GSK – GENERAL SHIPS KNOWLEDGE EXAM
QUESTIONS AND VERIFIED ANSWERS
Define the FP - ANSWER Forward Perpendicular - A vertical line
perpendicular to the base line from the point at which the LOAD WAERLINE
and the forward side of the stem intersect.
Define the AP - ANSWER The Aft Perpendicular - The vertical line erected
on the base line passing through the rudder stock. (or in a ship without a
conventional rudder this is the point at which the load waterline and the stern
intersect). This point is also used as the reference frame for numbering and is
marked as frame 0 on plans.
Define the LBP - ANSWER The Length Between Perpendiculars - The length
of the vessel measured between the forward and aft perpendiculars.
Define the LOA - ANSWER Length Over All - The extreme length of the
vessel
Define the LWL - ANSWER The length as measured on the waterline at the
actual draught.
Define Amidships - ANSWER The mid point of the LBP
Define Extreme Breadth - ANSWER The greatest breadth measured to the
OUTSIDE of the shell plating (aka beam width)
Define moulded breadth - ANSWER The greatest breadth of the vessel
measured to the INSIDE of the shell plating
Define Freeboard - ANSWER The vertical distance measured downwards
from the uppermost continuous (watertight) deck to the waterline at amidships
Define the Assigned Freeboard - ANSWER the vertical distance measured
downwards from the uppermost continuous watertight deck to the upper edge of
the summer load line at amidships
,Define Draught - ANSWER The verticle distance between the baseline and
any waterline. Draught is often also spelt draft and these two spellings are
interchangeable.
Define the Reserve of Buoyancy - ANSWER The volume of enclosed spaces
between the waterline and the freeboard deck. It may be expressed as a volume
in m3 or as a percentage of the total enclosed volume of the vessel
Define Camber - ANSWER Transverse curvature of the deck. It helps shed
water from the upper deck.
define sheer - ANSWER the rise in curvature of the deck fore and aft. It adds
buoyancy to the ends where it is most needed. CAMBER AND SHEER ARE
ARRANGED IN THE DESIGN OF THE VESSEL SO THAT WATER
SHIPPED IN A HEAVY SEA MAY FREELY MOVE ACCROSS OR ALONG
THE DECK AND OVERBOARD
define flare - ANSWER The curvature of the bow plating. Apart from
streamlining the bow section, flare increases the breadth of the forecastle head
and allows anchors to drop clear of the bow plating. In a seaway, the buoyancy
of the bow section will increase as is is immersed further into the water. This
increasing buoyancy helps to prevent the bow from diving too deeply in heavy
seas.
Define rake. - ANSWER The fore and aft slope from vertical. Bows, masts and
funnels are often raked.
Define Tun (Ton) (notice the spelling) - ANSWER This is a measurement of
volume and not weight. It is equivalent to a 200 gallon cask (a container of 60
cubic feet of 1.7m3
Tonne (Metric Ton) - ANSWER A measurement of weight and not volume,
1000kg or 2,200Ibs
define the load displacement (W or Δ) - ANSWER The mass of the hull and
everything on board at any given draught / densitywhich will vary depending
upon the the density of the water, cargo and stores on board.
, define the light displacement - ANSWER the mass of the vessle when
complete and ready for sea but with no passengers, stores or cargo on board.
Remember: Δ = Underwater volume x Relative Density of the Water -
ANSWER
Define the summer displacement (W or Δ) - ANSWER The mass of the hull
and everything on board at her summer draught which will vary depending upon
the density of the water and the stores onboard.
Define deadweight - ANSWER The difference between the lightship
displacement and the actual displacement at any given draft
Define summer deadweight - ANSWER this can be thought of as the cargo
capacity of the ship and the difference between lightship displacement and the
summer displacement at her assigned freeboard
define load displacement - ANSWER the maximum weight of the ship floating
at her assigned freeboard
Define Load Deadweight - ANSWER the difference between the lightship
displacement and the load displacement
define gross tonnage - ANSWER this is usually considered as the internal
volume less certain exemptions. Note that the gross tonnage is calculated at a
rate of 2.83 m3 per tonne
define net tonnage - ANSWER Obtained by deducting the non-freight spaces
(accommodation, machinery spaces, stores etc) from the gross tonnage
define trim - ANSWER the difference between the draught at the forward
perpendicular and the draught at the aft perpendicular. If there is no difference
in draughts then the ship is said to be "on an even keel"
define TPC - ANSWER Tonnes Per Centimeter immersion - the additional
tonnage displaced when the mean draught is increased or decreased by 1cm.
