LOADLINE CONVENTION

THE ILLC APPLIES TO SHIPS ENGAGED ON INTERNATIONAL VOYAGES WHETHER REGISTERED IN THE COUNTRY OF A CONTRACTING GOVERNMENT OR TERRITORY TO WHICH THE PRESENT CONVENTION IS EXTENDED OR UNREGISTERED BUT FLYING THE FLAG OF A CONTRACTING GOVERNMENT.

THE REGULATIONS DO NOT APPLY TO:

1.      SHIPS OF WAR,

2.      NEW SHIPS < 24m LENGTH,

3.      EXISTING SHIPS < 150GRT,

4.      PLEASURE VESSELS NOT ENGAGED IN TRADE,

5.      FISHING VESSELS,

CONDITIONS OF ASSIGNMENT OF FREEBOARD

1.      INFORMATION TO MASTER: THE MASTER IS TO BE SUPPLIED WITH SUFFICIENT INFORMATION TO LOAD AND BALLAST HIS SHIP WITHOUT UNACCEPTABLE STRESSES.

2.      SUPERSTRUCTURE END BULKHEAD: THESE MUST BE OF SUITABLE STREGTH TO THE SATISFACTION OF THE ADMINISTRATION.

3.      DOORS: ACCESS OPENING IN ENCLOSED SUPERSTRUCTURES ARE TO BE

1.      CONSTUCTED OF STEEL OR EQUIVALENT MATERIAL,

2.      PERMANENTLY OR STRONGLY ATTACHED TO THE BULKHEAD,

3.      FRAME STIFFENED AND FITTED TO SAME STRENGTH AS UNPIERCED BULKHEAD,

4.      WEATHERTIGHT, WITH PERMANENTLY ATTACHED GASKETS AND CLAMPING DEVICES,

5.      OPERABLE FROM BOTH SIDES,

6.      HAVE THE DOOR SILL 380mm ABOVE DECK.

4.      POSITION OF HATCHWAYS, DOORS AND VENTILATORS: POSITION 1 IS ON THE MAIN DECK OR ON ANY PLACE SITUATED FORWARD OF THE POINT ¼ OF THE LENGTH. POSITION 2 IS ON THE EXPOSED SUPERSTRUCTURE DECK AFT OF THE POINT MENTIONED ABOVE.

5.      CARGO AND OTHER HATCHWAYS: CONTRUCTION AND MEANS OF SECURING WATERTIGHTNESS ARE TO BE AS PER THE REGULATIONS.

6.      MACHINERY SPACE OPENINGS: MACHINERY SPACE OPENINGS ARE TO BE ENCLOSED BY STEEL CASINGS INTO WHICH ACCESS IS BY WEATHERTIGHT DOORS.

7.      MISCELLANEOUS OPENINGS IN FREEBOARD AND SUPERSTRUCTURE DECK: MANHOLES AND FLUSH SCUTTLES ARE TO HAVE SUBSTANTIAL WATERTIGHT COVERS PERMANENTLY ATTACHED OR FITTED WITH CLOSELY SPACED BOLTS.

8.      VENTILATORS: VENTILATOR COAMING MUST BE OF STEEL, OF AN APPROVED HEIGHT AND SHOULD HAVE PERMANENTLY ATTACHED CLOSING APPLIANCES.

9.      AIR PIPES: AIR PIPES SHOULD BE OF A SUBSTANTIAL CONSTRUCTION, SHOULD HAVE PERMANENTLY ATTACHED MEANS OF CLOSING. THE HEIGHT ON FREEBOARD DECK TO BE >= 760 mm AND ON SUPERSTRUCTURE DECK TO BE >=450mm.

10.  PROTECTION OF CREW:

1.      DECKHOUSES FOR CREW ACCOMODATION SHOULD HAVE SUFFICIENT STRENGTH,

2.      EFFICIENT GUARD RAILS OR BULWARKS TO BE PROVIDED ON ALL EXPOSED PARTS OF SUPERSTRUCTURE OR FREEBOARD DECKS UPTO A HEIGHT OF ATLEAST 1M, THE LOWER RAIL TO BE 230mm FROM DECK AND SUBSEQUENT RAILS TO BE 380mm APART.

