UNDERWATER SHIP HUSBANDRY MANUALS

CHAPTER 9SONAR DOMES

S0600-AA-PRO-090

Revision 0, Change A, 15 AUGUST 1999

DISTRIBUTION STATEMENT A: This document has been approved for public release and sale; its distribution is unlimited.

TABLE OF CONTENTS

SAFETY SUMMARYSECTION 1 - INTRODUCTION9-1.1 PURPOSE9-1.2 SCOPE9-1.3 APPLICABILITY9-1.4 GENERAL INFORMATION9-1.5 SONAR RUBBER DOMES9-1.5.1 Description9-1.5.2 Purpose9-1.6 REFERENCE DOCUMENTS9-1.7 PLANNING9-1.7.2 Ship Berthing9-1.7.3 Personnel Requirements9-1.7.4 Time Requirements9-1.7.5 Damage Assessment9-1.7.6 Technical Assistance9-1.8 PREPARATION9-1.8.1 Tools, Materials, and Equipment Requirements9-1.8.2 Recommended Tool Inventory for SRD Repair9-1.8.3 B.F.Goodrich HP-2 Elastolock® Adhesive9-1.8.4 Underwater Repair Patch Kits No. 1A (52" x 27")and No. 3 (27" x 27 ")9-1.8.5 Lag Bolts9-1.9 NOFOUL® PATCH9-1.10 COFFERDAM SYSTEMS

SECTION 2 - SONAR DOME RUBBER WINDOW (SDRW) COFFERDAM INSTALLATION AND REMOVAL PROCEDURE9-2.1 GENERAL9-2.2 REFERENCE DOCUMENTS9-2.3 SURVEY9-2.3.1 Inspection9-2.3.2 Marking9-2.4 PREDIVE RIGGING9-2.5 INSTALLING THE COFFERDAM9-2.6 INSTALLING THE HEATING SYSTEM9-2.7 HEATER OPERATIONS9-2.8 UNRIGGING AND REMOVAL

SECTION 3 - SONAR RUBBER DOME (SRD) COFFERDAM INSTALLATION AND REMOVAL PROCEDURE9-3.1 GENERAL9-3.2 REFERENCE DOCUMENTS9-3.3 SURVEY9-3.3.1 Inspection9-3.3.2 Marking9-3.4 PREDIVE RIGGING9-3.5 COFFERDAM RIGGING AND INSTALLATION9-3.6 INSTALLING THE HEATING SYSTEM9-3.7 HEATER OPERATIONS9-3.8 UNRIGGING AND REMOVAL

SECTION 4 - SDRW AND SRD REPAIR9-4.1 GENERAL9-4.2 INSPECTION9-4.3 ANALYZE INFORMATION9-4.3.1 Cavitation Theory and Noise Spokes9-4.3.2 Radiography9-4.3.3 Sonar Self-Noise Correlation Study

9-4.4 GROOMING REPAIRS9-4.4.1 Environmental Conditions9-4.4.2 Grooming Repair Procedure9-4.5 STRUCTURAL REPAIRS9-4.5.1 Environmental Conditions9-4.5.2 Structural Repair Procedure9-4.6 PRESSURE TEST OF PATCH9-4.7 SPEED TRIALS

LIST OF APPENDICES

APPENDIX A - HP-2 ELASTOLOCK® MIXING PROCEDUREAPPENDIX B - SDRW REPAIR KIT DRAWINGSAPPENDIX C - SRD REPAIR KIT DRAWINGS

LIST OF ILLUSTRATIONS

9-1 Typical Sonar Dome Configurations9-2 Dome Location and Configuration for CG 47 Class Ships9-3 Dome Location and Configuration for DD 963 and DDG 993 Class Ships9-4 Dome Location and Configuration for DDG 51 Class Ships9-5 Dome Location and Configuration for FFG 7 Class Ships9-6 Dome Location and Configuration for FF 1052 Class Ships9-7 SDRW Installation Cross Section9-8 SRD Installation Cross Section9-9 SRD Repair Decision Logic Diagram9-10 Sample NAVSURFPAC Request for Assistance9-11 SRD Repair Accomplishment Report Format9-12 Patches9-13 Cofferdam Hot Water Heating System9-14 SDRW Cofferdam System9-15 SRD Cofferdam System9-16 Marking the SDRW and Waterline9-17 Rigging the Skeg Bridle9-18 Strap Assemblies9-19 Attaching D Strap Assembly to Deck Stanchion9-20 Skeg Bridle - Positioning Second D Strap9-21 Positioning A Strap9-22 Positioning Locking Travelers9-23 Additional Hardware9-24 C Strap Assemblies9-25 Lowering Cofferdam to Repair Location9-26 B1 and B2 Strap Assemblies9-27 E Strap Assemblies9-28 Cofferdam in Place9-29 The Installed SDRW Cofferdam System9-30 Marking the SRD and Waterline9-30A Tugit Lever Hoists9-31 Main Deck Rigging9-32 Ship and Cofferdam Rigging

9-33 Rigging the Cofferdam9-34 Unrigging the Cofferdam9-35 Factory Inlaid Markings9-36 Smoothing the Tapered Areas9-37 SRD and Bolted Patch Cross Section9-38 Edge Bolt Installation9-39 Measurement of Expansion During PressurizationA-1 Adhesive Cure RateB-3 NAVSEA Drawing 6697651 - Main ArrangementB-5 NAVSEA Drawing 6697659 - Rigging AssemblyB-7 NAVSEA Drawing 6697665 - Water Heating SystemB-9 NAVSEA Drawing 6697666 - Water Heating System SchematicB-11 NAVSEA Drawing 6697668 - Steam Manifold AssemblyC-3 NAVSEA Drawing 6698203 - Keel Dome Cofferdam Assembly, Sheet 1C-5 NAVSEA Drawing 6698203 - Keel Dome Cofferdam Assembly, Sheet 2

LIST OF TABLES

9-1 Minimum Required Tools, Materials and Equipment9-2 Underwater Repair Patch Kit No. 1A9-3 Underwater Repair Patch Kit No. 39-4 Lag Bolt Length Selection

CHAPTER 9

SONAR RUBBER DOMES

SAFETY SUMMARY

GENERAL SAFETY PRECAUTIONS

The following general safety precautions supplement the specific warnings and cautions throughout this chapter. These generalprecautions are related to the task of underwater Sonar Rubber Dome (SRD) repair. They are precautions that must be understood and applied before and during work on the SRD. In addition to the following precautions, personnel must be familiar with and observe safety precautions set forth in the following publications:

a. Navy Occupational Safety and Health Program Manual for Forces Afloat, OPNAVINST 5000.19 (Series)

b. Naval Ships Technical Manual (NSTM)

c. Technical/Operating manuals for equipment

d. NAVSEA 0944-LP-001-9010, U.S. Navy Diving Manual, Volume I

Do Not Repair or Adjust Alone

Do not repair or adjust energized equipment alone. The presence of a qualified individual capable of rendering aid is required. Always protect against grounding hazards and make adjustments with one hand free and clear of equipment. Be aware that even after equipment has been de-energized, dangerous electrical hazards can exist due to capacitors retaining electrical charges. Circuits shall be grounded and capacitors discharged.

Test Equipment

Make certain electrical test equipment is in good condition and personnel are familiar with its safe operation. Handheld equipment must be grounded, if possible, to prevent shock injury. Because some types of equipment cannot be grounded, avoid holding them.

Equipment in Motion

Remain clear of equipment in motion. A safety watch will be posted if the equipment requires adjustment while in motion. The safety watch shall have a full view of operations and immediate access to controls which are capable of stopping equipment. If at any time the masker belt appears to be moving out of control, stop equipment immediately.

Limit Switches and Interlocks

Limit switches and interlocks are provided to protect personnel and equipment. They should not be overridden or modified except by an authorized person. Do not depend solely upon limit switches for protection. Disconnect power at the power distribution source before adjusting limit switches if possible.

Steam

Pier steam is normally used to provide a source of heat to the heat exchanger that produces hot water for the cofferdam. Use appropriate safety equipment (i.e., gloves and face shield) when connecting, disconnecting, adjusting, or operating equipment using steam.

Water

Pier potable water is heated by the heat exchanger and circulated through the cofferdam. Prior to energizing the water system, verify that all water system connections are properly fastened. Improperly fastened water system connections could fail causing equipment damage, serious injury, or death.

First Aid

Attend to all injuries, however slight, by obtaining first aid or medical attention immediately.

Resuscitation

Personnel working with or near high voltage shall be familiar with approved resuscitation methods. Begin resuscitation immediately if someone is injured and stops breathing. A delay could cost the victim's life. Resuscitation procedures shall be posted where electrical hazards exist.

Minimizing Relative Motion

Relative motion is the movement of two or more objects in relation to each other. This poses unique hazards to divers. A common example is a nest of ships swaying and bouncing against each other due to wind and wave action. This motion would easily crush a diver caught between the two ships. To reduce the hazards of relative motion and to simplify the task, suspend the work platform and rigging from fittings on the ship.

WARNINGS

Specific Warnings and Cautions appearing in this chapter are summarized below for emphasis and review.

WARNINGSAvoid inhaling NOFOUL® vapors, mist, dust, or fumes. Dust from buffing operations may cause irritation of upper and lower respiratory tract and mucous membranes, nausea, headache, and eye and skin irritation (page 9-16).

Avoid direct bare skin contact with NOFOUL® surfaces or dust. Avoid contact between hands and mouth, and hands and eyes, if hands have been exposed to the NOFOUL® rubber material Wash hands thoroughly before eating or smoking (page 9-16).

Ensure adequate ventilation when working with NOFOUL® (page 9-16).

Pier potable water is heated by the heat exchanger and circulated through the cofferdam. Prior to energizing the water system, verify that all water system connections are properly fastened. Improperly fastened water system connections could fail causing serious injury or death. Steam manifold must be used as part of the steam supply system as it provides a pressure release path for incoming steam (pages 9-32 and 9-43).

As the cofferdam rotates to the point where it is about to lift off of the pier, the outboard edge still in contact with the pier may "kick out" as the cofferdam lifts off of the pier. Ensure that personnel remain clear (page 9-40).

