Term
What are the purpose of cant frames in steel vessels? |
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Definition
provide strength to shell plating at stern |
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Term
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Definition
a vertical strength member |
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Term
what are the synonyms for pillar? |
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Definition
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Term
why should pillars always be fitted in a vertical line? |
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Definition
To transmit load directly down to the keel, and not onto beams and deck plates. |
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Term
why is a pillar fitted under the windlass? |
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Definition
to absorb the stress, vibration, and weight of the windlass |
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Term
what is a partial bulkhead |
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Definition
bulkhead that does not extend across a compartment; used to strengthen the structure |
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Term
what three things does the size of a pillar depend on? |
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Definition
load, location, and length |
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Term
How does acceleration affect the size of the pillar? |
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Definition
dynamic load can be double the static load |
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Term
what is the purpose of deck girders? |
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Definition
support deck beams by reducing span |
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Term
why should pillars be well protected when cargo is loaded/unloaded? |
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Definition
to prevent damage, bent pillars provide little to no vertical support |
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Term
what is the purpose of wood sheathing |
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Definition
insulates - wood has low heat transmission absorbs damage and protects deck keeps outer decks cool for passengers prevents sweating due to rapid temp change under deck add aesthetic value to appearance of ship |
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Term
what is the purpose of the stringer plate? |
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Definition
thicker outboard plating to prevent racking and provide support for cargo hatchess |
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Term
why should corners of all hulls cut into the strength deck be rounded, doubled, or both? |
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Definition
to prevent cracks and notches from forming due to stress |
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Term
differentiate between side stringer, girder, and longitudinal |
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Definition
side stringer: longitudinal strength member inside deck plating longitudinal: fore and aft strength members in bottom structure girder: fore and aft longitudinal strength members supporting decks |
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Term
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Definition
provide additional vertical support & act as structural diaphragms to resist racking create fire & flooding boundaries |
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Term
what is a 2 compartment ship? |
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Definition
A ship that can be flooded in 2 compartments and stay afloat |
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Term
max number of passengers a merchant ship can carry without being considered a passenger vessel? |
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Definition
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Term
what is the maximum distance the collision bulkhead can be from the stem? |
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Definition
1/20th the vessel length at summer load line |
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Term
what are the functions of the stem? |
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Definition
vertical extension of the keel gives strength and rigidity to hull along center-line ties shell plating gives rigidity to entire bow |
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Term
advantages of a clipper bow? |
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Definition
additional space and buoyancy flare throws water away from bow when headed into heavy seas |
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Term
what is the function of the stern frame? |
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Definition
vertical extension of the keel provides strength for rudder and single prop ties shell plating together at stern |
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Term
pillars give vertical support to... |
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Definition
girders deck beams decks heavy concentrated loads: ground tackle, anchor windlass, line handling winches, capstains |
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Term
why place pillar under deck beam or girder? |
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Definition
redices deflection by reducing span relieves stress on beam brackets & transverse frames |
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Term
top/bottom of pillar (names)? |
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Definition
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Term
purpose of doubling plate at bottom of pillars? |
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Definition
to spread the load over larger portion of deck plating |
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Term
ideal depth of beam brackets |
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Definition
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Term
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Definition
increases seaworthiness by forming watertight top of hull and contributes strength by acting as upper flange of hull girder |
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Term
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Definition
working platforms for operation of machinery and loading of cargo living spaces for passengers and crew |
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Term
Additional purpose of all decks |
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Definition
serve as horizontal diaphram, keeping the ship in shape longitudinally |
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Term
Girder stress concentration? |
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Definition
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Term
2 methods of insulation on ships? |
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Definition
insulation bats fixed to underside of deck via wire studs spray on insulation applied directly to steel deck |
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Term
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Definition
insulate space prevent sweating noise barrier in engine room decks and bulkheads on passenger vessels |
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Term
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Definition
paint cement composite that flexes with deck carpet, tile or linoleum over top of cement composite |
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Term
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Definition
flat plate steel or corrugated (adds strength, reduces need for additional framing) |
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Term
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Definition
acts as auxiliary watertight bow in event actual bow is punctured in collision |
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Term
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Definition
encloses shaft in watertight compartment required on all screw type vessels prevents broken prop shaft from flooding aft section of vessel |
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Term
machinery space bulkheads |
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Definition
enclose machinery spaces - watertight regulatory requirement due to large through-hulls in engine rooms |
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Term
3 bulkheads required by regulation |
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Definition
collision bulkhead afterpeak bulkhead machinery space bulkhead |
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Term
Bulkheads are usually plated... |
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Definition
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Term
plate thickness thicker towards the bottom of the ship.. |
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Definition
due to increased water pressure |
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Term
Why are longitudinal bulkheads avoided |
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Definition
danger of capsizing due to collision and flooding of one side of the ship but they are seen in tankers |
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Term
longitudinal bulkheads in tankers |
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Definition
single hull: port and starboard longitudinal bulkheads form boundaries between port, center, and stbd tanks double hull: usually only centerline longitudinal bulkhead |
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Term
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Definition
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Term
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Definition
straight up and down classic passenger ship, aided with riveted construction |
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Term
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Definition
flared bow, extra space and buoyancy, throws water when headed into seas |
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Term
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Definition
ice breaker, allows bow to ride up on ice and break it with the weight of the vessel |
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Term
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Definition
curved connection between stem and keel sometimes cast |
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Term
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Definition
lower stem section joining forefoot to upper stem |
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Term
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Definition
plate heated and rolled to form plating around upper stem |
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Term
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Definition
triangular plate that joins plating and reinforces the solid stem bar |
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Term
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Definition
located forward of collision bulkhead serves as forwardmost ballast tank exerts greatest moment for trim changes, good for lessening sag |
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Term
components of forepeak tank |
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Definition
valves and piping reach rods to open and close valves swash bulkheads reduce wave motion, can be longitudinally or transverse (generally longitudinal) |
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Term
Bulbous bow - what vessel speed? |
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Definition
higher vessel speed - improves vessel flow through water, overcomes wave making resistance acts to fill in trough of bow wave = less power needed to reach medium/high speed |
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Term
two primary types of sterns |
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Definition
cruiser: rounded, requires cant frames and beams to make curve. older construction transom: flat, modern construction cuz its cheaper, and waterline is carried further aft |
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