SHIBU Flashcards
Naval Architecture (110 cards)
1
Q
Types of Ship Resistance
A
- Frictional Resistance: water/hull interface
- Presssure (Form) Resistance: bow/stern, where water is pushed aside
- Wave resistance Cw: waves created by pressure differentials at bow, shoulders, stern (hence, bulbous bow to cancel out)
- Added Wave Resistance (pitching, rolling, heaving)
- Air Resistance
2
Q
Hull Shape: influence on
A
- cargo space
- Seaworthiness (stability, movements, manoevrability, vibrations/forces)
- Speed (resistance ~ v^2)
3
Q
Lll, Lwl
A
Load Line Length:
used for freeboard calculations, regulations, class certificate, etc
Lwl: distance between points where bow/stern are going through Summer draft mark , less shell plating (i.e. moulded!)
4
Q
Moulded
A
dimensions outside frames but inside shell (without shell plating)
5
Q
Ship dimensions, general
A
sheer: extra buoyance forward/aft
6
Q
Camber & co
A
- Camber: drainage of deck
- rise of floor: lead water inside to centreline for pumping out
7
Q
Plimsoll Mark
A
8
Q
Carene & co
A
Carene V [m^3] = moulded underwater volume according to lines plan so without shell plating
Water Displacement [m^3] = V * c (coefficient for shell plating, rudder, prop, appendices) ~ 1.01
Displacement [t] = V * c * rho
9
Q
Displacement
A
Displacement = Deadweight (DWT) + Lightship (LWT)
LWT: empty ship, no cargo, fuel, crew
DWT: everything a ship can carry
CCC (cargo carrying capacity) : everything the ship is designed to carry is part of the variable DWT
10
Q
Ship heights
A
- Air draught: vertical distance from waterline to highest point of ship
- Depth: base line to upper, continuous deck
- Draught: maximal depth underwater, incl shell plating
- Freeboard: waterline to Freeboard Deck Line above Plimsoll Mark
11
Q
GT ./. NT
A
Gross Tonnage: dimensionless, calculated based on (moulded) volume below maindeck and enclosed spaces above maindeck
Nett Tonnage: GT reduced by crew spaces, nav equipment, partly propulsion, ballast, etc (not less than 30% of GT)
12
Q
Block Coefficient
A
CB
13
Q
Other form coefficients
A
Waterplane coefficient: Cw
Midship Section coefficient: Cm
14
Q
Lines plan
A
- Waterlines : horizontal slices
- Ordinates/Stations: cross sections
- Verticals/Buttocks: longitudinal slices => sheer plan
- Diagonals = Sent Lines
15
Q
Lines Plan (example)
A
Greater spacing in water lines, buttocks, ordinates => finer lines = smaller coefficients
16
Q
Drawings : general
A
A number of plans have to be submitted for approval by Flag and Class
Construction drawings to be approved by class
Safety generally to be approved by Flag
17
Q
Drawings: Class required
A
- GA Plan
- Lines Plan
- Construction Plans Profile/Deck
- Transverse Sections, incl Midship Section
- Double Bottom Construction
- Fore-/Aft Ship
- Engine Foundation
- Deckhouse
….
18
Q
Drawings: Flag required
A
- GA Plan
- Capacity Plan
- Safety Equipment
- Stability Calculations
- all Class approved drawings
19
Q
GA Plan
A
Division and arrangement of the ship :
Views:
- Stb side view
- Plan view (horizontals) of most important decks
- Cross sections (like Ordinates/Stations)
division into compartments; location of bulkheads; location/arrangement of superstructure; major equipment
Data:
- principal dimensions
- volume of holds
- tonnage
- deadweight
- engine power; speed
- Class
20
Q
Drawing: Midship Section
A
Transverse section
Principal dimensions, quality, and thickness of: shell plating; deck plating; longitudinal stiffening; transverse frames; web frames
maximum longitudinal bending moment
Equipment Numbers (anchors and chains)
Principal vessel dimensions, engine power, speed, Classification
21
Q
Drawings: Shell Expansion
A
Showing every single shell plate and openings (eg for repairs)
Seems -
Butts |
22
Q
Bulkheads
A
Minimum 3 watertight bulkheads:
1. Forepeak bh (= collision bh)
2. Engine Room bh
3. Aftpeak bh
23
Q
Strakes
A
24
Q
Forces on vessel
A
Forces from the outside:
* Static waterpressure
* Waves hitting the hull
* Wind
* Movement of ship
Forces on the ship from inside:
* Cargo
* Ballast water
* Hull construction itself
* Accommodation & Bridge
* Equipment (engineroom, cranes, etc.
