A Data-Driven Monte Carlo A Data-Driven Monte Carlo Simulation Model of Vessel Simulation Model of Vessel

Movement in HarborsMovement in Harbors

David Moser, Keith Hofseth, David Moser, Keith Hofseth, Shana Heisey, Richard MalesShana Heisey, Richard Males, ,

Cory RogersCory Rogers

HarborSymHarborSymHarborSym

Flood Damage ReductionFlood Damage Reduction

NavigationNavigation Ecosystem RestorationEcosystem Restoration

Hurricane ProtectionHurricane Protection

CORPS OF ENGINEERSCORPS OF ENGINEERS

Coastal NavigationCoastal Navigation

• Benefit-cost analysisBenefit-cost analysis requiredrequired

• Navigation project Navigation project benefits:benefits:– Reduction in congestion Reduction in congestion

(transportation cost)(transportation cost)– Compare future conditionsCompare future conditions– 50 year analysis50 year analysis

• Standardized, transparent Standardized, transparent toolstools

Photo credit: Containerisation International/Lloyds List/Informa UK Ltd

Need for Navigation Need for Navigation ModelingModeling

Complex ProblemComplex Problem• Channel width & depth Channel width & depth

constraintsconstraints

• Multi-port issues Multi-port issues

• Conflicts from random Conflicts from random interactionsinteractions

Navigation ModelingNavigation Modeling

– Single portSingle port– Focus on channel Focus on channel

improvementsimprovements

Port

Port

Bar

Port ofInterest

HarborSym

HarborSym ModelHarborSym Model

• Planning-Level ModelPlanning-Level Model

• Data InputData Input– Port layoutPort layout– Vessel CallsVessel Calls– RulesRules

• Model CalculationModel Calculation– Vessel interactions Vessel interactions

within harborwithin harbor

• OutputOutput– Time in systemTime in system– Delay timesDelay times

HarborSym Modeling HarborSym Modeling ObjectivesObjectives

PORTABILITYPORTABILITY– Port specific information provided in dataPort specific information provided in data

EASE OF USEEASE OF USE– Discrete Event Monte Carlo Simulation Discrete Event Monte Carlo Simulation

ModelModel– C++ / Microsoft Access / Visual BasicC++ / Microsoft Access / Visual Basic

TRANSPARENCYTRANSPARENCY– Windows into delay calculationsWindows into delay calculations

HarborSym ArchitectureHarborSym Architecture

User Interface

ComputationalEngine

(SimulationKernel)

Database OutputData Files

Run

ReportsGraphics

Computational Engine

(Simulation Kernel)

Database

User Interface

RUN

Report

Graphics

Output Data Files

HarborSym

Application

Sabine-Neches

Waterway

Study Area

TEXAS

MEXICO

NODESNODES• DocksDocks

– 133 actual docks133 actual docks– 11 “virtual” docks11 “virtual” docks

• 10 Turning Basins10 Turning Basins

• Channel DimensionsChannel Dimensions

• Proposed Proposed ImprovementsImprovements

REACHESREACHES• Single route Single route

connecting nodesconnecting nodes• Uniform dimensionsUniform dimensions• TOTAL: 47TOTAL: 47

LEGLEG• Contiguous reachesContiguous reaches

Sabine NetworkSabine Network

Network builderNetwork builder

Data entry tablesData entry tables

Data explorerData explorerNetworkNetwork

Graphical User InterfaceGraphical User Interface

Sabine Transit RulesSabine Transit Rules

No sailing (single vessel)No sailing (single vessel)– by DWT, length, beamby DWT, length, beam

No meeting (multi-vessel)No meeting (multi-vessel)– by DWT, length, breadth, draft, combinationby DWT, length, breadth, draft, combination

No overtaking (multi-vessel)No overtaking (multi-vessel)– by vessel typeby vessel type

Transit Rule Type ID Transit Rule Type Transit Rule Type Description1 No Rule No Transit Rule

2No Meeting Combined Beam Width

No Meeting - Max Combined Beam Width > 1/2 channel width

3No Meeting Combined Draft

No Meeting - Combined Draft

4 No Meeting DWT Draft No meeting – dwt/draft: Max DWT OR Max draft

5No Meeting DWT Draft Either

no meeting - either vessel with dwt and draft greater than values

Generic Transit RulesGeneric Transit Rules

1.1. Vessel Arrival (departure) Event Vessel Arrival (departure) Event – Must pass all transit rules in leg to proceedMust pass all transit rules in leg to proceed

2.2. Conflict CheckingConflict Checking– Store projected arrival/departure time of Store projected arrival/departure time of

vessels in system (by reach)vessels in system (by reach)– Test rules in all leg reachesTest rules in all leg reaches– Vessels already moving have priorityVessels already moving have priority

3.3. If conflict occurs:If conflict occurs:– Wait, try againWait, try again– Proceed to anchorageProceed to anchorage

Model Processing LogicModel Processing Logic

Testing Conflicts in ReachTesting Conflicts in Reach

Additional HarborSym Features Additional HarborSym Features

Tidal InfluenceTidal Influence– Height of waterHeight of water

– Strength of Strength of currentcurrent

Priority VesselsPriority Vessels–Move unrestricted through harborMove unrestricted through harbor

•Cruise Ships, Gaseous TankersCruise Ships, Gaseous Tankers–Others anticipate arrival & face delaysOthers anticipate arrival & face delays

tide/currenttide/current

Vessel statusVessel status

Time of dayTime of day

Commodity Commodity movementsmovements

Additional HarborSym Additional HarborSym FeaturesFeatures

Within Simulation AnimationWithin Simulation Animation

HarborSym OutputHarborSym OutputCapturing Widening BenefitsCapturing Widening Benefits

Existing Condition

Intermediate Improvement

All Improvements

Avg Ves Time in System 71.202 70.2 68.8Avg Ves Time Waiting 10.2 9.2 7.9Avg Ves Time Wait Entry 3.9 2.8 2.5Avg Ves Time Wait Dock 4.9 5 2.7

Average Vessel Times Under Proposed Channel Improvements

Time in hours, results from 100 iteration simulation.

Total Annual Transport Cost

(US$1000)

Total Annual Benefit

(US$1000)Existing Condition $110,635.90Intermediate Improvement $109,199.60 $1,436.30All Improvements $107,442.10 $3,193.80

Transportation Cost and Incremental Benefits

Figures shown in 2002 dollars, based on 100 iteration simulations

HarborSym OutputHarborSym OutputCapturing Widening BenefitsCapturing Widening Benefits

HarborSym OutputHarborSym OutputPost Process AnimationPost Process Animation

DiscussionDiscussionDiscussion