Plimsol Mark (load line)

The Plimsol Mark (Load Line)

- LTF - Lumber, Tropical Fresh - this is the draft to which the vessel can load when carrying lumber in the tropical fresh designated zone

- LF - Lumber, Fresh - this is the draft to which the vessel can load when carrying lumber in the fresh designated zone

- LT - Lumber, Tropical - This is the draft to which the vessel can load when carrying lumber in the Tropical designated zone.

- LS - Lumber, Summer - This is the draft to which the vessel can load when carrying lumber in the Summer designated zone.

- LW - Lumber, Winter - This is the draft to which the vessel can load when carrying lumber in the Winter designated zone.

- LWNA - Lumber, Winter, North Atlantic - This is the draft to which the vessel can load when carrying lumber in the Winter North Atlantic designated zone.

- F - Fresh - This is the draft to which the vessel can load when not carrying lumber in the Fresh designated zone.

- TF - Tropical, Fresh - This is the draft to which the vessel can load when not carrying lumber in the Tropical Fresh designated zone

- F - Fresh - This is the draft to which the vessel can load when not carrying lumber in the Fresh designated zone

- T - Tropical - This is the draft to which the vessel can load when not carrying lumber in the Tropical designated zone

- S - Summer - This is the draft to which the vessel can load when not carrying lumber in the Summer designated zone

- W - Winter- This is the draft to which the vessel can load when not carrying lumber in the Winter designated zone

- WNA - Winter, North Atlantic - This is the draft to which the vessel can load when not carrying lumber in the Winter North Atlantic designated zone

- LR - Lloyds Register - The initals of the Classification Society which assigns the marks.

- TPC : Jumlah to yang harus dimuat atau dibongkar untuk merubah sarat rata-rata kapal sebanyak satu sentimeter (cm)

- Assume side wall is vertical in one cm
- TPC varies at the ship's draft because waterplan area change at the draft

Fresh Water Allowance (FWA)

sejumlah milimeter dari perubahan sarat rata-rat, bila kapal berlayar dari air laut ke air tawar dan atau sebaliknya.

W1L1 = Garis air Tawar (V + v)

WL = Garis air Laut (V)

Pembuktian rumus

Berat  = Volume x B.J

Berat air laut yang dipindahkan = 1025 V

Berat air tawar yang dipindahkan = 1000 (V= v)

Berat air tawar yang dipindahkan = berat air laut yang dipindahkan

1000 (V + v)         =   1025  V

1000 V + 1000 v  =    1025  V

1000 v                   =   25  V

                         v  =  V 

                                 40

Misalkan :  

w = v dan W = V

w  = W 

         40

FWA  x  TPC     =  W 

10                            40

FWA    =       W          . (mm)

                  4 x TPC

DWA (Dock Water Allowance)

adalah perubahan sarat kapal, jika kapal berpindah dari air laut ke air payau dan atau sebaliknya.

Misalkan :

X  =  Dock Water Allowance  (DWA)

D  = Density dari air payau (pelabuhan)

Maka :

   x      =     1025 - D    

  FWA       1025 - 1000

atau 

Dock water Allowance  =   FWA      ( 1025 - D )

                                                       25

Contoh soal 1 :

Sebuah kapal memuat di pelabuhan sungai dengan density 1.010 kgs / m3, FWA 150 mms, hitunglah perubahan draft kapal akan berlayar ke laut bebas ?

Jawab = 90 mms

Contoh soal 2 : 

Sebuah kapal memuat di pelabuhan dengan density 1.005 kgs / m3, FWA 62.5 mms dan TPC = 15 ton / cm, hitunglah berapa muatan yang dapat di muat ?

Jawab = 75 Tons

Contoh soal 3 :

Kapal tiba dimuara dengan density 1.025 kgs / me dan draft rata-rata 7.5 meter, berapa draft bila kapal tiba di pelabuhan muat yang density 1.005 kgs / m3, jika displacement 7500 ton dan TPC 35 ton / cm

Jawab = 

7 M 35 Cm

Contoh soal 4 :

Kapal berangkat dari pelabuhan dengan density 1.007 kg / m3 dengan draft 8 meter, jarak dari pelabuhan sungai ke laut bebas 680 mile dengan pemakaian bahan bakar 10 ton dan air tawar 5 ton dan kecepatan kapal 10 knots, jika displacement kapal 9.000 ton, TPC 40 ton / cm, berapa draft kapal bila tiba di laut bebas nanti ?

Jawab = 

7 M 97,89 cm

Contoh soal 5 :

Kapal tiba di pelabuhan sungai dengan density 1.015 kg / m3 dengan draft rata-rata 7 meter, masih harus memuat general cargo, jarak dari pelabuhan sungai ke laut bebas 480 mile kecepatan kapal 12.5 knot, pemakaian bahan bakar dan air tawar 25 ton draft di laut di karenakan adanya beting 7.5 meter, jika displacement kapal 8500 ton, TPC : 40 ton / cm, berapa draft tolak dan berapa ton yang dpat dimuat?

