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Section 2 Principles for the Construction of manned Submersibles

A. General Principles 1.5 Submersibles or parts thereof whose development is based on new principles and which have not yet been sufficiently tested in practical operation require special approval by GL. 1.6 In the cases mentioned in 1.4 and 1.5, GL is entitled to require the submission of additional documentation and the performance of special tests. 1.7 GL reserve the right to impose requirements additional to those contained in the Rules in respect of all types of submersibles when such action is necessitated by new knowledge or practical experience, or to sanction deviations from the Rules in specially justified cases. 2. National regulations

1. Wherever expedient and feasible, submersibles are to be designed and constructed in such a way that failure of any single component cannot give rise to a dangerous situation. 2. Submersibles and their components are to be designed to meet the service conditions stated in the specification. 3. Submersibles are to be designed and built to ensure safe operation and facilitate proper maintenance and the necessary surveys. 4. Submersibles are to be designed and constructed in such a way that the skipper has an adequate forward view when submerged. The possibility of an all-round vision when navigating on the surface shall be given. This can be reached either by suitable windows or optical instruments. 5. Submersibles with a diver's lockout are to be designed and constructed to ensure the safe transport and the safe exit and entry of the divers under pressure.

National regulations existing alongside GL's Rules are unaffected. 3. International Conventions and Codes

Where reference is made to international Conventions and Codes examples are listed in the following: 3.1 ILLC 66

B. 1.

Rules and Regulations to be considered Rules of GL

International Convention on Load Lines, 1966, as amended. 3.2 MARPOL 73/78

1.1 The following Rules are valid as additional requirements for the Classification and construction of submersibles in addition to the Rules for Classification and Construction of these vehicles:

International Convention for the Prevention of Pollution from Ships, 1973 including the 1978 Protocol as amended. 3.3 SOLAS 74

Part 0 Classification and Surveys Part 1 Seagoing Ships, Chapter 1 4 II Materials and Welding, Part 1 - 3

International Convention for the Safety of Life at Sea, 1974, as amended. 3.4 LSA

1.2 For submersibles with divers lockout besides of the rules defined in the following also the GL Rules for Diving Systems and Diving Simulators (I-5-1) have to be considered for the relevant components. 1.3 Concerning the supporting systems aboard the support ship see Section 17. 1.4 Designs differing from the Rules of Construction may be permitted provided that they have been recognized by GL as equivalent.

International Life-Saving Appliances Code issued by IMO in actual version. 3.5 COLREGS 1972

International Regulations of 1972 to prevent collisions at sea. 3.3 MSC/Circ. 981

Guidelines for the Design, Construction and Operation of Passenger Submersible Craft according to IMO MSC/Circ. 981 of 29 January 2001.

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C. 1.

Definitions General

Mating device The equipment necessary for the connection of a submersible with diver's lockout resp. rescue chamber to a compression chamber or another submersible. Non-autonomous submersible Submersible which is physically connected to the support ship (e.g. by an umbilical) during operation. Positioning system System for keeping a defined position (breadth, length, depth) Pressure hull The main component of a submersible which accommodates the crew at atmospheric pressure and withstands the diving pressure. Pressure vessel A container which is exposed to internal or external overpressure. Safe working load of the launching and recovery system SWL The safe working load SWL is the load which may be loaded directly to the launching and recovery system. The dead load of lifting tackles which are not fixed to the launch and recovery system, but are used as connection between load and loading gear, is part of the safe working load SWL. Submersible for tourist services Submersible which operates in already defined, explored diving areas in depths at any time accessible to surface divers and is able to transport more than 6 passengers. Supply systems Systems aboard of the support ship which are supplying non-autonomous, but also autonomous and independent submersibles with the supply goods necessary for operation, like e.g. electrical power, hydraulic fluid, breathing air as well as communication and monitoring data. Support ship A surface vessel resp. floating structure for support and supply of autonomous and non-autonomous submersibles. Within these Rules the support ship may also be a stationary supply station (e.g. on the coast or on a stationary offshore plant). Total system The submersible including its mating, launching, recovery, stowage, transport and supply systems. Umbilical/supply line Connection between support ship and nonautonomous submersible, which might contain hose lines for gas and liquid transport and control, communication/data transfer and energy supply cables as well as, if applicable, a lifting cable.

