SFLC-Std-Spec-8634-(2020).pdf_safe.pdf

SFLC STANDARD SPECIFICATION 8634

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DRY DOCKING

1. SCOPE

1.1 Intent. This Standard Specification describes the requirements for the Contractor to dock and undock Coast Guard surface assets.

1.2 Appendices. The following appendices apply to this standard specification.

PROCESS STANDARD APPENDIX

Requirement for Calculations A Requirements for Facility Inspection B Requirements for Docking and Lifting Cradles C Not Used D Conference and Inspection Checklists E

1.3 Acronyms and term definitions. Below are definitions of various acronyms and terms that are used in this standard or may be encountered in work item specifications.

DRY DOCK: When used generically in this specification, this term refers to all means of removing a vessel from the water, including Graving Docks, Floating Dry Docks, Marine Railways, Vertical Shiplifts (e.g. Syncrolift™) and crane (e.g. Travel Lift™).

COR: Contracting Officer’s Representative

GM: Transverse Metacentric height (stability index).

Haul out: A haul out is defined as lifting or hoisting of a vessel, where arrival condition is either afloat or in a cradle on a trailer, using a heavy lift rigging configuration with a crane, derrick, or gantry type crane (e.g. Travel Lift).

Facility: Refers to a specific dry dock operated by Contractor with unique identity (designator, model number, etc.)

Fleet/Fleeting: The action of refloating and shifting of a vessel to an alternate docking position to facilitate 100% preservation of the vessel's underwater body, or other necessary work.

KG: Height of Vertical Center of Gravity (VCG) above the baseline and/or keel.

KM: Height of Transverse Metacenter.

KO: Contracting Officer

LOA: Length over all.

Soft cap: Forms the top of the keel or side/bilge block, usually; has lower permissible compressive stress and proportional limit than other materials used in block construction.

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2. REFERENCES

COAST GUARD DRAWINGS

Coast Guard Drawing 87 WPB 085-012, Rev A, 87 Ft Lifting Cradle and Docking Plan

Coast Guard Drawing 87 WPB 085-013, Rev B, Docking Plan

Coast Guard Drawing 110 WPB 085-002, Rev 1, Docking Plan, A Class

Coast Guard Drawing 110B WPB 085-002, Rev B, Docking Plan, B Class

Coast Guard Drawing 110C WPB 085-002, Rev A, Docking Plan, C Class

Coast Guard Drawing 110 WPB 085-010, Rev C, Docking Plan, Docking/Lifting Cradle (‘A’,‘B’, & ‘C’ Classes)

COAST GUARD PUBLICATIONS

Surface Forces Logistics Center Standard Specification 0000 (SFLC Std Spec 0000), Latest Revision, General Requirements

Surface Forces Logistics Center Standard Specification 0740 (SFLC Std Spec 0740), Latest Revision, Welding and Allied Processes

OTHER REFERENCES

American Bureau of Shipping (ABS), Rules for Survey after Construction, 2017, Part 7, Chapter 10, Steel Floating Dry docks

American Bureau of Shipping (ABS), Rules for Building and Classing Steel Floating Dry Docks, Code of Federal Regulations (CFR) Title 29, Part 1917.50, July 2017, Marine Terminals, July

Code of Federal Regulations (CFR) Title 29, Part 1919, July 2017, Gear Certification

Code for Lifting Appliances in a Marine Environment, Lloyd’s Register 2017

The Society for Protective Coatings (SSPC)/NACE International (NACE) Joint Surface Preparation Standard SSPC-SP WJ-4/NACE WJ-4, 2012, Waterjet Cleaning of Metals – Light Cleaning.

Rules and Regulations for the Construction and Classification of Floating Docks, Lloyd’s Register 2017

MIL-STD-1625, 2009, Safety Certification Program for Dry-docking Facilities and Shipbuilding Ways for U.S. Navy Ships

3. REQUIREMENTS

3.1 General. The Contractor shall maintain facility certification and subsequently meet the requirements to dock/undock a designated Coast Guard surface asset as specified in this standard and in accordance with requirements specified in SFLC Std Spec 0000.

3.2 Requirement for certification. The Contractor’s dry dock shall first be certified by a Coast Guard-approved method as specified in this standard.

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NOTE

The certification methods, calculations and related items listed throughout this specification ensure that the contracted dry dock has sufficient lifting capacity and structural strength for safely handling a Coast Guard vessel within the trim and stability requirements for dry-docking. This certification also serves as verification that the Contractor shall maintain compliance with the industrial standards for safety.

3.2.1 Submittal of dry dock certification. The Contractor shall submit documentation of their facility’s dry dock certification to the KO for approval. Coast Guard approval is based on COR review and KO acceptance of the submitted certification.

3.2.2 DRY DOCK certification. The Contractor shall be aware that the criteria for their dry dock capability shall be based on an independent third-party inspection and certification, see Appendix B for details of inspection criteria. Each dry dock facility the Contractor possesses shall be certified individually.

3.2.3 DRY DOCK certification method. Proof of structural and operational integrity of a Contractor’s dry dock facility and certification shall be achieved by one of the following methods:

TABLE 1 - DRY DOCK CERTIFICATION METHOD

CERTIFICATION

TYPE

ACCEPTABLE

STANDARD/

DOCUMENTATION

TYPE OF DRY DOCK FACILITY APPLICABILITY

FLOATING

GRAV

ING

MARINE

RAILWAY

VERTICAL

LIFT

CRANE/

TRAVEL

LIFT

DOCKING/

LIFTING

CRADLE

NAVSEA

(See 3.2.3.1.2)

MIL-STD-1625

(Sections 1.2.4 and

4.10.5 do not apply)

Professional Engineer

(See 3.2.3.1.3)

Independent Professional Engineer inspection survey of the dry dock condition that is signed and sealed

Lloyd’s Register (See 3.2.3.1.4)

Rules and Regulations for the Construction and Classification of

Floating Docks.