Jawab = 

7 M 53,125 cm

2125 ton

Load Line

International Convention on Load Lines, 1966

Adoption: 5 April 1966
Entry into force: 21 July 1968

Introduction and history
Load Lines 1966 - Annexes
Amendments 1971, 1975, 1979, 1983
Adoption of tacit amendment procedure 1988 Protocol
The 1995 amendments
The 2003 amendments - revision of technical annex

Introduction and history
It has long been recognized that limitations on the draught to which a ship may be loaded make a significant contribution to her safety. These limits are given in the form of freeboards, which constitute, besides external weathertight and watertight integrity, the main objective of the Convention.

The first International Convention on Load Lines, adopted in 1930, was based on the principle of reserve buoyancy, although it was recognized then that the freeboard should also ensure adequate stability and avoid excessive stress on the ship's hull as a result of overloading.

In the 1966 Load Lines convention, adopted by IMO, provisions are made determining the freeboard of tankers by subdivision and damage stability calculations.

The regulations take into account the potential hazards present in different zones and different seasons. The technical annex contains several additional safety measures concerning doors, freeing ports, hatchways and other items. The main purpose of these measures is to ensure the watertight integrity of ships' hulls below the freeboard deck.

All assigned load lines must be marked amidships on each side of the ship, together with the deck line. Ships intended for the carriage of timber deck cargo are assigned a smaller freeboard as the deck cargo provides protection against the impact of waves

Load Lines 1966 - Annexes
The Convention includes Annex I, divided into four Chapters:
· Chapter I - General;
· Chapter II - Conditions of assignment of freeboard;
· Chapter III - Freeboards;
· Chapter IV - Special requirements for ships assigned timber freeboards.·

Annex II covers Zones, areas and seasonal periods.
Annex III contains certificates, including the International Load Line Certificate.

Amendments 1971, 1975, 1979, 1983
The 1966 Convention provided for amendments to be made by positive acceptance. Amendments could be considered by the Maritime Safety Committee, the IMO Assembly or by a Conference of Governments. Amendments would then only come into force 12 months after being accepted by two-thirds of Contracting Parties. In practice, amendments adopted between 1971 and 1983 never received enough acceptances to enter into force. These included:

· the 1971 amendments - to make certain improvements to the text and to the chart of zones and seasonal areas;
· the 1975 amendments - to introduce the principle of 'tacit acceptance' into the Convention;
· the 1979 amendments - to make some alterations to zone boundaries off the coast of Australia; and
· the 1983 amendments - to extend the summer and tropical zones southward off the coast of Chile.

Adoption of tacit amendment procedure 1988

The 1988 Protocol
Adoption: 11 November 1988
Entry into force: 3 February 2000

The Protocol was primarily adopted in order to harmonize the Convention's survey and certification requirement with those contained in SOLAS and MARPOL 73/78.

All three instruments require the issuing of certificates to show that requirements have been met and this has to be done by means of a survey which can involve the ship being out of service for several days.

The harmonized system alleviates the problems caused by survey dates and intervals between surveys which do not coincide, so that a ship should no longer have to go into port or repair yard for a survey required by one Convention shortly after doing the same thing in connection with another instrument.

The 1988 Load Lines Protocol revised certain regulations in the technical Annexes to the Load Lines Convention and introduced the tacit amendment procedure (which was already applicable to the 1974 SOLAS Convention).Amendments to the Convention may be considered either by the Maritime Safety Committee or by a Conference of Parties.

Amendments must be adopted by a two-thirds majority of Parties to the Convention present and voting. Amendments enter into force six months after the deemed date of acceptance - which must be at least a year after the date of communication of adoption of amendments unless they are rejected by one-third of Parties. Usually, the date from adoption to deemed acceptance is two years.

The 1995 amendments
Adopted: 23 November 1995
Entry into force: 12 months after being accepted by two-thirds of Contracting Governments.
Status: 7 acceptances have been received (currently, 95 acceptances are required before the amendments can enter into force).The amendments concern the southern tropical zone off the coast of Australia and are now likely to be incorporated in a general revision of the Convention.

The 2003 amendments
Adopted: June 2003
Entry into force: 1 January 2005 (under tacit acceptance)

The amendments to Annex B to the 1988 Load Lines Protocol (i.e. the International Convention on Load Lines, 1966, as modified by the Protocol of 1988 relating thereto) include a number of important revisions, in particular to regulations concerning: strength and intact stability of ships; definitions; superstructure and bulkheads; doors; position of hatchways, doorways and ventilators; hatchway coamings; hatch covers; machinery space openings; miscellaneous openings in freeboard and superstructure decks; cargo ports and other similar openings; spurling pipes and cable lockers; side scuttles; windows and skylights; calculation of freeing ports; protection of the crew and means of safe passage for crew; calculation of freeboard; sheer; minimum bow height and reserve buoyancy; and others.

The amendments, which amount to a comprehensive revision of the technical regulations of the original Load Lines Convention, will not affect the 1966 LL Convention and will only apply to approximately two-thirds of the world's fleet, i.e., to those ships flying the flags of States Party to the 1988 LL Protocol. (See Status of Conventions - Summary)