NOFOUL® rubber is permeated with antifoulant compounds designed to impede marine growth. A mask and goggles should be worn when preparing NOFOUL® rubber topside (page 9-51).

CAUTIONSIt is essential that all tools and materials brought to the underwater job site are accounted for and removed at the end of the job. Tools and materials inadvertently left at the job site can generate unacceptable noise and possibly cause severe damage to shipboard components. Locally generated work packages shall ensure that a general tool and material log sheet is prepared and maintained during all UWSH operations (page 9-12).

When tightening straps to secure the cofferdam to the SDRW, never exceed four clicks on the ratchet before checking connecting points and strap seal clearances (page 9-21).

Avoid over-tightening ratchet buckles as the strap system may fail (page 9-26).

Chain twist in the working chain loops of manual chain hoists and chain falls will cause chain failure. Chain twist in the working chain loop occurs when the chain has an improper reeve through the chain sprockets OR (more often) the running block has flipped up and through any of the chain loops (see figure 9-30A).

All chain hoists and chain falls issued with NAVSEA SUPSALV Underwater Ship Husbandry equipment kits have been checked for chain twist and the chain hoist/fall has been loosely two-blocked so that the running block can not flip over into the working chain loops during shipment.

OPERATORS must ensure that the running block is not flipped over into the chain loops creating chain twist while deploying and rigging the chain hoists/falls.

To check for chain twist in the chain loop: Hang the hoist from the top hook in a safe, accessible location. Tighten the hoist until less then one foot of separation exists between the hoist body and the running block. The short throw allows for much easier visual detection of twist in the individual chain reeves. Confirm that none of the chain lengths running from the working chain sprocket to the running chain sprocket (chain reeves) have any twist caused by the running block being flipped over and through the loop of the chain. If ANY chain twist is detected, flip the running block back through the chain loop until the twist is removed. If ANY twist can not be removed by flipping the running block, the hoist chain MUST be removed from the hoist bodyand re-reeve exercising care not to twist the chain during installation.(page 9-39)

HP-2 maximum bond strength is not reached until a minimum cure time of 5 days has elapsed. Operational SRD pressures should be avoided until this maximum cure strength is obtained. For bow mounted SDRW systems, test pressure should be 30 psig maximum. For keel mounted SRD systems, test pressure should be 20 psig maximum. If pressure test results are acceptable and the SRD holds test pressure for five days, the SRD operational pressure can then be applied. Refer to the proper SRD technical manual for operational pressures (page 9-56).

SECTION 1 - INTRODUCTION

NOTEWithin Section 1, the general term "Sonar Rubber Dome" or "SRD" refers to both the bow mounted Sonar Dome Rubber Window (SDRW) and the keel mounted Sonar Rubber Dome (SRD). The type of SRD installation (SDRW or SRD) will be specified only if clarification is necessary.

9-1.1 PURPOSE.

This chapter describes the Naval Sea Systems Command (NAVSEA) approved procedure for underwater repair of SRDs on Navy ships. These procedures provide step by step instructions for cofferdam installation and for SRD repair. Implementation of and adherence to these procedures will ensure underwater tasks are safely and efficiently completed and that stringent quality control requirements are satisfied before, during, and after underwater work on SRDs. A list of required tools, materials, and equipment is included.

9-1.2 SCOPE

The information and procedures provided in this chapter apply to underwater repairs that can be accomplished on SRDs. Currently, SRDs are installed on CG 47, DD 963, DDG 993, DDG 51, FFG 7, and FF 1052 Class ships. Typical sonar dome configurations are illustrated in Figure 9-1. Figure 9-2 shows the dome location and configuration for CG 47 Class ships. Figure 9-3 shows the dome location and configuration for DD 963 and DDG 993 Class ships. Figure 9-4 shows the dome location and configuration for DDG 51 Class ships. Figure 9-5 shows the dome location and configuration for FFG 7 Class ships. Figure 9-6 shows the dome location and configuration for FF 1052 Class ships. This chapter does not supersede any information contained in any equipment technical manuals, the U.S. Navy Diving Manual, or the Naval Ships' Technical Manual. This chapter contains repair procedures. SRD and SDRW inspection procedures can be found in the appropriate technical manuals referenced in paragraph 9-1.6.

9-1.3 APPLICABILITY

This chapter combines information from various sources to provide repair activity personnel with a document that can be used to plan and conduct Underwater Ship Husbandry (UWSH) on an SRD. The procedures described are necessary for divers, working in conjunction with qualified technical repair personnel, to safely and efficiently conduct the inspections, cofferdam rigging, and repairs needed to return an SRD to optimum operating condition.

9-1.4 GENERAL INFORMATION

These procedures have been used and validated at various Navy ship maintenance facilities. The proper use of these procedures will result in repairs which will enhance sonar detection and will eliminate the need in most cases for emergency unscheduled drydocking or the need to transit the ship to a clean, warm water location for repairs.

9-1.4.1 As in all UWSH, there are advantages and disadvantages to SRD repair while the ship is afloat. The most obvious advantage is the elimination of costly drydocking or moving the ship to a clean, warm water port. The SDRW and SRD cofferdam systems provide a warm, clean water environment in which to perform repairs on SDRWs and SRDs and allow the expeditious return of theship to operational status. The principal disadvantages include the diver's restricted ability to function at the same level of efficiency as would be possible in a dry environment, and the need for additional precautions to reduce the chances of contamination of repair materials due to pierside water conditions.

9-1.4.2 The following sections provide detailed procedures for using the appropriate cofferdam during waterborne repair of an SDRW (Section 2) or a SRD (Section 3). These procedures include surveying the SRD, predive rigging, securing the cofferdam to the SRD, and unrigging and removing the cofferdam. There are two types of repairs on the SRD: grooming repairs and structural repairs. Repair procedures are detailed in Section 4.

9-1.5 SONAR RUBBER DOMES

9-1.5.1 Description. The SRD is a synthetic rubber structure reinforced with steel wire plies which lead to a larger steel "bead" cable. This bead cable is mounted to the bow (Figure 9-7) or to the keel (Figure 9-8) with a series of bolted clamps. The SRD surrounds and protects the ship's sonar system. In service, it is filled with water at a pressure sufficient to withstand hydrodynamic loads. The SRD is designed to operate with minimal deformation in order to protect sonar transducers and to provide a low drag shape with smooth, quiet, non-cavitating water flow. The rubber dome is acoustically transparent and is superior to steel in corrosion resistance. The outer layers of antifouling rubber resist marine growth better than other systems available for use on sonar domes.

9-1.5.2 Purpose. The purpose of the SRD is to maximize sonar operational efficiency, and to protect the underwater components of a sonar system from physical damage which may be incurred from water turbulence or impact with submerged foreign objects while the ship is underway. A properly functioning sonar dome fulfills these purposes at the ship's required operational speeds, and at the same time minimizes the attenuation of acoustic signals passing to and from the sonar transducers. SRD function is compromised by corrosion, marine fouling, and damage to the rubber layers of the dome. The dome, together with its hull mounting, is required to have a low drag shape, smooth surface, and smooth fairing into the hull. Surface irregularities may create cavitation along the SRD surface, thereby "blinding" part of the sonar. The SRD is designed to be strong enough to withstand operational hydrodynamic forces and be as acoustically transparent as possible.

9-1.6 REFERENCE DOCUMENTS

The documents listed below contain the technical information required for the planning, preparation, and execution of an SRD repair. Care should be taken to obtain and use the most current version of these documents. They must be used during the planning phase and should also be available on site during a repair. NAVSEA S0600-AA-PRO-020, General Information and Safety Precautions (Chapter 2 of this manual), provides information on obtaining and using technical documents.

a. Ship's Drawing Index (for pertinent hull drawings)

b. NAVSEA S9165-AH-MMA-010, Technical Manual for Sonar Dome Rubber Window SDRW-1 for DD 963, DDG 993, and CG 47 Class Vessels.

c. NAVSEA S9165-AD-MMA-010, Technical Manual for Sonar Dome Rubber Window SDRW-1 and SDRW-2 for FF 1040, FF 1052, FF 1078, FF 1098, FFG 1, CG 26, CGN 35, CGN 36, and CGN 38 Class Vessels.

d. NAVSEA S9165-AF-MMA-010, Technical Manual for Sonar Rubber Dome (SRD) for FFG 7 Class Vessels.

e. NAVSEA S9165-AE-MMA-010/SDRW-1, Technical Manual for Sonar Dome Rubber Window (SDRW) for DDG 51 Class Vessels.

f. NAVSEA Drawing 6697651, Main Arrangement, SDRW Repair Kit.

g. NAVSEA Drawing 6698203, Keel Dome Cofferdam Assembly Drawing.

9-1.7 PLANNING

Proper planning is required to ensure the successful completion of any UWSH task. Planning should begin at the earliest possible time, involve all concerned parties, and result in a written operational plan. General planning guidelines are presented in Chapter 2 of this manual (NAVSEA S0600-AA-PRO-020).

9-1.7.1 In planning an underwater SRD repair, planners should consider not only general planning guidelines but also those aspects that are unique to this task. The scope of the work may vary from non-urgent repairs, such as simple grooming involving fairing in a hairline cut to urgent repairs needed to maintain pressure in the SRD, such as application of multiple bolt-on patches. The Logic Diagram (Figure 9-9) outlines the sequence of events in the SRD repair decision process. Regardless of the scope, the repairing activity must ensure maximum practical use of NAVSEA technical manuals.

9-1.7.2 Ship Berthing The ship should be moored repair side to pier, with at least 10 feet of water below the lowest point of the SRD appendage at mean low tide to allow for installation of the repair habitat (if necessary). Approximately 100 feet of pier space should be available near water/stream risers to allow layout of the equipment required to support the SRD repair. If water temperature is less 60° F and/or visibility is less than 10 feet (high turbidity), fresh water firemain, 110 VAC/60Hz electrical power, and pier steam will also be required for operation of repair cofferdams. If cofferdam installation is required, local water currents should be less than 1 knot. Installation of the keel dome cofferdam requires the use of a fork lift and a 10-ton crane capable of placing the assembled cofferdam in the water on the outboard side of the ship.