Code for Lifting Gear in a Marine

Environment; Chapter 3, 4, 6, 9 and 10

American Bureau of

Shipping (ABS) (See 3.2.3.1.5)

Rules for Survey After Construction

OSHA

(See 3.2.3.1.6)

29 CFR Part 1917 and Part 1919

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3.2.3.1 Required documentation.

3.2.3.1.1 Certification inclusions. Regardless of the type of certification provided, the Contractor shall submit to the KO the following information regarding the docking facility. This information shall accompany the required certification documents but is not required to be part of the formal certification;

the information may be taken from the contractor’s standard operating procedures, drawings, or other documents.

Fire alarm locations.

Emergency power plan.

Emergency ballast/dewatering pumping plan showing pump locations, applicable to floating dry docks and graving docks only.

3.2.3.1.2 Required Documentation for NAVSEA Certification. The Contractor shall provide the NAVSEA certificate showing certified capacity and dock ratings, the NAVSEA certification letter, and any status updates for scheduled maintenance items required by the certification.

3.2.3.1.3 Required Documentation for Professional Engineer Certification. The Contractor shall provide the certification form and inspection checklists that are found in Appendix B. Each certification shall include the checklist signature cover page; the checklist for all facilities types (see Appendix B3-B5), and the checklist specific to the type of facility certified (See appendix B6-B24 – as required.) The foundation checklist (see Appendix B-25) shall be included for all facilities where the final blocking location is not an integral part of the dry dock (required for crane and travel lift facilities).

3.2.3.1.4 Required Documentation for Lloyds Register Certification: The Contractor shall provide documentation of the most recent Lloyds Register periodical facility surveys including annual, underwater and 5 year special survey and documentation from surveyor or original drawings indicating the certified capacity and load ratings as approved and certified by Lloyds Register.

3.2.3.1.5 Required Documentation for ABS Certification. The Contractor shall provide documentation of the most recent ABS classed vessel condition survey and documentation from surveyor or original drawings indicating the certified capacity and load ratings as approved and certified by ABS.

3.2.3.1.6 Required Documentation for OSHA Certification. The Contractor shall provide the most recent annual certification from OSHA (Form 71), most recent quadrennial or quinquennial survey with proof weight test results, and any supplemental findings of deficient items as reported to OSHA (Form 72).

Since the OSHA inspections/certification is limited to the lifting equipment, a Professional Engineer’s certification is also required for the pier structure and blocking foundation portions of the facility (see 3.2.3.1.3).

3.2.3.1.7 Block/Cradle Foundation Certification. If the final docking location of the vessel on blocks/cradle is not on the dock floor of a certified graving dock, floating dry dock, marine railway, or vertical lift, the block/cradle foundation site shall be certified separately by a Professional Engineer (see

3.2.3.2 Clarification for dry dock certification methods). Facilities using a crane or travel lift, with or without a lifting cradle, shall also include a certification of the final block/cradle foundation site.

Permanent transfer tracks, built and used exclusively with a dry dock facility, may be certified along with the facility they service, no separate certification is required.

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3.2.3.2 Clarification for dry dock certification methods. The Contractor shall be aware that certification methods listed above are explained as follows:

3.2.3.2.1 Inspection survey. The inspection survey checklists for all types of dry docks and block/cradle foundations are defined in Appendix B (Requirements for Facility Inspection). The format of the inspection checklists, provided in Appendix B, shall be used in validation of certification by an independent Professional Engineer.

3.2.3.2.2 DRY DOCK certification period. Coast Guard approval of the submitted certification shall remain in effect as long as the certification is current and contractor is in compliance with the certifying agency’s requirements. In the case of an independent Professional Engineer’s inspection survey, the period of certification is defined in Appendix B.

3.2.3.2.3 Validation of operational test. Each method of certification shall include an operational test of the facility. If an operational test requirement is specified by the certification method (NAVSEA, ABS, OSHA, etc…) those methods shall be followed. If no other operational test requirements are specified (PE certification) the following guidance shall be followed. For a valid operational test for cranes and travel lifts, the lifting equipment shall be tested to a minimum of 125% of the weight of the vessel to be dry docked. For cranes, this test should be completed at a lift radius and angle suitable for docking the intended USCG asset. For floating docks, graving docks, vertical lifts, and marine railway facilities the operational test should be completed with an appropriately sized vessel (or other weight) to show all aspects of the facility are operational. The details and results of the load test should be reflected in the facility certification.

3.2.3.2.4 Cradle construction and test. The Contractor shall be aware that requirements for the construction and operational testing of docking and lifting cradles are defined in Appendix C (Requirements for Docking and Lifting Cradles).

3.2.3.2.5 Cradle inspection. In the presence of the certifying agency, the Contractor shall perform Non- Destructive Examination (NDE) of the cradle/spreader bar weld joints designated by the certifying agency in accordance with SFLC Std Spec 0740, Appendix C for each certification inspection cycle (see B2.3.1 (Cycle for cradle certification)). The certifying agent shall provide a signed/sealed written test report for the completed NDE test to the Contractor for submittal to the KO for approval.