Autonomous submersible Submersible which is not physically connected to the support ship during operation (e.g. by an umbilical). Breathing gas All gases/mixtures which are used for breathing during underwater operations. Compression chamber Chamber for accommodation of persons at more than atmospheric pressure. Control stand Central station at which all essential indicators, controls, regulating devices, monitoring devices as well as communication systems of the submersible are arranged. Diving pressure The respective overpressure, corresponding to the relevant diving depth, to which a submersible or diver is exposed during underwater operations. Diver's lockout A compression chamber including exit hatch in a submersible for the entry, egress and accommodation of divers at diving pressure. Exostructure External cladding, supporting structures and fixtures outside the pressure hull which are normally not designed to withstand the diving pressure. Fixing system Working device for short time fixing of a submersible e.g. on a structure. Gas cylinders Bottles for the storage and transport of gases under pressure. Independent submersible Submersible which is able to operate offshore without a support ship. Launching and recovering system The plant and equipment necessary for launching and recovering a submersible. Life support systems Systems for gas supply, purification, exchanging and conditioning of the atmosphere in the pressure hull as well as for the supply of water and food and for the removal of waste. Lifting cable Cable for launching and recovering, and also for lifting and lowering of a non-autonomous submersible.

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This bunched or integrated supply line can also be used between the submersible and a diver. Viewports Openings in pressure hulls or compression chambers for fitting pressure-tight, flat or spherical acrylic windows. Working devices (underwater) Devices, e.g. manipulator, sample container and tool, which is fixed to a submersible and which are designated to the performance of underwater works and of taking e.g. samples. Working machines (underwater) Machines, e.g. grab, driver, bucket and their combination, which are normally used from a support ship to perform underwater tasks (see GL Rules Unmanned Submersibles (ROV, AUV) and Underwater Working Machines (I-5-3), Section 5). 2. Main dimensions and main parameters

2.6

Total breadth B

The total breadth B is the maximum breadth of the submersible including all fixed installed parts of equipment, measured parallel to the y-axis [m]. 2.7 Radius of the pressure hull Rm

The radius of the pressure hull Rm is the radius of the cylinder or the sphere related to the middle of the wall thickness. 2.8 Total height H

The total height H is the total height from baseline to upper edge of the vehicle including all permanently installed parts of equipment, measured parallel to the z-axis [m]. 2.9 Draught T

All dimensions are related to permanently installed equipment in drawn in/turned in condition. 2.1 Co-ordinate system

The draught T in surfaced condition is the maximum vertical distance between the baseline and the water surface [m]. 2.10 Displacement

In relation to the submersible a fixed, right-handed coordinate system x, y, z according to Fig. 2.1 is introduced. The origin of the system is defined by the aft perpendicular, the centre line and the basis line of the submersible. The x-axis points in longitudinal direction of the vehicle positive forward, the y-axis positive to port and the z-axis positive upwards. Angular motions are considered positive in a clockwise direction about the three axes. 2.2 Aft perpendicular AP

The displacement of the surfaced submersible ready for surfaced operation is , the displacement of the completely dived vehicle is [t]. 2.11 Payload NL

The aft perpendicular AP is vertical to the x-axis through the intersection of rear edge of the stern boss with mid of propeller for vehicles with central shaft, for vehicles with several shafts and special propulsion arrangements to be defined case by case. 2.3 Forward perpendicular FP

The maximum additional load NL for devices, equipment, materials, which are not necessary for the direct operation of the submersible, but are serving for work to be performed, investigation of the sea and scientific research [kg]. This includes the passengers according to Table 3.1. The crew is not part of the payload. 2.12 Diving depths

The forward perpendicular FP is vertical to the x-axis through the intersection with foreside of the stem, for special arrangements to be defined case by case. 2.4 Length between the perpendiculars LPP

All diving depths are related to the lower edge of the pressure hull. 2.12.1 Nominal diving depth NDD

The length LPP is the distance between AP and FP measured parallel to the x-axis. 2.5 Length over all LOA

The nominal diving depth NDD is the diving depth for the unrestricted operation of the submersible [m]. 2.12.2 Test diving depth TDD

The length LOA is the length between the most forward and most aft point of the submersible including fixed installed components of equipment, measured parallel to the x-axis [m].

The test diving depth TDD is the diving depth which is related to an external overpressure, to which the submersible is subjected to test conditions after completion or after essential repairs [m].

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Rm

H T y

LPP LOA z

B z

LOA

Fig. 2.1 Fixed co-ordinate system and main dimensions 2.12.3 Collapse diving depth CDD 2. Inclined positions

The collapse diving depth CDD is the diving depth decisive for the design of the pressure hull, where a collapse of the pressure hull is to be expected [m]. 2.13 2.13.1 Velocities Velocity v0

The velocity v0 is the maximum operational speed of the surfaced submersible [kn] at a number of revolutions of the propeller according to the maximum continuous propulsion power surfaced (MCR1). 2.13.2 Velocity v0

Satisfactory operation shall be ensured at (static and dynamic) inclinations of up to 22,5 in any direction measured in relation to the datum level. Transient inclinations of up to 45 shall not adversely affect operation and shall not cause damage, particularly to machine mountings. Greater operational inclinations have to be adequately observed for design and testing. 3. Water

The velocity v0 is the maximum operational speed of the dived submersible [kn] at a number of revolutions of the propeller according to the maximum continuous propulsion power dived (MCR1).

