1. EFFECT OF DENSITY ON SHIP’S VOLUME & DISPLACEMENT

2. A-BOX SHAPED VESSELES 1-EFFECT OF DENSITY ON SHIP’S VOLUME
2-EFFECT OF DENSITY ON SHIP’DISPLACEMENT

3. EFFECT OF DENSITY ON SHIP’S VOLUME & DISPLACEMENT
ANY BOX SHAPED VESSEL SAILS FROM ONE PORT TO ANOTHER CERTAIN CHANGES OCCURES OVER THE SHIP, AS A RESULT OF THE EFFECT OF DENSITY ON SHIP’S VOLUME & DISPLACEMENT
AS WE KNOW THAT THE
A RELATION BETWEEN THE DENSITY & MASS WOULD BE ; DIRECT PROPORTION
DENSITY ∞ MASS ( DIRECT PROPORTION ) WHICH MEANS THAT
WHEN DENSITY DECREASES THE MASS DECREASES
WHEN DENSITY INCREASES THE MASS INCREASES
DENSITY = MASS kg
VOLUME

4. EFFECT OF DENSITY ON SHIP’S VOLUME & DISPLACEMENT
A RELATION BETWEEN THE DENSITY & VOLUME WOULD BE ; INV. PROPORTION
DENSITY / ∞ VOLUME ( INV. PROPORTION ) WHICH MEANS THAT
WHEN DENSITY DECREASES THE VOLUME INCREASES
WHEN DENSITY INCREASES THE VOLUME DECREASES
THE VOLUME IS THE SUM OF L * B * DRAFT ,
THE L & B NEVER CHANGE FROM PORT TO ANOTHER SO THE ONLY PARAMETER THAT CHANGES IS THE DRAFT ,THERFORE THE VOLUME CHANGES ASWELL

5. 1-EFFECT OF DENSITY ON VOLUME
A-BOX SHAPED SHIPS
1-EFFECT OF DENSITY ON VOLUME

6. EFFECT OF DENSITY ON VOLUME
LETS SAY A BOX SHAPED VESSEL DISPLACES 20,000 TONS SAILED
FROM PORT A HAS WATER DENSITY 1.OOO
TO PORT B HAS WATER DENSITY ,
ACCORDING TO THE RELATION BETWEEN DENSITY AND VOLUME “INV.PROPORTIONS” , WE DISCOVERS THAT AT PORT B, THE VOLUME WILL DECREASES AS THE WATER DENSITY INCREASES ( PORT A TO PORT B ) ,
WHILE THE SHIP STILL DISPLACES THE SAME 20,000TONS
SINCE THE VOLUME = L * B * DRAFT ,
SO THE CHANGE IN THE VOLUME COMES FROM THE CHANGE IN THE DRAFT

7. EFFECT OF DENSITY ON VOLUME
SHIP’S MASS AT PORT A = SHIP’S MASS AT PORT B WHERE THE MASS = DENSITY * VOLUME
( OLD DENSITY * OLD DRAFT ) = ( NEW DENSITY * NEW DRAFT )

8. 2-EFFECT OF DENSITY ON DISPLACEMENT
A-BOX SHAPED SHIPS
2-EFFECT OF DENSITY ON DISPLACEMENT

9. EFFECT OF DENSITY ON DISPLACEMENT
A BOX SHAPED VESSEL DISPLACES 20,000 TONS SAILED
FROM PORT A OF WATER DENSITY 1.OOO & DRAFT 7.0 mtrs
TO PORT B OF WATER DENSITY ,
AS SHE ARRIVED TO PORT B , THE SHIP’S DRAFT STAYED THE SAME 7.0 mtrs.
DESPITE THE DENSITY IS ALREADY CHANGED FROM TO ,
THAT MEANS A CHANGE OCCURRED ON THE SHIPS DISPLACEMENT (MASS)
YOU WILL FIND THE SHIP DISPLACEMENT BECAME 21,000 TONS AS EXAMPLE.
THE RELATION BETWEEN DENSITY & DISPLACEMENT (MASS) IS DIRECT PROPORTIONS ,AS A RESULT THE DISPLACEMENT INCREASED WHEN DENSITY INCREASED ( TO )