3.2.3.2.6 Modification of a certified dry dock. The Contractor shall report any changes, modifications or major repairs made to their dry dock structure/facility to the certification agency as well as to the KO. The certification shall be revised to document the structural/facility modification and resubmitted to KO for approval. The certification revision shall be approved prior to docking any USCG asset.

3.3 Docking personnel. The Contractor shall provide qualified docking personnel including a qualified Dockmaster.

3.3.1 Dockmaster. The Contractor shall provide written certification for the Dockmaster and include a resume stating training and experience that meets one of the following criteria:

Has served as a Dockmaster at the type of facility for which the individual is qualified during at least 10 docking/undocking evolutions, of which one has been accomplished within the previous 6 months.

Has served under a Dockmaster, in an apprentice or assistant role during at least 20 docking/undocking evolutions, of which 10 have been performed at the type of facility for which the individual is qualified with one docking/undocking evolution conducted within the previous 6 months.

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Has served under a Dockmaster in an apprentice or assistant role during at least 10 docking/undocking evolutions and has served as a Dockmaster at the type of facility for which the individual is qualified during at least 5 docking/undocking evolutions, of which one has been accomplished within the previous 6 months.

3.3.2 Manning personnel. The Contractor personnel stationed for the dry-docking evolution shall be experienced in dry-docking operations and equipped with appropriate tools and communication devices throughout the dock/undock evolution.

3.4 Safety.

3.4.1 All dry-dockings of cutters and boats shall require safety measures in accordance with this Standard Specification and its referenced documents.

3.4.2 While docked there shall be no shifting of weights, fuel, fresh water or ballast without the express permission of the Dockmaster.

3.5 Dry docking events.

3.5.1 Pre-award events.

3.5.1.1 Documentation Submittal. If certification is not currently on file with Coast Guard, the Contractor shall submit their dry dock certification (see 3.2.1 Submittal of dry dock certification) at the time of pre-award to the KO for approval. The contractor shall also submit written certification and resume of Dockmaster (see 3.3 Docking personnel).

3.5.1.2 Pre-award calculations. The Contractor shall provide to the KO a set of pre-award calculations, as described in Appendix A. As applicable, the contractor shall also submit an alternate blocking arrangement with the pre-award calculations which consists of any changes from the CG docking plan provided in the work package.

3.5.1.2.1 Vessel information. The KO will provide the Contractor with docking plan information/ drawings, hydrostatic information and specific vessel Principle Characteristics in the work package from the KO. For additional information necessary to perform dry dock calculations submit a request to the

KO.

3.5.1.2.2 Validation of dock capacity. The Contractor's maximum rated dry dock capacity, as stated in the submitted certification, shall be a minimum of 125% of the weight of the specific vessel to be dry docked (see 3.5.1.2.1 (Vessel Information)). In a case where the dry dock maximum rated capacity does not meet the validation requirement the Contractor’s pre-award calculations shall include liquid and dead loading instructions, with resultant VCG, TCG, LCG and GM values, for the specific vessel. The Contractor shall demonstrate the dry-docking can safely be accomplished. This shall be considered a unique Contractor requirement to dock the vessel and shall be approved by the KO.

3.5.1.2.3 Review of Contractor’s requirement. The Contractor shall provide the KO their unique requirements for the vessel’s loading or blocking at pre-award for review and approval. The KO shall provide the Contractor the results of the review prior to contract award. If an alternate blocking plan is required, the specific details of that plan, including the vertical block offsets and positioning, shall be provided for every block that does not fall in a location defined by the USCG standard docking plan.

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3.5.2 Pre-Docking events.

3.5.2.1.1 Vessel arrival load conditions. The Contractor will be provided with the vessel’s estimated arrival loading conditions by the COR no later than seven days before the docking day. If the vessel’s estimated trim or list requires a reduction, the Contractor shall coordinate with the COR to accomplish the following:

3.5.2.1.1.1 Trim considerations. The Contractor shall work with the COR and vessel’s CO/OIC to obtain minimal trim of the vessel being docked. The trim condition must account for any design drag; which occurs when the vessel’s keel is designed to not be parallel to the design baseline. When it is necessary or desirable to dock a vessel with appreciable trim, both the point load on the knuckle block and the maximum unit stress at the after end of the knuckle block must remain within permissible limits of the timber, as shown in Appendix A.

3.5.2.1.2 List considerations. The Contractor shall work with the COR and vessel’s CO to ensure that all list as practicable, shall be eliminated from the vessel being docked before attempting to dry dock (list angle shall be 0 degrees),.

NOTE

If examination of the vessel by the Contractor’s Dockmaster is not possible before docking, the COR/CO will inform the Contractor of the amount of list, and its probable cause. This information shall be furnished sufficiently in advance of the time of dry-docking to permit safe docking arrangements to be made without delay.

3.5.2.2 Block construction. The Contractor shall arrange blocks, as shown on the USCG docking plan for the vessel class, ensuring the following:

The Contractor shall establish a benchmark for centerline and baseline. The dock floor shall not be considered a baseline unless it can be proven flat, without slope, peaks or depressions

The dimensional tolerances for the vessel's docking plan shall be the following:

The height of the vessel's blocks are within ¼”.

The distances in the longitudinal direction are within 1”.

The distances of the half breadths (transverse) for side/bilge blocks are within ½”.

Soft caps shall be made of Douglas Fir or Pine. Keel block soft caps shall measure 2 inches minimum to 6 inches maximum in thickness. Side block soft caps shall measure 2 inches minimum to 6 inches maximum in thickness at their shortest (inboard) corner. Side blocks have no maximum thickness limitation at their longest (outboard) corners. Keel block soft caps shall not be thicker than the shortest corner of the side blocks. Reused soft caps shall be free from any permanent deformations, i.e. crushing, cracking or other material defects.

