Hong Kong Regulations

MERCHANT SHIPPING (PREVENTION OF OIL POLLUTION) REGULATIONS - SCHEDULE 6

SPECIFICATION FOR OIL TANKERS WITH DEDICATED CLEAN BALLAST TANKS

[regulations 20(2) & (4)]

1. PURPOSE

1.1 The purpose of these Specifications is to provide specific criteria,
operational requirements and control and enforcement procedures for those
oil tankers operating with Dedicated Clean Ballast Tanks as specified in
Section 2 of these Specifications.

2. APPLICATION

2.1 Under these Regulations these specifications apply to- .1 existing crude
oil tankers of 70000 tons deadweight and above until 2 October 1985 in
accordance with regulation 18(9)(a) of these Regulations; .2 existing crude
oil tankers of 40000 tons deadweight and above but below 70000 tons
deadweight, until 2 October 1987 in accordance with regulation 18(9)(b) of
these Regulations; and .3 existing product carriers of 40000 tons deadweight
and above.

2.2 Compliance by these ships with these Specifications shall be shown on the
IOPP or HKOPP Certificate.

3. INITIAL SURVEY

3.1 The initial survey referred to in regulation 4 of these Regulations shall
include the verification of- .1 the selection of ballast tanks and pumping and
piping arrangements; and .2 the Dedicated Clean Ballast Tank Operation Manual,
specifying detailed operational procedures and including a checklist of such
procedures.

3.2 The IOPP or HKOPP Certificate shall indicate which tanks are approved
solely for the carriage of dedicated clean ballast. It shall also state that
the master has been provided with a valid Dedicated Clean  Ballast Tank
Operation Manual showing operational procedures.

4. ON BOARD ARRANGEMENTS

4.1 Dedicated clean ballast tanks

4.1.1 The dedicated clean ballast tanks shall have sufficient capacity to
enable the tanker to meet the requirements of regulation 18(2) of these
Regulations.

4.1.2 The selection of the dedicated clean ballast tanks shall be such that
the hull stresses in the ballast and loaded conditions are to the satisfaction
of a Certifying Authority.

4.1.3 The dedicated clean ballast shall, in order to prevent accidental
pollution, be carried in wing tanks; provided that a Certifying  Authority may
permit the use of centre tanks where it can be shown that significant
advantage can be obtained in respect of hull stresses, tank volume or pumping
and piping arrangements.

4.1.4 Tanks shall be selected so as to require a minimum of involvement of the
cargo piping and pumping system.

4.2 Pumping and piping arrangements

4.2.1 The piping system for conveying the dedicated clean ballast shall be
such that it can be flushed to a slop tank with water, and shall be so
arranged that oily water does not enter any dedicated clean ballast tank when
the piping system is flushed.

4.2.2 The piping system of each dedicated clean ballast tank shall, not later
than 1 July 1983, have at least two valves that isolate that tank from the
piping systems serving the cargo tank.

4.2.3 The dedicated clean ballast tanks shall be connected to the least
practicable number of cargo pumps.

4.2.4 The discharge of dedicated clean ballast to the sea shall be monitored
by an oil content meter of an approved design and sufficient sample points
shall be provided in the discharge piping of pumps serving dedicated
clean ballast tanks to permit supervision of the oil content in the ballast
water being discharged.

5. OPERATIONAL PROCEDURES

5.1 The pumps and piping system conveying dedicated clean ballast shall be
flushed with water before clean ballast is loaded, discharged or transferred.

5.2 The water for flushing shall be pumped from a sea chest or dedicated
clean ballast tank through the pump and piping system of the dedicated
clean ballast tank and then to a slop tank.

5.3 If sections of the piping system for dedicated clean ballast are so
arranged that they can only be flushed with water from the dedicated
clean ballast tanks then the minimum quantity of flushing water to be provided
in such tanks at all times shall be the greater of either 10 times the volume
of the piping to be flushed or sufficient to provide that level in the tank
which would allow the piping to run full of water during the flushing before
vortexing starts to admit air into the piping. Any alternative methods to the
retention of clean ballast required by this paragraph shall be to the
satisfaction of the Director.

5.4 After the loading, discharging or transferring of the dedicated
clean ballast the valves specified in paragraph 4.2.2 shall be shut and the
piping system drained.

5.5 The overboard discharge through which the dedicated clean  ballast is
discharged shall be monitored by an oil content meter.

5.6 The simultaneous discharge of the dedicated clean ballast whilst loading
cargo or the simultaneous ballasting of the dedicated clean  ballast while
discharging cargo shall not be undertaken except where there is an effective
two-valve separation between the dedicated clean ballast tank system and the
cargo system or when cargo tanks are served by individual pumps.

5.7 Ballast water shall not be allowed to free fall into ballast tanks into
which hydrocarbon gases have leaked. The Dedicated Clean  Ballast Tank
Operation Manual shall provide either for such tanks to be gas freed before
ballasting or for alternative tanks to be used to obviate the danger posed by
splashing and free fall of water in tanks containing hydrocarbon gases within
the explosive range.

