Ships measurement

SHIP’S MEASUREMENTLesson 3

0. Basic vocabulary 1

0. Basic voacbulary 1 - answers

1. length2. height3. width4. depth5. diameter6. thickness7. area8. volume

0. Basic vocabulary 2

0. Basic vocabulary 2 – answers

length – longwidth – wideheight – highdepth – deepthickness - thick

0. Baisc vocabulary 3

1. General – Units of measurement

In engineering 3 types of METRIC UNITS are used:

1. BASIC METRIC UNITS refer to LINEAR DIMENSIONS, i.e. those which can be measured in a straight line and are:

a) LENGHTb) HEIGHTc) WIDTH or BREADTHd) THICKNESSe) DEPTH

Other basic units as KILOGRAMME, SECOND, RADIAN are used to describe physical quantities as MASS, TIME, ANGLE


2. DERIVED METRIC UNITS

DERIVED METRIC UNITS are the products of the BASIC units and are:

AREAVOLUMECAPACITY

AREA is obtained by multiplying the basic units of LENGHT and BREADTH (WIDTH) and is measured in SQUARE METRES


VOLUME and CAPACITY are measured in CUBED LINEAR UNITS as CUBIC METRES

The volume & capacity of liquids can be measured in LITRES.

VOLUME is the “ space occupied by an object or substance “

CAPACITY is the “ ability of a container or tank to hold something”.


3. COMPOUND METRIC UNITS

COMPOUND UNITS are made up of BASIC and DERIVED UNITS OF MEASUREMENT such as :

STRESSPOWERENERGYACCELERATIONWORK

1.1 Basic metric units- exercises

The bar is three metres ( GB ) / meters ( US ) long.The bar is three meters in lenght.The bar has a lenght of three meters. The lenght of the bar is three meters.

The driving belt is sixty millimeters broad / wide.The driving belt is sixty millimeters in breadth / width.The driving belt has a breadth / width of sixty millimeters.The breadth / width of the driving belt is sixty millimeters.

The support tower is one / a hundred meters high.The support tower is one hundred meters in height.The support tower has a height of one hundred meters.The height of the support tower is one hundred meters.

1.1 Basic metric units- exercises

The sheet is three millimeters thick.The sheet has a thickness of three millimeters.The thickness of the sheet is three millimeters.

The trench is two meters deep.The trench is two meters in depth.The trench has a depth of two meters.The depth of the trench is two meters.

The block has a mass of 50 kilogrammes ( GB ) / kilograms ( US ).The block is of 50 kg. mass.The mass of the block is fifty kilogrammes.

1.2 Derived metric units - exercises

The plate has an area of six square meters.The plate is six square meters in area.The area of the plate is six square meters.

The brick has a volume of one thousand six hundred cubic centimeters.The brick is one thousand six hundred cubic centimeters in volume.The volume of the brick is one thousand six hundred cubic centimeters.

The tank has a capacity of twenty - four cubic meters.The tank is twenty - four cubic meters in capacity.The capacity of the tank is twenty - four cubic meters.

2. Shapes

2. Shapes - exercise

It is shaped like a circle. – It’s circular in shape.

It is shaped like a cylinder. – ...

It is shaped like a sphere. – ...

3. Tonnage

= a measure of the size or cargo carrying capacity of a ship = the amount of cargo the vessel is capable of carrying

Gross Register Tonnage

Net Tonnage

Deadweight Tonnage

3.1 Gross Register Tonnage

the entire volume of the enclosed spaces of the vessel that can be used for cargo, stores and accommodation

3.2 Net tonnage

volume that can be used to carry cargo

it is calculated by deducing the spaces that are not used for cargo from the gross tonnage

often used to calculate harbour dues

3.3 Deadweight tonnage

the weight of all the contents a vessel is capable of carrying when loaded to summer mark

4. Cargo spaces

Bale space

Grain space

Oil space

Ullage

4.1 Bale space

the volume of the cargo holds that can be used to carry general cargo

4.2 Grain space

the volume of the cargo holds that can be used to carry dry bulk cargo

4.3 Oil space

98 % of the total volume of wet bulk tanks

4.4 Ullage

empty space on top of the liquid level that will prevent a tank from overflowing when oil expands due to heat

5. Displacement

the amount of water that the ship displaces while floating

the weight of the displaced fluid is directly proportional to the volume of the displaced fluid (if the surrounding fluid is of uniform density).

5. Displacement

Archimedes’ principls (Archimede’s principle) states that the buoyant force on an object is going to be equal to the weight of the fluid displaced by the object, or the density of the fluid multiplied by the submerged volume times the gravitational constant, e.g. among completely submerged objects with equal masses, objects with greater volume have greater buoyancy.

6. Dimensions

Length Over All (L.O.A.)

Length between Perpendiculars

Breadth / Width

Moulded breadth

Moulded depth

Beam

6. Dimensions

6. Dimensions

6.1 Length Over All (L.O.A.)

the length from the extreme point ofstern to the extreme point of stem (bow)

6.2 Breadth / Width

the breadth (width) measured to the outside surface of plating

6.3 Moulded breadth

the horizontal distance between the insides of the moulds

breadth at the widest point measured to the outside surface of the frames

6.4 Moulded depth

vertical distance between the insides of the moulds (including the double bottom)

the vertical distance amidships from the top of keel to the top of deck beam at the underside of the deck plating at ship's side

6.5 Beam

the extreme breadth of the vessel

important for obtaining clearance to proceed in restricted, narrow fairways

6.6 Length Between Perpendiculars

is measured between the fore perpendicular and aft-perpendicular

6.7 Construction waterline

line to which the ship may be loaded in summer

6.8 Draught (draft)

the vertical distance from the surface of the water (waterline) to the vessel's bottom

loaded draft, light draft, salt-water draft, fresh-water draft

6.9 Freeboard

the vertical distance from the water to the weather deck edge at any point in the lenght of the ship

distance between the deckline and waterline

6.10 Hight or Air draught

distance from the waterline to the highest point of the vessel

vertical clearance

6.11 Underkeel Clearance

the distance between keel and seabed

Ships measurement

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