The line of normal force for all blocking shall pass through the middle one-third of the block base as shown in Figure 1 (Side/Bilge Block Construction).

Docking blocks shall be made of homogeneous materials. Keel blocks shall be fabricated of the same materials. Side/bilge blocks shall all be fabricated of uniform structure and materials. The side/bilge blocks shall not be of stiffer construction material than the keel blocks. Block material below the soft cap shall be constructed of one of the following materials: concrete, hard wood or steel.

Blocks shall be secured to prevent wood from floating out of position during the docking/undocking evolution

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Bilge blocks higher than six feet, as measured from the bottom of the block to the highest point of the soft cap, shall be stiffened both front and back sides from top to bottom to prevent buckling and tied together in pairs by means of cribbing or bracing. If the side blocks are hauled into position during the docking evolution while tied together, then they shall be hauled simultaneously. When stiffening high bilge blocks or bracing two blocks together, the minimum acceptable bracing material shall be four (2”x6”) wooden planks in a normal-to-hull pattern or a cross-braced pattern and lag bolted in place, shown in Figure 2 (Stiffened or Braced Bilge Blocks). Keel blocks higher than six feet shall be cribbed together in the both forward and after one third of the keel block line. The cribbing shall be a minimum of 12-inch thick when used with timber blocks.

While constructing blocks, according to the docking plan provided in the work package, the Contractor shall ensure that no obstructions exist between the dry dock surface and hull openings or fittings. The Contractor shall also ensure horizontal and vertical clearance to remove and replace appendages, including but not limited to rudders, shafts, fin stabilizers, transducers, sonar domes, and retractable bow thrusters, as applicable. This clearance shall be considered whether or not removals are specified in the work package.

Blocks constructed for vessel dockings/haul outs, shall be placed on a permanent solid foundation such as concrete, concrete aggregate, dock floors, or cradle fixtures. Cradle fixtures used for vessel haul outs shall be placed on a permanent solid foundation. No block or cradle shall rest on loose soil, gravel, sand or other non-permanent foundation. (See

3.2.3.1.7 (Block/Cradle foundation certification).)

CAUTION!

In cases where cradle fixtures are combined with additional blocks, both shall be placed on a permanent solid foundation of uniform composition.

NOTE

The position of the vessel on the blocks, as found in the docking plan drawing, will be specified in the work item provided in the work package. Sequential positioning (1, 2, etc) allows for paint schedules to cover the hull plate over multiple docking cycles.

3.5.2.3 Vessel arrival. The Contractor shall dock the vessel within 72 hours after the vessel has arrived at the Contractor's facility, except in the case where a pre-docking shaft alignment check shall be performed.

When a pre-docking shaft alignment is performed, ensure that the vessel is dry docked within 120 hours after arrival.

3.5.2.4 Three (3) business days before docking. Three (3) business days before docking the Contractor shall submit the docking calculations to the KO for review by the COR, as required in Appendix A. As applicable, the Contractor shall also submit an alternate docking block arrangement, which consists of any changes from the USCG docking plan provided in the work package. A Contractor’s alternate docking plan/block arrangement shall be approved by the KO prior to docking a Coast Guard asset.

3.5.2.5 Twenty-four hours before docking. The Contractor shall convene the Pre-Docking Conference a minimum of 24 hours prior to docking. All of the following docking items shall be discussed to the satisfaction of the COR.

3.5.2.5.1 Docking checklists. The Contractor shall provide, upon request, information needed by the COR to complete the COR’s Pre-docking Conference checklist, Pre-docking Dock Inspection, During & Post Docking Inspection, as well as the Pre-Undocking Conference Check List and Undocking Evolution

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Checklists. Checklists are provided in appendix E.

3.5.2.5.2 Block inspection. The Contractor shall not remove any instruments used to set block heights and verify block position until the COR has completed the block inspection. The Contractor shall establish a benchmark for centerline and baseline. The dock floor shall not be considered a baseline unless it can be proven flat, without slope, peaks or depressions. If a lifting cradle is used, that cradle shall be inspected on its final foundation. The cradle foundation shall not affect the final block height due to any induced twisting or bending from an unleveled or uneven grade.

3.5.2.5.3 Manning for dry dock evolution. The Contractor shall provide to the COR a list of dry-docking procedure and operations that describes all stations to be manned and functions to be performed, including but not limited to, line handling, reference point sights over the build, draft readings, watertight integrity checks, casualty and damage control plans of action.

3.5.2.5.4 Dry Docking procedure documentation. At the Pre-Docking Conference, the Contractor shall provide to the COR a written dry-docking procedure, which shall include the following:

A short statement of operating procedure, safety requirements, and yard security plans.

The flooding and pumping plan for a floating dry dock (guidance for preparation of a pumping plan is provided in Appendix A).

Specific list and trim conditions of the vessel during docking.

Any special precautions or actions required because of characteristics of the docking facility, the vessel, or a combination, e.g. tidal constraints, grade of dock railway.

3.5.3 Docking day events.

3.5.3.1 Docking evolution. The Contractor shall safely dry dock the vessel, during daylight hours, in one continuous evolution. Dry-docking outside of normal daylight hours shall be by special request approved by the KO. Requests for night dockings shall include documentation of adequate lighting and safety procedures and justification for the need. The dry dock is free of all debris and blasting material. As the first extremity of the vessel crosses the sill or plane of the dry dock, the point of the dry dock closest to the navigable channel, the Contractor’s Dockmaster shall relieve the CO/OIC and take responsibility for the safety of the vessel.

