the voyage begins.” The document “IMO Guidelines for Safe


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Language should not be a barrier.

Ocean Towing” reference two Masters; “Tug Master – The Master of the Towing Vessel and Towing Master The manager responsible for the towage. A Tug master may be designated as Towing Master.” The International Safety Management Code specifically requires that every Company should develop, implement and maintain a safety management system to include: “defined levels of authority and lines of communication between, and amongst, shore and shipboard personnel” “The Company should establish in the safety management system that the master has the overriding authority and the responsibility to make decisions with respect to safety and pollution prevention and to request the Company’s assistance as may be necessary.” No one can serve two masters. The ISM Code requires that the Company define the level of authority Master however the IMO also recognizes TWO types of Master for Towing Operations. The commercial realities of the ocean towing of MODU’s, SPAR’s, large


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production structures and similar vessels engaged in the exploration and exploitation of oil and gas resources have caused a system of the towing vessel master and the tow master having both separate and concurrent authorities and responsibilities that is unique to rig moves. The large expense, the great potential for exposure to liabilities and the difficulties of distance, geographical location, rig design and the vagaries of wind, wave and weather have caused the insurers of, and the owners and operators of, such vessels to leave little to chance. That being said, the required voyage and tow planning typically delineates the duties of both the towing vessel master and the tow master. An additional consideration is whether the person in charge of the towed rig, the Offshore Installation Manager (“OIM”) is the same individual as the tow master. For pipelay/bury barges or jack-up rigs, for example, the Barge Engineer may be the OIM but if the person overseeing the move has little towing experience a marine advisor may be required. Many semi-submersibles and self-propelled drill ships to be towed may require a

• MatthewsDaniel "Guidelines for MODU Field Moves & Ocean Towages" October 2015 - Section 14.2


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licensed master to be on board the rig. There is little doubt that once the towing vessel has connected its terminal gear and is underway, the master of the towing vessel is legally responsible for the conduct during the move encompasses much more than the transit from one location to another. In fact, where multiple tugs are engaged to tow a rig, one tug is nominated as the lead tug and the rest are subordinate to the lead tug. However, nothing limits the responsibility of the towing vessel master for the safety of their own vessel during such operations. The locomotive power provided for the rig move whether from a single towing vessel or multiple tugs is just one factor of the safe and successful transit whether in field or going a distance. It takes a group of people with specialized skills, knowledge and experience to control any move—the towing vessel master is just one part of the whole. Thus, the persons overseeing the rig move, the Marine Superintendent, the OIM and/or tow master supervising the move and directing the tow operations


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all are in line of the command authority for the move. Breaking down the lines of responsibility for a rig move results in an explanation of the typical division of duties. The OIM who may or may not be the Tow Master for a rig move bears the direct responsibility for the placement, movement on or off location and bears the ultimate responsibility for the rig’s safety, commercially successful positioning and use and production of effort. The OIM is responsible for the rig at all times. Compounding the difficulty of identifying the person in charge is the fact that multiple persons may be charge during different phases as when a jack-up rig is underway versus raising/lowering its legs. The OIM is usually the ultimate authority for the towed rig while on board and responsible for the riding crew and overall operations, including marine operations. The Tow Master, however, directs the towing vessels operations especially for moves that have a spread of multiple towing vessels pulling in several directions. The Tow Master may be, and should be, an experienced vessel master with towing knowledge gained by commanding tugs engaged in rig tows.


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They must be also knowledgeable of the marine operational procedures of the rig to be moved whether it is a semi-submersible, MODU, jack-up rig or another type of oilfield vessel or structure. Water tight integrity, ballasting and de-ballasting procedures are crucial points of knowledge for the Tow Master. Finally, the towing vessel master at various points of the voyage may be considered subordinate to the OIM/Tow Master and the reverse may also be true depending upon the specific situation. While the towing vessel master cannot be relieved of the solemn authority for their vessel and the tow while underway that is vested in them by virtue of long custom, maritime law and common sense, the successful rig move is not overall controlled by the towing vessel master. The comprehensive sight picture is typically retained by the Tow Master and/or OIM. Of course, it would be foolish for the Tow Master to ignore the advice and observations of the involved towing vessel master(s) during a rig move if it bears upon safe operations, forecast and un-forecast weather that could cause delays or other known or unknown difficulties while en route.