9-1.7.3 Personnel Requirements. Scheduling and personnel requirements depend greatly on the ship's operating schedule and the time available to complete the task. Coordination among the dive team, surface support team, ship's force personnel, and local logistics support is mandatory and should be reflected in the operational plan. Divers tasked with SRD repair shall have completed the NAVSEA 00C5 sonar dome repair course and should have recent experience in sonar dome repairs.

9-1.7.4 Time Requirements. Typical non-structual grooming repairs require less than 1 hour (for each groomed area). Installation of a #3 patch can be completed within 3 hours (for each patch), while installation of a #1A patch (3 piece patch) requires 6-8 hours. After grooming or patch installation is complete, the Elastolock® adhesive must be allowed to cure. Cure time is related to ambient

water temperature and can be derived from Figure A-1 in Appendix A. After cure time has elasped, pressure testing (approximately 3 hours required) and speed trials (approximately 3 hours plus open sea transit time required) must be completed.

9-1.7.5 Damage Assessment Activities requiring SRD repairs should request assistance following the most current guidance established by either Commander, Naval Surface Force, Atlantic Fleet (COMNAVSURFLANT) or Commander, Naval Surface Force, Atlantic Fleet (COMNAVSURFLANT) or Commander, Naval Surface Force, Pacific Fleet, (COMNAVSURFPAC). Both Atlantic Fleet (LANTFLT) and Pacific Fleet (PACFLT) repair activities should forward requests by message or letter via the appropriate chain of command. Repair requests should specify the problem, assistance required, proposed primary and alternate dates for repair accomplishment, point of contact with phone numbers, availability of local Navy divers with SRD repair experience to provide support, and additional information as appropriate. Figure 9-10 illustrates a sample request for assistance.

9-1.7.6 Technical Assistance. The cognizant LANTFLT and PACFLT activities will evaluate repair requests and task the appropriate Intermediate Maintenance Activity (IMA) to accomplish repairs. Depending upon the scope of work, IMAs may requesttechnical assistance and equipment support from the Commander, Naval Sea Systems Command (COMNAVSEASYSCOM) Underwater Ship Husbandry Division, Code 00C5. LANTFLT and PACFLT activities accomplishing actual work should use the sample format in Figure 9-11 to report SRD repairs to NAVSEA 00C5.

9-1.8 PREPARATION.

Preparation for the SRD repair task using the appropriate SRD Cofferdam System consists of assembling all necessary materials and personnel identified in the planning phase and properly arranging those resources on site. Note that a typical repair site will be required to have adequate steam, electrical power, and fresh water available to support repairs. If cofferdam installation is not required, only fresh water is needed for repairs.

CAUTIONIt is essential that all tools and materials brought to the underwater job site are accounted for and removed at the end of the job. Tools and materials inadvertently left at the job site can generate unacceptable noise and possibly cause severe damage to shipboard components. Locally generated work packages shall ensure that a general tool and material log sheet is prepared and maintained during all UWSH operations.

9-1.8.1 Tools, Materials, and Equipment Requirements. Tables 9-1 through 9-3 provide a listing of the tools, materials, and equipment required to perform SRD repairs.

9-1.8.2 Recommended Tool Inventory for SRD Repair. SRD repair requires basic hand tools generally available from local resources. Table 9-1 lists a recommended minimum inventory of tools, materials, and hardware that the repair activity should have on hand before starting a repair. Basic hand tools are used to mix adhesive, groom the SRD, and apply the patch. Basic hand tools are also used to assemble the cofferdam. Divers will use a hydraulically powered underwater rotary wire brush to prepare the SRD surface. All tools, materials, and equipment are available as a pre-assembled kit from NAVSEA 00C5.

9-1.8.3 B.F. Goodrich HP-2 Elastolock® Adhesive. NAVSEA 00C5 maintains an inventory of current HP-2 Elastolock® at ESSM bases. Adhesive is labeled with expiration dates. Expired HP-2 Elastolock® shall not be used. Shipment of adhesive to repair activities within CONUS requires a minimum of three days. Shipment outside of CONUS requires more time and is subject to the customs regulations of the receiving country.

9-1.8.4 Underwater Repair Patch Kits No. 1A (52" x 27") and No. 3 (27" x 27"). Tables 9-2 and 9-3 list the materials used to apply patches to various size ruptures on an SRD. Figure 9-12 shows the geometry of the assembled repair patches. The adhesive (HP-2 ELASTOLOCK®) used to secure and seal the patch has a limited shelf life and is maintained by NAVSEA 00C5 on an as needed basis.

9-1.8.5 Lag Bolts Verify the availability of stainless steel lag bolts (full thread - no bolt shoulder), as specified, from a local source in case the bolts do not arrive with the bolt-on patches.

NOTEContact NAVSEA 00C5 for patch and HP-2 ELASTOLOCK® availability.

WARNINGAvoid inhaling NOFOUL® vapors, mist, dust, or fumes. Dust from buffing operations may cause irritation of upper and lower respiratory tract and mucous membranes, nausea, headache, and eye and skin irritation.

WARNINGAvoid direct bare skin contact with NOFOUL® surfaces or dust. Avoid contact between hands and mouth, and hands and eyes, if hands have been exposed to the NOFOUL® rubber material. Wash hands thoroughly before eating or smoking.

WARNINGEnsure adequate ventilation when working with NOFOUL®.

9-1.9 NOFOUL® PATCH

The B.F. Goodrich NOFOUL® underwater repair patch is the only approved waterborne structural repair patch. It is used for structural repairs and contains active ingredients which impedes the growth of marine organisms.

9-1.10 COFFERDAM SYSTEMS

The currently available cofferdam systems are manufactured to conform to the specific SRD configurations. The cofferdam systems consist of the hot water heating system and either the bow mounted SDRW cofferdam or the keel mounted SRD cofferdam (Figures 9-13 through 9-15). The cofferdam enables divers to work in a clean, warm, fresh water environment. This temperature controlled environment enhances the curing and bonding characteristics of HP-2 ELASTOLOCK® applied underwater. The SDRW cofferdam system may be fabricated and assembled in accordance with NAVSEA Drawing 6697651 and is discussed in Section 2 and shown in Figure 9-14. The SRD cofferdam system, may be fabricated and assembled in accordance with NAVSEA drawing 6698203, and is discussed in Section 3 and shown in Figure 9-15.

SECTION 2 - SONAR DOME RUBBER WINDOW (SDRW) COFFERDAM INSTALLATION AND REMOVAL PROCEDURE

NOTEWithin Section 2, the term Sonar Dome Rubber Window or SDRW refers to bow mounted Sonar Dome Rubber Window systems.

9-2.1 GENERAL

This section provides a detailed procedure for using the SDRW Cofferdam System during underwater repair of a SDRW on a Navy ship. This procedure includes surveying the SDRW, predive rigging, securing the cofferdam to the SDRW, and derigging and removing the cofferdam.

9-2.2 REFERENCE DOCUMENTS

The drawings and technical manuals listed in Section 1 support the information contained in this section. Each document is unique in subject matter, therefore all applicable documents listed must be available for ready reference while conducting underwater SDRW repair procedures.

9-2.2.1 Follow the inspection steps in the applicable NAVSEA SDRW technical manual referenced in Section 9-1.6 for the class of ship that you are repairing. Detailed repair procedures are located in section 4 of this chapter.

NOTEInformation received from other inspection activities cannot always be assumed to be completely accurate. Diving conditions, experience level of the inspection team providing the report, and interpretation of information vary from one dive team to another. Personnel carrying out these cofferdam procedures should rely primarily on the information obtained in the on-site survey of each repairing activity along with technical guidance provided by NAVSEA Code(s).

9-2.3 SURVEY

The survey enables the diving supervisor to gather all the information that may affect this repair. Survey information may beaccumulated from one or preferably all of the following sources: NAVSEA, Intermediate Maintenance Activities, Readiness Support Groups, Regional Maintenance Centers, the weapons or combat systems officer aboard the vessels requesting repair, andthe contractor hull survey reports used by the above sources. The waterborne inspection results gathered by the repair dive team will be included in the survey.

9-2.3.1 Inspection. To inspect the SDRW, follow the inspection steps in the applicable technical manual referenced in Section 9-1.6. These steps will give the repair team a complete SDRW profile.

9-2.3.2 Marking. While inspecting, divers should mark the hull and SDRW with a high contrast (yellow/white) paintstick as follows (Figure 9-16):

a. Mark all damaged areas to be repaired

b. Mark marriage line and waterline directly above the damaged areas

c. Mark marriage line at SDRW centerline (000 radial)

d. Mark waterline where the skeg meets the keel

9-2.4 PREDIVE RIGGING

NOTEThe following predive rigging procedures are SDRW specific. The dive team (DV) performing the actual rigging on the SDRW should perform the predive rigging.

Before cofferdam installation, ensure that steam, fresh water firemain, and 110 VAC 60 Hz power sources are available.

Since all underwater procedures require the joint effort and close coordination of divers (DV), topside support personnel (TOP), and ship's force (SF), the activity responsible for each step in these procedures is identified in parentheses at the beginning of the procedural step.

9-2.4.1 (TOP) Assemble and install rib assemblies in the cofferdam:

a. Join the half-rib pieces using the swaged unions to form the U-shaped rib assembly.

b. Starting at one end of the cofferdam, place the ends of each rib onto a pair of the slider tubes which are permanently mounted in the cofferdam.

c. Swing the rib down into place, lining it up with the applicable row of grommets on the interior of the cofferdam, and secure the rib using nylon tie wraps.

NOTENylon compression fittings are installed in various places on the cofferdam sides. These are used for thermistor installation later in the procedure. The threads should be lubricated with a silicon gel prior to cofferdam submersion in order to ease thermistor installation. Take care not to step on these fittings during cofferdam assembly.

9-2.4.2 (TOP) Rig the skeg bridle so that each of the uppermost D-rings are rigged with the following (see Figure 9-17):

a. One D strap with 2-inch ratchet buckle.

b. One 3-inch ratchet buckle

9-2.4.3 (TOP) Rig the A strap with the following: four locking travelers attached to each side of the fixed D-ring within 4 feet of the D-Ring (Figure 9-18). Tape the last locking traveler on each side to avoid loss.