For the design of submersibles and components the temperature range of the water as well as the range of salt content and therefore of the density is to be defined. If not agreed otherwise, seawater with a temperature range from -2 C to +32 C, with a salt content of 3,5 % and a density of 1,028 kg/m3 may be used as a basis. A value of 0,101 bar/m is to be applied when converting diving depth to pressure. 4. Seaway

D. 1.

Environmental Conditions General

As a minimum requirement, the design, selection and arrangement of all machinery, instruments and equipment located on board submersibles are required to conform to the environmental conditions stated below. For submersibles which are operating in defined areas only, deviating environmental conditions may be approved. For special missions, like diving under ice or in caves the environmental conditions experienced there are to be considered and special measures agreed with GL.
1 MCR = maximum continuous rating

The seaway up to which the submersible shall be operated in surfaced condition are to be agreed with GL. If not agreed otherwise, submersibles are to be designed for sea states with a significant wave height of at least 2 m, allowance being made for accelerations of 2 g downwards and 1 g upwards in the vertical and 1 g each in the longitudinal and transverse directions (g = 9,81 m/s2). 5. Tide and currents

For the design of the propulsion and manoeuvring arrangement the different factors influencing currents according to the operation area and their possible combinations are to be considered.

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As basis for the design the maximum as well as the minimum tide at the relevant operation area shall be included. In addition currents created by storms or geographic specialities (e.g. narrow channels) are to be considered. 6. Climate

1.3 Once the documents submitted have been approved by GL, they become binding for the execution. Any subsequent modifications require GL's consent before they are implemented. 2. Total system

The following documents are to be submitted: 2.1 A description of the submersible with details of its mode of operation, the proposed application and the essential design data like e.g.: nominal diving depth maximum operating time and maximum survival time maximum range of a mission (radius) maximum number of persons in pressure hull divers' compression chamber diving procedure operating limits for launching and recovery (seaway) other operating limits in relation to environmental conditions (e.g. operating temperatures, fresh/salt water or geographical or current conditions) speed above or below water level as well as maximum towing speed type of drive and manoeuvring equipment type and extent of working devices and equipment type of fixing system weight of vehicle, pay load and ballast, displacement (submerged)

In all spaces, allowance is to be made for oil and salt impregnated air ranging in temperature from 0 to +55 C. Atmospheric humidity may attain 100 % in the lower temperature range. Condensation is liable to occur. In specially protected control rooms, a relative atmospheric humidity of 80 % at a reference temperature of +45 C is to be assumed. Equipment and instruments have to continue to function satisfactorily despite fluctuations in the air pressure inside the pressure hull ranging from 0,7 to 1,3 bar. 7. Vibrations and shaking

Machinery shall not cause any vibration or shaking which imposes unacceptable stresses on other machines, equipment or the hull of the submersible. The amplitudes and accelerations defined in the GL Rules Machinery Installations (I-1-2), Section 1, C. are to be complied with. 8. Explosion protection

Submersibles which are used in respectively from explosion endangered areas (e.g. from oil or gas production platforms) are to be designed for the relevant explosion endangered zones. This is also valid for control stands. 9. Further environmental conditions

For the design of the submersible also the environmental conditions which may occur during an eventual air transport (e.g. underpressure/temperature) are to be considered.

2.2 General drawing and plans showing arrangement and design details of the submersible, including specifications for materials, manufacture and testing. 2.3 Arrangement drawings (block diagrams) of the total system.

E. 1.

Documents for Approval General

2.4 Failure Mode and Effects Analysis (FMEA), if required. 2.5 A comprehensive presentation of the measures taken to prevent corrosion. 2.6 Stability documentation

1.1 Before the start of manufacture, documentation of the total system and drawings of all components subject to compulsory inspection, wherever applicable and to the extent specified below, are to be submitted in triplicate respectively in case of electronic transmission as single issue. 1.2 The documentation shall contain all the data necessary to check the design and loading of the system. Wherever necessary, calculations relating to components and descriptions of the system are to be submitted.

For every submersible a proof of stability is to be delivered, which shall contain: results of the stability investigations for the intact and damaged submersible, as well in submerged as surfaced condition and if applicable also in intermediate conditions permissible ice load

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2.7

presentation of the stability behaviour of the submersible measures for maintaining sufficient stability Manual for operation and maintenance

4.

