Dynamic Under Keel Clearance

DUKC®Underkeel Clearance Risk Mitigation

and

Channel OptimisationCaptain Jonathon PearceBusiness Development Manager

Houston2 December 2014

Who is OMC International?

• Inventor and sole supplier of DUKC®

• Dr Terry O’Brien involved in 2 PIANC committees

WG 54 (Chairman): Use of Hydro/Meteo Information to

Optimise Port Access

WG 49:Harbour Approach Channel Design Guidelines

• Technical advisors to UKHO TSMAD committees

Data Quality

Tides and Water Levels

• Industrial member of IALA, and VTS committees

Development of UKC Standards for VTS Systems

DUKC® Overview

• Installed at 24 Australian and overseas ports with Port of Montreal system commissioned March 2014

• Safety Record: 110,000+ bulk, container and tanker movements since 1993 without incident (about 1 movement per hour)

• All DUKC® systems covered by PI and PL insurance from TT Club since 2001

• DUKC® is supported 24/7 by an experienced team

PIANC WG49 Channel Depth factors

2.1

UKC Factors

SOMS UKC Concept Study

Wave Response/Setdown

Heel

Squat

Tidal Residual

Static Rule – TOP DOWN approach

Variable Nett UKC Clearance

VARIABLE RISK

Nett Clearance changes for every transit

Is it Safe, Marginal or Unsafe? Static Allowance

Fixed UKC Allowances

Wave Response/Setdown

Heel

Squat

Tidal Residual

NETT – BOTTOM UP approach

Required Water Depth

Fixed NETT Allowance: Minimum Predetermined Clearance

CONSTANT RISK Minimum NETT

Clearance maintained for every transit

Always Safe!

NETT UKC (using real time data)

is referred to as a DYNAMIC APPROACH

SOMS UKC Concept Study

Variable UKC Allowances

Overview: Dynamic UKC (DUKC®)

• Provides a consistent scientific approach to UKC management

• Utilises near real time and forecast environmental data (tides, waves, currents) and uses sophisticated ship modelling to calculate ship motions and UKC

• Rigorous application of PIANC guidelines and limits

• Effective mitigation of grounding hazards

• Implements a shared picture between ship and shore

• Extensive full-scale DGPS validation (>300 vessels)

Squat

• Affected by:– vessel speed through water (inc.

effect of currents)

– acceleration profile

– water depth

– undulations in the depth profile

– vessel block coefficient

– channel blockage factor

– bed roughness and material

– salinity

Squat

• Calculated Squat affected by Equation used

• Effectiveness in relation to the • Vessel,

• Speed profile,

• Surroundings, and

• Environment

Source: PIANC Report 121-2014, Fig D-13

Squat – Channel Blockage

Squat is Unique

Channel Blockage is

like a fingerprint –

\its different for

every port

Squat: Port and Vessel Specific

- Maximum Modelled Speed

- Measured Speed

- Measured Squat

- Maximum Modelled Squat

Inertial Heel

• Sustained inclination of a vessel about its longitudinal axis

• Two primary causes:– Drag due to wind – wind heel– Turning dynamics – inertial heel

and rudder effect

• Occurs when a vessel changes course

• Affected by:– Speed, Radius of Curvature of

Turn– Stability Characteristics (Gm

VCG), Beam

Wave Response

• Only some components of vessel motion lead to vertical hull motion:– Heave, Roll, Pitch

• However, all components (inc. surge, sway & yaw) are modelled to capture coupling effects

• Affected by:– Hull Geometry, Stability Characteristics,

– Vessel Speed (relative to waves)

– Wave Height & Period, Wave to Hull Angle of Incidence

– Wave-Current-Vessel Interaction

• Inherent difficulty and dangerous to generalise wave response of one vessel against another

Validation of Components

SOMS UKC Concept Study

- Maximum Modelled

Speed

- Measured Speed

- Measured Squat

- Maximum Modelled

Squat

No.2 No.1 No.3 No.5 No.7 No.9 Berth

0.0

0.5

1.0

1.5

2.0

2.5

3.0

0 5 10 15 20 25

Distance [km]

Wa

ve

Re

sp

on

se

[m

]

Maximum Wave Response Significant Wave Response Measured Wave Response

DUKC® - System Inputs/Outputs

Win/Win - Productivity & Safety

• OMC’s evidence from existing studies show:

• 95% existing static rule conservative

• Potential for draught increases and/or productivity gains through increased tidal windows

• 4% existing static rule marginal

• Potential for a touch bottom incident. High risk but actual risk never quantified

• 1% existing static rule unsafe

• Very high potential for a touch bottom incident

Under most conditions a static rule will be conservative

However, groundings can occur when a ship is sensitive to the prevailing conditions (this is actual data!)

Case Study - Failure of Static Rule

A static rule won’t tell you when this is the case!

Conservative (95%)

Marginal(4%)

Unsafe(1%)

Marsden Point NZ, Groundings: Eastern Honor & Capella Voyager 2003

Case Study - Port Taranaki

Blue Area

Static Tidal

Window

Orange Area

DUKC Tidal

Window

Static Rules not Sufficient in High Swell Conditions

Primary Outcomes

• Exploits inefficiencies of the Static Rule

– Maximises Safety and

– Maximises productivity and efficiency and

– Increased economic benefits

• Enhanced decision making with transit plan accuracy

• Detailed reports Improved Master/Pilot Information Exchange

• Enhanced vessel scheduling/reduced channel conflicts

• Enhanced contingency planning

• Removes commercial pressures

DUKC® Economic Benefits

“The DUKC program continues to be a major asset forBHP and the Port. As the port grows so does the value ofthe DUKC program, the value is in the order of 7% ofthroughput (circ. 15 million tonnes).The benefits are many:

1) Direct tonnage gain from the additional 50cm inavailable draft over a static system, which adds anextra 7,000 tonnes to a vessels loading

2) The increased sailing window available enables usto sail multiple vessels on a tide.