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Consideration should be given to local knowledge, preferable routing and other strategic and tactical information to safely and efficiently prosecute the voyage. Moreover, communication and pre-planning are key. The Tow Master and the Towing Vessel Master(s) should understand their respective roles, agree upon clear lines of authority at any given phase of the intended move and satisfy each other that they together have the requisite knowledge and experience to carry out the mission safely. In summary, the division of authority and concurrent responsibilities for a successful rig move may be appear convoluted to an outsider but this system distilled from thousands of rig moves appears to be the practical and sensible approach.

12. Critical motion curves should be provided to the rig crew and the towing vessel(s) prior to departure. (see addendum B) Manufacture recommendations for proper leg length and shimming should be adhered to for the tow.


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13. An emergency towing line should be strapped along the side of the hull just below top deck level in a manner permitting quick release. me tow line should be of a size suitable for the tow intended accounting for the bollard pull of the tow vessel(s), including shock loads.

What spares do I need on board e.g. filters, shackles, spare tow line.


• MatthewsDaniel "Guidelines for MODU Field Moves & Ocean Towages" October 2015 - Sections 2.3.2, 9, 18, & 20.3.

14. A polypropylene shock line, the size and length suitable for the bollard pull of the tow vessel(s) being used, should be attached to the emergency tow line with suitable connectors.

Shock Lines. NVIC No. 11-91 mentions, "A polypropylene shock line, the size and length suitable for the bollard pull of the tow vessel(s) being used, should be attached to the emergency tow line with suitable connectors." Polypropylene does not stretch over 25% before parting and thus makes it a less than ideal shock absorber. Polyamides (Nylon) or Polyesters (Dacron) are acceptable materials to be used as shock lines. Some towing companies are getting away from Synthetics for a 'Stretcher' and are going to

• IMO MSC Circ. 884 "Guidelines for Safe Ocean Towing" December 1998 - Sections 12.12, 13.13, & 14.

• Noble Denton 0030/ND Rev 4. Technical Policy Board "Guidelines for Marine Transportation" March 2010 - Section 13.11.


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Chain as a 'Surge Chain' to increase the catenary.

15. A main tow line bridle recovery line(s) should be fitted and run from the and of the bridle or tow plate to a winch on the barge to allow retrieval in the event the main tow wire(s) part.

Area highlighted in red is not clear…

A chain section can also be utilized to minimize shock loads.

• IMO MSC Circ. 884 "Guidelines for Safe Ocean Towing" December 1998 - Section 12.15.


Stability

16. Stability calculations addressing the tow conditions should be performed to insure positive stability in compliance with the rig operating manual. These calculations should be submitted to and approved by the underwriter’s Marine Survey company being utilized in time for proper review. (see Addendum A)

• The MODU/MOU/FOI will be operated in conformance with the vessel specific, class approved, operating manual (including trim and stability booklet).

• Intact and damaged stability criteria will conform to IMO codes.

• The variable deck load of the MODU/MOU/FOI will be monitored in accordance with the vessel specific, class approved, and operating manual.

• IMO MSC Circ. 884 "Guidelines for Safe Ocean Towing" December 1998 - Sections 13.12.

• MatthewDaniel 9105 "Guidelines for MODU Field Moves & Ocean Towage" October 2015- Section 12.1.

• Noble Denton 0030/ND Rev 4. Technical Policy Board "Guidelines for Marine Transportation" March 2010 Section 13.10.


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• Stability calculations will be performed at least daily.

Draft and Trim

17. Within the limits of the loadline certificate, the man draft for the tow should be determined from the stability calculations in item 16 above.

Grammatical edit: "...the mean draft for the tow…"

• IMO MSC Circ. 884 "Guidelines for Safe Ocean Towing" December 1998 - Sections 13.2 - 13.5.

• MatthewDaniel 9105 "Guidelines for MODU Field Moves & Ocean Towage" October 2015 - Section 6.

• Noble Denton 0030/ND Rev 4. Technical Policy Board "Guidelines for Marine Transportation" March 2010 Section 10.

