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Resilience of Coal Transport on the Three Rivers Waterway System. Ryan S. Engel, LCDR, USCG TJ Clement, MAJ, USA Naval Postgraduate School OA4202 – Network Flows and Graphs Course Project November 2011. Background - Pittsburgh. PITTSBURGH 2 nd Largest Inland Port in the U.S.
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Resilience of Coal Transport on the Three Rivers Waterway System Ryan S. Engel, LCDR, USCG TJ Clement, MAJ, USA Naval Postgraduate School OA4202 – Network Flows and Graphs Course Project November 2011
Background - Pittsburgh • PITTSBURGH • 2nd Largest Inland Port in the U.S. • 20th Largest Port in the U.S. • Produces 25% of U.S.’s steel • $9 Billion of goods annually • 200 River Terminals
Commodities through Pittsburgh • 13.6 Million TONS of Coal Annually • 50% of the U.S. electricity comes from Coal • Steel Production Requires Coal Coke • Power Plants use Coal Lignite
Multi-Modal Coal Transport Transport Mode:National Cost:** Barge $.005 / ton-mile Rail $.05 / ton-mile Truck $.10 / ton-mile ** To be visited later
Cargo Capacity Comparison Source: Port of Pittsburgh website
Study Area Demand Supply Emsworth Lock & Dam Allegheny River Lock & Dam 2 Ohio River Pittsburgh Monongahela River Braddock Lock & Dam Supply
Supplies and Demands Terminals:Tons of Coal / weekSupply/Demand Gulf Materials (Mon) 14.0K Demand Neville Island (Ohio) 10.7K Demand Rivers: Allegheny: In: 30.0K Demand Out: 0.62K Supply Net 29.4K Demand Monongahela In: 101.5K Demand Out: 137.4K Supply Net: 36.90K Supply Ohio: In: 112.9K Demand Out: 123.6K Supply Net: 10.7 Supply * Assumption: 1 Commodity
Study Area Emsworth Lock & Dam AlleghenyRiver Lock & Dam 2 Ohio River Pittsburgh MonongahelaRiver Braddock Lock & Dam Supply = Demand = Lock and Damn =
Normal Operation • Coal primarily moves by barge (least expensive) • Movement is constrained by capacities • River segments • Locks and dams • Terminal crane and lift operations • System flow is driven by supply and demand • Objective of System: • Minimize overall transit cost • Meet demand for coal
What Can Go Wrong • Blockage on river segment • Loss of function at Lock or dam • Contingencies • Move Coal by rail • Subject to • Offloading capacities at terminals • Increased distances and costs • Objective: To minimize overall cost
How to Model • Min cost flow problem: Use a mixed integer linear program • Quantify Costs: ** • Barge = distance x 1 • Rail = distance x 2.5 • Truck = infeasible • Quantify Capacities ** • Terminal offload = 1 million tons a year • Railroad offload = 4.25 million tons / year • Waterway = f(distance, bridge delay, shipment size) • Objective: To minimize overall cost given attacks on system ** To be revisited
