Hull and Structure Flashcards
AMI Systems Hull and Structure (124 cards)
Aft
An adjective or adverb meaning, towards the stern (rear) of the ship.
After Peak
Aftermost tank or compartment of a ship.
After Perpendicular
A line to the base line intersecting the after edge of the rudder post at the designed load water line. For stern counters that are well submerged, such as “cruiser sterns,” barges, and similar sterns. The after perpendicular is a line to the base line intersecting the after side of the stern counter at the designed load water line.
Air ports
Often referred to as side scuttles or port holes.
Amidship
The mid or center transverse plane of a vessel located midway between the forward and after perpendiculars.
Anchor
The purpose of the anchor gear or ground tackle is to secure a ship to the seabed in shallow water. Reasons for doing so can be the ship has to wait until a berth becomes available, to load or discharge cargo when a port does not have a berth alongside for the ship, to help with maneuvering in emergency to avoid grounding. In general, ships have two bow anchors and sometimes a stern anchor. There are two bow anchors for safety. Under normal circumstances, one anchor is sufficient, but under severe weather conditions or in a strong current both anchors may be needed. Also, if one anchor fails the second anchor is a backup.
Anchor Chain
An anchor chain is a chain connecting a ship to its anchor. The chain runs from the chain locker, through the Sperling pipe, via the gypsy wheel of the windlass, through the hawse pipe, to the anchor. The anchor chain consists of links with studs to prevent kinks in the chain (stud link chain).
Anode
Cathodic protection using a sacrificial material (usually zinc or aluminum). Intended to protect the Hull structure from corrosion.
Appendage
An underwater surface which protrudes from a hull. That’s to say any sort of keel, rudder, or skeg.
Athwartships or Transverse
Across the ship, at right angles to the keel.
Auxiliaries
Machinery other than main propulsive machinery.
Baffle
A plate or structure placed in the line of flow of fluids or gases to prevent the free flow in order to slow down or stop fluids from surging (e.g. oil tanks). Increases the stability and prevents the center of gravity moving when fluids shift from one side to another.
Ballast
Weight (usually sea water in tanks) loaded into a ship to increase stability when the ship is empty, or when cargo, etc., has a high vertical center of gravity. Also, used to control trim.
Base Line
Horizontal reference line, usually at the lowest boundary. For vessels with a flat keel plate outside of the bottom strakes, the base line is at the top of the flat keel. For vessels with a hanging bar keel, the base line is usually at the lower contour of the molded surface. For vessels with a designed trim or drag, the base line is at the lowest point.
Bilge
Rounded portion of hull between side and bottom.
Bilge Keel (or Rolling Chock)
A longitudinal member fitted to the outside of the shell on the bilge strake of plating to prevent excessive rolling of the ship.
Bitter End
The inboard end of a mooring line or anchor chain.
Bitts
A pair of short, vertical wooden or iron uprights for securing mooring or towing lines.
Bollard
An upright, somewhat stronger than a bitt, on a pier or wharf: used for mooring lines.
Boom
A term applied to a spar used in handling cargo.
Bow
The front of a vessel.
Bow Thruster
A motor driving a propeller near the bow that operates laterally to move the bow one way or the other to help with maneuvering.
Bracket
A steel plate, usually of triangular shape, and commonly with a reinforcing flange, used to stiffen or tie beam angles to bulkheads, frames to longitudinals, or any two structural parts which meet at an angle, in order to strengthen the joint against flexing.
Brow
A portable gangway or gangplank.