• Noble Denton 0021/ND Rev 10. Technical Standards Committee "Guidelines for the approval of Towing Vessels" December 2015 Section 9.

18. Weight should be distributed to produce a level condition transversely with a slight trim by the stern. Trim is to be obtained by locating material or equipment carried with necessary liquid trimming ballast kept to a minimum.

19. Liquid variable load should be kept to a minimum. Hull tanks that contain liquids should be pressed and maintained full during the voyage.


• MatthewDaniel 9105 "Guidelines for MODU Field Moves & Ocean Towage" October 2015 - Section 6.1.


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20. All tanks, including active mud tanks, not required on the voyage, should be empty at the time of departure.



• Noble Denton 0030/ND Rev 4. Technical Policy Board "Guidelines for Marine Transportation" March 2010 - Section 10.5.13.

Watertight Integrity

Add to replace some of the legacy 11-91 guidance: Will be maintained at all times in conformance with:

a. Class approved vessel operations manual.

b. Class society requirements.

c. IMO MODU regulations.


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21. The operating manual for the rig should clearly show the location of watertight closures and should be complied with during the tow.




22. Deck openings such as sounding tubes should be protected from damage




23. Consideration should be given to the modification all weather deck preload hatch covers, vent fan covers, cargo hatch cover, etc. with clamp bars or welded strapping to prevent opening from sea action.


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24. Rig service take on lines Such as out, barite, fuel, potable water, or drill water located on the outer lull areas should be capped and protected from sea damage by sea action.

Unsure of area highlighted in red…

In today's environment, this would require approval from Owner Eng. Dept., MWS approval and possibly Class approval. Consider removal/modification.

25. All weather/watertight closures, ventilation ducts, etc. with the exception of intakes necessary for the operation of the vessel, should be seed from sea action.

Grammatical edit believed to be: "...should be secured from sea action."

Not specifically identified in any of the references documents other than refer to operations manual.

Pumping Arrangements

• IMO MSC Circ. 884 "Guidelines for Safe Ocean Towing" December 1998 - Sections 13.3.




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26. The vessel’s bilge/ballast service pumps should be tested and determined to be in good working order prior to departure. Pumps are to be maintained in a state of readiness throughout the tow.

• Noble Denton 0030/ND Rev 4. Technical Policy Board "Guidelines for Marine Transportation" March 2010 - Section 15 (Pumping and Sounding).

Compartment Sounding

27. All hull compartments and void spaces should be fitted with sounding tubes. All sounding tubes should be clearly identified and fitted with caps that are capable of being tightly secured.



• Noble Denton 0021/ND Rev 10. Technical Standards Committee "Guidelines for the approval of Towing Vessels" December 2015 - Section 12.2.

28. Soundings should be taken at least every 12 hours of all void and preload tanks. Hull compartments should be inspected or sounded also and the results should be logged for the duration of the

Content edit believed to be: "...should be logged for the duration of the tow."




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29. A diagram of the sounding tube locations should be posted in the machinery deck spaces and in the control room.

For Semisubmersible moves, normal industry practice for soundings is to conduct a manual sounding prior to departing a location. During the transit, monitor remote tank gauges along with all void tank and bilge alarms. After arrival and ballast down to Operations or Survival draft, another set of manual soundings should be taken to confirm no undesired water ingress has occurred.



30. A means of determining the changes in liquid levels in the perimeter hull tanks must be available for use from a protected location.

31. The manufacturer’s data should be furnished to indicate that the derrick can withstand the roll motions anticipated for the tow. This data should be in the rig operating manual.


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32. All Derrick traveling equipment should be seared for the tow.

• MatthewDaniel 9105 "Guidelines for MODU Field Moves & Ocean Towage" October 2015 - Section 9 (Stowage and Seafastening).

33. Bow anchors should be removed from below water racks and strapped to the deck or stored if there is the possibility of becoming entangled in the tow gear.

• MatthewDaniel 9105 "Guidelines for MODU Field Moves & Ocean Towage" October 2015 - Section 20.1 Point 9.


