Introduction to Stability Ships Stability Definitions Lets state

Introduction to Stability

Ships & Stability -Definitions Let’s state the obvious! Bow Stern

Ships & Stability -Definitions Let’s state the obvious! Bow Stern The front bit of a ship. (Maybe termed “For’d”) The back bit of a ship. (Maybe termed “Aft”)

Ships & Stability -Definitions Adding some more basics: Port Starboard

Ships & Stability -Definitions Adding some more basics: Port The left (RED) side when looking Forward Starboard The right (GREEN) side when looking Forward

Ships & Stability -Definitions Now let’s get a bit technical: Keel Deck

Ships & Stability -Definitions Now let’s get a bit technical: Keel The bottom of a ship. Deck The top bit of the ship.

Ships & Stability -Definitions Now let’s add some measurements: Length Beam Depth

Ships & Stability -Definitions Now let’s add some measurements: Length Beam Depth From For’d to Aft From side to side From top to bottom I told you it was obvious!

Ships & Stability -Definitions BUT!!! There are two lengths of a ship: LBP LOA

Ships & Stability -Definitions BUT!!! There are two lengths of a ship: LBP Length Between Perpendiculars & LOA Length Over All

Ships & Stability -Definitions The Forward and Aft Perpendiculars are where the Length Between Perpendiculars are measured. Forward is taken as the water line when the ship is full. Aft is taken as the Rudder Post.

Ships & Stability -Definitions The other length of a ship is Length Over All (LOA) which –surprisingly- is extreme length, measured from the furthest bit forward to the furthest bit aft. Beam is also measured from the extremes.

Vessel Length

Ships & Stability -Definitions Now let’s get really technical: Draft Trim Heel

Ships & Stability -Definitions Now let’s get really technical: Draft The depth of the ship in the water. Trim The difference between the for’d and aft drafts. Heel The difference between the port and starboard drafts. (Sometimes measured as an angle & called a list)

Ships & Stability -Weights Now let’s look at a few tonnages: just to confuse you, the first 2 aren’t weights, but spaces; but called tons. Gross Net

Ships & Stability -Definitions Now let’s look at a few tonnages: just to confuse you the first 2 aren’t weights, but spaces; but called tons. Gross The amount of space in a ship. Net The amount of space in a ship available for cargo.

Ships & Stability -Definitions Historically, the first ships were measured by the amount of wine it could carry, and the wine came in containers or barrels called “tuns”. The name has been kept, just to confuse you.

Ships & Stability -Definitions Some proper tonnes: Light displacement Load displacement Deadweight

Ships & Stability -Definitions Some proper tonnes: Light displacement Load displacement Deadweight The weight of the ship when it is fully loaded. The difference between the two, or the amount of cargo it can carry.