25
Sheering forces
26
SWBM
Still Water Bending Moment
extreme fibres <=> neutral axis
27
WBM
Wave Bending Moment
extreme fibers <=> neutral axis
28
Local Stresses
* **Panting** stresses, pitching (changing water pressure), hull frames and plating (bow and
sometimes stern)
* **Pounding** stresses, extreme pitching (slamming), bottom plating bow
* Diagonal: **Racking**, due to rolling or unequal loading: transversal stiffeners required
**Vibration** stresses, by engine and propeller, good propeller design (no cavitation) and
heavy foundation in engine room
* **Dry docking** stresses, vertical local upwards forces
* **Vertical stresses**, by deck loads and masts
29
Transverse Framing System
* for smaller ships < 70m
* frames transversal
* Girders for longitudinal stiffening
* pillars - angle struts
**solid floor = full floor**
30
Longitudinal Framing System
* longer ships > 120 m
* frames longitudinal
* Bulkheads and floors for transverse stiffening
**solid floor = full floor**
where members go through watertight floors: **horseshoe plates**
31
Shipareas
32
Double Bottom:
purpose
**Strength, Stability, Storage, Safety**
* Increase strength
* For ballast tanks in low point of ship, low KG
* List and trim control
* Tanks for fuel, water, oil, etc.
* Additional safety for load and ship in case of damage by collision or
running aground
* Flat cargo deck / square box hold
33
Double Bottom:
constrution drawing
34
Double Bottom:
parts in picture
1. Full Floor
2 Side girder
6 Airholes
8 Tanktop
19 Bottom Shell
20 Heating coils
21 Ballast Tank pipe
35
Double Bottom
construction longitudinal
Lightening and Manholes in girders and floor: to reduce weight and for
accessibility / inspection.
Bracket Floor, Solid Floor & Solid Floor Watertight for transverse strength
36
Buckling vs Bending
36
Double Bottom
construction longitudinal (2/2)
36
Ship bottom
longitudinal
Longitudinal:
* Every transverse frame length a bracket floor
* Every third or fourth transverse frame length a solid floor
* Fore ship, pounding area: Every second transverse frame length a solid floor
* Engine room: Every transverse frame length a solid floor
* Watertight floors are thicker because of a corrosion addition, if frames go through: horseshoe plates to make it watertight again
37
Double bottom:
transverse framing
* For shorter ships, the SWBM and WBM are less, so for longitudinal
stiffening the girders are sufficient.
* Every frame spacing the frames are constructed as floors.
* In Engine room and pounding area’s: all solid floors
* Elswhere: in between solid floors 2 or 3 bracket floors:
38
Double Bottom
Construction traverse
Double bottom construction transverse
* Centre girder
* Side girder
* Bottom strake
* Tanktop
* Bottom frame
* Inner bottom frame
39
McGregor hatches
| 1. Coaming
2. wheels
3. hatch panel
4. horse
5. pull wire
40
Pontoon hatchcovers
1. pontoon hatch cover
2. hatch cradle
3. beam
4. hatch coaming
5. top rail
6. hold
7. tanktop
8. wedges
41
Hydraulic hatches
1. (hatch) hinges
2. hatch
3. main hinge
4. hydraulic cylinder
5. wheel
6. ramp
42
bulkheads:
goal
1 **Strength and stiffness**
2 **water barrier**: Watertight divisions
3 **fire barrier**: Slowing down or preventing fire
4 **segregation**: cargo, ballast, fuel, etc.
**minimum 3 transverse bulkheads**
43
Watertight subdivision
3 transversal bulkheads: requirements
**Collision bulkhead**
* Extra requirements for strength and location
* No openings, manholes or doors allowed in collision bulkhead
* Position between 5 and 8% of total length of ship from FPP
=> Too far forward?
> danger of damage in case of collision
=> Too far aft?