10. EFFECT OF DENSITY ON DISPLACEMENT
SHIP’S VOLUME AT PORT A = SHIP’S VOLUME AT PORT B
THE SHIP DISPLACES THE SAME VOLUME OF WATER IN BOTH PORTS A & B
WHERE THE VOLUME =
OLD MASS NEW MASS =
OLD DENSITY NEW DENSITY

11. EFFECT OF DENSITY ON SHIP’S VOLUME & DISPLACEMENT
B- SHIP SHAPED VESSELS
EFFECT OF DENSITY ON SHIP’S VOLUME & DISPLACEMENT

12. EFFECT OF DENSITY ON VOLUME & DISPLACEMENT
INORDER TO UNDER STAND THE EFFECT WE SHOULD VERY WELL UNDERSTAND THE PLYMSOL MARK ( DRAFT MEASURES)
FREE BOARD
(RESERVE BOUYANCY ) 54
230mm
Tropical
Tropical F
Fresh
FWA
Summer
300mm
Winter
540mm
WNA

13. EFFECT OF DENSITY ON VOLUME & DISPLACEMENT
FWA ( FRESH WATER ALLOWANCE )
DEFINED AS THE NUMBER OF MM THAT INCREASES OR DECREASES IN SHIPS MEAN DRAFT WHEN THE SHIP SAILS FROM SALT WATER TO FRESH WATER & VISE VERSA
T P C ( TONS PER CENTIMETRE)
DEFINED AS THE NUMBER OF TONS LOADED OR DISCHARGED INORDER TO CHANGE SHIPS DRAFT 1 CM IN SALT WATER
FWA = DISPLACEMENT
4 * TPC

14. EFFECT OF DENSITY ON VOLUME & DISPLACEMENT
DWA (DOCK WATER ALLOWANCE)
DEFINED AS THE NUMBER OF MM THAT INCREASES OR DECREASES IN SHIPS MEAN DRAFT WHEN THE SHIP SAILS FROM SALT WATER TO DOCK WATER & VISE VERSA.
Example : FWA 200mm (0.2mtrs) , DW DENSITY = 1.015
SO DWA = 0.2 * ( 10 ) = mtrs ( 80 mm ) 25
( DWD)
DW A = FWA 25

15. EFFECT OF DENSITY ON VOLUME & DISPLACEMENT
IF THE SHIP SAILS FROM PORT A WHOSE WATER DENSITY IS TO PORT B WHOSE WATER DENSITY IS ( THE DENSITY INCREASED) , SO ACCORDING TO THE RELATION BETWEEN DENSITY & VOLUME.
DENSITY / ∞ VOLUME ( INV. PROPORTION ) WHICH MEANS THAT
WHEN DENSITY DECREASES THE VOLUME INCREASES
WHEN DENSITY INCREASES THE VOLUME DECREASES
THE SHIPS DRAFT WILL DECREASES , THE VALUE OF DRAFT DECREASING EQUALS THE FWA.
Eg. SHIP SHAPE V/L SAILED FROM PORT A WITH DENSITY TO PORT B WITH DENSITY FWA 200MM .OLD DRAFT 7.0mtrs so the new draft will decrease to 7.0 mt FWA 200MM ( 20CM, 0.2mt )
= mt ( NEW DRAFT )

16. EFFECT OF DENSITY ON VOLUME & DISPLACEMENT
EXAMPLE
SHIP SHAPE V/L SAILED FROM PORT A WITH DENSITY TO PORT B WITH DENSITY FWA 200MM .OLD DRAFT 7.0mtrs , DWA 200MM ,
SO THE NEW DRAFT WILL INCREASE “ACCORDING TO THE INV. RELATION “ BY THE VALUE OF THE DWA ( FROM SALT WATER DENSITY TO DOCK WATER DENSITY ) ,
OLD DRAFT DWA = NEW DRAFT
mm( 0.2mtrs) = mtrs