9-2.4.4 (TOP/DV) Prepare and make ready for use the remaining straps, assemblies, and equipment (Figure 9-18):

a. B1 and B2 strap assemblies rigged with a 3-inch ratchet buckle on one end. Roll and tape excess strap.

b. Two C strap assemblies, rigged with a 3-inch ratchet buckle on each end and a locking traveler between the ratchet buckles. Coil and tape the excess strap

c. Three E strap assemblies.

d. Two AB strap assemblies with one 2-inch ratchet buckle. Roll and tape the excess strap.

e. Four 3-inch ratchet buckles.

9-2.4.5 (TOP) Unpack, inventory, inspect and make ready the following equipment for use at the repair site:

a. Hot water heating system.

b. Remaining tools and hardware on the inventory.

9-2.5 INSTALLING THE COFFERDAM

CAUTIONWhen tightening straps to secure the cofferdam to the SDRW, never exceed four clicks on the ratchet before checking connecting points and strap seal clearances.

9-2.5.1 (TOP) Man the bow with two people, two 75-foot rigging lines with swivel eyes, and one 100-foot bow line.

9-2.5.2 (DV) Pass one end of the 100-foot bow line from the bow through the D-ring on the A strap on the pier and return it to the bow.

NOTEThe 100-foot bow line will be fixed to the deck to support the A strap at a specific point in the water.

9-2.5.3 (TOP) Position the skeg bridle by passing the inboard 2-inch D strap tack shackle end from the main deck using the inboard 75-foot rigging line at the skeg/keel waterline mark (see section 9-2.3.2 for marking procedure required during inspection).

9-2.5.4 (TOP) Secure the D strap tack shackle end to the D-rings on a tube strap, which is placed around the bottom of a main deck stanchion directly above the skeg/keel waterline mark (Figure 9-19).

NOTESome classes of ships may not have a stanchion in the appropriate place. If so, an alternate location of attachment will be required. The D straps may angle forward or aft, as long as the skeg bridle can be properly secured.

9-2.5.5 (DV/TOP) Swim the outboard D strap under the keel at the skeg and attach it to the 75-foot outboard rigging line swivel eye hanging at the water's edge. Topside support will secure it to the deck (as in the previous step). Match locations for both inboard and outboard straps as shown in Figure 9-20.

9-2.5.6 (DV/TOP) Position the D straps per diver instructions. Take up slack evenly in the D straps at the 2-inch ratchet buckles. Do not draw the skeg bridle up hard to the keel. Leave about 3 inches between the keel and the bridle.

NOTEThe skeg bridle will be left suspended at the skeg/keel at this time. The divers will adjust the bridle position with the two D strap ratchet buckles at the keel and the two A strap ratchet buckles at the keel in a later step in this procedures (step 9-2.5.10).

9-2.5.7 (TOP) Pass the A strap to the divers. The A strap should be secured at a fixed depth point by the 100-foot bow line at the centerline of the SDRW just above the marriage line (Figure 9-21).

9-2.5.8 (DV) Position middle D-ring on the stem and take the bitter ends to the 3-inch ratchet buckles attached to the upper D-rings on the skeg bridle (Figure 9-21).

9-2.5.9 (DV) Pull up all slack in the A strap by hand, secure the strap in the ratchet buckle with a locking turn, and swim out the Astrap to ensure that there are no twists and that the A strap's D-ring is on the centerline and above the marriage line of the SDRW.

9-2.5.10 (DV) Firmly tighten the A and D straps to ensure the skeg bridle and all rigging remain in position. Mentally number each locking traveler from forward to aft, port and starboard, 1 thru 4 (Figure 9-22).

NOTEThe skeg bridle and A strap are now ready to accept the remaining hardware. The A strap and skeg bridle must be taut against their respective surfaces to prevent slippage.

CAUTIONAvoid over-tightening ratchet buckles as the strap system may fail.

9-2.5.11 (DV) Position the inboard and outboard locking travelers in reference to the damage mark at the upper marriage line (see section 9-2.3.2 for marking procedure required during inspection). The #2 locking traveler should be centered over the damage mark (Figure 9-22).

NOTEPosition a locking traveler forward and aft of the locking traveler located directly over the damage. The fourth locking traveler is a spare (Figure 9-22).

9-2.5.12 (DV) Rig the remaining hardware.

a. AB straps to the #1 and #3 inboard locking travelers (Figure 9-23).

b. B1 and B2 ratchet buckles to the skeg bridle lower D-rings (Figure 9-23).

c. C strap assemblies attached to the outboard #1 and #3 locking travelers (Figure 9-24).

9-2.5.13 (TOP) Rig the following:

a. 3-inch ratchet buckles to the lower D-rings on the inboard side seal straps on the cofferdam.

b. Swivel eye ends of two long tri-sling lines to the upper D-rings on the inboard side seal straps on the cofferdam and the short tri-sling line to the upper D-ring on the outboard centerline spine strap of the cofferdam.

c. (TOP) Attach the 75-foot rigging line to the bitter end of the tri-sling. Ensure that the divers are clear and lower the cofferdam into the water. As the cofferdam sinks, it will unfold (Figure 9-25).

NOTEOnce the cofferdam is lowered to the repair site on the 75-foot rigging line and secured to the AB straps by the upper vertical D-rings on the side seal straps, the rigging line may be slacked.

9-2.5.14 (DV) Adjust the ratchet buckles on the AB straps so that the top seal of the cofferdam is at least 2 feet above the damaged area.

9-2.5.15 (DV) Attach the B1 and B2 strap assemblies with the 3-inch ratchet buckles to the upper horizontal D-rings on the cofferdam side seal straps. Take the bitter ends to the 3-inch ratchet buckles attached to the lower set of D-rings on the skeg bridle. Pull up the slack by hand and take a locking turn (Figure 9-26).

9-2.5.16 (DV) Swim out the straps to ensure there are no twists and that the B straps run near parallel with the A strap.

9-2.5.17 (DV) Connect the 3-inch ratchet buckles attached to the lower vertical D-rings on the cofferdam side seal straps to the C strap assemblies using a crossing pattern or a straight pattern, whichever will result in the best cofferdam seal (Figure 9-24). Pull slack through by hand and take a locking turn. Position the locking traveler on the banjo near the lower marriage line closest to the cofferdam.

9-2.5.18 (DV/TOP) Pass the divers the three E strap assemblies. Attach one strap from the center D-ring on the top of the cofferdam to the #2 locking traveler on the A strap (Figure 9-27). Attach one E strap from each of the lower D-rings on the cofferdam to the locking travelers on the C straps and adjust the cofferdam top so that it is perpendicular to the SDRW and fully opened.

NOTEThe cofferdam is now completely rigged to facilitate a seal (Figure 9-28). If properly sealed, it should be difficult for the divers to insert their fingers between the dome and the cofferdam seal straps.

9-2.5.19 (DV) Tighten the B straps and ensure there is no gap between the cofferdam and the hull.

NOTEPrior to tightening the C straps, the E straps may need to be released so they will not prevent the side seal straps from sealing.

9-2.5.20 (DV) Tighten the C straps and ensure there is no gap between the cofferdam and the hull.

9-2.5.21 (DV) Rig internal lights, video camera, and other necessary gear (i.e., tool bags) inside the cofferdam.

9-2.6 INSTALLING THE HEATING SYSTEM

NOTEThe following steps reference NAVSEA drawing numbers 6697665 and 6697666 (in Appendix B).

9-2.6.1(TOP) Rig the water heating system:

a. Attach the condensate drain hose to the condensate drain valve at the bottom of the heat exchanger. Run the condensate hose over the side of the pier.

b. Connect the pier potable water supply hose assembly to the heater cold water inlet.

c. Connect the heater hot water outlet to the cofferdam hot water supply hose (1-1/2" reinforced tygon tubing).

NOTEThe steam supply line connected to the pier steam supply should be blown down prior to connection to the steam manifold in order to rid the steam line of particulate matter which may have collected there.

9-2.6.2 (TOP) Attach the 6-foot steam hose assembly to the manifold inlet and the 3-foot steam hose assembly to the outlet of the steam manifold assembly. Attach the other end of the 3-foot steam hose assembly to the steam inlet on the water heater (steam to heater).

WARNINGPier potable water is heated by the heat exchanger and circulated through the cofferdam. Prior to energizing the water system, verify that all water system connections are properly fastened. Improperly fastened water system connections could fail causing serious injury or death. Steam manifold must be used as part of the steam supply system as it provides a pressure release path for incoming steam.

9-2.6.3 (TOP) Attach the potable water hose assembly and other end of the 6-foot steam hose assembly to pier water and steam supplies.

9-2.6.4 (DV) Attach the other end of the hot water supply hose to the lower inboard manifold on top of the cofferdam (Figure 9-29).

9-2.6.5 (DV/TOP) Tie off one end of the air exhaust hose (1-1/2" tygon tubing) to a main deck stanchion, and lower the other end to the divers. Attach the other end of the air exhaust hose to the higher outboard manifold on top of the cofferdam.

9-2.6.6 (DV) Attach monitoring wires T1, T2, and T3, which are used to monitor cofferdam water temperature at the top, middle, and bottom (respectively) of the cofferdam, to the cofferdam using the thermistor port compression fittings installed on the side of the cofferdam. Divers should take care not to back the fittings completely off the threads during thermistor installation. Put monitoring wire T6, which monitors the ambient water temperature, in the water outside the cofferdam.

9-2.6.7 (DV/TOP) Verify all connections are properly fastened.

9-2.7 HEATER OPERATIONS

9-2.7.1 Secure steam valve on manifold.

9-2.7.2 Open condensate bleed valve on manifold.

9-2.7.3 Slowly open steam manifold supply.

9-2.7.4 Drain off all condensate.

9-2.7.5 Secure steam supply.

9-2.7.6 Secure condensate bleed valve.

9-2.7.7 Open steam manifold supply.

9-2.7.8 Open potable water supply to obtain a continuous flow of water into the cofferdam.

9-2.7.9 Open steam supply valve on heater.

9-2.7.10 Commence pumping heated water to the cofferdam.

NOTEMonitor steam line pressure. If pressure exceeds 80 psig, reduce pier steam supply until pressure is stabilized between 50 -70 psig.

NOTECofferdam side door should remain closed and bottom door should remain open until seawater is displaced by the fresh warm water at the desired temperature.