3.5.3.2 Modification of loads. During the docking evolution, the Contractor shall ensure that no load has been shifted, added, or removed from the vessel, including liquids such as fuel or water, unless authorized by the Dockmaster. Submit a CFR for all liquid and dry load modifications during the docking evolution.

3.5.3.3 Personnel onboard vessel. During the docking evolution, the Contractor shall be aware of all personnel onboard, including both Coast Guard and civilian. The Contractor’s Dockmaster shall have direct contact via radio with the personnel and shall provide them direction as necessary during the evolution. Personnel onboard during the docking shall be limited to minimal required for manning stations and their movement shall be limited as the vessel is positioned over and landed with full contact on the dock block build.

3.5.3.4 Assistance for safe docking of vessel. The Contractor shall provide all resources necessary to safely dry dock the vessel. Resources shall include but not be limited to, tugs and/or pusher boats, line handlers, and radio communications. The Contractor shall not use shipboard winches or any other deck machinery to control or winch the vessel into position, but may use appropriate attachment points on the vessel to secure and control the vessel during the docking/undocking evolution.

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3.5.3.5 Weather delay. If the docking day is postponed for reasons of weather, including but not limited to excessive winds, freezing temperatures, heavy rains, the date shall be tentatively moved to the next forecasted good weather day. The Contractor shall communicate with the COR and KO the reason for the delay and the anticipated rescheduled date for the event.

3.5.3.6 Floating dry dock operational limits. The Contractor shall operate a floating dry dock with the following limitations (see Appendix A for pumping plan and calculation requirements):

Trim between the blocks and keel shall not exceed 1 foot per 100 feet of length during the landing of the vessel. Once the vessel is fully landed, a maximum ship/dock trim of 4 feet per 100 feet of length shall not be exceeded at any time. The dock may be trimmed to match the vessel’s trim but shall not exceed the aforementioned limits.

A minimum of 12 inches shall be maintained between the dry dock and the harbor bottom at all times.

The final lifted pontoon deck freeboard shall be no less than 12 inches.

3.5.3.7 Divers. The Contractor shall use qualified divers to monitor block clearances during the positioning of the vessel over the blocks.

3.5.3.7.1 Divers are required for the following instances:

When the distance between the hull and the blocks is expected to be nine inches or less.

When hauling bilge blocks and to verify the success of hauling operations.

When cradles are used for docking.

When alternate blocking plans are used and a diver is determined to be necessary by the Coast Guard.

3.5.3.7.2 Divers are not required if the Coast Guard determines that conditions, such as diver visibility and/or safety, during the dive will render the divers inspection impractical and not beneficial to the Coast Guard. If divers will not be used in conditions that would typically require them; an alternate means of verifying block placement and contact shall be discussed in the docking calculations.

3.5.3.8 Hull and block contact inspection. Immediately after the vessel has been docked, the Contractor shall perform the following:

Examine all blocks for total contact. Shim the blocks as necessary to provide total block contact with the vessel's hull.

Install any supplemental blocking or shoring for the bow and/or stern overhanging structure as specified in docking plan.

Refloat the vessel and take corrective action if any tendency to strain or damage the vessel is observed, or if the vessel is more than 6 inches off the center of the keel blocks. Concur with the COR before corrective measures are taken and before continuing with docking.

3.5.4 Within twenty four hours after docking. The Contractor shall begin the following:

3.5.4.1 Underwater body cleaning - removal of marine growth. The Contractor shall start cleaning the hull within four hours after the vessel has been docked, as specified below, to facilitate marine growth removal. The Contractor shall complete the hull cleaning before marine growth hardens

3.5.4.2 Hull cleaning. Remove all marine growth and oxidized coatings from the entire underwater hull from the upper edge of the boot top down, including sea chest strainer plates, sea chest interiors, 2020 11 8634 fairwaters, rope guards, rudder, shaft strut, z-drive, and thruster tunnel, and zinc anodes, as applicable by water-jetting to a WJ-4 visual surface condition, in accordance with SSPC-SP WJ-4/NACE WJ-4.

Cleaning shall be supplemented with stiff bristle brushes and scrapers as necessary, to remove all visible marine growth, loose rust, loose mill scale, and loose coatings. Do not use chemical additives in the freshwater wash or scrapers on bearing surfaces or transducer faces. Take extreme care to avoid damaging or removing existing intact underwater body coating.

3.5.4.3 Protective measures. As soon as practicable after dry-docking, underwater body surface cleaning, and in conjunction with work package items that involve appendages, the Contractor shall do the following:

Install protective covering over transducers, zinc anodes, propeller blade seals, rudder bearings, stern tube and strut bearings, spool pieces, spud wells, fin stabilizer seals and bow thrusters, as applicable.

NOTE

Transducer cover plate(s) may be provided as GFP – see Section 1.2 (Government-furnished property) of the work item in the specification package.

Wrap bearings and seals, and insert soft caulking material into the open ends of rudder and shaft stave bearings to prevent entry of foreign materials during surface preparation and painting procedures.

Place drain channels in overboard discharges in use to direct discharges away from the hull.

Provide and install wooden plugs or coverings in sea chest spool pieces and overboard discharges not in use to prevent entry of sandblast grit or paint.

CAUTION!

Do not remove protective covers during the dry dock period except to accomplish specific work items or for inspection.

