Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

General Ship Knowledge. OOW, MCA > Ship Construction > Flashcards

Ship Construction Flashcards

1
Q

Define: freeboard deck

A

The upper most deck exposed to the weather and sea which has permanent means of closing all openings and below which all openings in the side of the ship are fitted with permanent means of closure

There’s a direct link between a vessel’s freeboard and :
Safety with regard to personnel 
Stability 
Strength hull structure
Prevention of ingress of water
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Assigned freeboard

A

The distance measured vertically downwards at amidships from the upper edge of the freeboard deck to the upper edge of the summer load line

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Weathertight

A

In any sea condition water will not penetrate the ship

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Define Panting

A

Panting is the in and out movement of the shell material due varying pressure changes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Briefly explain how the locality is stiffened to resist this stress (Panting)

A

Reduce the unsupported opener area by close frame spacing and/or additional stiffening members (eg panting beams) and/or increase shell thickness

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Wood - advantages

A

Floats, strength, appearance, easy to work with

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Wood - disadvantages

A 
Rots, 
can burn
expensive
poor radar reflector
Marine borers
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Steel - advantages

A

Relatively strong, widely available, easy to work with, cheap to produce and recyclable, good radar reflector.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Steel - disadvantages

A

Corrosion, relatively heavy 3x heavier than aluminum, conducts heat, needs regular maintenance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Aluminum- advantages

A

High strength to weight ratio, doesn’t corrode as easy as steel, good radar reflector, recyclable

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

GRP/FRP - advantages

A

High strength to weight ratio,
non corrosive
low cost if moulds are used
Readily available

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

GRP - disadvantages

A 
Blistering and delamination, 
once of fire - burns intensely giving off toxic gas, 
poor radar reflector
Poor in bending 
Specialist Labour
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Explain How chemical corrosion in steel occurs

A

Caused when the oxygen in the atmosphere combines with the metal and forms iron oxide. The oxide film is not firmly attached to the parent plate and thus permits further oxidation to occur

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Discuss the factors and conditions that would cause chemical corrosion to be accelerated and how good ship design could reduce this

A

Accelerated by and prevention :
Good ventilation
Reduce heat
Avoid water traps

Accessibility for preservation :
Regular inspection and maintenance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Center grider - importance/function

A

Furthest from the neutral axis

Contributes substantially to the Longitudinal strength to resist sagging and hogging

Receives load when in dry dock

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Plate floor - importance/function

A

Vertical plates running transversely across the bottom to stiffen the bottom

Transfer loads from the tank top and gives support to the side and center griders

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Shell material - importance/function

A

Watertight skin of the ship. Major part of the ships strength.

Efficiently unites the supporting longitudinal and transverse members the make up the framing system.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Upper deck -

importance/function

A

Furthest from neutral axis;

Top flange of the grider

Strength deck

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Deck beam - importance/function

A

Part of deck framework (with griders)

Supports deck plating

Transfer loading to frames bulkheads and pillars

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Beam knee - importance/function

A

Unites the beam and frame enabling stresses to be transferred from one to the other

They offer some resistance to racking

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Transverse frame - importance/function

A

Part of the framing system

Receives the deck loading via the beams and transfer the load to the bottom structure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Transverse bulkhead - importance/function

A

Subdivides the yacht into separate compartments

Contain flooding and fire

They contribute greatly to the structural integrity of the ship by providing the primary resistance to transverse deformation and so resist racking

They also are efficient load bearers and effectively distribute loads to the adjacent structure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Pillar - importance/function

A

Supports deck and transfers loading downwards, the unsupported span of the beam is reduced and hence beam sections can be reduced in depth so the clear space

Where extra deck loading is need ie: helicopter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Give four items of information to be found on a general arrangement drawing

A

plan, profile and section views

Division into compartments (tanks, engine room, holds)