9-2.7.11 Once warm water starts circulating into the cofferdam, divers should check for leaks in the seal.

9-2.7.12 Leaks can be detected from topside by monitoring water temperatures at thermistors T1, T2, and T3 using the systems monitor installed on the water heater. T1 should show a temperature increase first, followed by T2, and then T3. If T2 and/or T3 show little or no increase, a leak is present.

9-2.7.13 Upon reaching the desired temperature, repair can begin. Refer to section 4.

9-2.7.14 When repairs are complete, close the bottom door of the cofferdam and maintain the temperature of the water inside the cofferdam for the duration of the curing process of the repair.

9-2.8 UNRIGGING AND REMOVAL

The cofferdam is unrigged and removed by reversing the rigging and installation procedures. When unrigging the straps with ratchet buckles, take a locking turn in the binder to prevent loss of the binder or strap. Leave a tape tail when securing rolls of belt material. All cofferdam components should be rinsed with fresh water and allowed to dry before packing in shipping containers. All metal components should be treated with water displacement agents (WD-40/LPS-1) and preservatives (LPS-3).

SECTION 3 - SONAR RUBBER DOME (SRD) COFFERDAM INSTALLATION AND REMOVAL PROCEDURE

NOTEWithin Section 3, the term Sonar rubber dome or SRD refers to keel mounted Sonar rubber dome systems.

9-3.1 GENERAL

This section provides a detailed procedure for using the SRD Cofferdam System during underwater repair of a keel mounted SRD on a Navy ship. This procedure includes surveying the SRD, predive rigging, securing the cofferdam to the SRD, and derigging and removing the cofferdam.

9-3.2 REFERENCE DOCUMENTS

The drawings and technical manuals listed in Section 1 support the information contained in this section. Each document is unique in subject matter, therefore all applicable documents listed must be available for ready reference while conducting underwater SRD repair procedures.

9-3.2.1 Follow the inspection steps in the applicable NAVSEA SRD technical manual referenced in Section 9-1.6 for the class ship you are repairing. Detailed repair procedures are located in Section 4 of this chapter.

NOTEInformation received by other inspection activities cannot always be assumed to be completely accurate. Diving conditions, experience level of the inspection team providing the report, and interpretation of information vary from one dive team to another. Personnel carrying out these cofferdam procedures should rely primarily on the information obtained in the on-site survey of each repairing activity along with technical guidance provided by the cognizant NAVSEA Code(s).

9-3.3 SURVEY

The survey enables the diving supervisor to gather all the information that may affect this repair. Survey information may beaccumulated from one or preferably all of the following sources: NAVSEA, Intermediate Maintenance Activities, Readiness Support Groups, Regional Maintenance Centers, the weapons or combat systems officer aboard the vessels requesting repair, andthe contractor hull survey reports used by the above sources. The waterborne inspection results gathered by the repair dive team will be included in the survey.

9-3.3.1 Inspection. To inspect the SRD, follow the inspection steps in the applicable technical manual referenced in Section 9-1.6. These steps will give the repair team a complete SRD profile.

9-3.3.2 Marking. While inspecting, divers should mark the hull and SRD with a high contrast (yellow/white) paintstick as follows (Figure 9-30):

a. Mark all damaged areas to be repaired

b. Mark waterline points fore and aft where the SRD skirt meets the keel

9-3.4 PREDIVE RIGGING

NOTEThe following predive ship rigging procedures are SRD specific. The dive team (DV) performing the actual rigging on the SRD should perform the predive rigging.

Before cofferdam installation, ensure that steam, fresh water firemain, and 110 VAC 60 Hz power sources are available.

Since all underwater procedures require the joint effort and close coordination of divers (DV) and topside support personnel (TOP)and surface force (SF), the activity responsible for each step in these procedures is identified in parentheses at the beginning of the procedural step.

The SRD cofferdam system consists of a large aluminum box cofferdam which is assembled on the pier, transferred to the water, and then rigged under the ship. The cofferdam system includes all rigging necessary to assemble, transfer, and rig the cofferdam. Rigging consists of polyester roundslings and eyeslings. Throughout this procedure, the term "pendant" refers to the supplied polyester rigging or to 1/2 inch wire rope. Due to the size of the individual cofferdam panels and the assembled cofferdam, the

repair activity must supply a fork lift (for panel movement during assembly) and a 10-ton capacity crane (capable of transferring the cofferdam from the pier to water).

The cofferdam can be transferred to the water between the ship and the pier (between mooring lines and camels) via a two point lift. When assembled, the cofferdam is 14-feet wide and 28-feet long. If the path from the pier to the SRD is obstructed by lines or camels and the path cannot be cleared, the crane must be capable of transferring the cofferdam to the water on the outboard side of the ship.

Assembly instructions for the SRD cofferdam panels are included with the SRD cofferdam system.

CAUTIONChain twist in the working chain loops of manual chain hoists and chain falls will cause chain failure. Chain twist in the working chain loop occurs when the chain has an improper reeve through the chain sprockets OR (more often) the running block has flipped up and through any of the chain loops (see figure 9-30A).

All chain hoists and chain falls issued with NAVSEA SUPSALV Underwater Ship Husbandry equipment kits have been checked for chain twist and the chain hoist/fall has been loosely two-blocked so that the running block can not flip over into the working chain loops during shipment.

OPERATORS must ensure that the running block is not flipped over into the chain loops creating chain twist while deploying and rigging the chain hoists/falls.

To check for chain twist in the chain loop:

Hang the hoist from the top hook in a safe, accessible location. Tighten the hoist until less then one foot of separation exists between the hoist body and the running block. The short throw allows for much easier visual detection of twist in the individual chain reeves. Confirm that none of the chain lengths running from the working chain sprocket to the running chain sprocket (chain reeves) have any twist caused by the running block being flipped over and through the loop of the chain. If ANY chain twist is detected, flip the running block back through the chain loop until the twist is removed. If ANY twist can not be removed by flipping the running block, the hoist chain MUST be removed from the hoist body and re-reeve exercising care not to twist the chain during installation.

9-3.4.1 (TOP) Stage 3-foot and 12-foot roundslings, and 3-ton chain hoists on the main deck. Outboard chain hoists should be completely slacked, and inboard chain hoists should have approximately 10 feet of chain between the blocks.

9-3.4.2 (TOP) Loop 12-foot roundslings over the forward port and starboard bitts, lead the roundslings thru the forward enclosed chocks at the main deck edge (Figure 9-31) and connect them to 30-foot pendants with 3/4-inch shackles.

9-3.4.3 (TOP) Bring the end of the 30-foot pendants to the main deck, attach 3-ton chain hoists, and lower the hoists. The end of the pendant and the entire chain hoist should hang below the waterline (Figure 9-32).

9-3.4.4 (TOP) Pass 3-foot roundslings thru the port and starboard aft chocks (closest to the bridge) at the main deck edge (Figure 9-31) and connect them to 30-foot pendants with 3/4-inch shackles.

9-3.4.5 (TOP) Bring the end of the 30-foot pendants to the main deck, attach 3-ton chain hoists, and lower the hoists. The end of the pendant and the entire chain hoist should hang below the waterline (Figure 9-32).

9-3.5 COFFERDAM RIGGING AND INSTALLATION

NOTEFor the purposes of this procedure, "inboard" means the pierside side of the ship, and "outboard" means the seaward side of the ship. Installation is done from pierside (inboard).

9-3.5.1 (TOP) Attach 3-foot pendants with 3/4-inch shackles to the four lifting pad eyes on the cofferdam. These are the primary shackles (Figure 9-32, detail).

9-3.5.2 (TOP) Using another 3/4-inch shackle, attach a 30-foot pendant and a tending line to each of the inboard primary 3/4-inch shackles attached in 9-3.5.1 (Figure 9-32, detail). A four point lift may also be used, if required by rigging two additional 30-foot pendants. This will allow the 30-foot pendants (which lead to the crane) to be easily removed later in the procedure.

WARNINGAs the cofferdam rotates to the point where it is about to lift off of the pier, the outboard edge still in contact with the pier may "kick out" as the cofferdam lifts off of the pier. Ensure that personnel remain clear.

9-3.5.3 (TOP) Attach the two inboard 30-foot pendants to the crane hook and slowly lift the cofferdam.

9-3.5.4 (TOP) Once the cofferdam is clear of the pier, transfer the cofferdam into the water.

CAUTIONRefer to Caution immediately before paragraph 9-3.4.1

9-3.5.5 (DV) Connect the inboard chain hoists to the inboard 3-foot pendants. (Figure 9-33, step 2)

9-3.5.6 (TOP) Lower the cofferdam until the load is transferred to the inboard hoists.

9-3.5.7 (DV) Disconnect the 30-foot crane pendants from the primary shackles. (Figure 9-33, step 3)

9-3.5.8 (TOP) Remove crane pendants from the repair area.

9-3.5.9 (DV) Swim the outboard chain hoists under the keel and connect the hoists to the 3-foot outboard pendants on the cofferdam. (Figure 9-33, step 4)

9-3.5.10 (DV) Adjust inboard and outboard chain hoists until cofferdam is centered under the SRD. (Figure 9-33, step 5)

9-3.5.11 (DV) Slowly adjust chain hoists and raise the cofferdam until the top of the cofferdam passes the marriage line. Divers should raise the cofferdam a small amount, inspect the distance between the SRD, the cofferdam top, and the inflatable seal, and readjust the cofferdam in order to avoid damage to the SRD and cofferdam seal. Raise the cofferdam in this fashion until the standoffs engage the keel. Ensure that the standoffs are located on keel centerline. Once in place, the distance between the SRD skirt and the inflatable seal should be 3 inches or less. (Figure 9-33, step 6)

9-3.5.12 (TOP) Connect the air hose to the electric air compressor, turn the compressor on, and give the hose to the divers.

9-3.5.13 (DV) Take the hose to the quick disconnect fitting located on the inflatable seal approximately 2 feet to port of the cofferdam centerline. Connect the air hose to the fitting and inflate the seal to a maximum pressure of 4 psig. Disconnect the air hose.

9-3.5.14 (DV) Swim the entire top perimeter of the seal and inspect the seal and sealing surface to ensure a good seal.