3.      SATISFACTORY MEANS TO BE PROVIDED TO ENABLE THE CREW TO GO TO AND FROM THEIR QUARTERS, MACHINERY SPACES AND OTHER AREAS OF THE SHIP.

TYPES OF SHIPS:

1.      TYPE A SHIP:

1. IT IS DESIGNED TO CARRY LIQUID,
2. IT HAS HIGH INTEGRITY OF EXPOSED DECK DUE TO SMALL OPENINGS WHICH CAN BE CLOSED WATER-TIGHT,
3. HAS LOW PERMEABILITY OF CARGO SPACES,
4. IF OVER 150m OF LENGTH, WHEN FULLY LOADED, SHOULD BE ABLE TO WITHSTAND THE FLOODING OF ATLEAST ONE COMPARTMENT WITH AN ASSUMED PERMEABILITY OF 95%, THE MACHINERY SPACE IS TREATED AS A FLOODBLE COMPARMENT WITH 85% PERMEABILITY,
5. A TYPE A SHIP SHALL NOT BE ASSIGNED A FREEBOARD LESS THAN THE TABULAR FREEBOARD AS GIVEN FROM TABLE A.
6. THE MACHINERY CASING TO BE SURROUNDED BY AN ENCLOSED SUPERSTRUCTURE. NO DOOR FROM THE ENGINE ROOM SHOULD LEAD DIRECTLY ONTO THE FREEBOARD DECK, IT SHOULD FIRST LEAD INTO SOME OTHER SPACE AND THEN TO THE FREEBOARD DECK, THE IDEA BEING IF ONE DOOR OR BULKHEAD FAILS, THE ENGINE ROOM SHOULD NOT GET FLOODED.
7. SINCE THE FREEBOARD OF THESE SHIPS IS REDUCED, THERE SHOULD BE A WALKWAY (CATWALK) FOR THE CREW TO MOVE FROM CREW ACCOMODATION TO ALL OTHER WORKING PARTS OF THE SHIP. THIS SHOULD EITHER BE IN THE FORM OF A RAISED CATWALK ON THE MAIN DECK OR AN UNDERDECK PASSAGE.
8. ATLEAST HALF THE LENGTH OF THE EXPOSED PART OF WEATHER DECK SHOULD HAVE RAILS AND NOT BULWARK TO QUICKLY DRAIN THE WATER WHICH WASHES ONTO THE DECK.

2.      TYPE B60 SHIP:

1. ALL OTHER SHIPS WHICH ARE NOT TYPE A SHIPS ARE TYPE B SHIPS.
2. THE FREEBOARD FOR TYPE B SHIP IS GIVEN FROM TABLE B, THIS FREEBOARD CAN BE INCREASED AND DECREASED.
3. THE TABULAR FREEBOARD SHALL BE INCREASED WHEN:

1.      THE HATCH COVERS AT POSITION 1 AND 2 ARE NOT OF STEEL,

2.      WHEN A SHIP BETWEEN 24M AND 100M IN LENGTH HAS AN EFFECTIVE LENGTH OF SUPERSTRUCTURE LESS THAN 0.35L.

4. THE TABULAR FREEBOARD MAY BE DECREASED WHEN:

1.      THERE ARE ADEQUATE MEANS FOR PROTECTION OF THE CREW,

2.      THERE ARE ADEQUATE FREEING PORTS,

3.      THERE ARE FIXED STEEL HATCH COVERS WITH ADEQUATE SECURING ARRANGEMENTS,

4.      THE SHIP WHEN FULLY LOADED SHALL BE ABLE TO WITHSTAND THE FLOODING OF ANY COMPARTMENT LONGITUDINALLY OR ANY COMPARTMENTS TRANSVERSELY AS PER THE DAMAGE ASSUMPTIONS SPECIFIED AND REMAIN AFLOAT IN A SATISFACTORY CONDITION. IF LENGTH IS OVER 150m THE PERMEABILITY OF MACHINERY SPACE SHALL BE CONSIDERED 85% AND ALL OTHER SPACES AS 95%.