QUESTIONS AND VERIFIED ANSWERS
Define the FP - ANSWER Forward Perpendicular - A vertical line
perpendicular to the base line from the point at which the LOAD WAERLINE
and the forward side of the stem intersect.
Define the AP - ANSWER The Aft Perpendicular - The vertical line erected
on the base line passing through the rudder stock. (or in a ship without a
conventional rudder this is the point at which the load waterline and the stern
intersect). This point is also used as the reference frame for numbering and is
marked as frame 0 on plans.
Define the LBP - ANSWER The Length Between Perpendiculars - The length
of the vessel measured between the forward and aft perpendiculars.
Define the LOA - ANSWER Length Over All - The extreme length of the
vessel
Define the LWL - ANSWER The length as measured on the waterline at the
actual draught.
Define Amidships - ANSWER The mid point of the LBP
Define Extreme Breadth - ANSWER The greatest breadth measured to the
OUTSIDE of the shell plating (aka beam width)
Define moulded breadth - ANSWER The greatest breadth of the vessel
measured to the INSIDE of the shell plating
Define Freeboard - ANSWER The vertical distance measured downwards
from the uppermost continuous (watertight) deck to the waterline at amidships
Define the Assigned Freeboard - ANSWER the vertical distance measured
downwards from the uppermost continuous watertight deck to the upper edge of
the summer load line at amidships
,Define Draught - ANSWER The verticle distance between the baseline and
any waterline. Draught is often also spelt draft and these two spellings are
interchangeable.
Define the Reserve of Buoyancy - ANSWER The volume of enclosed spaces
between the waterline and the freeboard deck. It may be expressed as a volume
in m3 or as a percentage of the total enclosed volume of the vessel
Define Camber - ANSWER Transverse curvature of the deck. It helps shed
water from the upper deck.
define sheer - ANSWER the rise in curvature of the deck fore and aft. It adds
buoyancy to the ends where it is most needed. CAMBER AND SHEER ARE
ARRANGED IN THE DESIGN OF THE VESSEL SO THAT WATER
SHIPPED IN A HEAVY SEA MAY FREELY MOVE ACCROSS OR ALONG
THE DECK AND OVERBOARD
define flare - ANSWER The curvature of the bow plating. Apart from
streamlining the bow section, flare increases the breadth of the forecastle head
and allows anchors to drop clear of the bow plating. In a seaway, the buoyancy
of the bow section will increase as is is immersed further into the water. This
increasing buoyancy helps to prevent the bow from diving too deeply in heavy
seas.
Define rake. - ANSWER The fore and aft slope from vertical. Bows, masts and
funnels are often raked.
Define Tun (Ton) (notice the spelling) - ANSWER This is a measurement of
volume and not weight. It is equivalent to a 200 gallon cask (a container of 60
cubic feet of 1.7m3
Tonne (Metric Ton) - ANSWER A measurement of weight and not volume,
1000kg or 2,200Ibs
define the load displacement (W or Δ) - ANSWER The mass of the hull and
everything on board at any given draught / densitywhich will vary depending
upon the the density of the water, cargo and stores on board.
, define the light displacement - ANSWER the mass of the vessle when
complete and ready for sea but with no passengers, stores or cargo on board.
Remember: Δ = Underwater volume x Relative Density of the Water -
ANSWER
Define the summer displacement (W or Δ) - ANSWER The mass of the hull
and everything on board at her summer draught which will vary depending upon
the density of the water and the stores onboard.
Define deadweight - ANSWER The difference between the lightship
displacement and the actual displacement at any given draft
Define summer deadweight - ANSWER this can be thought of as the cargo
capacity of the ship and the difference between lightship displacement and the
summer displacement at her assigned freeboard
define load displacement - ANSWER the maximum weight of the ship floating
at her assigned freeboard
Define Load Deadweight - ANSWER the difference between the lightship
displacement and the load displacement
define gross tonnage - ANSWER this is usually considered as the internal
volume less certain exemptions. Note that the gross tonnage is calculated at a
rate of 2.83 m3 per tonne
define net tonnage - ANSWER Obtained by deducting the non-freight spaces
(accommodation, machinery spaces, stores etc) from the gross tonnage
define trim - ANSWER the difference between the draught at the forward
perpendicular and the draught at the aft perpendicular. If there is no difference
in draughts then the ship is said to be "on an even keel"
define TPC - ANSWER Tonnes Per Centimeter immersion - the additional
tonnage displaced when the mean draught is increased or decreased by 1cm.
