# data[].attributes.headline
To get the best English performance we need to use different tools. This is an outstanding way to enjoy it!!

# data[].attributes.subject
To get the best English performance we need to use different tools. This is an outstanding way to enjoy it!!

# data[].attributes.attachment_link.title
HELICOPTER RESCUE - SESSION 1-WEEK 2 (1)

# data[].attributes.attachment_link.readable_text
Principal Dimensions
The shapes shown in a lines plan delineate what is called the molded form of the vessel. The principal dimensions of a ship are length between perpendiculars, beam, draft, and depth. These quantities are shown in Figure 5 and are defined as:

Length Between Perpendiculars (LBP or L): The horizontal distance between the forward and aft perpendiculars is called the length between perpendiculars. It is constant for a given ship and does not depend on the loading condition of the ship.

Beam (B): The breadth of the ship at the broadest point is called the beam.

Draft (T): The vertical distance between the waterline and the deepest part of the ship at any point along the length is the draft. Drafts are usually measured at the forward, Tf, and the aft, Ta, perpendiculars although they can also be defined at the fore and aft draft marks which may not coincide with the perpendiculars. The mean draft, Tm, is the average of the forward and aft drafts.

Other Measurements
In addition to the principal dimensions, the following, also shown in Figure 5, are also used in describing ships:

Length Overall (LOA): The extreme length of the ship along the centerline is called the length overall.

Length on Waterline (LWL): This is the length along the centerline at the waterline in the ship's design loaded condition.

Freeboard (F): This is the distance between the waterline and the uppermost watertight deck at any location along the ship.

Displacement Volume (V): The displacement volume is the total volume of the underwater hull at any given waterline.

Displacement (W): The displacement is the weight of the water of the displaced volume of the ship; for static equilibrium it is the same as the weight of the ship and all cargo on board. Therefore, displacement is directly related to displacement volume and it can be found by multiplying the volume with the specific gravity of the water in any set of consistent units. For example if the volume is in cubic feet, we may divide it by 35 to get the displacement in long tons in seawater, or by 36 in fresh water.

Buoyancy: Any ship partially or wholly imersed in water will experience an upward push called buoyancy. The force of buoyancy is equal to the weight of the volume of water the ship displaces.

Reserve Buoyancy: The watertight volume between the waterline and the uppermost continuous watertight deck is the reserve buoyancy of the ship. It enables the ship to take on additional weight, and it is closely related to the ability of the ship to survive a damage.

Moment of Inertia (I): For hydrostatic calculations we will always refer to the moment of inertia as the second moment of area unless specified otherwise. It is a measurement of a plane surface's resistance to rotation about an axis in the same plane. The magnitude of the moment of inertia depends upon the shape of the area and the location and orientation of the axis of rotation. The moment of inertia is measured in the fourth power of a linear unit, such as ft⁴, in⁴, or a combination.

Tonnage: Tonnage is a description of the cargo capacity of a merchant ship. It is a volume measurement and does not directly indicate displacement

Sheer: The difference between the design trim freeboard at any point and that of the midship section. The sheer line is the line of intersection of the main or weather deck with the side of the ship.

Camber: This represents the curvature in an athwartship or transverse vertical plane; it is the height of the deck at the centerline above the height at the side.

Tumble Home: The slant inward from the vertical of a transverse section of a hull above the design waterline. Tumble home is the opposite of flare.

Flare: the slant upward and outward from the vertical of a transverse section of a hull above the design waterline.

Deadrise: The athwartship rise of the bottom from the keel to the bilge.

Flotation Characteristics
The following terms are used with regards to ship flotation:

Trim: Trim is the difference between the drafts forward and aft. Typicallu, we assign positive and negative values to trim to indicate trim (down) by the stern or trim (down) by the bow respectively.

List,Heel, and Roll: Angular transverse inclinations of ships are described as list, heel, or roll, depending on the nature of the situation. List describes a definite attitude of transverse inclination of a static nature. Heel describes a temporary inclination generally involving motion, while roll indicates periodic inclination from side to side. For example, a shiprolls in a seaway, lists due to a side damage, andheels in a turn.

# data[].attributes.attachment_link.description
Principal Dimensions The shapes shown in a lines plan delineate what is called the molded form of the vessel. The principal dimensions of a ship are length between perpendiculars, beam, draft, and depth. These quantities are shown in Figure 5 and are defined as: Length Between Perpendiculars (LBP or L): The horizontal distance between the forward and aft perpendiculars is called the length between perpendiculars.

# data[].attributes.body
Tanker ships are identified because of the pipelines, manifolds and valves on their main decks