Connecticut Maritime Association Shipping 2000 , March 21

1. Connecticut Maritime AssociationShipping 2000,March 21 Ballast Water: Searching for Sensible Solutions: “How to deal with the issue in New Construction” by Robert.Loeseth@dnv.com

2. Ballast Water Management

3. Ballast Water Management • IMO Res. A.868(20) Guidelines for the control and management of ships’ ballast water to minimise the transfer of harmful aquatic organisms and pathogens • IMO is working on a mandatory annex to Marpol 73/78 with basis in the Guidelines • ICS/ Intertanko: Model Ballast WaterManagement Plan

4. Ballast Water Management Possible Hazards • Deficient Stability • Excessive Hull Girder Bending or Shear Forces • Excessive Torsional Stresses • Structural Damage of WBT Tanks • Structural Damage to Flat Bottom Forward • Loss of Manoeuvrability • Structural Damage due to Over/Under Pressure • Personnel Safety

5. Ballast/loading/unloadingExcessive Hull Girder Bending or Shear Forces

6. SHIP TYPE Bulk Carrier SIZE(GRT) 28 700 YEAR OF BUILD 1986 • OVER-PRESSURISING OF TOP SIDE TANKS - HULL DAMAGE No. 5/93 Probable Cause:“The damage found was typical of that found in tanks over-pressurised as a result of choked air vent heads.” “An under-dimensioned air vent system is the most probable cause of the damage, as no obvious sign of clogged or obstructed air vents was observed during the survey. “ http://exchange.dnv.com

7. Capsize due to assumed ballasting error SHIP TYPE General Cargo SIZE(GRT) 312 YEAR OF BUILD 1973 No. 3/96 “During a survey of the engine room it was noted that the vessel was equipped with a rather complex ballast tank arrangement and change-over valve chest system with unclear marking and identification labelling.” “The Chief Engineer had just signed on the vessel prior to departure, and confusion relating to operation of the valves during ballasting cannot be ruled out. “ http://exchange.dnv.com

8. SHIP TYPE Product Tanker SIZE(GRT) 28000 YEAR OF BUILD 1996 Listing of double hull tanker during cargo operation No. 3/99 While loading at terminal, the ship listed heavily to port during shifting of ballast. the initial lolling to port caused a flow of ballast water through the cross-over valves, which might have been left open due to human error or mechanical/electrical failures. http://exchange.dnv.com

9. Past practice : ballast operations in open waters • Bulk : Cleaning of tanks (even with open hatches) and exchange of dirty ballast water. • Container/RoRo : Trim and stability adjustments • Tank : Standard operation before MARPOL • Ballast exchange is a risk, but can be managed if well planned and considered at new-building.

10. Pressure drop / over pressure Experience show that manual operation of valves / ventilation may be forgotten : => Advise installation of fail safe pressure valves Size of ventilation / Air pipe should be checked to avoid overpressure = > DNV previous : Area of outlet > 1.25 time Area of intake : Require caution = > DNV present : Require pressure drop calculation to document pressure limit Pressure valve Manual opening

11. EXCHANGE OF COASTAL WATER BALLAST 149100 t DWT BULK CARRIER Modified normal ballast condition Proposed sequence 0.214 L 0.214 L Seq. No. 0 WB TK 5 WB TK 4 WB TK 3 WB TK 2 WB 1 Ta= 7.46 m Tf= 7.10 m Trim = 0.36 m 0.214 L 0.214 L Seq. No. 11 WB TK 5 WB TK 4 WB TK 3 WB TK 2 WB 1 Ta= 7.46 m Tf= 7.10 m Trim = 0.36 m

12. EXCHANGE OF “POLLUTED” COASTAL WATER BALLAST 149100 t DWT BULK CARRIER 0.214 L 0.214 L Seq. No. 11 WB TK 5 WB TK 4 WB TK 3 WB TK 2 WB 1 Ta= 7.46 m Trim = 0.36 m Tf= 7.10 m

13. Violation of conventions in sequential exchange(even the above “best case”) • SOLAS : visibility (due to trim) • Propeller immersion (manoeuvrability and thrust) • Mimimum draft forward (slamming) • Should be acceptable if low seastate, open water with limited traffic and a planned operation. Not recommend carried out if seastate Hs > 4.0 m expected within 24 hours.

14. BALLAST WATER TRANSFER ATLAS Risk based ballast water management

15. BIOLOGICAL REGIONS

17. EMBLA The Ballast Water Risk Based Approach • A number of ballast voyages are undertaken between ports representing biological incompatibility. • Development of a methodology identifying those specific voyages representing actual risk. • Reduction of “unnecessary” re-ballasting. • Reduction of potential procedural error during mid-ocean re-ballasting operations. Ref : Aage.Bjorn.Andersen@dnv.com

18. Recommendations Tank/bulk newbuildings • Sequential exchange a must (save fuel, wear) • Ask for documentation. Pressure drop & stability booklet including strength. • Establish a ship specific Ballast Water Exchange Manual • Keep number of steps low (10-12). • Time of exchange : Handy/panmax < 24 hrs Capesize/Aframax < 48 hrs • May in some cases be beneficial with more subdivision of ballast tanks (for flexibility and less risk of sloshing). • Install intuitive and fail-safe ballast handling. BWE manual : Nils.Hemivik@dnv.com

19. Slender vessel new-building (low GM) • Sequential exchange a must (save fuel, wear) • Additional problems with Stability. Must establish strict procedures and plans - verification. • More ballast tanks to enable on-board shifting of ballast, increasing flexibility and limiting exchange. • Stability sensor? • Even more important to have an intuitive system for ballast handling.

20. Ballast Water Management Control Strategies • Emptying and Refilling of Tanks • Flow Through Method • Reception facilities • Thermal Methods • Filtration • Disinfection including ultraviolet light • Risk Based Ballast Water Management Approach Current Future