Section
2 Periodical Surveys
2.1 Annual Surveys (Manned submersibles and chambers)
2.1.1 The Surveyors are to carry out an Annual Survey of each classed manned
submersible, diving system or deck compression chamber. At each survey the Surveyors
are to examine the log book, the calibration records of instruments essential for
safety and verify that the Operator’s inspections and maintenance have been
recorded.
2.1.2 Where a manned submersible is part of a sea bed installation or is
attached to or forms part of a submerged structure, the Surveyors are to undertake
the survey as agreed with LR. The survey may be carried out by the use of television
or video recording equipment.
2.1.3 The Surveyors are to carry out a General Examination of the hull,
chamber, pressure controls and equipment for damage, deterioration or contamination
such as may be caused by the leakage, spillage or carry-over of oil or other
detrimental substances. The Surveyors are also to examine the following where
applicable:
- Life-support system including umbilicals;
- Instruments such as time clocks, pressure gauges and depth gauges. The
accuracy of main instruments reading is to be checked (e.g. depth gauge, gas
analyser, etc.);
- Navigational, tracking and communications systems;
- Electric batteries, fuel cells and other power sources;
- Corrosion control system;
- Manoeuvring controls, including ballast systems and arrangements for ballast
movement or jettisoning;
- Emergency arrangements;
- Propulsion equipment;
- Examination of viewports and confirm certification remains valid;
- Safety interlocks/medi locks fitted on equipment such as food
and medical locks, or on other equipment requiring the placement of a safety
interlock, and should be tested to confirm their correct operation and that
no accidental pressure loss can occur resulting from their operation;
- Compressors, Safety devices and gas purity test records;
- Heating, cooling and ventilation arrangements;
- Control, alarm and safety systems;
- Analysers;
- Gas storage and safety device arrangements;
- Fire protection, detection and extinction arrangements to be examined;
- Escape and evacuation arrangements including hyperbaric lifeboats where
fitted;
- Documents relating to the diving system and operational records;
- Entire compression chamber system, including all fixtures, penetrations,
doors and covers, seals, locking systems etc. inspected for visible damages,
cracks, deformation, corrosive attack and fouling;
- All other pressure vessel apparatus, valves, fittings and safety equipment
subject to external inspection;
- Entire power supply system, including the emergency supply, of the diving
system is to be subjected to external inspection. Insulation measurements
are to be performed on the electrical equipment.
- Switching from the main to emergency electricity supply is to be tested;
- All high-pressure gas supply and charging hoses and the hoses belonging to
the heating system and the umbilical are to be checked for visible damage
and tightness.
In general, controls, systems and circuits need not be stripped down or
dismantled for the surveys unless this is normal maintenance procedure or the
Surveyors have reason to believe that the system or any component part is defective.
2.1.4 For the lifting gear the following is to form part of an Annual Survey:
See also LR Code for Lifting Appliances in a Marine Environment, July 2022
Ch 12, 1.7 Manned submersible handling systems and Ch 12, 3 Survey requirements, Table 12.3.6 Annual Thorough Examination of
cranes (incuding derrick cranes) and launch and recovery systems for diving
operations regarding periodic survey of
lifting gear:
- An inspection of the wire, rope or cable;
- A reeving test is to be made in conjunction with the inspection
of the cable anchoring device on the drum, and the spool mechanism, if
fitted;
- A General Examination of the frame and operating equipment;
- A static test of 1.5 times the safe working load, and having
regard to the range of operation a functional test at 1.25 times the safe
working load;
- A static test of the secondary brake, where fitted;
- A dynamic test on the brake. The brake should be capable of
stopping 1.1 times the safe working load in air under simulated power
failure;
- Where the diving system is approved with hoisting factor of
more than 1.7, the test loads indicated in d) and f) are to be increased by
the ratio of Fh/1.7 as specified in Code for Lifting Appliances in a Marine Environment, July 2022
Ch 12, 1.7 Manned submersible handling systems 1.7.3.
A test is to be carried out for lifting gear designed to operate on
dynamic response, or for those incorporating shock absorption other than relying on
the rope, to demonstrate satisfactory operation of the controls under simulated
power failure at maximum outreach with maximum in air working load.
2.1.5 On completion of the examination and tests, submersibles other than those
with permanent moorings are to undergo a test dive to a depth agreed by the
Surveyors. On completion the Surveyors are to examine the submersible for leaks or
damage.