> working deck will be flooded when fore peak fully flooded
**Engine room bulkheads (fore and aft)**
* Fore: for watertightness and fire protection towards cargo / passengers
* Engine room aft bulkhead and aft peak bulkhead **mostly the same**.
* Stern tube is constructed in watertight aft peak tank. Water in aft peak tank can be used as cooling for propeller shaft.
44
Watertight vs Weathertight
* **Watertight** as defined in SOLAS is: capable of preventing the passage of water in any direction under the head of water likely to occur in intact and damaged conditions.
* **Weathertight** is defined as that in any sea conditions water will not penetrate the ship.
**Watertight doors**: swing or sliding
More than 5 closing devices, latcheds (Vorreiber); activation must be possible from bridge
45
Anchor equipment
46
Anchor windlass
5 Electro-motor
4 Gearbox
3 Band brake
7 Anchor chain
13 Chain stopper
47
Anchor
Parts
1. crown/shackle
2. shank
3. flukes
4. crown pin
5. crown plate
6. anchor chain w swivel
48
anchor chain
each lenghth = shackle: 27.5 m
1. anchor shank
2. anchor link
3. swivel
4. open link
5. enlarged link
6. kenter shackle
7. crown shackle
49
Rope buildup
protection agains shaving & UV
1 fibre
2 thread
3 yarn
4 strand
5 3 strand rope
50
Turnbuckle
1. Gaff
2. House
3. Thread
4. Eye
51
Shackles
1. bow with safety pin
2. bow with screw-bold
3. D-shackle with safety bolt and nut
4. D-shackle with screw bolt
54
Pounding - Panting
55
3 main strakes
56
cargo gear:
advantatges ./. disadvantages
+
faster
everywhere/anytime available => flexibility
control condition / quality
greater t/c earning potential
familiarity w system
layout specific for this vsls cargo carrying characteristics
-
extra weight
extra space
extra Class inspections / certifications
crew occupied / certification
extra mainenance
stability
visibility
upfront CAPEX and OPEX
57
Why to anchor
SHIBU
- safety / emergency
- manoevring
- waiting
- cargo operations
58
Different anchor types
(SHIBU)
*no need to know the anchor pics/names*
conventional: **SPEK, Hall, Pool**
**HHP** anchors: high holding power
**SHHP** SUPER HHP (for yachts only)
59
where to find equipment number
Class certificate
Midship Section
60
Why ballasting
Stability
Trim
Decrease bending moment
Increase manoeuvrability
Heeling angle during on/of loading
61
water piping diagram
diamond w interrupted line: strainer
non-return vv: from white to black
seacocks
62
Steering System components
1. steering wheel/autopilot
2. transfer system: bridge -> steering engine
3. steering engine
4. rudder stock
5. rudder blade
63
3 most important bulkheads
forepeak (5-8% from Fpp), aftpeak, engine room
can have doors/penetrations but **not in collision bulhead**
64
duct keel
space in between **2 centre girders**
65
transversal frames
66
Floors
If manholes in floors: **solid floor**
If no openings: **watertight floor**
+ **bracket floors**
67
Mixed framing
FWD (pounding; panting) / AFT (weight; vibrations => needs **stiffness** for e.g. prop alignment): **transversal**
Midships: longitudinal
68
Bracket floor
If not full across; but just pieces (individual plates)
69
Webframe
**above double bottom**
À big plate (almost like a huge bulkhead; but open in middle)
70
tansversal framing:
why?
cheaper, lighter, easier to build
when bending moments are lesser (shorter vsls; fore-/aftship)
71
sternframe
at stern (12)
other name for centregirder, which continues after prop
11: rudder horn
72
hatches: goals
access holds
close holds weathertight
strength of the vessel
space for deck cargo
73
watertight doors ./. weathertight
differences
5+ latchings (Vorreiber)
sliding/hinged
withstand water column, if entire adjacent compartment flooded
weathertight: only for **above** water
74
Forces on Ship
| SHIBU
**static ./. dynamic**
Forces from the **outside**:
* Static waterpressure
* Waves hitting the hull
* Wind
* Movement of ship
Forces on the ship from **inside**:
* Cargo
* Ballast water
* Hull construction itself
* Accommodation & Bridge
* Equipment (engineroom, cranes, etc.)