Network Model OHIO 20.8 (35, 81.7) (35, 81.7) ALLE -10.7 (1, 4536) (1, 4536) ELM1 (5,81.7) LD21 ELA1 (5,81.7) (0, 1134) AZCN (0, 336) (0, 336) ELM2 LD22 ELA2 NISI (1, 4536) (1, 4536) ALLT 10.5 OHT GTS1 (0, 19.2) (7, 4536) (6.2, 4536) (47.8, 81.7) (47.8, 81.7) MRIE PTPT (46.3, 81.7) JS (12.1, 4536) 14.4 TURR MONT GTC River Route Railroad Route River Node Land Node (1, 4536) BCBT BLM2 (0, 1134) (0, 19.2) BLA2 BLM1 (0, 336) (5,81.7) (46.3, 81.7) BLA1 (1, 4536) -35 MON
Normal Operations OHIO ALLE ELM1 LD21 ELA1 AZCN ELM2 LD22 ELA2 NISI Cost 452 ALLT OHT GTS1 MRIE PTPT JS TURR MONT GTC River Route RR Route River Node Land Node BCBT BLM2 BLA2 BLM1 BLA1 MON
#1 Worst 1-Arc Attack OHIO ALLE ELM1 LD21 ELA1 AZCN ELM2 LD22 ELA2 NISI Cost 1026 ALLT OHT GTS1 MRIE PTPT JS TURR MONT GTC River Route RR Route River Node Land Node Arc Attack BCBT BLM2 BLA2 BLM1 BLA1 MON
#2 Worst 1-Arc Attack OHIO ALLE ELM1 LD21 ELA1 AZCN ELM2 LD22 ELA2 NISI Cost 1022 ALLT OHT GTS1 MRIE PTPT JS MONT GTC River Route RR Route River Node Land Node Arc Attack BCBT BLM2 BLA2 BLM1 BLA1 MON
Comparing 1-Arc Attacks 1026 1022 483 483 483 456 452 452 452 452
#1 Worst 2-Arc Attack OHIO ALLE ELM1 LD21 ELA1 AZCN ELM2 LD22 ELA2 NISI Cost 1026 ALLT OHT GTS1 MRIE PTPT JS MONT GTC River Route RR Route River Node Land Node Arc Attack BCBT BLM2 BLA2 BLM1 BLA1 MON
#2 Worst 2-Arc Attack OHIO ALLE ELM1 LD21 ELA1 AZCN ELM2 LD22 ELA2 NISI Cost 1026 ALLT OHT GTS1 MRIE PTPT JS MONT GTC River Route RR Route River Node Land Node Arc Attack Arc Defense BCBT BLM2 BLA2 BLM1 BLA1 MON
#1 Worst 3-Arc Attack OHIO ALLE ELM1 LD21 ELA1 AZCN ELM2 LD22 ELA2 NISI Cost 1934 ALLT OHT GTS1 MRIE PTPT JS MONT GTC River Route RR Route River Node Land Node Arc Attack Arc Defense BCBT BLM2 BLA2 BLM1 BLA1 MON
#2 Worst 3-Arc Attack OHIO ALLE ELM1 LD21 ELA1 AZCN ELM2 LD22 ELA2 NISI Cost 1263 ALLT OHT GTS1 MRIE PTPT JS MONT GTC River Route RR Route River Node Land Node Arc Attack Arc Defense BCBT BLM2 BLA2 BLM1 BLA1 MON
#1 Worst 4-Arc Attack OHIO ALLE ELM1 LD21 ELA1 AZCN ELM2 LD22 ELA2 NISI Cost 25,838 ALLT OHT GTS1 MRIE PTPT JS TURR MONT GTC River Route RR Route River Node Land Node Arc Attack Arc Defense BCBT BLM2 BLA2 BLM1 BLA1 MON
#2 Worst 4-Arc Attack OHIO ALLE ELM1 LD21 ELA1 AZCN ELM2 LD22 ELA2 NISI Cost 2337 ALLT OHT GTS1 MRIE PTPT JS TURR MONT GTC River Route RR Route River Node Land Node Arc Attack Arc Defense BCBT BLM2 BLA2 BLM1 BLA1 MON
Cost vs. Number Attacks 25,837 1934 1026 1026 452
Things to be Revisited • Assumptions: • Use of net flow for the locks and dams • - Coal in and out is not distinguishable • Option: Use a multi-commodity for each river • Timeline = 1 Week • Other timelines may have varying delays in the arc. Attacks would need to be recalculated • Costs: Railway 2.5 times more expensive in our model.
Summary • Notable Results: • 1 Attack on the waterway doubles the cost • 4 Attacks on system has enormous economic impact • Coast Guard defends most critical 4 arcs: The system is resilient • Future Study: • Validate assumptions • Implement multi-commodity flow • Broaden study area