9-3.5.15 (TOP/DV) Transfer Herculite bottom cover to the divers and rig it to the bottom of the cofferdam using the integral bungee cords and hooks at the bottom of the cofferdam.

9-3.5.16 (DV) One diver should enter the cofferdam to inspect the seal from the inside. The outside diver can look for leaks defined by the inside diver's exhaust.

9-3.5.17 (DV) Rig internal lights, video camera, and other necessary gear (i.e., tool bag) inside the cofferdam.

9-3.6 INSTALLING THE HEATING SYSTEM

NOTEThe following steps reference NAVSEA drawings 6697665 and 6697666 (Appendix B), which detail the heating system for the SDRW cofferdam system. The same system is used for the SRD cofferdam.

9-3.6.1 (TOP) Rig the water heating system:

a. Attach the condensate drain hose to the condensate drain valve at the bottom of the heat exchanger. Run the condensate hose over the side of the pier.

b. Connect the pier potable water supply hose assembly to the heater cold water inlet.

c. Connect the heater hot water outlet to the cofferdam hot water supply hose (1-1/2" reinforced Tygon tubing).

NOTEThe steam supply line connected to the pier steam supply should be blown down prior to connection to the steam manifold in order to rid the steam line of particulate matter which may have collected there.

9-3.6.2 (TOP) Attach the 6-foot steam hose assembly to the manifold inlet and the 3-foot steam hose assembly to the outlet of the steam manifold assembly. Attach the other end of the 3-foot steam hose assembly to the steam inlet on the water heater (steam to heater).

WARNINGPier potable water is heated by the heat exchanger and circulated through the cofferdam. Prior to energizing the water system, verify that all water system connections are properly fastened. Improperly fastened water system connections could fail causing serious injury or death. Steam manifold must be used as part of the steam supply system, as it provides a pressure release path for incoming steam.

9-3.6.3 (TOP) Attach the potable water hose assembly and other end of the 6-foot steam hose assembly to pier water and steam supplies.

9-3.6.4 (DV) Attach the other end of the hot water supply hose to the hot water supply manifold located at the top front panel of thecofferdam.

9-3.6.5 (DV/TOP) Tie off the plain end of the air exhaust hoses (1-1/2" tygon tubing) to a main deck stanchion, and lower the other ends to the divers. Attach the ends of the air exhaust hoses to the air vent fittings at the top forward corners of the cofferdam.

9-3.6.6 (DV) Attach monitoring wires T1, T2, and T3, which are used to monitor cofferdam water temperature at the top, middle, and bottom (respectively) of the cofferdam, inside the cofferdam. Put monitoring wire T6, which monitors the ambient water temperature, in the water outside the cofferdam.

9-3.6.7 (DV/TOP) Verify that all connections are properly fastened.

9-3.7 HEATER OPERATIONS

9-3.7.1 Secure the steam valve on manifold.

9-3.7.2 Open the condensate bleed valve on manifold.

9-3.7.3 Slowly open the steam manifold supply.

9-3.7.4 Drain off all condensate.

9-3.7.5 Secure the steam supply.

9-3.7.6 Secure the condensate bleed valve.

9-3.7.7 Open the steam manifold supply.

9-3.7.8 Open the potable water supply to obtain a continuous flow of water into the cofferdam.

9-3.7.9 Open the steam supply valve on the heater.

9-3.7.10 Commence pumping heated water to the cofferdam.

NOTEMonitor steam line pressure. If pressure exceeds 80 psig, reduce pier steam supply until pressure is stabilized between 50 -70 psig.

NOTEA corner of the Herculite bottom cover should remain open until seawater is displaced by the fresh warm water at the desired temperature.

9-3.7.11 Once the warm water starts circulating into the cofferdam, divers should check for leaks in the seal.

9-3.7.12 Leaks can be detected from topside by monitoring water temperatures at thermistors T1, T2, and T3 using the systems monitor installed on the water heater. T1 should show a temperature increase first, followed by T2, and then T3. If T2 and/or T3 show little or no increase, a leak is present.

9-3.7.13 Upon reaching the desired temperature, repair can begin. Refer to section 4.

NOTEIn colder regions two heater systems can be used to supply hot water to the cofferdam. Contact NAVSEA 00C5 for heater system availability.

9-3.7.14 When repairs are complete, secure the Herculite cover and maintain the temperature of the water inside the cofferdam for the duration of the curing process.

9-3.8 UNRIGGING AND REMOVAL

After the inflatable seal has been depressurized (using the detachable air hose fitting) and all hoses and herculite cover have been removed, the cofferdam is unrigged and removed (Figure 9-34). All cofferdam components should be rinsed with fresh water before packing in the shipping van. All mechanical components exposed to seawater (i.e. standoff threads, air hose quick disconnect fittings) should be treated with water displacement agents (WD-40/LPS-1) and preservatives (LPS-3).

SECTION 4 - SDRW AND SRD REPAIR

NOTEWithin Section 4, the term sonar rubber dome or SRD refers to both bow mounted SDRW systems and keel mounted SRD systems.

NOTESRD repair training classes are available from NAVSEA 00C5. Contact NAVSEA to schedule training.

9-4.1 GENERAL

This section describes a logical decision process which can be used to guide divers, planners, and other repair personnel in identifying and classifying urgent and non-urgent SRD repairs. This section also contains step by step repair procedures for grooming and structural repairs to SRD systems which, when correctly followed, can restore the SRD to operational condition. Strict adherence to these procedures is required to ensure a successful repair. Procedures related to surface preparation and adhesive mixing are highly critical.

NOTEIf water conditions are cold and/or turbid, the cofferdam system can be used during the inspection phase of any SRD repair operation to increase the comfort and effectivness of the diver.

9-4.2 INSPECTION

Before beginning grooming or structural repair procedures, conduct an inspection of the SRD in accordance with the appropriate technical manual. This process requires the diver to mark the SRD (see paragraph 9-2.3.2) if there are no identifiable markings. For example, the factory inlaid markings on SDRW systems (Figure 9-35) may be covered by fairing epoxy at installation, or the painted markings on SRD systems may have been obscured by rust, wear, or marine fouling.

9-4.3 ANALYZE INFORMATION

Before deciding on repair plans and priorities, planners should review all available sources of information, including noise spoke data analysis, radiography results, and inspection reports.

9-4.3.1 Cavitation Theory and Noise Spokes. Most noise spokes are created by a process called cavitation. Cavitation can be caused by cosmetic or structural damage to the rubber layers of the SRD, marriage line, fairing plates, fouling, low dome pressure, or anything else which creates a surface irregularity. The irregularity causes local flow velocity to increase which causes a local pressure decrease causing the formation of bubbles. As these bubbles move aft of the damaged area, pressure in the area of the bubbles increases and they collapse, creating noise. Thus a noise spoke is produced which can aid in pinpointing the location of damage which is causing the cavitation. Bubbles can also blind areas aft of areas of surface damage due to the large change in fluid density related to their presence. This alters the path of sound energy created by the sonar transducers and effectively "blinds" the sonar in that area.

9-4.3.1.1 A noise spoke is a serious problem which compromises sonar operations. It is important to perform dome grooming repairs on areas which are responsible for noise spokes in order to regain the original acoustic transparency of the SRD, arrest any structural damage, and protect the SRD from further damage. If the damage cannot be corrected by waterborne grooming repairs or the use of flexible patches, the ship should obtain further guidance from NAVSEA.

9-4.3.1.2 The dive team may be unable to locate the source of cavitation because there is no visible damage. Two common sources of cavitation are razor sharp cuts and old repairs.

NOTEDamage which consists of a small flap of dome material is difficult to locate. Feeling the dome with bare hands or using a water jet hose can assist in locating the damage.

9-4.3.2 Radiography. NAVSEA has a procedure for the radiographic inspection of sonar dome rubber windows (SDRW) which can be used to locate wire ply damage that may lead to dome rupture. These procedures cannot be used on keel mounted SRDs, asthey do not allow access to the dome interior. Radiography can be performed in drydock or when the ship is waterborne. Use the latest SDRW radiography data, available from NAVSEA or the ship's Weapons or Combat Systems Officer, to help analyze suspected damage. If no damage is found, a correlation study may be required.

NOTETo obtain additional information on noise spokes and radiography, contact NAVSEA .

9-4.3.3 Sonar Self-Noise Correlation Study. There may be mechanical or electrical problems with the ship's sonar hardware. When repair investigators are certain the systems are operating correctly, the Commanding Officer of the vessel should be advised to conduct a correlation study. This method of identifying noise can pinpoint the origin of noise within 6 inches. The ship can then be scheduled for another waterborne inspection of the SRD at the location pinpointed by the correlation study.

NOTEAlways inform NAVSEA of the findings from the waterborne inspection before implementing SRD repairs.

9-4.4 GROOMING REPAIRS

Grooming repairs are completed to correct minor damage. This applies to gouges, pits, blisters, bubbles, flaps (less than 2 square inches), and cuts.

NOTEGrooming repairs should only be conducted on areas which are causing noise spokes or associated problems. If an area which isnot creating noise is repaired and subsequently fails due to inadequate surface preparation, the flap of epoxy may now create noise where it did not previously exist.

NOTEB. F. Goodrich HP-2 ELASTOLOCK® is the only adhesive approved for use in underwater rubber sonar dome grooming and/or structural repairs.

9-4.4.1 Environmental Conditions. Water temperature and turbidity are critical factors that determine whether the cofferdam system should be used when making grooming repairs. Chemical bonding and complete curing of adhesives are affected primarily by the surface preparation and the temperature inside and outside the SRD. The temperature may fall within the adhesive cure curve parameters (Appendix A, Figure A-1) but the ship's operational schedule may not be compatible if cure time exceeds the ship's availability time. Also, increased temperature will increase the bond strength between the rubber and the adhesive. A second factor is turbidity (the amount of suspended particulate matter in the water.) Turbidity affects the mechanical bonding of adhesives to the SRD by creating a "release agent" between the adhesive and rubber. If the water temperature and turbidity are acceptable, make grooming repairs in accordance with the appropriate technical manual and the following procedures. These step-by-step procedures shall be followed without variation unless authorized by NAVSEA. Successful application of HP-2 requires proper water temperature, a properly prepared SRD surface, and surrounding water that is relatively free from turbidity (particulate contaminants). If these conditions are not met, the probability of a successful repair decreases significantly. If the water quality and temperature are doubtful, conduct repairs following the appropriate technical manual using the cofferdam system. See Section 2 or Section 3 for procedures for rigging SDRW and SRD cofferdam systems.