* **vibration**
75
Bending moment
def
| SHIBU
The result of **vertical forces** acting on a ship as a result of local **differences between weight and buoyancy**. The total of these forces should be zero, otherwise
change of draft will occur. At sea, the bending moment will change as a result of wave impact which than periodically changes the buoyancy distribution.
Note: The maximum allowed bending moment of a vessel is **restricted by the class society to certain limits**, which are different under port and sea conditions.
76
Flagstate
| SHIBU
National authorities (ILT) by choice of Flagstate
* safety of people on board and interaction with environment
* Often on basis of IMO conventions
* Certificates like Tonnage Certificate
* And often but not always the rest is delegated to classification societies
* Surveyors
77
types of floors
| SHIBU
**solid floors
wateright floors
bracket floors**
78
Double bottom construction longitudinal
* **Keel strake + centre girder/centre keel + top plating = backbone of the
ship** see page 162 for all strakes
* Centre girder (vertical keel) is watertight and can be double constructed: page 172 nr 6 Duct keel, can be used as a cofferdam or pipe tunnel
* Keel strake, from bow to stern is part of the hull plating / bottom strake, very important for longitudinal strength, always thicker or doubled
* Side girders, as long as possible, 1 or 2 on each side, sometimes
watertight
79
holes in e.g. full/solid floors
| SHIBU
* lightening holes
* manholes
./.
* air holes
* drain holes
80
3 different floors
| SHIBU
watertight floors
solid = full floors
bracket floors
81
Longitudian framing
floor layout
| SHIBU
* Every transverse frame length a **bracket floor**
* Every third or fourth transverse frame length a **solid floor**
* **Fore ship, pounding area**: **every second** transverse frame length a **solid floor**
* **Engine room**: **Every transverse** frame length a **solid floor**
* Watertight floors are thicker because of a corrosion addition, if frames go through: horseshoe plates to make it watertight again
82
Transversal framing
floor layout
* **Every frame spacing** the frames are constructed as **floors**.
* In **Engine room and pounding area’s**: all **solid floors**
* **Elswhere**: in between solid floors **2 or 3 bracket floors**
83
Holland Profile
type of stiffening profile: a rolled steel section with a distinctive asymmetrical shape, designed to provide **structural strength** while **reducing weight**.
Key Features of the Holland Profile:
* **Asymmetrical** Shape: Unlike traditional flat bars or angles, the Holland Profile has a wider flange on one side and a narrower web, **improving load distribution and efficiency**.
* Efficient **Strength-to-Weight Ratio**: The design optimizes structural strength while minimizing the amount of steel used.
84
Steel vs Iron
difference: **composition and properties**
Composition
* Iron (Fe): A **pure metal** extracted from iron ore.
* Steel: An **alloy of iron and carbon**, sometimes with other elements like chromium, nickel, or manganese for enhanced properties.
Strength and Hardness
* Iron: **softer and more malleable** in its pure form (wrought iron), but brittle in its impure form (cast iron).
* Steel: **stronger and harder** due to the carbon content, which improves durability and resistance to deformation.
Corrosion Resistance
* Iron: **rusts easily** when exposed to moisture and oxygen.
* Steel: more **resistant to rust**, especially stainless steel, which contains chromium to prevent oxidation.
85
Equipment number:
relevance
| SHIBU
- **anchor weight** (smaller for HHP than conventional)
- size of chain **studlinks**
- **length of anchor chain**
- **towing lines**
- number, lengths and MBL of **mooring lines**
86
why ballast
| SHIBU
- trim
- stability
- decrease bending moment
- increase manoevrability
- compensate healing during loading/unloading
87
Rudder types
| SHIBU
Spade
Flap
Mariner
88
shipbuilding material:
considerations
| SHIBU
* Usability / practicality
* Costs
* Strength
* Toughness
* Hardness
* repairability (worldwide!)
* sustainability en recycling ability
89
different shipbuilding materials
| SHIBU
* Wood
* Concrete
* Iron
* Steel
* Aluminum
* Synthetic: Polyester / Epoxy / polyethylene with reinforcing fibers as glass, carbon, aramid (Kevlar, Twaron), composite with foam, wood, etc.