34. Secure or remove anchor buoys from their racks to prevent dislodging by sea action.


Cranes

[1] 33 CFR Subchapter P Part 164 Section 80 (c)

35. Crane should be lowered into steel support structures and secured against vertical or lateral movement.

[2] 33 CFR Chapter I, Subchapter P, Part 164, Section 01


36. Cranes should be secured against revolving per manufactures recommendations.

[3] 33 CFR Chapter I, Subchapter P, Part 164, Section 80 (c) 3


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Navigation Lights, Signals and Safety Equipment

37. Side lights and stern light should be checked to make sure they are in good working order.

• Noble Denton 0030/ND Rev 4. Technical Policy Board "Guidelines for Marine Transportation" March 2010 - Section 13 (Towing & Miscellaneous Equipment on Tow).

38. Life vests, throw over life rings and other means of rescue should be checked and readied for deployment, if need.

• Noble Denton 0030/ND Rev 4. Technical Policy Board "Guidelines for Marine Transportation" March 2010 - Section 14 (Manned Tows and Transportation).

39. Signaling devices should be stored in the control room, inspected and determined that they are within inspection dates for use, if needed.

Potable Water and Fuel Oil

40. Sufficient potable water and fuel for the length of the tow, plus 25% safety factor, should be carried.

41. A potable pump should be available to obtain water from the potable water tanks in

• Noble Denton 0030/ND Rev 4. Technical Policy Board "Guidelines for Marine Transportation" March


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the event of pump failure.

2010 - Section 15 (Pumping and Sounding).

42. Because sediment in the fuel tanks can be stirred up during tow, a centrifuge should be installed prior to departure to remove contaminants from the fuel pumped to the engine day tanks. Extra engine fuel filters should be in supply.

Damage Control

43. The following emergency and/or damage control equipment and material is recommended to carried aboard for the tow, or its equivalent. 400 lbs. cement 400 lbs. sad 20 lbs. concrete mix accelerator 40 ft. of 1” x 12” timber 24 lbs. of oakum or similar caulking compound 24 wooded wedges 2

Noble Denton 0030/ND Rev 4. Technical Policy Board "Guidelines for Marine Transportation" March 2010 - Section 13 (Towing & Miscellaneous Equipment on Tow).


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4 wooden plugs of various sizes Welding and cutting apparatus 50 ft. of 4” x 4” angle iron 100 sq. ft. of ½” steel plate 100 sq. ft. of 1” steel plate 500 ft. 1” polypropylene rope 500 ft. 1” wire rope 20 Ton Portapower hydraulic jack 100 ft. 2” x 4” x 10” timber Two portable diaphragm air pumps 44. Spare shackle, heaving lines, turnbuckles, etc. should be aboard for the tow.

• MatthewDaniel 9105 "Guidelines for MODU Field Moves & Ocean Towage" October 2015 - Section 18 (The Tow).

45. Fog horn, ship whistle or bell, search light, etc. should be in operating condition.


46. Secure all equipment in the accommodations areas for heavy seas.

• Noble Denton 0030/ND Rev 4. Technical Policy Board "Guidelines for Marine Transportation" March 2010 - Section 8 (Design & Strength).


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• MatthewDaniel 9105 "Guidelines for MODU Field Moves & Ocean Towage" October 2015 - Section 8 (Securing of the Tow) & 9 (Stowage and Seafastening)

47. Strip water from the preload tanks, unused drill water tanks and void tanks prior to and during the tow.

• Noble Denton 0030/ND Rev 4. Technical Policy Board "Guidelines for Marine Transportation" March 2010 - Section 9 (Design and Strength)

48. Lifeboat machinery and equipment should be checked for compliance with existing regulations and be in proper operating condition. Lifeboat fuel tanks should be checked for contaminants and feel cleaned or replaced as necessary. Spare fuel filters should be stowed aboard the lifeboat for use, if required.

Correction edit: "… and fuel cleaned or replaced as necessary."


49. The emergency power source should be available for use at all times and teed at periodic intervals.

Correction edit: "… and tested at periodic intervals."

• IMO MSC Circ. 884 "Guidelines for Safe Ocean Towing" December 1998 - Section 13.17 high level and ensure all LSA equipment is available and maintained ready for use per regulatory requirements.