9-4.4.2 Grooming Repair Procedure. (DV) Once the area of repair has been designated, remove all loose rubber material.

NOTECare must be taken not to cut through the 1/4 inch NOFOUL® cover or fill rubber and expose the steel wire strength ply.

9-4.4.3 (DV) Use a new scalpel to skive around the perimeter of the damaged area on a 45 degree angle.

9-4.4.4 (DV) Use a hand-held hydraulic rotary grinder and a new wire cup brush to clean the entire surface of the area being repaired to a distance of 1 foot away from the edge of the damage. This will serve to remove fouling, old rubber, slimes, and other contaminants which act as release agents and degrade the bonding properties of the HP-2 ELASTOLOCK®. New wire cup brushes shall be used. Old or dirty wire brushes will transfer contaminants to the SRD surface and will degrade adhesive bonding properties. This step shall be done immediately preceding the application of HP-2. If contaminants settle onto the repair area, the HP-2 will not adhere. Divers should direct topside to start HP-2 mixing when they are within 10 minutes of completing surface preparation. During surface preparation, abrasion of the dome surface and a change in surface appearance and texture should be evident.

NOTEDue to power and torque losses related to their use underwater, air powered/pneumatic tools shall not be used for SRD surfacepreparation.

9-4.4.5 (TOP) Mix HP-2 ELASTOLOCK® topside in accordance with the procedure in Appendix A.

NOTEHP-2 pot life is approximately 50 minutes. Workability of HP-2 starts to degrade within 30 minutes.

9-4.4.6 (DV) Clean the repair area again with a hand-held hydraulic rotary grinder and wire cup brush immediately before application of HP-2 in order to remove slimes which may have started to build up on the surface.

9-4.4.7 (DV) Apply HP-2 to the damaged area ensuring that the damaged area is filled completely. Overfill the area and "work" the HP-2 into the damaged area with fingers.

9-4.4.8 (DV) Use a scalpel or the edge of a spatula to remove the excess HP-2 from the perimeter of the damage.

9-4.4.9 (DV) Using a piece of pipe as a roller, smooth the exposed surface of the HP-2 so that it conforms to the curvature of the rubber window and provides a smooth surface contour (Figure 9-36).

9-4.4.10 (TOP) Clean the tools used with HP-2 immediately. Acetone is the recommended cleaning solvent, but appropriate safety precautions must be taken when it is used.

9-4.4.11 (DV) Allow HP-2 to cure according to Appendix A, Figure A-1 and inspect for proper adhesion. Remove any excess HP-2 to ensure a smooth final repair surface.

9-4.5 STRUCTURAL REPAIRS

Structural repairs are required when one or more of the wire plies have been exposed or broken. When performing a repair, water conditions, surface preparation, timing of adhesive and patch application, and the curing of HP-2 ELASTOLOCK® adhesive is extremely critical.

NOTEB. F. Goodrich HP-2 ELASTOLOCK® is the only adhesive approved for use in underwater rubber sonar dome grooming and/or structural repairs. The B.F. Goodrich NOFOUL® patch is the only approved waterborne repair structural patch.

9-4.5.1 Environmental Conditions. Water temperature and turbidity are critical factors in determining whether the cofferdam system should be used when making grooming repairs. Chemical bonding and complete curing of adhesives are affected primarily by the surface preparation and the temperature inside and outside the SRD. The temperature may fall within the adhesive cure curve parameters (Appendix A, Figure A-1) but the ship's operational schedule may not be compatible if cure time exceeds the ship's availability time. Also, increased temperature will increase the bond strength between the rubber and the adhesive. A second factor is turbidity (the amount of suspended particulate matter in the water.) Turbidity affects the mechanical bonding of adhesives to the SRD by creating a "release agent" between the adhesive and rubber. These step-by-step procedures shall be followed without variation unless authorized by NAVSEA. Successful application of a bolt-on patch requires proper water temperature, a properly prepared SRD surface, and surrounding water that is free from turbidity (particulate contaminants). If these conditions are not met, the probability of a successful repair decreases significantly. The repair may fail the pressure test and drydocking of the vessel may be required. Each patch can be applied only once. There is no margin for error. Repairs shall be conducted following the procedures detailed in the appropriate technical manual and this manual. For structural repairs a cofferdam system shall be used unless otherwise approved by NAVSEA .

NOTESee Section 2 or Section 3 for rigging procedures for cofferdam systems.

9-4.5.2 Structural Repair Procedure. Before any repair on the SRD begins, the nature and extent of the damage must be assessed (i.e. rupture, delamination, structural damage, size, location, etc). This information will allow the repair activities to plan properly for the repair and to obtain the proper repair materials.

9-4.5.3 (DV) The exact position and dimensions of the rupture of the SRD must be determined, including position (port/starboard, radial, and distance in inches from upper/lower marriage lines); length of rupture (in inches); width of opening (in inches) with fire main pressure on and off; orientation of the rupture (vertical, horizontal, or other angle). Check for unusual features on the SRD surface such as distinct indentations or bulges in the vicinity of the rupture that may indicate a near rupture. Photographs and/or video of the damage should be taken.

9-4.5.4 (DV) Transfer the patch and a paintstick to the repair area and test fit the patch over the rupture. After the patch is properly oriented with the dome with respect to placement and curvature, one diver will hold the patch against the dome while the other diver marks the dome at the patch corners approximately 1 foot from the patch edge. This will define the dome surface to be prepared for

the patch adhesive and the adhesive that extrudes from under the patch during bolt installation. Mark the patch and dome orientation to ensure that the patch is not mistakenly turned 90 degrees before installation.

NOTEDue to the orientation of the steel strength plies, repair patches bend only in one direction. Divers should make sure that the patch is oriented so that the patch will bend with the curvature of the dome.

9-4.5.5 (DV/TOP) Return the patch to topside for cleaning and surface preparation. Topside personnel should place the patch on a clean plastic sheet and use a hand-held hydraulic rotary grinder and a new wire cup brush to clean and prepare the back side of the patch (no lettering) for application of HP-2. This will serve to remove oxidized rubber and other contaminants. New wire cup brushes shall be used. Old or dirty wire brushes will transfer contaminants to the patch surface and will degrade epoxy bonding properties. During surface preparation, abrasion of the patch surface, rubber particulate, and a change in surface appearance and texture should be evident. This step shall be done immediately preceding the application of HP-2. Once surface preparation is complete, remove rubber particulate/dust with a clean dust brush and cover the patch with a clean plastic sheet.

WARNINGNOFOUL® rubber is permeated with antifoulant compounds designed to impede marine growth. A mask and goggles should be worn when preparing NOFOUL® rubber topside.

9-4.5.6 (DV). Transfer the grinder and wire cup brush to the divers. Divers shall prepare the entire surface of the SRD within the corner marks placed in paragraph 9-4.5.4. This will serve to remove fouling, old rubber, slimes, and other contaminants which act as release agents and degrade the bonding properties of the HP-2 adhesive. This step shall be done immediately preceding the application of HP-2. If contaminants settle onto the repair area, the HP-2 will not adhere. Divers should direct topside to start HP-2 mixing when they are within 10 minutes of completing surface preparation. During surface preparation, abrasion of the dome surface and a change in surface appearance and texture should be evident.

NOTEDue to power and torque losses related to their use underwater, air powered/pneumatic tools shall not be used for SRD surfacepreparation.

9-4.5.7 (TOP) Mix HP-2 ELASTOLOCK® topside in accordance with the procedure in Appendix A.

NOTEThe following step must not be skipped. Dome surface condition is critical to the proper adhesion of HP-2 ELASTOLOCK®. Ensure that the repair area is clean.

9-4.5.8 (DV) Clean the repair area again with a hand-held hydraulic rotary grinder and wire cup brush immediately before application of HP-2 in order to remove slimes which may have started to build up on the surface.

NOTEHP-2 pot life is approximately 50 minutes. Workability of HP-2 starts to degrade within 30 minutes.

9-4.5.9 (TOP) Fill a ziplock bag with clean fresh water, place a ball of HP-2 in the bag, and seal the bag. The bag and the fresh water will protect the adhesive from contaminants on the water surface (i.e. fuel slicks). Transfer the HP-2 to the divers.

9-4.5.10 (DV) Apply HP-2 to the prepared repair area, "working" it into the roughened dome surface 2 to 3 inches beyond the boundary of the patch (within the boundary defined by the corner marks). This will allow for fairing the extruded adhesive into the patch edges after the bolting procedure is complete.

9-4.5.11 (DV) Press HP-2 into the rupture to fill the opening.

NOTEAs much as four square feet of HP-2 may have to be applied for a particular patch. This is a time consuming process requiring at least two divers. The strength of the final bonding of the patch to the SRD surface is dependent on proper surface preparation and application of HP-2 by the divers. Care must be taken to ensure that the HP-2 has been pressed firmly and evenly over the cleaned and roughened repair area. To provide for the initial mechanical contact between the patching surfaces while chemical bonding progresses during the cure cycle, it is critical that HP-2 be properly applied in the area around the rupture to seal the opening and eliminate a leak path between the patch and sonar dome.

9-4.5.12 (DV) Notify topside to begin applying HP-2 to the patch when they are within 10 minutes of completing adhesive application.

9-4.5.13 (TOP) Upon notification by divers, apply a thin uniform layer of HP-2 (approximately 1/4-inch thick) to the prepared back surface of the patch, "working" the adhesive into the surface of the patch. This is best completed with wet latex gloves. HP-2 will not stick to wet latex gloves.

NOTEThe prepared patch should be placed in a garbage bag or a wrapped plastic sheet (containing enough water to cover the patch and adhesive) before lowering the patch to the divers. This will protect the patch from contact with contaminants on the water surface which are present at most repair sites. HP-2 will not adhere to the dome after contact with oil or other contaminants.

9-4.5.14 (DV/TOP) After divers have confirmed that the repair area has been completely covered with HP-2, deliver the prepared patch, lag bolts, and speed wrenches to the divers.