90
steel: weakening
| SHIBU
- **corrosion**
- **erosion** (caviation)
- **fatigue** mechanical wear&tear (vibration; bending; etc)
91
corrosion:
types
| SHIBU
- **electrochemical** (slow/non aggressive; prevent through coating, epoxy, paint)
- **galvanic** (less noble eaten up: Magnesium, Zinc, Aluminium, Steel, Copper, Nickel, ... Gold)
92
prop/hull corrosion
| SHIBU
bronze prop would eat up steel hull
=> sacrificial anodes:
Magnesium (FreshW)
Aluminium (brackish)
Zinc (SeaW)
93
paint coat buildup
| SHIBU
Primer
Paint system
Antifouling
* Tough layer releasing the biocide
* Soft layer with binding agent which slowly dissolves
* Self Polishing where outer layer continuously shreds.
94
Dry Docking preparation
| SHIBU
* Tanks and holds clean and free of gasses
* Certificate gas proof when welding or cutting is required
* Ship cleaned according to Marpol
* Cranes or derricks parked
* Deck closed
* Toilets cleaned and locked
* Dock list with duties prepared
* Appropriate trim / ballast
* Switch off depth gauge
* paint/consumables/spares ordered and delivered
95
Dry Docking: procedure
| SHIBU
* Dock master is supervisor (time in logbook)
* Centre the ship with lines in dock
* Engine stopped – dock based winches used to position the ship
* Dry dock is pumped empty
* Draft marks to know water level above keel blocks
* When ship touches keel blocks: on the blocks (time in logbook)
* Stability of ship decreases when half afloat / half on blocks / deballasting
* Stability of dry dock! Large Free surface area
* Clean outside of hull immediately, dirt and fouling easier to remove when still wet
96
Dry Dock
surveys
| SHIBU
* Propeller, tail shaft, stern tube
* Rudderstock, rudder
* Underwaterhull
* anchor, anchor chain, chain locker
* Water inlet / outlet; **overboard valves**
* Sea chest, cooling system
* sacrificial anodes
* sterntube
97
why practically all ships build in steel
fire resistance
98
dry dock layout
keel blocks; side blocks; side sponso; crane rail
floating; graving; slip; lift
99
bulkhead fire protection
A (best) - C
C: only **non-combustible**
B: preventing **30 min** flame & smoke passage standard fire test
A: preventing **1 hour** flame & smoke passage standard fire test
-30; -60 ...
**minutes** within which temperature rise on non-exposed side must not exceed +140 deg bzw max 180 deg
100
how to calculate equipment number
arguments:
**displacement; windage area**
find where: **SOLAS**
101
main components of any steering gear
| SHIBU
1. Steering wheel / automatic pilot
2. Transfer system brigde – steering engine
3. Steering engine
4. Rudder stock
5. Rudderblade
102
Steering gear: requiremnets
| SHIBU
Rudder has to be strong enough to **withstand**:
* **Shifting from maximum angle PS to SB** or back within time frame
* **Maximum rudder angle running ahead and aft**
* **Helm to SB, ship to SB**
* **Helm straight ahead: rudder straight ahead**
* Helm place where helmsman has **non obstructed view** over fore part ship
* **Emergency steering gear**
* **Rudder angle indicator**
103
transverse framed stern
(example pic)
| SHIBU
1: frames
2: ice strengthening frames
3: web frames
4: (transversal) deck beams
5: (longitudinal) deck girders
6: duct kee
104
longitudinal framing w double bottom
(example pic)
| SHIBU
1: shell plating
2: longitudinal bulkhead
3: transverse bulkhead
4: longitudinal bulkhead
5: lower hopper
6: tanktop
7: d//b tank
8: side longitudinals
9: bottom longitudinals
10: upper longitudinals
11: bulkhead stiffener
13: cross tie
16: water tight floor
17: bracket floor
18: side girder
105
static forces
(also; examples)
- water on deck
- ice accretion
- cargo on deck
106
structural members of various panels
107
longitudinal framing
| SHIBU - picture from youtube video
108
Transverse framing
| SHIBU - pic from youtube
109
Where stiffening is required
* shell plating
* decks
* bulkheads
* tanktop
110
Eselsbrücke:
Galvanic Corrosion
Calva hat ne Schraube locker