A SHIP COMPLYING WITH ABOVE REQUIREMENT IS KNOWN AS B60 SHIP.

3.      TYPE B100 SHIP: TABULAR FREEBOARD DECREASED UPTO 100% OF THE DIFFERENCE BETWEEN TYPE A AND TYPE B SHIPS.

1. A SHIP COMPLYING WITH THE REQUIREMENT ABOVE FOR B60 EXCEPT FOR 4.4 A TRANSVERSE BULKHEAD WILL BE ASSUMED TO BE DAMAGED SO THAT TWO ADJACENT F & A COMPARTMENTS ARE FLOODED SIMULTANEOUSLY. (PERMEABILITY 95%). IF LENGTH IS OVER 150m THE PERMEABILITY OF MACHINERY SPACE SHALL BE CONSIDERED 85%. THUS A VESSEL MAY HAVE TO WITHSTAND FLOODING OF 4 COMPARTMENTS IF THE LONGITUDINAL BULKHEAD FALLS WITHIN THE TRANSVERSE EXTENT OF DAMAGE.
2. THE SHIP COMPLIES WITH POINT 6, 7 AND 8 FOR TYPE A SHIPS EXCEPT THAT THE HATCOVERS NEED NOT BE WATERTIGHT BUT WEATHERTIGHT.

CORRECTION TO TABULAR FREEBOARD:

TABULAR FREEBOARD

1. CORRECTION FOR EFFECTIVE LENGTH OF SUPERSTRUCTURE. (ONLY +): IF ELSS IS LESS THAN 0.35L FREEBOARD SHALL BE INCREASED BY

7.5(100 – L) (0.35 – E/L) mm (ONLY FOR TYPE B SHIPS)

2. CORRECTION FOR BLOCK CO-EFFICIENT: IF THE Cb IS EXCEEDS 0.68, THEN THE TABULAR FREEBOARD SHALL BE MULTIPLIED BY (Cb + 0.68) / 1.36.

BASIC FREEBOARD

3. CORRECTION FOR DEPTH (+ OR -): WHEN D>L/15 THEN F/B IS INCREASED BY (D-L/15)R, WHERE R=L/0.48 FOR SHIPS<120M LENGTH AND R=250M FOR SHIPS>120M LENGTH. IF D<L/15 THE F/B SHALL BE REDUCED ONLY IF THE SHIP HAS AN ENCLOSED SUPERSTRUCTURE OF STANDARD HEIGHT COVERING 0.6L AMIDSHIPS.
4. CORRECTION FOR POSITION OF DECKLINE (+ OR -): THE FREEBOARD IS MEASURED FROM THE UPPER EDGE OF THE DEK LINE, IF DUE TO SOME REASONS THE DECKLINE CANNOT BE PLACED IN LINE WITH DECK, BUT IS SOMEWHERE ABOVE OR BELOW IT, THEN THE DIFFERENCE IS ADDED OR SUBTRACTED AS REQUIRED.
5. CORRECTION FOR EFFECTIVE LENGTH OF SUPERSTRUCTURE AND TRUNKS (ONLY -): SUPERSTRUCTURES AND TRUNKS PROVIDE BUOYANCY BUT THEY MUST BE ENCLOSED AND SECONDLY MUST BE OF A PARTICULAR VOLUME (LENGTH, BREADTH AND HEIGHT), THEN ONLY A REDUCTION IN FREEBOARD MUST BE ALLOWED.
6. CORRECTION FOR SHEER OF THE VESSEL.
7. CORRECTION FOR MINIMUM BOW HEIGHT: BOW HEIGHT IS THE VERTICAL DISTANCE AT THE FORWARD PERPENDICULAR FROM THE SUMMER LOAD LINE TO THE TOP OF THE EXPOSED DECK. THE MINIMUM BOW HEIGHT REQUIRED IS GIVEN BY A FORMULA. THE MIMIMUM BOW HEIGHT CAN BE ACHIEVED BY A SUPERSTRUCTURE WHICH MUST EXTEND ATLEAST 0.07L AFT OF THE FORWARD PERPENDICULAR OR BY A SHEER WHICH MUST EXTEND ATLEAST 0.15L AFT OF THE FORWARD PERPENDICULAR.