NOTEDue to the orientation of the steel strength plies, repair patches bend only in one direction. Divers should make sure that the patch is oriented as marked in paragraph 9-4.5.4.

NOTELag bolt lengths should be chosen so that the bolts will engage the internal wire strength plies (Figure 9-37). The dome is thickest at the marriage lines, and dome thickness decreases as distance from the marriage line increases. Minimum dome thickness is approximately 1 inch. Minimum lag bolt length for any location is 2 inches. Patches are supplied with bolts up to 5 inches in length. Refer to table 9-4 for bolt selection.

9-4.5.15 (DV) After making sure that the patch is properly oriented with respect to SRD curvature and the previous dome markings, the patch should be immediately set and pushed into place over the rupture.

9-4.5.16 (DV) Using the speed wrench, commence bolting the patch into place from the patch center outwards, bolting through the existing pre-drilled holes. Compression of the patch/SRD interface will force excess HP-2 to be extruded to the sides of the patch. This excess HP-2 can then be used to fair in the edges of the patch later in this procedure. Lag bolts of various lengths are provided with the patch. Ensure that bolts are long enough to engage structural wire plies (Figure 9-37 and Table 9-4). The speed wrench should be used manually to drive the bolts in until the patch draws up against the dome, compressing the patch and SRD HP-2 layers. This will ensure direct contact between the two adhesive layers and allow proper bonding. Take care not to overtorque the lag bolts and strip out the internal wire strength plies.

9-4.5.17 Once lag bolts have been installed in each pre-drilled hole, install 1 1/2-inch lag bolts around the perimeter of the patch at 3-inch intervals, approximately 1 inch away from the patch edge (Figure 9-38). As one diver installs the edge bolts, the other diver should be using the extruded HP-2 to fair the edges of the patch to the dome contour, also making sure to cover the exposed edge bolt heads.

NOTEThe edges of the structural patch create surface irregularities which will cause cavitation and flow noise which will adversely affect sonar performance while the ship is underway. Therefore, the edges of the patch must be faired to the SRD surface. This procedure should be underway during, and immediately after, the torquing of the lag bolts, thus requiring a diver dedicated to this task.

9-4.5.18 (DV) Apply additional HP-2 where necessary along the boundary of the patch where HP-2 has been extruded and fair the patch edges to the SRD surface contour using this excess HP-2, creating a tapered edge from the patch to the SRD surface. This "fairing band" should be at least 3 inches wide and should be as smooth as possible. A piece of pipe can be used as a roller for smoothing the taper areas (Figure 9-36).

9-4.5.19 (DV) Use a new wire hand brush to brush out all patch bolt head recesses. Fill recessed spaces around the lag bolt heads with HP-2 (notify topside if fresh HP-2 is needed). Only enough HP-2 should be used to fill the cavity and cover the bolt heads. Using the scalpel, trim excess HP-2 away and smooth the filled cavities out to the patch surface in order to create a smooth surface contour.

9-4.5.20 The patch should now be allowed to cure according to Figure A-1 in Appendix A.

9-4.6 PRESSURE TEST OF PATCH

After the cure cycle has been completed, the patch must be tested by pressurizing the sonar dome.

CAUTIONHP-2 maximum bond strength is not reached until a minimum cure time of 5 days has elapsed. Operational SRD pressuresshould be avoided until this maximum cure strength is obtained. For bow mounted SDRW systems, test pressure should be 30 psig maximum. For keel mounted SRD systems, test pressure should be 20 psig maximum. If pressure test results are acceptable and the SRD holds test pressure for five days, the SRD operational pressure can then be applied. Refer to the proper SRD technical manual for operational pressures.

NOTEBefore pressurization test begins, make sure that the dome pressure gauge's calibration status is current.

9-4.6.1 (TOP) Establish communications between personnel at the pressurization controls and the dive supervisor.

9-4.6.2 (DV) Divers should inspect the patch before pressurization and check for proper cure of the HP-2, especially at the edges of the HP-2 fairing. Photographs and/or video should be taken, if possible.

9-4.6.3 (DV) Place measurement marks on the SRD surface. The marks should be located so that a tape measure placed on them will cross the patch perpendicular to the orientation of the rupture at the rupture midpoint (Figure 9-39). This will allow measurement of SRD and patch expansion during dome pressurization.

9-4.6.4 (DV) Place a similar set of marks of equivalent distance, geometry, and orientation on an undamaged area of the SRD opposite to the rupture with respect to the ship/SRD centerline. This will allow a comparative measurement of SRD expansion in an undamaged area for comparison with the expansion across the patch.

9-4.6.5 (SF) Note the ambient pressure within the SRD as read on the appropriate pressurization system gauge.

9-4.6.6 (DV) Measure the distance between both sets of marks while the dome is unpressurized.

9-4.6.7 (DV/TOP/SF) Increase pressure in 5 psig increments. After each 5 psig increase, hold pressure for 10 minutes and visually inspect the patch for leaks. Measure the distances between both sets of marks to check for expansion (topside should record these measurements). If the SRD does not hold pressure, a drydock repair may be required. Contact NAVSEA immediately.

9-4.7 SPEED TRIALS

After successful dockside pressure testing, the ship should get underway and monitor SRD pressure while operating at the following speeds (avoiding slamming seas):

a. One hour at 12 knots.

b. One hour at 15 knots.

c. One hour at 18-20 knots

9-4.7.1 After completion of speed trials, the ship should return pierside for diver inspection of the entire SRD, focusing on the patch repair. Minor debonding of the fairing strip edge is to be expected due to SRD expansion and pressure cycling. Debonded fairing HP-2 can be removed and faired with a scalpel.

9-4.7.2 Notify NAVSEA of test results immediately.

APPENDIX A

HP-2 ELASTOLOCK® MIXING PROCEDURE

HP-2 ELASTOLOCK ® is a two part synthetic rubber adhesive designed for underwater repair of sonar rubber dome systems. It can be used in both fresh water and salt water. The water temperature must be above 60° F to ensure proper curing and predictable mechanical properties. HP-2 ELASTOLOCK ® should be stored in a cool environment and never be exposed to high temperatures. The epoxy has a shelf life of 12 months. B. F. Goodrich will recertify adhesive, but NAVSEA prohibits use of recertified adhesive for repair of sonar rubber dome systems due to historical evidence of unpredictable results.

HP-2 ELASTOLOCK ® consists of two components:

HP-2 Part A: resin (yellow color, amine odor)

HP-2 Part B: curing agent (red color, epoxy odor)

HP-2 adhesive is designed to be mixed in a 7 (part A) : 1 (part B) ratio by weight.

HP-2 ELASTOLOCK ® is available from B. F. Goodrich or NAVSEA 00C5 in pre-weighed gallon containers.

Mixing HP-2 ELASTOLOCK ® from Gallon Containers.

NOTEIf a large amount of HP-2 is needed, an entire can of part A can be mixed with an entire can of part B without having to weigh

out component portions. The cans are pre-measured and mixing the entire contents of both cans will result in a 7:1 (by weight)

mixture.

Smaller amounts of HP-2 can be mixed in accordance with the following procedure:

In order to mix the components and minimize loss due to sticking to mixing tools and containers, the appropriate amounts of parts A and B can be mixed by hand while wearing latex gloves. Make sure to keep gloves wet at all times in order to avoid adhesive sticking to gloves.

1. Using a scale, place an amount of part A (yellow) into a clean, flat bottomed mixing container. Record the weight of the part A component.

2. Multiply the weight by 1.14 (this will provide the required final weight of the mix).

3. Add part B to the container until the measured weight equals the weight calculated in step 2.

4. Mix the components in the container with a heavy-duty spatula or remove the components and mix by hand while wearing latex gloves (pulling and folding like taffy), making sure to keep the gloves wet. Mix parts A and B thoroughly until a homogeneousamber color is obtained throughout. There should be no visible streaks in the mixture.

5. The preferred cleaning agent is acetone or methyl ethyl ketone (MEK). Both are commercially available (not shipped with adhesive).

APPENDIX B

SDRW Repair Kit Drawings

Appendix B-3 Drawing 6697651, Main Arrangement

Appendix B-5 Drawing 6697659, Rigging Assembly

Appendix B-7 Drawing 6697665, Water Heating System

Appendix B-9 Drawing 6697666, Water Heating System Schematic

Appendix B-11 Drawing 6697668, Steam Manifold Assembly

1

2

Appendix B-3 Drawing 6697651, Main Arrangement

Appendix B-5 Drawing 6697659, Rigging Assembly

1

2

Appendix B-7 Drawing 6697665, Water Heating System

Appendix B-9 Drawing 6697666, Water Heating System Schematic

2

Appendix B-11 Drawing 6697668, Steam Manifold Assembly

APPENDIX C

SRD Repair Kit Drawings

Appendix C-3 Drawing 6698203, Keel Dome Cofferdam Assembly Drawing, sheet 1

Appendix C-5 Drawing 6698203, Keel Dome Cofferdam Assembly Drawing, sheet 2

Appendix C-3 Drawing 6698203, Keel Dome Cofferdam Assembly Drawing, sheet 1

Appendix C-5 Drawing 6698203, Keel Dome Cofferdam Assembly Drawing, sheet 2

L

FIGURE 9-2

FIGURE 9-3

FIGURE 9-4

FIGURE 9-5

FIGURE 9-6

FIGURE 9-7

FIGURE 9-8

FIGURE 9-9

FIGURE 9-11

FIGURE 9-12

FIGURE 9-13

FIGURE 9-14

FIGURE 9-15

FIGURE 9-16

FIGURE 9-17

FIGURE 9-18

FIGURE 9-19

FIGURE 9-20

FIGURE 9-21

FIGURE 9-22

FIGURE 9-23

FIGURE 9-24

FIGURE 9-25

FIGURE 9-26

FIGURE 9-27

FIGURE 9-28

FIGURE 9-29

FIGURE 9-30

FIGURE 9-30A

FIGURE 9-31

FIGURE 9-32

FIGURE 9-33

FIGURE 9-34

FIGURE 9-35

FIGURE 36FIGURE 9-36

FIGURE 9-37

FIGURE 9-38

FIGURE 9-39

TABLE 9-1

TABLE 9-2

TABLE 9-3

TABLE 9-4