Riding Crew Instructions


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50. Sea watches should be maintained at all times during the tow. The following information should be entered into the log:

• MatthewDaniel 9105 "Guidelines for MODU Field Moves & Ocean Towage" October 2015 - Section 18 (The Tow).


50.a. Weather data including; wind force, wave/swell height/Period.

Grammatical edit: "… wave/swell height/period."

50.b. Motion characteristics of the vessel are of the utmost importance. The Drill Barge Master (licensed or unlicensed) must observe degrees of pitch and roll and their corresponding periods and request the tug to change course and/or speed to prevent the Drill Barge motions from exceeding the values given in the Operations Manual critical motion curves.

• Noble Denton 0030/ND Rev 4. Technical Policy Board "Guidelines for Marine Transportation" March 2010 - Section 6 (Design Environmental Conditions), 7 (Motion Response), 8 (Loadings) & 10 (Stability).


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50.c. All important communication with the towing vessel(s) including speed, course, change in tow wire length, etc. should be recorded.

• Noble Denton 0030/ND Rev 4. Technical Policy Board "Guidelines for Marine Transportation" March 2010 - Section 7 (Motion Response).

50.d. me Position should be obtained from the towing vessel(s) every 6 hours and recorded in the rig log.

With GPS navigational technology that the rig would possess, believe this is a legacy guideline that can be

Removed. Correction edit: "The Position should be…"

• MatthewDaniel 9105 "Guidelines for MODU Field Moves & Ocean Towage" October 2015 - Section 14 (Crew and Radio Communication).

51. Each hull tank should be sounded and logged every 12 hours.

• MatthewDaniel 9105 "Guidelines for MODU Field Moves & Ocean Towage" October 2015 - Section 10 (Watertight Integrity)

52. All watertight doors between compartment and from the compartments to outside exits should be kept closed at all times except when personnel pass.

53. Tow gear should be inspected every 6 hours and the results logged.

54. At least two (2) members of the crew should be awake at all times.


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55. Radio contact mist be maintained on a 24 hour basis with the tow vessel(s).

Correction edit: "Radio contact must be…"

56. Emergency drills should be help prior to departure and once a week during the tow. Results should be logged.

Correction edit: "Emergency drills should be held prior…" Emergency Evacuation Plan for the Riding crew

57. All navigation lights should be checked every 6 hours and the results logged.


58. Daily reports are should be forwarded to the Contractor’s headquarters at least daily.

Ocean Tow Loading Plan Addendum A

Delete this addendum

Addendum B (Design Limits of Legs Afloat)

Delete this addendum

Endurance

A rig move will not commence unless supplies are on board to cover fuel, water, and provisions for a


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period 25% greater than either:

The time needed to complete the tow.

The time needed to reach a secure position of re-supply.

Severe revolving storm system contingency planning for a self-elevating unit may allow for relocation if a risk assessment shows that there is enough time for the unit to be safely moved completely clear of the storm track envelope.

Semi-Submersible MODU

In addition to the criteria established in previous sections, the plan for a semi-submersible unit will address the following elements:

a. Ability to transition between transit and survival drafts in all loading conditions reasonably expected during the duration of the move.

b. The minimum quantities of consumables (e.g., fuel, water, provisions) required


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by the MODU operator for the duration of the move and any foreseeable delays.

c. Identification of the MetOcean conditions arising during long distance tows which trigger decisions to move between transit and survival drafts, or suspend routine progress of the tow (heave to or deviate from the planned course).

Tow Plan & Planning

Any recommendations issued prior to commencement of or during the execution of a rig move by an attending MWS will be subject to the approval of the MODU/MOU/FOI OIM.

• MatthewDaniel 9105 "Guidelines for MODU Field Moves & Ocean Towage" October 2015 - Sections 11 (Tow Route and Navigational Procedures), 20 (Wet Manned Tow) & 21 (Move Checklist).


• IMO MSC Circ. 884 "Guidelines for Safe Ocean Towing" December 1998 - Sections 6 (Planning) & 7 (Preparation).