Exostructure

The manual for the operation shall include in detail the steps necessary for normal operation as well as for emergency operation in a clear and conceptual form and in the necessary sequence (e.g. as checklist). In addition the measures for the loading of the operating systems (e.g. batteries, gases) mostly with external installations are to be defined. In addition the planned lifetime and the permissible load and mission cycles of components of the equipment (e.g. acrylic windows, batteries, etc.) is to be defined herein. The maintenance manual shall include all procedures for the preventive maintenance as well as for periodic inspections. 2.8 Operational records

Plans and sectional drawings of the vehicle envelope and supporting structure are to be submitted including details of such pressure hull fixtures as diving tanks, gas tanks, buoyancy elements, stabilizing fins, rudder, disengaging gear, umbilical connection, keel runners, anti-ramming device, streamlining elements, manipulators, instrument mountings, anchoring equipment, masts and venting pipes, etc. 5. Diving, compensating and trimming systems, ballast systems

5.1 Submission of details for arrangement of diving, compensating and trimming tanks and of the ballast system with mathematical proof of the vehicle's static diving capability. 5.2 For the open and closed loop control are to be submitted: Description of the control systems for depth, trim and positive and negative buoyancy as well as of the safety devices to prevent the nominal diving depth NDD from being exceeded, including the necessary piping diagrams and component drawings. This includes drawings of: compressed air system for blowing diving tanks ballast systems solid buoyancy elements and their mountings weights and gear capable of being jettisoned and their means of release Pressure vessels and apparatus

All conditions relevant for operation (diving depth, mission time, damages, etc.) are to be documented herein. 2.9 3. Trial program. Pressure Hull

3.1 Drawings and calculations for the pressure hull are to be submitted with all essential particulars and details necessary for appraising the safety of the equipment and including the specifications for materials, manufacture and testing. The drawings have to show all the internal and external fixtures of the pressure hull (e.g. strengthening ribs, machine bedplates, mountings, etc.). 3.2 In addition, component drawings of the pressure hull equipment are to be submitted, like e.g.: entry and exit hatches windows, window flanges and counter flanges pressure tight bulkheads including doors block flanges pressure hull wall penetrations and their arrangement diver's lockout, if existing

6.

Drawings and calculations of the pressure vessels and apparatus are to be submitted with all essential particulars and details necessary for appraising the safety of the equipment and including the specifications for materials, manufacture and testing. 7. Piping systems, umbilicals, pumps and compressors

The following are to be submitted: 7.1 Schematic diagrams of all piping systems including details of: materials maximum allowable working pressure allowable working temperature dimensions (diameter, wall thickness) media carried type of valves and connections used and their operational parameter type of hose lines

3.3 Drawings and descriptions of the space allocation and internal arrangements are to be submitted.

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7.2 Description of pumps and compressors and their drives together with all important design and operating data. 7.3 Description of the design of the umbilical and its single elements according to Annex E, C. if applicable. 7.4 Listing of the components filled with liquids with definition of the type of liquid (e.g. oil, water, etc.). 8. Propulsion and manoeuvring equipment

11.1 A general arrangement drawing of the electrical equipment containing at least the following information: voltage rating of the systems power or current ratings of electrical consumers switchgear and safety devices (e.g. overcurrent relay) with indicating settings for short-circuit and overload protection; fuses with details of current ratings cable types and cross-sections

Drawings and descriptions are to be submitted of the propulsion and manoeuvring equipment including gears, couplings, shafting, propellers and rudders with details of: 9. mode of operation and control of the systems power consumption (type and quantity) method of power transmission to propulsion unit seals of pressure hull wall penetrations operating range and response time of rudder Positioning system

11.2 The energy balance of the main and emergency power supply systems. 11.3 Drawings of switchgear and distribution equipment with parts lists. 11.4 Complete documentation for electric motor drives with details of control, measuring and monitoring systems. 11.5 Battery installation drawing with details of battery types, chargers and battery room ventilation. 11.6 Details of electrical penetrations through pressure hull walls. 11.7 Diagrams showing allocation of electrical pressure hull wall penetrations. 11.8 Diagrams showing arrangement of emergency light fittings. 11.9 Calculation of short-circuit conditions with details of circuit-breakers, power protection switches and fuses fitted to main, emergency and distribution switchboards indicating their current ratings and breaking capacity. 11.10 The installer of the electrical equipment has to submit confirmation on form F 184 to the effect that the electrical equipment in hazard areas is of explosion-proof design. The form can be obtained from GL. The hazard areas are to be specified. 11.11 For the operation in explosive endangered areas the required explosion classes are to be proven. 12. Automation, communication, navigation and locating systems

The type and control of the positioning system is to be explained. 10. Working devices

(Compare also Chapter 3, Section 5, G.) 10.1 For extension elements and working devices the effects on the total system are to be defined. 10.2 Plans and descriptions of the planned working devices are to be submitted with data about: task of the devices type of operation and energy supply control and monitoring safety devices location and fixing at the carrying structure applied materials type of release system, if applicable

10.3 Plans and descriptions of the fixing system are to be issued with information for 11. type and control of the fixing system size of holding power behaviour at energy failure type of release system Electrical equipment

The following are to be submitted: 12.1 Description of the complete instrumentation layout of the control stand. 12.2 Description of the control and operating elements for the submersible and its equipment.