Location of bulkheads

Location and arrangement of superstructure

Parts of the equipment (winches, loading gear, bow thruster, life boats)
 Dimensions (Length, Breadth, Draft)
Volumes of the holds (Cargo Capacity Grain & Bale)
Tonnage
Deadweight
Engine power
Speed (Service Speed)
Class
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Sketch and explain the term “pounding”
Is the vertical slamming of the forefoot of the vessel onto the trough of a wave being caused by a combination of pitching and heaving. Produces large impulsive forces on bottom plating
26
Explain how the locality is stiffened to resist this stress (pounding)
Frame spacing reduced Additional stiffeners introduced Shell plating thickness increased
27
State two reasons/functions for fitting each of the following : Transverse bulkheads
Subdivides yacht into separate compartments Contains flooding and fire Contribute to resisting of racking Contribute to load bearing Effectively distributes loads to adjacent structures
28
State two reasons/functions for fitting each of the following : Deck beams
Supports deck plating Transfers loads to frames Transfers loads to bulkheads Transfers load to pillars
29
Describe the routine maintenance necessary to ensure that a weather-tight door prevents ingress of water
Ensure rubber seals intact, paint free Ensure securing arrangement fully functional and greased No obstructions to door closure Door fits frame, seals.
30
Sketch aluminum and steel immersed in slat water and connected electrically, Explain how a current is caused to flow from one material to the other and how this gives rise to ‘galvanic corrosion’
The galvanic action is a form of electrolysis whereby different metals will react with one another to form an electric cell when they are placed in suitable medium (an electrolyte) In this case the less noble metal is the aluminum which will give up its ions and become eaten away. The aluminium is known as the anode whilst the steal becomes the cathode. The process is speeded up due to the Efficient salt water electrolyte
31
Describe a method of cathodic protection
Sacrificial - That galvanic action is an electro-chemical form of corrosion where one fo two dissimilar metals are eaten away. The metal that is eaten away is the one higher in the galvanic series ( ie the ignoble or anodic end) to counteract this in respect to mild steel, a metal more ignoble/anodic eg zinc or magnesium may be used and these are termed sacrificial anodes which will waste in presence to the steel
32
Describe another method of cathodic protection
Impressed current That galvanic action is a flow of electrical particles (iones) through an electrolyte (SW) from the anodic metal to the cathodic metal - i.e an eclectic current. By passing a current of the same strength through the electrolyte but in the opposite direction the galvanic action is cancelled out and no corrosion occurs. Comprises of a controller rectifier and anodes
33
Sketch a ship being made to hog in a seaway Explain why the upper deck will be subjected to high stress
As neutral axis is below half depth of vessel, tensile stress will be high
34
State two functions/reasons for fitting each of the following : Pillars Plate floors
Pillars: Supports deck and transfers loading downward. The unsupported span of the beam is reduced and hence beam sections can be reduced in depth so increasing head height in the compartment (but at the expense of intrusion into the clear space) Plate vertical plates running transversely across the bottom to stiffen the bottom; transfer floors loads from the tank top and gives support to the side and center griders
35
State four tasks provided by a classification society
``` Construction rules Statutory authority Material spec Insurance premium Resale value Surveyors available ```
36
Explain the term ‘fresh water allowance’
Amount by which the summer mark can be immersed when in FW due to less dense FW allowing floating at correct marks when emerging into higher density SW
37
Advantages and disadvantages of - | Aluminium alloy
Advantages - Easy to work with Less maintenance Light Disadvantages- Melts at lower temp than steel bi-metallic corrosion Distortion with welding
38
Advantages and disadvantages of - | Steel
Advantages- Good strength/weight ratio Easy welding Cheap ``` Disadvantages- Distortion in welding Needs insulation against condensation Heavy corrosion ```
39
Sketch a pumping system that could be fitted to a yacht Identify all the associated valves and fittings
``` Needs to have- Mud box Strum Vale’s Fwd-middle-laz sections Holding tank Pump/s Disch-ashore facility O/b discharge Others ```
40
Sketch - | Sagging
Compressive stress in deck | Tensile stress in keel
41
Sketch - | Racking
Swell/waves on the beam of the vessel
42
Sketch - | Panting
+ & - Panting is an in-and-out movement of the shell plating resulting from the variations of water pressureas waves pass along the hull and when the vessel pitches.
43
Sketch - | Pounding
Bow lifting at the crest of a wave and slamming/pounding in the trough of the next
44
Explain- | Reserve buoyancy
Intact volume between waterline and freeboard deck
45
Explain- | Gross tonnage
Internal volume of ship
46
Explain- | Net tonnage
Gross tonnage less deductions
47
A yacht is to undergo an annual survey. | State four items that would be inspected
Any examples of weather tight openings (doors, hatches, vent openings, side scuttles). Stability data, general structural condition