2.1.6 For the purpose of Annual Survey the Surveyors may accept at their
discretion a report from a competent representative of the Owner or a recognized
Authority as an alternative to witnessing the whole or part of the foregoing tests
and inspections.
2.2 Intermediate Survey (Manned submersibles and chambers)
2.2.1 Intermediate Survey shall be carried out at the second or third Annual
Survey after a Special Survey, of a manned submersible or compression chamber. The
following requirements apply in addition to those given in Pt 1, Ch 3, 2.1 Annual Surveys (Manned submersibles and chambers).
- The hull or main pressure vessel is to be tested in accordance
with Pt 5, Ch 4, 6.4 Gas leak test for all chambers and breathing gas systems;
- Pressure circuits are to be tested for leaks and correct
functioning at the working pressure. This is to include pressurized sanitary
discharges where fitted. The life-support system is to be checked over a
period of at least one hour. To conserve helium, air testing with the
minimum of this gas for leak detection may be used on appropriate
circuits;
- Functional tests on mechanical and electrical equipment, life
support systems, fire warning and extinguishing systems, all alarm systems.
Functional and purity check on all breathing gas compressors.
2.3 Intermediate Survey (Unmanned submersibles and containers)
2.3.1 Unless more frequent surveys are requested by the Owners or deemed
necessary by the Committee, unmanned submersibles and containers are to be surveyed
by LR’s Surveyors at or around second or third anniversary of Special Survey
provided interval between any two periodical surveys does not exceed thirty six
months. The requirements equivalent to Pt 1, Ch 3, 2.1 Annual Surveys (Manned submersibles and chambers) relevant to the particular unmanned submersibles are to
be complied with.
2.4 Special Surveys (Manned and unmanned submersibles, containers, diving systems or deck compression
chambers)
2.4.1 Prior to the commencement of the Special Survey, a meeting is to be held between the
attending Surveyor(s), the Owner/Owner’s representative and the thickness
measurement company representative so as to ensure the safe and efficient conduct
of the survey and thickness measurements to be carried out. In preparation for the
survey and thickness measurements and to allow for a thorough examination, some
removal of insulation may be required.
2.4.2 Thickness measurements are normally to be taken by means of ultrasonic test equipment
and are to be carried out by a firm approved in accordance with LR’s Approval
for Thickness Measurement of Hull Structure.
2.4.3 The survey will not be considered complete until all required thickness measurements
have been carried out. Such measurements are to be witnessed by the Surveyor(s) to
the extent necessary to control the process.
2.4.4 At the Special Survey the Surveyors are to complete the tests and
inspections required at Annual Surveys, see
Pt 1, Ch 3, 2.1 Annual Surveys (Manned submersibles and chambers), and are to undertake all the tests
and inspections required to establish to their satisfaction, the condition and
operation of the unit as a whole. The Owner is to provide proper facilities for the
survey to permit thorough inspection of the shells, fittings and attachments.
Important equipment is to be opened up, as necessary, for inspection.
2.4.5 Acrylic viewport windows are to be dismounted and examined for incipient
cracks. Window seating’s are to be examined for corrosion, Unless otherwise agreed,
the windows should be renewed at 10 year intervals.
2.4.6 Where a submersible is anchored to the sea bed or forms part of an
underwater structure, the whole or selected areas of the external surface as deemed
necessary by the Surveyors are to be suitably cleaned by water jet equipment or
other means to permit inspection. If the underside of the submersible is silted up,
this is to be cleaned to facilitate inspection of the surface and any attachments.
2.4.8 The extent of the Special Survey on a sub-sea installation is to be
defined before it is effected, and the divers are to be approved by LR and informed
fully of the required work and competent to undertake it. Sub-sea installations may
be externally inspected by the means of ROV provided the operator of the vehicle is
approved by LR for the in water survey activities. Divers and ROV operators are to
be provided with close circuit television equipment and video recording equipment so
that the Surveyors can view the necessary areas of the chamber, and the equipment,
and check that any tests and opening up have been effected.
2.4.9 Following examinations and tests to be carried out:
- The pressure vessel or hull, and associated items contributing
to the strength are to be examined for cracks, wastage and damage. Stripping
of the shell to bare steel or other material of construction will not
normally be required. However, some regions may be required to be exposed if
the Surveyors have doubts about the condition and cannot establish it by
other means.
- All ballast systems are to be examined and checked for proper
operation. This includes releasable ballast weights;
- Pressure chambers and pressure hulls, except those located
permanently under the sea, are, unless otherwise approved, to be subjected
to over pressure tests generally to the level applied at the time of
manufacture. In the case of a deck compression chamber, diving bell or other
type of submersible, which may be subjected to external or internal
pressure, either directly or due to differential pressure between
compartments, over pressure tests are to be applied appropriate to the modes
of service pressurisation. Prior to a pressure test, any delicate equipment
that might be damaged by the test pressure should be removed or protected
otherwise. Pressure tests may be hydrostatic or pneumatic. In the latter
case the test pressure should be 1.1 times the maximum working pressure and
conditions are to be in accordance with the requirements of a design
pressure vessel code, including measures to protect personnel;
- On completion of these pressure tests, equipment which was
subjected to the pressure should be examined for damage and checked for
satisfactory operation;
- Emergency ballast release and buoyancy tests are to be
performed with the diving bell;
- All important piping systems are to be pressure tested
hydraulically, or by gas as appropriate. The test pressure and conditions
are to be in accordance with the requirements of a design pressure vessel
code, including measures to protect personnel;
- Where a system normally contains a fluid or material which
could present a hazard in the event of leakage or rupture, the integrity and
tightness are to be established. This applies particularly to systems
containing mercury. As this material can also promote cracking of certain
metals, components should be examined for cracks;
- Propulsion and other components or systems are not normally
required to be opened up where they are originally accepted on ‘maintenance
by replacement’. The Surveyor is to ascertain that these units have not
exceeded the scheduled running time or time for replacement or overhaul, or
are unlikely to do so before the next Annual Survey is due. The mountings of
these items are to be examined and the state of each item is to be judged
from external appearance and functional tests as far as practicable;
- All glands at penetrations of the hull are to be carefully
examined together with associated cables, shafts, etc. Propellers fitted to
submersibles and their connections are to be examined;
- Lifting gear, including winches and frames, is to be carefully
examined together with the attachments to the floating or fixed structure
and is to be opened up for examination as necessary;
- Dimensional checks and non-destructive wall thickness tests are
to be performed on the diving bell. Where necessary, buoyancy aids, cladding
and layers of thermal insulation are to be removed for this purpose;
- Shackles and links of lifting gear for tethered or towed
submersibles are to be thoroughly examined and tested;
- Pressure vessels and apparatus not capable of satisfactory
internal inspection and those whose satisfactory condition cannot be
definitely established by internal inspection are to be inspected by another
non-destructive method of examination or are to be subjected additionally to
a hydraulic pressure test.
2.4.10 At the first special survey critical areas as established by the
attending surveyor and areas with the indications of coating defects should be
subject to random ultrasonic thickness measurements.
2.4.11 At the second and subsequent special surveys dimensional checks and
ultrasonic thickness measurements are to be performed on the diving bell, deck
compression chambers and hyperbaric lifeboat compression chamber to the extent
necessary to establish any corrosion diminution. Buoyancy aids, cladding and layers
of thermal insulation are to be removed for this purpose where necessary.
2.4.13 At the Special Survey, any component found not to be in accordance with
the Rules or the terms of approval, or any material, workmanship or arrangements
found to be unsatisfactory are to be rectified or replaced to the satisfaction of
the Surveyor.
2.4.14 On completion of all inspections and tests, trials are to be carried out
to the Surveyor’s satisfaction.
2.5 Survey requirements for reactivation after lay-up
2.5.1 At the end of a period of storage and before re-commissioning the Owner
is to submit the unit and equipment to a survey by the Surveyors, as indicated in
Table 3.2.1 Surveys after lay-up.
Table 3.2.1 Surveys after lay-up
| Period of
storage
|
Manned (M) or unmanned
(U)
|
Type of
survey
|
| 6 to 18 months
|
M
|
Annual Survey
|
| 18 months to 5 years
|
M
|
Intermediate Survey
|
| Over 5 years
|
M
|
Special survey
|
| 1 to 5 years
|
U
|
Intermediate Survey
|
| Over 5 years
|
U
|
Special survey
|
2.5.2 If the Surveyors consider as a result of any of these surveys that the hull or
chamber, or equipment has been damaged or dismantled, or has deteriorated
significantly, the Owner will be advised and requested to make provision for further
examination by the Surveyors.
|