PREPARATION FOR A LOADLINE SURVEY

1.      A VISUAL EXAMINATION OF LOADLINE CERTIFICATE AND ALL OTHER CERTIFICATES TO ENSURE THEY ARE VALID AND PROPERLY ENDORSED.

2.      A GENERAL INSPECTION TO ENSURE NO MODIFICATIONS ARE CARRIED OUT TO THE CONIDTIONS OF ASSIGNMENT OF LOADLINES.

3.      LOADLINE MARKS PROPERLY PLACED AND PAINTED ON THE PORT AND STBD SIDE.

4.      PORTHOLES ARE WEATHERTIGHT, AND THOSE BELOW THE MAIN DECK ARE FITTED WITH DEADLIGHTS AND CAPABLE OF BEING CLOSED WATERTIGHT,

5.      MASTER MUST BE PROVIDED WITH LOADING AND BALLASTING INFORMATION TO BE CAPABLE OF CARRYING OUT SUCH OPERATIONS WITHOUT CAUSING EXCESSIVE STRESSES.

6.      STABILITY BOOKLET TO BE AVAILABLE.

7.      HATCH COVERS TO BE IN GOOD CONDITION, CAPABLE OF BEING CLOSED WEATHERTIGHT. ALL FITTING OF HATCH COVERS SUCH AS RUBBER PACKING AND CLOSING APPLIANCES TO BE IN GOOD CONDITION. TESTS MAY BE CARRIED OUT ON HATCH COVER AS THE SURVEYOR DECIDES.

8.      VENTILATORS TO BE IN GOOD CONDITION, CAPABLE OF BEING CLOSED. FLAPS TO BE MARKED OPEN AND SHUT. RUBBER PACKINGS IN GOOD CONDITION.

9.      WATERTIGHT DOOR RUBBER PACKING, RETAINING CHANNELS TO BE IN GOOD CONDITION. TO BE MARKED OPEN AND SHUT.

10.  AIR PIPE FLAPS TO BE IN GOOD CONDITION, CAPABLE OF BEING SHUT, PACKING IN GOOD CONDITION AND VALVES OPERABLE.

11.  SOUNDING PIPE COVERS AND THREADS TO BE IN GOOD CONDITION.

12.  MACHINERY SPACE OPENING ON THE FIDDLET TO BE CAPABLE OF BEING TIGHTLY SHUT.

13.  FREEING PORTS PROVIDED ON THE BULWARK SHOULD NOT BE BLOCKED.

14.  SPURLING PIPE COVERS MUST BE CAPABLE OF BEING CLOSED.

15.  FOREPEAK AND CHAIN LLOCKER EDUCTOR SYSTEM MUST BE OPERABLE.

16.  GUARD RAILS AND BULWARK TO BE IN GOOD CONDITION.

17.  CATWALKS PROVIDED ON TANKERS.

18.  A LIFELINE TO BE PROVIDED ON DECK FOR USE IN ROUGH WEATHER.

19.  ALL INLET AND OUTLET VALVES TO BE CHECKED THAT THEY ARE WATERTIGHT.

20.  FOREPEAK TANK SCREW DOWN VALVE IS TO BE CAPABLE OF BEING CLOSED WATERTIGHT.

21.  THICKNESS MEASUREMENT MAY BE CARRIED OUT ON THE TRANSVERSE FRAMES, GIRDERS, ETC. SUPERSTRUCTURE BULKHEADS AND MACHINERY CASING WALLS MAY BE CHECKED.