6. DEDICATED CLEAN BALLAST TANK OPERATION MANUAL

6.1 The Dedicated Clean Ballast Tank Operation Manual specified in regulation
20(4) of these Regulations shall contain the following- .1 the complete text
of the "Specifications for Oil Tankers with Dedicated Clean Ballast Tanks" as
set out in this Schedule; .2 the drawings of the dedicated clean ballast tanks
systems; .3 the description of the systems connected to the dedicated clean
ballast tanks including the identity of the dedicated clean ballast tanks and
of the slop tank which may be any designated cargo tank; .4 the dedicated
clean ballast tanks operation procedures containing specific operational
procedures for valve operations, line cleaning and for loading and discharging
dedicated clean ballast when conducted as follows- .1 prior to arrival and at
the loading port; .2 after departure from the loading port; .3 prior to
arrival at the final discharge port; .4 in final discharge port; and .5 after
departure from the final discharge port. In Appendix 1 to these Specifications
Dedicated Clean Ballast Tank Operation Procedures are set out which apply
generally to all tankers operating under the CBT concept; .5 the checklists
for ballasting and de-ballasting dedicated clean ballast tanks; .6 the
carriage of additional ballast; .7 compliance procedures for regulation 13 of
these Regulations; and .8 additional precautions against oil pollution.

7. DOCUMENTS

7.1 The IOPP or HKOPP Certificate and the valid Dedicated Clean  Ballast Tank
Operation Manual shall at all times be available on board the tanker.

APPENDIX

DEDICATED CLEAN BALLAST TANK OPERATION PROCEDURES

1. PRIOR TO ARRIVAL AT THE LOADING PORT

1.1 The pumping and piping designated for clean ballast operation shall be
properly cleaned to permit the discharge of clean ballast in the loading port.

1.2 The valves to the slop tanks and the cargo tanks which are connected to
the clean ballast system shall be closed.

1.3 An inspection of the surface of the dedicated clean ballast shall be made
before discharge to ensure that there is no contamination with oil.

1.4 Discharge clean ballast until sufficient quantity remains for safe
berthing and for flushing lines if necessary.

1.5 If no further ballast discharge is anticipated in the loading port shut
all valves to the clean ballast tanks and drain the clean  ballast piping.

2. IN THE LOADING PORT

2.1 After the tanker has been safely berthed ballast may be discharged: .1
before the cargo is loaded; and .2 during the loading of cargo either
simultaneously or by interrupting the loading provided that there is an
effective two-valve separation between the cargo and the clean ballast system,
or the cargo tanks are served by individual pumps.

2.2 Until sufficient clean ballast has been discharged the piping and pumping
arrangement servicing the dedicated clean ballast tanks must be kept clean.

2.3 Upon completion of ballast discharge all valves to the dedicated
clean ballast tanks shall be shut, the clean ballast piping shall then be
drained and may be utilised for the loading of cargo.

2.4 The tanker shall be loaded taking into account the requirements of a
discharge sequence compatible with the operational procedures for dedicated
clean ballast tanks with particular reference to trim and stress levels if the
cargo is to be unloaded at two or more discharge ports.

2.5 Slop tanks shall be loaded with cargo that will be discharged well before
any ballasting operation has to be carried out. If pipe flushing is required
during the loaded passage sufficient ullage must be left in the slop tanks to
accommodate the necessary flushing water.

2.6 At the completion of loading all valves to the cargo tanks shall be
closed.

3. AFTER DEPARTURE FROM THE LOADING PORT

3.1 If any clean ballast is to be discharged overboard the pumps and piping
serving the dedicated clean ballast tanks shall be flushed into the
slop tanks.

3.2 The valves to the slop tank shall be closed before pumping clean ballast
overboard.

3.3 The valves to the dedicated clean ballast tanks shall be closed after
discharging ballast.

3.4 During the loaded passage the dedicated clean ballast tanks shall be
periodically checked for any hydrocarbon gas content and if any gas is
detected the tank shall be ventilated until safe for entry and inspected for
leakage in bulkheads and piping.

4. PRIOR TO ARRIVAL AT THE FINAL DISCHARGE PORT

4.1 The dedicated clean ballast tanks may be ballasted through clean pumps and
piping with sufficient ballast to clear port draught requirements.

4.2 The required amount of water for flushing the piping may be taken into the
dedicated clean ballast tanks overdeck or through clean cargo piping.

5. IN FINAL DISCHARGE PORT

5.1 The cargo discharge and ballasting sequence must be compatible with the
operational requirements of dedicated clean ballast tanks.

5.2 Clean ballast may be taken on board: .1 before the cargo is discharged; .2
during the discharge of cargo either simultaneously or by interrupting the
discharge provided that there is an effective two-valve separation between the
cargo and the clean ballast system or the cargo tanks are served by individual
pumps; and .3 after cargo has been discharged completely.

5.3 When clean ballast is to be taken on board the pumps and piping serving
the dedicated clean ballast tanks are to be flushed.

5.4 Upon completion of ballasting all the valves to the dedicated
clean ballast tanks shall be closed.

6. AFTER DEPARTURE FROM THE FINAL DISCHARGE PORT

6.1 Dedicated clean ballast tanks may be topped up using clean pumps and
piping.

6.2 The slop tank contents are to be processed in accordance with load-on-top
procedures.

6.3 The surface of the CBT ballast is to be periodically inspected for the
presence of oil, and the causes of any contaminations carefully investigated.

6.4 After cargo tank cleaning operations the pumps and pipelines to be used
for clean ballast shall be flushed.

7. PUMP AND PIPE FLUSHING

7.1 The pipe flushing water must never be passed into dedicated clean ballast
tanks.

7.2 Water for flushing pipelines may be drawn from the sea and from the
dedicated clean ballast tanks and this will be determined by the configuration
of the tanker's piping system.

7.3 When flushing from dedicated clean ballast tanks it is essential that the
line has first been thoroughly drained of oil. Flushing should normally start
from the tank farthest from the pump. After the line has been primed and
suction established, the pumping shall be stopped and the valves closed for a
period to allow the oil to separate from the pipe walls. Pumping is then
resumed at a moderate speed with throttling of the output at the pump's
delivery side.

7.4 Water shall first be drawn from individual dedicated clean  ballast tanks
to clear branch pipes.