3.5.4.4 Interferences. The Contractor shall identify interferences to the hull openings or appendages by the blocking and/or cribbing, e.g. the skeg plug location identified on the docking plan as 6 inches forward of the end of skeg, after docking it’s found to be 18 inches forward and a block cap has landed on

it. The Contractor shall submit a CFR, including red line markup of the docking plan detailing the interference. The COR will review CFR and provide guidance to the Contractor for any removal of blocking or caps that is required to complete production work.

3.5.5 During the dry dock period. The Contractor shall track the weight and moment changes to the vessel caused by relocating or removal of liquid loads and/or dead loads (dunnage). Submit a CFR.

3.5.6 Fleeting. As specified in the work package, the Contractor shall fleet the vessel to another position on the blocks. Pre-docking, docking day, pre-undocking and undocking day events specified in this standard shall be adhered to in conducting the fleeting evolution. This entails floating/undocking the vessel, changing caps on side/bilge blocks to fit hull in next sequential position, and then docking the vessel. In this case cofferdams may be required for any hull opening that is mid-repair at the time of fleeting. Special consideration shall be made for the watertight integrity checks during the undocking.

Calculations for planned fleeting evolutions (undocking and re-docking) shall be submitted along with the initial docking calculations, prior to docking the vessel. If the fleeting evolution is not determined to be required until after docking is complete, the calculations shall be submitted at least three (3) business days before fleeting. The calculations shall be completed using an estimated loading condition for the vessel at time of fleeting and include the block details for the second blocking position. Should the vessel be

2020 12 8634 fleeted missing any ship’s equipment, including but not limited to small boats, deck machinery or main space machinery, shafts, propellers; the calculations for fleeting shall be revised to suit the existing load conditions at the time of fleeting.

3.5.7 Pre-Undocking events.

3.5.7.1 Four (4) business days before undocking. The Contractor shall notify the vessel crew and the COR of the schedule for undocking, including undocking conference date and time, a minimum of four business days in advance of the undocking evolution.

3.5.7.2 Three (3) business days before undocking. The Contractor shall submit to the COR the undocking calculations, as required in Appendix A. The calculations shall include the effects of the weight and moment changes during the dry dock period, e.g. weight additions, removals or relocations as a result of ship's actions and/or the Contractor equipment and materials.

3.5.7.3 Twenty four hours before undocking. The Contractor shall convene the undocking conference. At the conference discuss all undocking items to the satisfaction of the COR.

3.5.7.4 Twelve hours before undocking. The Contractor shall submit to the COR a written report attesting that the following conditions have been met and the COR will verify these items prior to undocking:

All transducers are uncovered.

Zincs are uncovered and free of paint.

Shaft rope guard and fairwaters are in place.

All hull opening blanks and plugs are removed.

All sea chest strainers are bolted in place and lock-wired or otherwise permanently secured, as in the condition before being disturbed.

All sea valves and waster pieces are properly installed and seated in the closed position.

All underwater body work has been completed and hull accesses are closed.

DRY DOCK is free of all debris and blasting material.

3.5.7.5 Undocking preparations. The Contractor shall provide personnel stationed for watertight integrity checks as the vessel undocks. Special attention shall be paid to the sea chests that were overhauled during the availability.

3.5.8 Undocking day events.

3.5.8.1 Undocking evolution. The Contractor shall safely undock the USCG vessel, during daylight hours, in one continuous evolution. Undocking outside of normal daylight hours shall be by special request, approved by the KO. The request for night un-dockings shall include documentation of adequate lighting and safety procedures, and justification for the need. The Contractor shall ensure the dry dock is free of all debris and blasting material. As the last extremity of the vessel crosses the sill or plane of the dry dock, the point of the dry dock closest to the navigable channel, the Contractor’s Dockmaster shall return the responsibility for the safety of the vessel to the CO/OIC.

3.5.8.2 Undocking tasks. The Contractor shall perform the tasks specified in the following paragraphs for undocking the vessel:

3.5.3.2 (Modification of loads).

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3.5.3.3 (Personnel onboard vessel).

3.5.3.4 (Assistance for safe docking of vessel).

3.5.3.5 (Weather delay).

3.5.3.6 (Floating dry dock operational limits).

3.6 Documentation of dry-docking significant events. The Contractor shall submit the following information in a separate written report to the COR within 48 hours after undocking the vessel.

The precise time that the vessel's first extremity crossed the dry dock boundary upon docking.

The precise time that the vessel's last extremity crossed the dry dock boundary upon undocking.

The forward and aft draft readings just before docking and immediately after undocking.

Removal of the temporary closures when the threat to watertight integrity no longer exists.

FIGURE 1. SIDE/BILGE BLOCK CONSTRUCTION

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FIGURE 2. STIFFENED & BRACED SIDE/BILGE BLOCKS

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APPENDIX A

REQUIREMENTS FOR CALCULATIONS

A1. SCOPE

A1.1 Intent. This appendix describes particular requirements for the contractor to perform dry dock calculations.

A2. REQUIREMENTS

A2.1 General. The Contractor shall submit a minimum of three sets of dry dock calculations for review and approval: Pre-award, Docking and Undocking. Each set of calculations shall be prepared by a Naval Architect or a certified Dockmaster (see Error! Reference source not found.Dockmaster) or under the supervision of a Professional Engineer.

A2.2 Calculations. The Contractor shall be aware that the stability calculations for the vessel and vessel/dock combined system, as applicable, shall include the KG, KM, and GM (stability index), in addition to drafts (estimated drafts for pre-award, actual arrival drafts for docking, and predicted drafts for undocking) and corresponding displacement values.

A2.3 Vessel's information. The KO will provide docking plan information/drawings, hydrostatic information and vessel Principal Characteristics in the specification work package. The Contractor shall submit a request to the KO for additional information necessary for performing dry dock calculations.

A2.4 Pre-award calculations. The Contractor shall submit to the KO a pre-award set of calculations, as listed in Table A1 (Dry Docking Calculation Requirements) and specified below.

A2.4.1 Vessel hydrostatics. The calculations shall reflect the values given in the Routine DRY DOCK work item provided in the work package as the Principle Characteristics of the vessel specified. The given displacement and Center of Gravity data shall be conservative, at vessel’s Full Load values, and shall not be considered a prediction of the vessels arrival load condition.

A2.4.2 Pre-award calculations for class. The Contractor may have previously submitted pre-award calculations for a vessel of the same class that is scheduled to dry dock. In this case only, they shall be permitted to resubmit the class calculations as proof of capability for the current dry-docking availability.

Exceptions to this case shall include when the vessel characteristics are significantly different from previously docked vessel and/or the certification capacity of the dry dock has been modified.

A2.5 Docking calculations. The Contractor shall submit a set of docking calculations to the KO for review and approval as listed in Table A1 and specified below. Calculations shall reflect the expected condition of the vessel when it enters the dry dock. The Facility shall ensure that work performed dock side that affects the stability condition prior to dry-docking is accounted for in the docking calculations.

This includes but is not limited to antennae removal, contractor equipment on-loads, tank emptying, and/or anchor removal, which may be performed by the Contractor and/or the vessel’s crew between the time of arrival and before dry-docking.

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A2.6 Undocking calculations. The contractor shall submit a set of undocking calculations to the KO, or their representative, for review, as listed in Table A1 (Dry Docking Calculation Requirements) and specified below, before undocking. The Facility shall ensure that work performed while in the dock which affects the stability condition prior to undocking is accounted for in the undocking calculations.

TABLE A1 - DRY DOCKING CALCULATION REQUIREMENTS

CALCULATIONS Notes:

P=Pre-award D=Docking

U=Undocking

TYPE OF DRY DOCK FACILITY

Floating Graving Marine Railway

Vertical Lift

Crane/ Travel

Lift

Blocking Calculations (A2.7.1) P, D, & U X X X X X

Stability for vessel afloat D & U X X X X X

Draft at landing (A2.7.2.1) D & U X X X X

Stability at landing (A2.7.2.2) D & U X X X X

Draft at instability (A2.7.2.3) D & U X X X X

Vessel's draft when side blocks are hauled (A2.7.2.5)

D & U X X X X

*System stability at Phase 3 P, D, & U X

*System stability at Phase 4 P, D, & U X

*System stability at Phase 5 P, D & U X

*Pumping plan (A2.8.2) P, D & U X

Stabilizing Moment (A2.7.2.6) D, & U X X

Cable, Sling or Strap Tension (A2.7.2.7)

D & U X X

* Floating dry dock specifics can be found in paragraph A2.8

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A2.7 Types of calculation.

A2.7.1 Blocking calculations. The Contractor shall provide the following:

A2.7.1.1 Trapezoidal (L Tons / ft). Trapezoidal loading along the keel line. This is distributed load bearing along the keel line and into the structure of the dry dock floor. Typically it is trapezoidal in nature due to the trim on the vessel. Generally the longitudinal center of gravity (LCG) of the vessel is aft of amidships, therefore the majority of load is applied aft. This trapezoidal loading is compared against the docking facility’s maximum rated loading (LT/ft) from the facility certification package.

Trapezoidal Load (LT/ft) = where:

= (LT) Vessel Displacement (From Curves of Form) Lk – (ft) Length of supported keel (calculated) e = eccentricity = distance from center of Lk to the vessel LCG (calculated)

(See Figure A2)

NOTE

For vessels utilizing a cradle, built per USCG Drawings, the only blocking calculations required are the trapezoidal loading per foot and knuckle loading.

A2.7.1.1.1 Trapezoidal (L Tons / ft) with cradle. For vessels utilizing a cradle, the distributed load bearing along the keel line and into the structure of the dry dock floor has two parts-the loading per foot experienced by the cradle for a given vessel’s loading condition, and the weight of the cradle. The loading on the cradle is typically distributed along bilge blocks. In some cases, as with the 110 WPB, additional blocks are constructed after the vessel docks in the cradle. For the trapezoidal loading calculation for vessels using a cradle, the length of the supported keel shall be considered the length along the vessel that is supported by the cradle.

Trapezoidal Load (LT/ft) with Cradle =

C

C kk L

W

L e

L 2

= (LT) Vessel Displacement (From Curves of Form) Lk – (ft) Length of supported keel (calculated) e = eccentricity = distance from center of Lk to the vessel LCG (calculated) Wc = (LT) Weight of Cradle

Lc = (ft) Length of Cradle kk L e

L

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A2.7.1.2 Knuckle load (L Tons). When docking a vessel that has trim or design drag (typically down by the stern), there is a knuckle load applied on the first keel block and an equal knuckle reaction (Rkn) created on the vessel as the keel touches at landing. This load is applied as a pivot point that rotates about the block at the point of touch down as the cutter lands on the blocks. This first block, which may be called the knuckle block (KB), will be at the extreme end of the keel line. Its location either Forward or Aft, depends on the trim of the vessel entering the dock. This load is typically seen on keel blocks, however, if no keel blocks are present then the knuckle load will be bearing on the first pair of side blocks. The knuckle load bearing on the keel block and subsequently through to the dock floor. This knuckle load increases as the buoyancy forces are taken off the vessel hull and as the vessel lands completely along the keel line. The knuckle load (LT) should be converted into a pressure based on the area of the contacting blocks to ensure the blocks are not compromised by this additional load, by comparing the knuckle pressure to the block timber stress limits.