SUB-DIVISION LOADLINE

QUESTIONS ASKED:

1.      WHAT DO YOU UNDERSTAND BY THE TERM “SUBDIVISION LOADLINES”. WHY IS IT NECESSARY-EXPLAIN. EXPLAIN THE PROCEDURE OF CALCULATING “PERMISSIBLE LENGTH”. WHERE AND HOW DO WE USE IT. (JAN 08), (JAN 09)

2.      EXPLAIN “FACTOR OF SUB-DIVISION” AND “CRITERIA SERVICE NUMERAL”. HOW ARE BOTH RELATED TO “FLOODABLE LENGTH” AND “PERMISSIBLE LENGTH” OF PASSENGER SHIPS W.R.T. SUB-DIVISION REQUIREMENTS AS PER SOLAS. (MAY 08), (MAY 09), (NOV 09)

3.      EXPLAIN FLOODABLE LENGTH, MARGIN LINE, FACTOR OF SUBDIVISION. (NOV 08)

4.      EXPLAIN WHAT IS “UNIFORM AVERAGE PERMEABILITY”. WHERE AND HOW DO YOU USE THIS. (JAN 09)

THE TERM SUB-DIVISION LOADLINES MEANS THE CONSTRUCTIONAL REQUIREMENTS FOR SUB-DIVISION AND STABILITY OF PASSENGER SHIPS AS GIVEN IN SOLAS CHAPTER II-1. IT IS NECESSARY TO LIMIT THE FLOODING OF THE VESSEL AND KEEP THE VESSEL STABLE AFTER DAMAGE SO THAT PROGRESSIVE FLOODING DOES NOT OCCUR.

A BULKHEAD DECK IS THE UPPERMOST CONTINUOUS DECK TO WHICH THE WATERTIGHT BULKHEADS ARE CARRIED.

A MARGIN LINE IS AN IMAGINARY LINE DRAWN ABOUT 76mm BELOW THE BULKHEAD DECK.

TO KEEP THE VESSEL STABLE AND IN ORDER TO MAINTAIN HER WATERTIGHT INTEGRITY, THE BULKHEAD DECK AND INFACT THE MARGIN LINE SHOULD NOT GET SUBMERGED IN CASE OF FLOODING OF ANY COMPARTMENT. IF THE BULKHEAD DECK GETS SUBMERGED, THE OPENINGS TO OTHER COMPARTMENTS MAY GO BELOW WATERLINE THUS RESULTING IN PROGRESSIVE FLOODING.

AT ANY GIVEN POINT, THE FLOODABLE LENGTH IS THE MAXIMUM PORTION OF THE LENGTH OF THE VESSEL WHICH HAS ITS CENTRE AT THE POINT IN QUESTION, WHICH CAN BE FLOODED WITHOUT THE MARGIN LINE GETTING SUBMERGED.

THE FLOODABLE LENGTH AT THE ENDS OF THE VESSEL WILL BE SMALL BECAUSE A FLOODING AT THE END WOULD CAUSE MORE TRIM AND THUS THE MARGIN LINE WOULD GET SUBMERGED EARLIER AS COMPARED TO THE MIDSHIP SECTION WHERE THE FLOODABLE LENGTH IS LARGER. THE FLOODABLE LENGTH AT ANY POINT IS DETERMINED BY TAKING INTO ACCOUNT THE FORM, DRAUGHT, PERMEABILITY OF THE SPACE AND OTHER CHARACTERICTICS OF THE SHIP.

UNIFORM AVERAGE PERMEABILITY OF A VESSEL IS DIFFERENT FOR MACHINERY SPACES AND OTHER SPACES.

A MACHINERY SPACE IS TAKEN FROM THE KEEL TO THE MARGIN LINE AND BETWEEN THE WATERTIGHT BULKHEADS THAT CONTAIN MAIN AND AUX PROPULSION MACHINERY, BOILERS AND PERMANENT BUNKER SPACES.

