Give definitions for the below mentioned terms.
Camber
The purpose of rounding the beam is to ensure a good drainage of the water and also to strengthen the upper deck and the upper flange of the ship girder against longitudinal bending stresses- especially the compression stresses.
Rise Of Floor
This is the distance from the line of floor to the horizontal, measured at the ship side.
Purpose basically is to allow drainage of the double bottom water/ oil to the centre line suctions.
Tumblehome
This is the inward slope of the side plating from the water line to the upper deck. Today, ships generally do not have a tumblehome
Flare
This is the curvature of the side plating at the forward and gives additional buoyancy and thus helps to prevent the bows from diving too deeply into the water when pitching. The anchors are also clear when lowered from the flare of a ship.
Sheer
This is the rise of ships deck fore and aft. This again adds buoyancy to the ends where it is needed during pitching. For calculating the freeboard, a correction is applied for the sheer. In modern ships the after sheer has been greatly reduced.
Rake
This is the slope, which the forward end has with between the bottom plating and the upper deck. The length between perpendiculars and the length overall difference is mostly due to the rake forward. It helps to cut the water and thus adds to the ships form.
Parallel Middle Body
This is the part of the main body of the ship and it is a box like structure enabling maximum cargo carrying capacity. It also helps in the pushing when tugs are used to assist the vessel in berthing. Cargo stowage is also greatly facilitated.
Entrance
This part is the fore end of the ship and helps give the box like mid length a ship shaped structure.
Run
The after part similarly to the fore part entrance helps in giving the box like mid length a ship shaped structure and thus the handling of the vessel is enhanced.
Length Overall
Length means 96% of the total length on a waterline at 85% of the least moulded depth measured from the top of the keel, or the length from the fore side of the
stem to the axis of the rudder stock on that waterline, if that be greater. In ships designed with a rake of keel, the waterline on which this length is measured shall be parallel to the designed waterline.
Moulded breadth
It is the greatest moulded breadth -measured inside plating.
Breadth (B) is the greatest moulded breadth of the ship at or below the deepest subdivision load line.
Draught (d) is the vertical distance from the moulded baseline at midlength to the waterline in question.
Depth and the draught both are measured from the top of the keel. The depth is measured from the top of the deck beam. If there is a camber then allowance is given as 1/3 rd of the camber.
Forward perpendicular
This is represented by a line, which is perpendicular to the intersection of the designed load water-line with the forward side of the stem
After perpendicular
A line represents this, which is perpendicular to the intersection of the after edge of the rudderpost with the designed load water line This is the case for both single and twin-screw ships. For some ships having no rudderpost, theafter perpendicular is taken as the centre
line of the rudderstock.
Length between perpendiculars
This is the horizontal distance between the forward and after perpendiculars.
Length on the designed load waterline
This is the length, as measured on the water-line of the ship when floating in still water in the loaded, or designed, condition.
Length overall
This is the length measured from the extreme point forward to the extreme point aft.
Base line
This represents the lowest extremity of the moulded surface of the ship. At the point where the moulded base line cuts the midship section a horizontal line is drawn, and it is this line, which acts as the datum, or base line, for all hydrostatic calculations. This line may, or may not, be parallel to the load water line depending on the type of ship.
Moulded depth
This is the vertical distance between the moulded base line and the top of the beams of the uppermost continuous deck measured at the side amidships
Moulded beam
This is the maximum beam, or breadth, of the ship measured inside the inner shell strakes of plating, and usually occurs amidships.
Moulded draught
This is the draught measured to any water line, either forward on aft, using the moulded base line as a datum.
Extreme beam
This is the maximum breadth including all side plating, permanent fenders etc.
Extreme draught
This is obtained by adding to the draught moulded the distance between the moulded base line and a line touching the lowest point of the underside of the keel. This line is continued to the FP and AP, where it is used as the datum for the sets of draught marks.