3) Increased safety because all calculations aremeasurable and are accurate.”

BHP (Port Hedland)

DUKC® System

DUKC® Series 5 Package

• Web based

– Improved access to, and distribution of, information

• Long range planning integrating met-ocean forecasting

• Real time monitoring (onshore & aboard)

– Contingency planning (late departure, vessel overloaded, changing conditions, vessel responsiveness)

– Emergency response (engine failure, rudder failure)

• Upstream integration

– Dynamic Port Capacity Model - analysing port capacity considering many variables dynamically

DUKC® Components

PLAN

Planning

Optimiser

SAIL

Passage Planning

Passage Monitoring

SHORE

Passage Monitoring

SHIP

DATA

Vessel

Met-Ocean

Reporting

ADMIN

System Notification

System Health

User Management

What is DUKC®? An example

Planning and Monitoring

Outputs and Reports

Dredging ConsiderationsUsing DUKC® Methodology

Existing Dredging Planning

• Based on static UKC rules

• “Rule-of-thumb” requirements can translate into millions of tonnes of material being dredged that isn’t required

• A more scientific approach can reduce dredging significantly whilst also improving port access

Current Depths

Proposed Depths

Proposed Depths

REQUIRED DREDGE VOLUME

Current Depths

Planning Dredging Using DUKC®

• DUKC® can help minimise the amount of dredging required

• Exact port accessibility can be determined

• Effects of siltation on operations can be explicitly calculated

• Dredging management plans can be devised to minimise maintenance dredging

DUKC Model Development

• Years of measured and predicted environmental data are collected – (waves, tides, currents, long waves,

wind, atmospheric pressure)

• Custom hydrodynamic models developed for the port

• Custom DUKC solution is developed using the port specific modelling

• Full scale vessel measurements can be used to validate the modelling

measured tide conditions

measured wave conditions

The Analysis Process

• A database of vessels is developed based on previous, and planned vessel visits to the port

• Port operations are simulated with thousands of DUKC calculations using real vessels and real measured climate conditions

• Each DUKC simulation provides an optimised bed depth for that vessel in those conditions

range of container ships

range of tankers / bulk carriers

Optimised bed depth based on DUKC simulation

Thousands of simulations provide thousands of optimised bed depths

Interpretation of Results

• From the thousands of DUKC simulations, OMC collates the optimised bed depth profiles

• Different design depths can be chosen based on operating condition requirements. For example:– Access for 14.5 metre draft tankers on 95% of high

waters,– Access for all inbound vessels on 90% of occasions

regardless of tide,– Minimum requirement of 4 hour operating windows

for container vessels in winter,– Etc.

Different requirements result in different optimised depths.

1. Access for 14.5 metre draft tankers on 95% of high waters.

2. Access for all inbound vessels on 90% of occasions regardless of

tide.

3. Minimum requirement of 4 hour operating windows for container

vessels in winter.

VOLUME OF DREDGING SAVED

Reporting of Results

• Dredge plan profiles

• Charts and maps displaying dredge areas

• Corresponding tables of chainages and depths

Profile Diagrams

Required Minimum Depths by % Access Arrangement for 14.00m T General Containers

Western Option

13

14

15

16

17

18

19

20000 20010 20020 20030 20040 20050 20060 20070 20080 20090 20100 20110 20120 20130 20140 20150

Location Id

Requir

ed D

epth

(m

)

90% 92.5% 95% 97.5% 99%

Very non-uniform optimal profile.Localised depth requirements change steeply due to inertial heel and change of wave incident angle as vessel negotiates turns.

Channel Design Options

Cost-benefit: Dredging for 13.50m T General Container Ships

500,000

550,000

600,000

650,000

700,000

750,000

800,000

850,000

900,000

94.5 95 95.5 96 96.5 97 97.5 98 98.5 99 99.5

Access Arrangement (%)

Vo

lum

e R

eq

uir

ed

(c

ub

ic m

)

Eastern Option Dredging Required (cubic m)

Western Option Dredging Required (cubic m)

Detailed Maps

Average Draft Increases

Channel Depth Option

Dredge Volume

[m3]

Average Draft [m]

Average Benefit to Draft [m]

Existing Depths 0 18.59 0

1 8,000 18.64 0.05

2 25,000 18.67 0.08

3 39,000 18.70 0.11

4 58,000 18.79 0.19

5 163,000 18.88 0.29

6 442,000 18.99 0.40

7 650,000 19.10 0.51

Channel Design/Dredge Optimisation

Minimisation of over-dredgingMaintenance dredging planning

Benefits

• Reduced dredging

– Save money

– Save time

– Minimise environmental impact

– Know exactly what you are getting for your dredging

• Previous studies have saved ports up to 50% on their dredging required

DUKC® for Channel Design

• Considerable benefit for ports operating with DUKC® to optimise their channel profile for best yield

• Derived access percentages reflect future operating outcomes

• Can be used to identify UKC “hot-spots” to prioritise maintenance dredging

Chart Overlays

Chart Overlay Generation

Due to dynamic components:• Overlays are

unique to a vessel• Multiple vessels =

multiple overlays

14.7m Vessel – 12k Area 1

14.7m Vessel – 14k Area 1

14.7m Vessel – 16k Area 1

No Overlay

Squat – Dead Slow Ahead

Squat – Slow Ahead

Squat – Half Ahead

Squat – Full Ahead

Squat – Full Sea Speed

Thank You

SOMS UKC Concept Study