            UAP (FOR MACHINERY SPACE) = 85 + 10 (a – c)

                                                                                              V

       WHERE,   a = VOLUME OF PASSENGER SPACES BELOW THE MARGIN LINE WITHIIN THE

                             LIMITS OF MACHINERY SPACE.

                       c = VOLUME OF CARGO SPACES,BUNKERS OR STORES SITUATED BELOW THE

     MARGIN LINE WITHIN THE LIMITS OF MACHINERY SPACE.

                        V = THE WHOLE VOLUME OF THE MACHINERY SPACE BELOW THE MARGIN LINE

            UAP (FOR SPACES FWD AND AFT OF MACHINERY SPACE) = 63 + 35 a

                                                                                                                                              V

                        a = VOLUME OF PASSENGER SPACES BELOW THE MARGIN LINE FWD OR AFT

                              OF THE MACHINERY SPACE.

                        V = THE WHOLE VOLUME OF THE SHIP BELOW THE MARGIN LINE FWD OR AFT

                               OF THE MARGIN LINE.

THE FACTOR OF SUBDIVISION IS ALWAYS <= 1, SO THAT THE SHIPS CAN HAVE SUB-DIVISIONS AS EFFICIENTLY AS POSSIBLE. THE FACTOR OF SUB-DIVISION VARIES ACCORDING TO:

1.      THE LENGTH OF THE SHIP,

2.      THE MATURE OF SERVICE.

THE F.O.S. DECREASES IN A REGULAR MANNER AS THE LENGTH OF THE SHIP INCREASES. THE F.O.S. IS DIFFERENT FOR CARGO SHIPS AND PASSENGER SHIPS AND IS FOUND OUT BY THE BELOW FORMULAS;

                        A =  58.2  + 0.18 (FOR CARGO SHIPS OF LENGTH >=131)

                               L-60

                        B =  30.3  + 0.18 (FOR PASSENGER SHIPS OF LENGTH >=79)

                               L-42

FOR CARGO SHIPS OF LENGTH LESS THAN 131 AND PASSENGER SHIPS OF LENGTH LESS THAN 79, THE FACTOR OF SUBDIVISION IS TAKEN AS 1.

THE ACTUAL LENGTH BETWEEN TWO BULKHEADS IS NOT EQUAL TO FLOODABLE LENGTH BUT IS EQUAL TO THE PERMISSIBLE LENGTH.

            PERMISSIBLE LENGTH = FLOODABLE LENGTH x FACTOR OF SUBDIVISION

TO DETERMINE IF A SHIP IS A CARGO SHIP OR A PASSENGER SHIP, A CRITERIA OF SERVICE NUMERAL (Cs) IS ASSIGNED TO IT.

            Cs = 72 (M + 2P₁) / (V + P₁ – P),        (WHERE P₁ < P)

           

            Cs = 72 (M + 2P) / V,                         (IN ALL OTHER CASES)

M = VOLUME OF MACHINERY SPACES INCLUDING BUNKER SPACES,

P = VOLUME OF PASSENGER SPACES BELOW THE MARGIN LINE,

V = WHOLE VOLUME OF THE SHIP BELOW THE MARGIN LINE,

P₁ = KN, WHERE K = 0.056L (L = LENGTH OF THE VESSEL)

                               N = NUMBER OF PASSENGER FOR WHICH THE SHIP IS CERTIFIED.

IF Cs <=23 IT IS A CARGO SHIP.

IF Cs >=123 IT IS A PASSENGER SHIP.

IF Cs <=23 AND LENGTH >=131, THE SUBDIVISIONS WILL BE GOVERNED BY FACTOR A.

IF Cs >=123, THE SUBDIVISIONS WILL BE GOVERNED BY FACTOR B.

IF Cs IS BETWEEN 23 AND 123 THE SUB-DIVISION IS GOVERNED BY FACTOR F;

                        F = A – [(A-B) x (Cs-23)] / 100