The following are to be submitted:

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12.3 Description of the nautical and diving instrumentation, including speed and position indicators. 12.4 tems. A description of the safety and alarm sys-

14.6 If submersibles are used in explosion endangered areas, a description of the measures for explosion protection is to be presented. 15. Rescue systems

12.5 Arrangement drawings/block diagrams of monitoring systems including lists of measuring points. 12.6 Documentation for electronic components such as instrument amplifiers, computers and peripheral units. 12.7 General diagrams and equipment lists for the data transfer systems and signalling equipment. 12.8 General diagram and description of the TV system. 12.9 Descriptions, general diagrams and equipment lists for the locating equipment. 13. Life support systems

Drawings and descriptions are to be submitted of the systems and equipment for evacuating the vehicle crew, passengers and divers. 16. Mating system

16.1 Description of system with details of operating conditions 16.2 16.3 Data concerning connecting conditions. Design drawings of the mating system.

16.4 Control diagram and description of safety devices.

F. 1.

Failure Mode and Effects Analysis (FMEA) General

The following are to be submitted: 13.1 Piping diagrams, block diagrams and descriptions of the systems and equipment used for breathing gas supply, circulation, purification and conditioning of the atmosphere in the pressure hull, including the monitoring equipment, for both normal and emergency operation. 13.2 Mathematical proof of the adequate capacity of the breathing gas supply and air renewal systems under normal and emergency conditions. 13.3 Description of the facilities for supplying water, food and medicines and for disposal of waste. 13.4 In the case of non-autonomous submersibles, drawings and descriptions of the umbilical are to be submitted. 14. Fire protection and fire-extinguishing equipment

1.1 The Failure Mode and Effects Analysis (FMEA) has the purpose to identify possible failures in the total system, in subsystems and components of manned submersible and to describe the effects on the total system and its submersibles resp. components.. 1.2 For manned submersibles an analysis concerning the function and availability of the submersible after occurrence of a single failure has to be submitted if requested by GL. 1.3 The FMEA shall be executed in an early stadium accompanying the design to be able to realize system modification in due time. A tabular form, e.g. according to IEC 60812 or IMCAD 039 is to be used. 2. Description of the subsystems relevant for the analysis

The following are to be submitted: 14.1 14.2 Description of preventive fire precautions. Fire protection plans.

14.3 Details of the nature and quantity of combustible materials in the submersible. 14.4 Drawings and descriptions of: fire detectors fire extinguishers fire alarms

2.1 The FMEA shall represent an independent document and be understandable without consulting further documentation. This means that all relevant submersible are to be described concerning the structure of their basic functions, the installed redundancies and especially the interfaces of the subsystems to each other. 2.2 The description shall provide the crew with a good overview of the vehicle structure and the functionalities of the relevant subsystems. For all subsystems typical failure modes and their effects on the overall function of the submersible shall be indicated. Further on the corrective actions to manage these failures and their effects are to be provided.

14.5 Analysis of the dangers arising from possible outbreaks of fire.

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2.3 For manned submersibles the following subsystems are relevant for maintaining the overall function: pressure hull penetrations and equipment interior arrangement exostructure and related equipment systems for diving/ballasting, control/compensation and trimming vessels and apparatus under pressure piping systems, pumps and compressors umbilicals, for non-autonomous submersibles propulsion and manoeuvring equipment generation and distribution of electrical power emergency power supply electrical protective systems automation, communication, navigation and locating equipment life support systems fire protection rescue systems additional arrangement for tourist services, as far as relevant systems for control aboard the support ship supply systems aboard the support ship launch and recovery system coil-up/coil-off mechanism for umbilicals stowage and deck transport mating equipment The system descriptions are to be completed by block diagrams according to 3. 3. Block diagrams of the relevant subsystems For each relevant subsystem a block diagram is to be established. This block diagram shall contain the essential information on the system required for the failure analysis, which is normally: definition of the subsystems all essential components of the subsystems interfaces between the components of the subsystems interfaces to or from other subsystems (typical for hydraulic drives, compressed air systems and controls, etc.) arrangement for control of the total system Table 2.1
ID Number

supplies from outside the total system, if applicable further aspects depending on the actual design of the total system

At interfaces the different types of power, media and data may be transferred. 4. Analysis of the different relevant subsystems

Each relevant subsystem is to be analyzed with regard to the following essential aspects, in course of which further aspects may occur during the execution of the analysis, compare worksheet in 5.: failure of subsystems malfunctions of subsystems failure of components in a subsystem malfunctions of components interface failures between the subsystems, a subsystem and its components as well as between components themselves Interface analysis of which data, medium and power are transferred and how failures are spread via the interfaces to other subsystems/compo-nents. hidden failures check for hidden failures and the evidence of alarms to be provided arrangement of periodic testing where alarms are not practical failures because of external influences which may lead to simultaneous failure of redundant subsystems, e.g. changed environment conditions and their control, voltage and amperage fluctuations on power supply, contamination of supply media, etc. faulty operation of subsystems or components, only with certain probability Tabular work sheet

5.