Tow Gear Arrangement

• Noble Denton 0030/ND Rev 4. Technical Policy Board "Guidelines for Marine Transportation" March


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2010 Section 14.22 Channel Width & Restricted Maneuverability.

• IMO MSC Circ. 884 "Guidelines for Safe Ocean Towing" December 1998 - Sections 6 (Planning), 7 (Preparation) & 12 (Towing Equipment).

• MatthewDaniel 9105 "Guidelines for MODU Field Moves & Ocean Towage" October 2015 - Section 12 (Towing Gear).

Emergency Procedures

• Noble Denton 0030/ND Rev 4. Technical Policy Board "Guidelines for Marine Transportation" March 2010 - Section 13 (Towing Miscellaneous Equipment on Tow).

• MatthewDaniel 9105 "Guidelines for MODU Field Moves & Ocean Towage" October 2015 - Section 15 (Emergency Procedures).

• IMO MSC.1 - MSC.1/Circ.1255 "Guidelines for Owners/Operators on preparing emergency towing procedures" May 2008.

• IMO MSC Circ. 884 "Guidelines for Safe Ocean Towing" December 1998 - Section 14 (In an emergency).


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Weather

• MatthewDaniel 9105 "Guidelines for MODU Field Moves & Ocean Towage" October 2015 - Section 13 (Weather Forecasts). & 18 (The Tow).

• Noble Denton 0030/ND Rev 4. Technical Policy Board "Guidelines for Marine Transportation" March 2010 - Section 6 (Design Environmental Conditions).

• IMO MSC Circ. 884 "Guidelines for Safe Ocean Towing" December 1998 - Section 9 (Design environmental conditions) & 10 (Weather forecast).

Towage of Vessels and Structures in Ice Covered Waters

Recommend: Towage in Ice-Infested Waters

A risk assessment will be performed for MODUs/MOUs/FOIs which can encounter risk from operations where drifting ice or pack ice can be present including the following:

a. Management and mitigation of that risk within the limitations of the vessel.

• MatthewDaniel 9105 "Guidelines for MODU Field Moves & Ocean Towage" October 2015 - Section 13 (Weather Forecasts).

• Noble Denton 0030/ND Rev 4. Technical Policy Board "Guidelines for Marine Transportation" March 2010 - Section 6 (Design Environmental Conditions) & 22 (Special Considerations for the Towage of Vessels and Structures in Ice Covered Waters).


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b. The level of external support from shore bases or infrastructure, or other marine, aviation, or logistics assets which can be accessed, whether formally engaged in oilfield activities or not.

• IMO MSC Circ. 884 "Guidelines for Safe Ocean Towing" December 1998 - Section 9 (Design Environmental Conditions) & 10 (Weather forecast).

Guidelines for Towing Vessels

• Noble Denton 0021/ND Rev 10. Technical Standards Committee "Guidelines for the approval of Towing Vessels" December 2015 Section 5 (Documentation), 6 (Towing Equipment) & Section 7 (Towing Winch).

• Noble Denton 0030/ND Rev 4. Technical Policy Board "Guidelines for Marine Transportation" March 2010 Section 12 (Towing Vessel Selection and Approval) & 13 (Towing & Miscellaneous Equipment On Tow).

Transport of Jack-ups

Suggested adding: Jack-Up Units - Scope of plan

a. The plan for a self-elevating MODU will identify the intended duration of the move and the maximum

• Noble Denton 0030/ND Rev 4. Technical Policy Board "Guidelines for Marine Transportation" March 2010 - Section 19 (Special Considerations for the Transport of Jack-Ups).


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operational weather parameters which are expected to occur during its execution.

b. Leg towing position will be defined.

c. The requirements for provision of leg restraint systems or leg lowering procedures during long tows or heavy weather exposure will be determined.

d. Leg restraint systems will be witnessed as functional, in accordance with the marine operations manual, by the MWS.

• IMO MSC Circ. 884 "Guidelines for Safe Ocean Towing" December 1998 - Section 11 (Towing vessel requirements).

Documents

Comments received for TSAC Preliminary NOSAC Towing SC … · 2017. 10. 11. · • IMO MSC Circ. 884 "Guidelines for Safe Ocean Towing" December 1998 -Section 9. • MatthewsDaniel