20141009 planning and d planning and design of port water areas

September 11, 2014

1

Planning and Design of Port Water Areas

CIE4330 Ports & Waterways 1

Bas Wijdeven

Section of Hydraulic Engineering

September 11, 2014 2

Planning and Design of Port Water Areas

Determines to a large extend the port layout

Major part of the overall investment

Difficult to modify once built

www.hima.com


A. Nautical design Hydraulic design

Planning elements

1. Access channel

2. Turning circle

3. Basins

4. Berths

NPA, Port of Durban


1. Access channel

a) Alignment

b) Width

c) Depth

d) Maneuvering space inside port


a) Channel Alignment

Design considerations

Minimize dredging costs

Avoid bends near the port entrance

Minimize effect of cross-currents

Small angle with dominant wave direction

Some are conflicting compromises

www.cruisingthevirginislands.com


a) Channel AlignmentTurning radius as a function of rudder angle and water depth

www.mykomec.blogspot.com

Turning radius at 35 rudder angle in

deep water at service speed:

Fast container vessels 26 knots: 6-8L

Bulk vessels 16 knots: 2.5-4L

GC/multipurpose/LNG: 2-2.5L

x

x

x


b) Channel width

Planning stage: PIANC method

Fast Time Simulation

Design stage: Real Time Simulation


b) Channel width: PIANC Method

PIANC Method

One-lane channel: W = WBM + Wi + 2WB

in which: WBM = basic width

Wi = width additions

WB = bank clearance

Two-way channel: W = 2(WBM + Wi + WB) + WP

Wp = separation distance



Basic width WBM

Additional widths WiExample: cross current/wind

Bank clearance WB


b) Channel width: Port entrance

Transition to

reduced width

inside the port

2-3L


c) Channel depth

PIANC: d = 1.1 1.5 Ds

Planning stage: d = Ds T + smax + r + m

Design stage: probabilistic computer model


c) Channel depth

1.

2.

3.

4.


c) Channel depth: PIANC Method

Rule of thumb (PIANC)

- d = 1.1 Ds sheltered water

- d = 1.3 Ds Hs 1.0 m

- d = 1.5 Ds Hs > 1.0 m

For large ships: not realistic!


c) Channel depth

Example location specific application:

Gross Underkeel Clearance Westerschelde fixed at:

Sea Vlissingen: 15 %

Vlissingen- Rilland: 12.5 %

Scheldt River: 10 %

PLAATJE WESTERSCHELDE

15%12.5%

10%


c) Channel depth: Planning stage

Deterministic formula:

d = Ds T + smax + r + m

in which:

d = guaranteed depth

Ds= draught design ship

T = tidal restriction

s = sinkage (squat and trim); rule of thumb: s = 0.5

r = response to waves; rule of thumb: r = Hs / 2

m = safety margin / net underkeel clearance


c) Channel depth

m depends on seabed characteristics:

- Soft bottom m = 0.3 m

- Sandy bottom m = 0.5 m

- Rock bottom m = 1.0 m


c) Channel depth: Tidal window

Tidal restrictions:

d is always related to Chart Datum (CD)

CD is defined by Lowest Astronomical Tide (LAT)

or by LLWS

Without tidal window T = 0

Tidal window: a reduction of required depth related to CD


c) Channel depth

Example planning stage formula:

d = Ds T + smax + r + m

Ds = 18.0 m )

smax= 0.5 m ) Without tidal window

r = Hs/2 = 1.0 m ) d = 20 m

m = 0.5 m )

Rule of thumb: d = 1.5 x 18 = 27 m!


c) Channel depth: Tidal window


c) Channel depth: Ship factors

Squat: sinkage due to water flow around the ship

Many formulae

For straight sailing

in shallow water

Barrass formula

Trim: difference in draught fore and aft, due to loading condition: generally 0, due to fuel efficiency!



Responses to waves:

Vertical motions



Response depends on the wave length

(actually the wave period)

Lateral motion:Pitch

L=2Ls

Heave

L>Ls

Roll

Te=7-17 s



Apparent wave period Ta for a sailing ship:

L = cT = caTa = (c Vs)Ta

c = wave celerity (m/s)

Stern waves: - Vs Head waves: +Vs

Stern waves: Ta is longer!



Wave

spectrum ------

Ship motion

spectrum ____

RAO ..

T=17 secT=7 sec


d) Maneuvering space inside port: Turning circle

Rule of thumb: D = 2 Ls (normal tug assistance)

In case of high freeboard and wind/current: more

(or more/stronger tugs)

Limited space available: possibly less, but subject to

simulations


d) Maneuvering space inside port: Basins

Rules of thumb for quay length and basin width

Special considerations:

Long basins : required possibility to turn ships (wide basins

or turning circle at the end)

Exposed ports: wave resonance effects in the basins

Container terminals: uncertainty future ship dimensions

flexibility needed



Rule of thumb: 5B + 100 m, with B = beam design ship

Orientation: berthing line preferably // main wind direction



Example: Amazonehaven

Width 255 m, just suited for

Panamax ships (B=32.2 m: 261 m)

New generation container ships

much wider: B=46 m, so required

330 m


d) Maneuvering space inside port: Berths

Terminal with more berths: try to put them in line

(marginal quay):

more flexibility in allocation of ships and use of cranes

less waiting time for ships / better berth occupancy

less sensitive to changes in ship sizes

Lq = 1.1 x n x (Loa+ 15) + 15

with:

n number of berths

Loa length overall, average ship

Port of Bremerhaven


Preliminary design stage: Fast Time Simulation

Computer model of the sailing ship

Using all characteristics of the real ship

Simulating actual currents, wind and waves (various conditions)

With or without tug assistence

But: pre-defined track and auto-pilot: no human factor!


Example fast-time simulation: track plot


Example fast-time simulation: output along track


Detailed design stage: Real Time Simulation

Mock-up ship bridge (Full Bridge Simulator)

Computer generated outside view

Real helmsman (captain, pilot, etc.)

Tug assistance automatic or separate tug RTS

Human factor included

Relatively costly

Mainly used to confirm final layouts, to investigate emergency manoeuvres, to find the operational limits and to train pilots


Example Realtime simulations: Beira Mozambique


Full-mission bridhe


Example RTS: Beira Mozambique real situation

20141009 planning and d planning and design of port water areas

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