The analysis shall be carried out in tabular form with a work sheet according to the following example or e.g. according to IEC 60812. The analysis has to consider all operational modes.

Example of a tabular work sheet

Subsystem/ component Type of failure Failure cause Failure detection Consequences Consequenfor subsystem/ ces for total component system Failurecorrection Remarks

1 2 3

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6.

Assumptions and defined limits for the analysis

During the analysis the assumptions are to be defined which influence the result of the analysis. Typical assumptions are e.g.: the crew is qualified and trained to safety operate the manual submersible the supply of energy and as far as necessary with other consumables from outside the manned submersible is secured in redundant way (for non-autonomous submersibles) the adjustments and switching operations prescribed in the operation manual are followed by the crew, etc. Treatment of changes

turers works. As a minimum requirement, this shall include verification of compliance with the approved documents, inspection of workmanship, verification of materials and checking of dimensional tolerances. All the tests prescribed in the following are to be performed and documented, wherever applicable. About the presence of GL Surveyors at these tests and trials GL will decide in each individual case. Tests and trials for supporting systems aboard the support ship in connection with the submersible are defined in Section 17. 1.2 For series-manufactured parts, test procedures other than those prescribed may be agreed with GL provided that they are recognized as equivalent by GL. 1.3 GL reserve the right to extend the scope of the tests where necessary and also to subject to test those parts for which testing is not expressly prescribed in the Rules. 1.4 Parts subject to approval are to be replaced with tested parts. The same also applies to spare parts. 1.5 Where submersibles are equipped with a diver's lockout, the components and equipment concerned are also to be subjected to the tests prescribed in Chapter 1 Diving Systems and Diving Simulators. 1.6 A summary of the test pressures, as well as of the design and lay-out pressures is contained in Section 4, Table 4.2. 2. Total system

7.

In case of changes at the submersible respectively at the supporting systems aboard the support ship the FMEA is to be adjusted accordingly. 8. Conclusions

The FMEA shall contain a summary of the results of the analysis for the relevant submersible. In addition it should contain a listing of the main failures which may occur for the operation of the vehicle and especially for keeping the manoeuvrability and ability for submersing as well as the desired atmosphere in the pressure hull. For the crew and the service personnel aboard the support ship training measures for incontestable handling of the vehicle and the supporting systems in the event of such failures are to be proposed. A periodic check of the FMEA including practical trials is recommended. 9. FMEA test program

On completion, the submersible is to be subjected to a functional and acceptance test in accordance with the trial programme approved by GL. This shall include at least the following individual tests: inspection of assembly (where not already performed during supervision of manufacture) measurement of weight and buoyancy and checking of stability under normal and emergency conditions inspection of internal equipment, partition bulkheads with doors, floors and ladders testing of all safety devices functional testing of diving and trimming equipment functional testing of mechanical, electrical and optical equipment functional test of the working devices related to the effects on the submersible statical diving test under controlled conditions heeling test submerged and surfaced trimming test submerged and surfaced testing of emergency release equipment

9.1 According to the FMEA a test program is to be established. The purpose of this program is to verify the assumptions and the expected operation behaviour of the submersible as defined in the analysis. 9.2 The program has to consider typical modes in the relevant systems and components including the worst case failure. All possible operational modes of the submersible are to be reflected. 9.3 The test program is to be agreed with GL and needs to specify in detail how the test shall be carried out respectively how simulation is done.

G. 1.

Tests and Trials General

1.1 Manned Submersibles are subject to constructional and acceptance testing at the manufac-

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trial trip on surface with verification of buoyancy trial trip submerged testing of mating system functional testing of life support systems verification of the accuracy of all essential instrument readings high voltage test and insulation test on the electrical equipment

3.5 Doors in pressure-tight bulkheads are, if not possible otherwise, to be tested at the manufacturers works with test diving pressure TDP. In installed condition a tightness test with 0,2 bar underpressure has to be performed. 3.6 For pressure-tight bulkheads a tightness test with 0,2 bar underpressure is to be performed. 4. Exostructure

The tests of the total system under water are to be performed with diving depths up to nominal diving depth NDD, see Section 4, B. 3. Pressure hull

4.1 A check is to be carried out on the arrangement, mounting and fastening of such equipment items as stairways, gratings, handrails, bitts, masts, navigating lights, towing devices and draught marks. 4.2 External structural components such as anchoring equipment, rudders, etc. are to be subjected to a functional test. 4.3 The lifting points at the submersible are to be tested statically with 2,2 times the safe working load SWL (= weight and payload NL of the submersible) 4.4 The fixing point of the umbilical at the submersible is to be tested statically with 2,2 times the maximum permissible tension load of the umbilical. 5. Diving, compensating and trimming tanks, as well as ballast systems

3.1 On completion of the machining work and any necessary heat treatment, pressure hulls are to be subjected to a hydraulic external pressure test. This test may be performed either on the raw hull in a compression chamber or as part of a submersion test carried out on the completed submersible. The test pressure is to be determined in accordance with Table 4.1 in Section 4. Pressure hull compartments (tanks) in which an internal overpressure may occur are to be subjected to a hydraulic internal pressure test at 1,5 times the maximum allowable working pressure. After the pressure tests, the pressure hull is to be examined for leaks, permanent deformations and cracks. 3.2 Pressure hull penetrations and closing appliances are to be tested for tightness by the application of an underpressure of at least 0,2 bar below atmosphere pressure. In addition pressure hull penetrations and hatch covers are to be tested with an internal pressure of 1,3 bar absolute. 3.3 All pressure hull windows are to be subjected to a hydraulic pressure test. The test may be performed after installation together with the pressure hull or individually in a testing device. The test pressure is to be determined in accordance with 3.1. For the pressure test it has to be observed that the test pressure is not higher than 1,5 times the design pressure of the window. After the pressure test, windows may exhibit no scratches, cracks or permanent deformation. 3.4 At the pressure test of the submersible the tightness of pressure-tight hatch covers is to be verified with test diving pressure TDP.

5.1 Lockable diving tanks are to be subjected to a tightness test using air at a test pressure of about 0,2 bar respectively for open diving tanks a tightness test of the ventilation valves has to be performed. 5.2 Compensating tanks, which vary their filling level by compressed air, are to be subjected to a hydraulic pressure test at 1,5 times the maximum allowable operating pressure, but at least at test diving pressure TDP. 5.3 Trimming tanks, which are internally in the pressure hull and which change their filling level by pumps are to be considered as gravity tanks, but if the filling level is varied by compressed air , they are to be subjected to an internal hydraulic pressure test with 1,5 times the maximum allowable working pressure. Trimming tanks, which are arranged outside the pressure hull in the exostructure and which are varying their filling level by pumps are to be subjected to a test at external test diving pressure TDP, for the case of varying the filling level with compressed air, an additional internal test at 1,5 times maximum allowable working pressure will be required. 5.4 Diving, compensating and trimming systems are to be subjected to a functional test for normal and emergency operation.

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The measuring system and the safety and alarm systems are to be checked. 5.5 The venting of the diving tanks and the elements for operation are to be subjected to a functional test. 6. Pressure vessels and apparatus

sible contamination of the compressed gas are also to be determined. The safety devices are also to be checked. 7.3 Umbilicals/supply lines

6.1 Pressure vessels are to undergo a hydraulic pressure test before being insulated or painted. The vessel walls shall not show permanent deformations or shall not leak. 6.2 The test pressure applied to vessels and apparatus with stress from internal pressure shall generally be equivalent to 1,5 times the maximum allowable working pressure PB. 6.3 Vessels and apparatus which may be subjected to external overpressure have to undergo an external pressure test. The test pressure shall be at least the test diving pressure TDP of the pressure hull. 6.4 If the strength against pressure of vessels and apparatus cannot be sufficiently proven by calculation, an alternative verification has to be agreed with GL. 7. 7.1 Piping systems, umbilicals, pumps and compressors Piping systems

Umbilicals/supply lines of non-autonomous submersibles have to meet special requirements. The required tests are to be divided in a type test for the prototype and a routine test of each end product. All aspects for the tests and trials of umbilicals are defined in Annex E, D. 7.4 Hose lines

As far as the requirements in 7.3 are applicable for hose lines they shall be used. 8. Propulsion and manoeuvring equipment

The entire propulsion plant is to be subjected to a functional test within a trial trip under water and surfaced. 9. Positioning system

The positioning system is to be checked. 10. Working devices

(Compare also Chapter 3, Section 5, H.) 10.1 The effect of the working devices on the total system is to be tested. 10.2 The working devices have at least to be checked with reference to: ability to function according to the specified task at relevant capacity of the device control and monitoring functioning of safety devices avoiding dangers for divers and the submersible

7.1.1 On completion but before being insulated or painted, all piping systems are to undergo a hydraulic pressure test at 1,5 times the maximum allowable working pressure. Pipes under diving pressure are to be checked in addition with test diving pressure TDP (inside or outside according to the actual load case). 7.1.2 After installation on board, all pipes are to undergo a tightness test at the maximum allowable working pressure. 7.1.3 The safety devices are to be checked.

