Priority Pontoon Stability Information Booklet Sheet/MST Priority Stability...MST WORKBOATS Ltd 10 Swanbridge Road, Bexleyheath, Kent, DA7 5BP Telephone: 07973 820018 • 07966 022979

MST WORKBOATS Ltd 10 Swanbridge Road, Bexleyheath, Kent, DA7 5BPTelephone: 07973 820018 • 07966 022979 Email: [email protected]

Stability Information Booklet

Priority Pontoon

Lightship


Index

General Particulars ........................................................................................................................................................3

General Details...............................................................................................................................................................4

Plan - GA.........................................................................................................................................................................5

Plan - Frames .................................................................................................................................................................6

General Precautions against capsizing ......................................................................................................................7

Special Notes Regarding the stability and Loading ..................................................................................................7

Metric Conversions ........................................................................................................................................................8

Hydrostatic particulars...................................................................................................................................................9

Capacities and Centres of Gravity............................................................................................................................... 9

Notes on Free Surface Moments.................................................................................................................................9

Cross Curves of Stabilities (KN Curves)................................................................................................................... 10

Deadweight Sale ..........................................................................................................................................................10

Trim and Stability Calculation.....................................................................................................................................11


General Particulars

Ships Name Priority

Official Number Owner No: 3139 PLA No: 19459

Port of Registry London

Owners Name and Address Marine Support Thames MST Ltd 10 Swanbridge Road Bexleyheath Kent DA7 5BP

Builders Name, Address and Ship Number Currently Unknown

Date Keel Laid Currently Unknown

Moulded Dimensions (in metres) LOA 36.6 LBP 36.6 Beam 9.2 Depth 2.5

Summer Load Draught (in metres) 0.6 (Lightship)

Block Coefficient 0.9422 (Lightship)

Displacement (in tonnes) 184.45 (Lightship)

Deadweight (in tonnes) 184.45 (Lightship)

Gross Tonnage Currently Unknown

Net Tonnage Currently Unknown


General Details

Stability information booklet for the pontoon Priority, in Lightship condition with the base of the spud legs flush with the keel of the pontoon The vessel is considered as a pontoon by MSIS003, Part 8, Paragraph 8.17.1 because:

• It is non-self propelled • It will be unmanned during movement • There will only be deck cargo • The block coefficient is greater than 0.9 (0.9422 – Lightship) • The breadth/depth ratio is greater than 3 (3.68) • There are no hatchways in the deck, except small manholes closed with gasketed deck covers.

Hydrostatics and cross curves of stability were produced for the pontoon by a hydrostatics package.

The lightship weight and centre of gravity was calculated from a weights and centres calculation of the structural elements of the pontoon. Appendix 5. From these calculations a light weight of 125.35 Te and KG of 1.207m was obtained.

A conservative weight of 140 Te with KG of 1.4m was used in the stability calculations.


Plan - GA


Plan - Frames


General Precautions against capsizing

• Compliance with the stability criteria indicated overleaf does not ensure immunity against capsizing regardless of the circumstances or absolve the master from his responsibilities. Masters should therefore exercise prudence and good seamanship having regard to the season of the year, weather forecasts and the navigational zone and should take the appropriate action as to speed and course warranted by the prevailing circumstances.

• Care should be taken to ensure that the cargo allocated to the ship is capable of being stowed so that compliance with the criteria can be achieved. If necessary the amount should be limited to the extent that ballast weight may be required.

• Before a voyage commences care should be taken to ensure that the cargo and sizeable pieces of equipment have been properly stowed or lashed so as to minimize the possibility of both longitudinal and lateral shifting while at sea, under the effect of acceleration caused by rolling and pitching.

Special Notes Regarding the stability and Loading

This vessel ship is required to comply with Schedule 2, Part 1, Paragraph 2 of MSN 1752(M) by the Merchant Shipping (Load Line) Regulations 1998, it is most important to ensure that in any sailing condition the stability complies at least with the following minimum criteria:-

Static Stability Curve


Under MSIS 003, Part 8, Paragraph 8.17.4, for pontoons, if the vessel characteristics make compliance with paragraph 2(2)(c) of Schedule 2 for MSN 1752(M) impossible the following criteria can be used:

Metric Conversions

Multiply By To Convert From To Obtain 0.03937 Millimetres Inches 25.400 0.3937 Centimetres Inches 2.5400 3.2808 Metres Feet 0.3048 2.2046 Kilogrammes Pounds 0.45359 0.0009842 Kilogrammes Tons (2240 lbs) 1016.047 0.9842 Tonnes (1000Kg) Tons (2240 lbs) 1.016 2.4998 Tonnes per centimetre

(of immersion) Tons per inch (of immersion)

0.4000

8.2014 Moment to change trim one centimetre

Moment to change trim 0.122 one inch

(tonnes meter units) (foot ton units) 187.9767 Meters radians Feet degrees 0.0053 0.01745 Meters degrees Meter radians 57.30 To Obtain To Convert From Multiply by

Relationship between weight and volume

10 mm cubed = 1 cubic centimetre 1 cubic centimetre of freshwater (S.G. 1.0) = 1 gramme 1000 cubic centimetre of freshwater (S.G. 1.0) = 1 Kilogram (1000 grammes) 1 cubic metre of freshwater (S.G. 1.0) = 1 Tonne (1000 Kilos) 1 cubic metre of saltwater (S.G. 1.025) = 1.025 Tonnes 1 tonne of saltwater (S.G. 1.025) = 0.975 Cubic Metres 1 cubic metre = 35.316 cubic feet 1 cubic foot = 0.0283 cubic metres


Hydrostatic particulars

Hydrostatics were calculated by Freeship software, using a model of the pontoon.

The data is contained within “Hydrostatics and Windage” sheets in Appendix 3

Capacities and Centres of Gravity

The weights and centres for the loading condition were calculated based on the following:

o Lightship A conservative weight of 140 Te with KG of 1.4m was used, based on the results of a

weights and centres calculation of the structural elements of the pontoon. o Deck Cargo

Spud legs with bottom of spud leg flush with the keel of the pontoon. No other deck cargo loaded

o Tanks No tanks. Pontoon compartments are to be kept empty during operation

o Spud Leg Tubes The lost buoyancy and free surface of the spud tubes is included

The data is contained within “Weights and Centres” in Appendix 2

Notes on Free Surface Moments

Provided a tank is completely filled with liquid no movement of the liquid is possible then the effect on the ship's stability is precisely the same as if the tank contained solid material. Immediately a quantity of liquid is withdrawn from the tank the situation changes completely and the stability of the ship is adversely affected by what is known as the "free surface effects". This adverse effect on the stability is referred to as a "loss in G.M." or as a "virtual rise in V.C.G." and is calculated as follows:

N.B. The "free surface effects" of a proportion of all oil-fuel, fresh water, feed- water and service tanks should be taken into account in both the Arrival and Departure Conditions.


Cross Curves of Stabilities (KN Curves)

KN values were calculated by Freeship software, using a model of the pontoon.

The data is contained within “KN Curves” in Appendix 4

Deadweight Sale


Trim and Stability Calculation

Trim and stability was calculated for the Lightship condition of Priority in excel using standard Naval architecture formulas. Full calculations are contained within: “Trim and Stability Calculation” in Appendix 1

The resultant GZ curve and adherence to the required criteria was:

Documents

Priority Pontoon Stability Information Booklet Sheet/MST Priority Stability...MST WORKBOATS Ltd 10 Swanbridge Road, Bexleyheath, Kent, DA7 5BP Telephone: 07973 820018 • 07966 022979