Knuckle Load Reaction, Rkn (LT) = knXk trimMT

12*"*1

MT1” = (ft-LT) Moment to Trim 1” (from Curves of Form or Hydrostatics) trim = (ft) Trim between vessel keel and keel blocks (should include trim of dock and vessel drag) k = overhang constant = 0.94 for large overhang or 0.97 for short overhang Xkn = (ft) Calculated distance from outer edge of the first block to make contact with the vessel, the knuckle block (KB) to the vessel LCF (Value of LCF from Curves of Form or Hydrostatics).

Knuckle Load Pressure (psi) = Rkn / AKB Where:

AKB = (in2) Area of knuckle block, the first block(s) to make contact with the hull

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A2.7.1.3 Side Blocks. The number of side blocks required to meet seismic and hurricane overturning moments with dead loads included at 15% of total load.

MS = ( / g ) * a* KG * 2240 where:

MS = (ft-LT) Seismic Moment = (LT) Vessel Displacement (from Curves of Form) g = Acceleration of gravity = 32.2 ft/sec2 a = 0.2 * g KG = (ft) Vessel’s afloat vertical center of gravity (from stability book, incline test, DC Book) MH = ASail * SailHt * (0.004) *V2

MH = (ft-LT) Hurricane Moment ASail = (ft2) Sail are of vessel exposed to wind forces (calculated) SailHt = (ft) Height of the Center of the Sail Area (calculated) V = (knots) Velocity of wind Force (typically use 110 knots) If MH > MS, use MH; If MS > MH, use MS.

N2 = MH/S / (AS * SP * L2)

Where:

N2 = Number of side blocks required to resist seismic or hurricane forces AS = (in2) effective contact area for one side block (calculated) SP = (psi) Strength proportional limit of cap timber (typically 800 psi) L2 = (ft) Average half breadth of side blocks (from Docking Plan or Block Arrangement)

N1 = [(N2 * AS) + (DL * 2240 / SP )] / AS

Where N1 = Number of side blocks on one side DL = (LT) Dead Load on one set of side blocks = * 0.075

NS = N1 *2 = Total Number of side blocks required to support the entire ship’s dead load plus seismic or hurricane overturning forces

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A2.7.1.4 Bearing area. Total bearing area (side blocks + keel blocks) on hull and total distributed load throughout blocking build (psi). This bearing area shall consider the effective contact area of each block (e.g. if a 24 inch by 24 inch keel block is being used under a vessel with a 6 inch wide keel; the effective area is only 6 inches x 24 inches, not the entire upper surface of the block).

Bearing Area (in2) = (NK * AK) + (NS * AS) where:

NK = Total number of Keel Blocks (from docking plan) AK = (in2) Effective contact area for one keel block (from docking plan) NS = Total number of side blocks (calculated above, or actual number from docking plan) AS = (in2) Effective contact area for one side block (from docking plan) Distributed Load = 2240 * / Bearing Area where:

= (LT) Vessel Displacement (from Curves of Form)

Bearing Area = (in2) Total bearing Area (calculated)

A2.7.1.5 Timber stress. The Contractor shall provide the safe allowable block timber stresses. The permissible compressive stress, listed below, shall be used when considering side and keel block bearing loads applied to the blocking. The proportional limit loads are to be used when calculating the block stress due to overturning moments.

TABLE A2- WOOD PROPERTIES

WOOD PROPERTIES

Block Material

Permissible Compressive Stress Perpendicular to the grain (psi)

Permissible Compressive Stress Parallel to the grain (psi)

Proportional limit Perpendicular to the grain (psi)

SOFTWOOD

Douglas Fir 400 1400 800 Yellow Pine 300 900 700

HARDWOOD

Red & White Oak 600 1300 1300

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A2.7.1.6 Additional blocks. As needed, the Contractor shall propose additional keel and/or side blocks, to support underwater hull work ensuring that timber block permissible stress is not exceeded. Be aware that additional blocking is an alternate blocking arrangement.

A2.7.1.7 Alternate blocking arrangement. The Contractor shall submit an alternate blocking arrangement for approval to the COR when the vessel's docking plan does not match the dry dock structural limitations or when the keel/bilge blocks are considered interferences to scheduled work. The Contractor shall ensure that final block positions are adequately supported from both dock and ship structures. Calculation requirements shall be met using the alternate blocking arrangement. The alternate blocking plan must show sufficient detail to build and place the blocks, similar to the standard blocking arrangement. Plans must include the following details: block dimensions (length, width, and vertical height offsets to each corner and intermediate point); block locations and/or spacing from a known and measureable baseline (for example: vessel centerline and stern reference point); block materials and construction details;

location of hull penetrations, appendages or other obstructions that must be avoided when blocking; and special notes for block construction including required bracing or wedging.

NOTE

A safe overhang is considered to be 1.5 to 2 times the molded depth of the vessel at the forward or aft most keel block for the bow or stern, respectively.

A2.7.2 Stability during docking/undocking.

A2.7.2.1 Draft at landing. The draft at landing, for a vessel with trim (typically down by the stern), shall be calculated to ensure the bow has fully landed prior to slacking mooring lines and hauling side blocks.

As the force exerted by the keel block at the knuckle point takes on the weight (displacement) of the vessel and the buoyancy forces are reduced, the waterline along the length of the vessel’s hull will recede as…