7.1.4 Pipes for breathing gas and oxygen are to be tested for cleanliness. 7.2 Pumps and compressors

10.3 The fixing system is to be subjected to a function test where at least the following individual tests are to be performed with reference to: 11. specified holding power of the fixing system the power and way limitations of the fixing system as well as the directing of the vehicle simulation of an energy failure Electrical equipment

7.2.1 Pump and compressor components subjected to pressure are to undergo a hydraulic pressure test. For pumps the test pressure shall be 1,5 times the maximum allowable working pressure, for compressors 1,5 times the delivery pressure of the compressor stage concerned. 7.2.2 On completion, pumps and compressors are to be subjected to a tightness test at their maximum allowable working pressure. In addition, a performance test is to be carried out. With breathing gas compressors, the final moisture content and any pos-

11.1 Electrical machines, components, including steering and control positions, cables and lines are to be tested in the manufacturer's works in accordance with the GL Rules Electrical Installations (I-1-3).

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11.2 All electrical systems and equipment are to be inspected and tested before the submersible is put into service. 11.3 Electrical protective devices are to be checked; in addition, an insulation test is to be performed on the electrical equipment. 11.4 Electrical cables under external pressure are to be checked according to the electrical requirements for umbilicals defined in 7.3. 11.5 All electrical equipment which is exposed to diving pressure shall be checked additionally for isolation after the first diving. 12. Automation, communication, navigation and locating equipment

14.3 Fire alarm, detection and extinguishing appliances are to be subjected to a functional test. 15. Rescue systems

Elements of the rescue system arranged outside the pressure hull are to be tested at test diving pressure TDP. In addition it shall be proven that the rescue systems function properly even with the submersible at the maximum permissible inclination and that sufficient stability of the vehicle is maintained. 16. Mating systems

16.1 A test is to be performed to ensure that mating respectively release of the submersible proceed smoothly and safely under normal and emergency operating conditions. 16.2 Where a mating device is provided, it is to be checked that release can only take place when the connecting trunk is not under pressure. 16.3 The safety devices are to be checked.

12.1 Indicating and monitoring instruments are to be tested for the accuracy of their readings and their limit value settings according to the GL Rules Automation (I-1-4). 12.2 Automation systems are to be checked for satisfactory performance under service conditions. 12.3 Communication systems for normal and emergency operation are to be subjected to a functional test. 13. Life support systems

H. 1.

Marking Fittings, indicators and warning devices

13.1 A functional test is to be carried out to verify the satisfactory functioning of the life support system under normal and emergency conditions. 13.2 The arrangement of the O2, CO2 and H2 measuring devices is to be inspected, and they are to be checked for the accuracy of their readings and their limit value settings. 13.3 The sanitary facilities are to be checked for proper functioning. 13.4 The installation of the ventilation system is to be inspected and the operation of the fans and fire flaps is to be checked. 14. Fire protection and fire extinguishing systems

All valves, fittings, controls, indicators and warning devices are to be provided with permanent and seawater resistant markings. 2. Pressure vessels, gas cylinders and pipe systems

2.1 All pressure vessels and gas cylinders are to be permanently marked at an easily visible position with the following details: name or company designation of manufacturer year of construction and serial number (pressure vessels) serial number (gas cylinders) type of gas maximum allowable working pressure [bar] maximum allowable working temperature (for > 50 C and < -10 C) capacity [] test pressure [bar] empty weight (of gas cylinders) [kg] date of test test stamp

14.1 The fire behaviour of the internal fittings and equipment is to be checked by reference to the relevant test certificates and symbols. 14.2 A check is to be made as to whether the electrical heating systems and heaters are fitted with protection against overheating.

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2.2 Permanently installed gas cylinders, gas containers and gas piping systems are, in addition, to be marked with a permanent colour code in accordance with Table 2.2 and with the chemical symbol designating the type of gas concerned. The marking of pressure vessels and gas cylinders has to be visible from the valve side. Systems for other media are also to be marked in suitable way. The distances of the markings are to be chosen for pipe systems according to function and safety. Table 2.2 Marking of gas systems
Chemical symbol O2 N2 He O2/He Colour code white black white and black brown white and brown

I.

Spare Parts

1. Independent submersibles are to be provided with spare parts. 1.1 In order to restore machinery operation and manoeuvring capability of the submersible in the event of a damage at sea, spare parts for the main propulsion plant and the essential equipment shall be carried on board together with the necessary tools. 1.2 For batteries arranged within the pressure hull a sufficient set of cables with adequate cross section to bridge parts of the batteries or single cells has to be on board. 1.3 The scope of spare parts is to be documented and a relevant listing has to be on board. 2. Deviating requirements are possible in the case of submersibles which can only operate in conjunction with, or are supplied by, accompanying surface vessels.

Type of gas Oxygen Nitrogen Air Helium Oxygen/Helium gas