48
Explain - | Camber
Is the transverse curvature of the deck
49
Explain- | Flare
Is the outward curvature of the bow
50
Explain why camber may be incorporated in a yachts design
To shed water from the deck. Provides additional longitudinal strength
51
Explain why flare would be incorporated into a yachts design
Increases buoyancy of the bow - helps head up. Reduces breaking water on deck
52
A motor yacht with a steel hull is to have a 300mm hole cut in the bottom plating amidships in order to install an underwater fitting i)Explain how stresses would arise in this vicinity
High stress area already due to being amidships (tensile/compressive) and farthest from neutral axis Change of section due cutting of hole will cause stress lines to be concentrated
53
A motor yacht with a steel hull is to have a 300mm hole cut in the bottom plating amidships in order to install an underwater fitting ii)describe the structural compensation that should be fitted in way of opening
By use of an insert plate of increased scantling with chamfered thickness reduction
54
Give four examples of information to be found on a general arrangement drawing
Side elevation/profile and plan of decks showing: accommodation; storerooms Tanks bridge layout Principle dimensions: LOA, LBP; opening/doors/windows/ports/scuttles/alleyways/ladders/companionways
55
Explain reserve buoyancy
Intact volume between waterline and freeboard deck
56
Explain gross tonnage
Internal volume of ship
57
Explain net tonnage
Gross tonnage less deductions
58
Explain the reason for fitting sacrificial anodes to a steel hull in the vicinity of a propeller made of non-ferrous material
The galvanic action (electro chemical process)- Is a form of electrolysis whereby different metals will react with one another to form an electric cell when they are placed in a suitable medium (an ELECTROLYTE) In this case the less noble metal is the zinc which will give up its IONS and become eaten away (it corrodes) The zinc is known as the ANODE Whilst the prop non ferrous metal becomes the a CATHODE. The process is speed up due to the efficient salt water electrolyte
59
Explain the term sheer? | Give two reasons why the upper deck of a yacht might be given sheer?
Rise of the deck above the horizontal. Added buoyancy forward, keeps head dry, aids drainage
60
Explain, with reference to galvanic corrosion, why the means of joining aluminum superstructure to a steel upper deck needs to be carefully made?
Galvanic corrosion is an electrochemical process whereby one metal corrodes in preference to another metal the it is in contact with through an electrolyte. In this case aluminum is anodic to steel and needs to be insulated (Example of an insulated product is ‘triclad’)
61
Give any explain of ‘discontinuity of strength’ in a yacht’s construction and explain how stress concentration will arise in the vicinity?
Local loading stress- Can be caused by heavy weights concentrated on small areas (under main engines) (Longitudinal stress carrying members of the structure meet transverse members) Poor design (A sharp angle cut in a plate produces a discontinuity) - When a Tensile stress is applied, the stress is concentrated at the angle Vibration Causes cyclic forces in steel usually resulting in tensile stresses. After a long period this will cause the structure to fail by cracking. This can cause corrosion in steel, and weld fractures particularly in aluminum
62
Summarize the Lloyds notation below X100A1 SSC G6 UMS
100 - considered sutiable for seagoing service A - built in ACCORDANCE with lloyds class rules 1 - anchor and mooring equipment comply wiht lloyd’s class rules. X(Maltese Cross) New ship built under supervision of a society surveyor SSC special service craft G6 geographical restrictions UMS unmanned machinery spaces
63
Main functions of a classification society include..?
Outline specific standards of construction for different types of vessels (rule book) Provision of surveyors to to classify vessels, inspect at prescribed intervals Damage surveys and supervise work to restore damage Confirm statutory compliance, load line assignment and inspections, tonnage measurements, anchor and cable testing, approval of lifesaving and fire appliances Testing materials Research on failure of materials and equipments Performance data on its vessels Publish a list (register) of its shipping for use by industry
64
What is assessed/checked during an annual survey
General condition of the vessel,machinery and equipment Other items include: Closing appliances such as, hatches, ventilators and air pipes Water tight doors and bulkheads Steering arrangements The provision of structural fire protection is verified Anchors and cables
65
Disadvantages of aluminum?
``` Weaker than steal (half strength) More expensive Special technique to weld Not fireproof Not ecologically friendly. ```
66
Carbon and Kevlar RP | Advantages
Stronger and lighter than glass Excellent stiffness If correctly designed stronger than steel and light than aluminum
67
Carbon and Kevlar RP | Disadvantages
Very very expensive Epoxy is not compatible with polyester resins Very had to laminate Requires very skill workforce and specialists facilities and equipment.
68
Illustrate how dissimilar metals should be fitted
Can’t be touching Washes rubber plastic

General Ship Knowledge. OOW, MCA (4 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions