Modeling Shallow Draft and Deep Draft Traffic in Deep Draft Harbors September 15, 2011 Joe Berlin Anne Watkins
National Economic Development Benefits of Channel Widening Widening projects decrease congestion within a waterway or harbor Allow more vessels to pass each other, reduce oneway restrictions Decrease in vessel wait time decreases vessel operating costs Decrease in vessel operating costs are considered NED benefits
National Economic Development Benefits Contributions to national economic development (NED) are increases in the net value of the national output of goods and services, expressed in monetary units. Contributions to NED are the direct net benefits that accrue in the planning area and the rest of the Nation. Contributions to NED include increases in the net value of those goods and services that are marketed, and also of those that may not be marketed.
HarborSym - Overview Data-driven model of vessel traffic Simulates vessel traffic moving in and out of a harbor using navigation rules Calculates vessel wait times and operating costs By comparing the operating costs of different scenarios, USACE planners can determine the NED Benefits of improvement alternatives Designed to model deep draft traffic, but can be adapted to model shallow draft traffic
HarborSym - History Development by USACE Institute for Water Resources (IWR) starting in 2002 HarborSym Widening certified in 2011 HarborSym Deepening certification in 2012 Once a model is certified, USACE planners are required to use it
Port of Corpus Christi (2007-2008) Ranked 5 th in U.S. by tonnage Handled over 76 million tons in 2008 55 million tons foreign 21 million tons domestic Mostly crude oil and petrochemical products Almost 1,500 deep-draft vessel calls in 2007 Approximately 3,350 barge tows
Corpus Christi Ship Channel Currently at 45 deep, proposed depth 52 Width within Corpus Christi Bay is 500 in Cut A and 400 in Cut B Studying widening Cuts A & B to 530 Studying adding two 200 wide by 12 deep barge shelves in Cut B
Corpus Christi Ship Channel
Corpus Christi Ship Channel
HarborSym Node Network
Barge Traffic in the U.S. Generally bulk commodities Grain Petrochemicals GIWW is 12 deep x 125 wide Tank barges are 54 wide x 300 long Dry bulk barges are 35 wide x 195 long
Barge Traffic in CCSC Barges share the ship channel with deep draft vessels Vast majority tank barges (petrochemicals) Up to 6-barge tows Most tows consist of 2 barges A tow consisting of 2 tank barges would be 300 long x 108 wide
Selected Hourly Operating Costs Vessel Class Tank Barge 2-barge tow Crude Oil Tanker 100 130 K DWT Bulk Carrier 50 65 K DWT Petrochemical Tanker 45 70 K DWT At-sea Costs In-port Costs $ 393 $ 279 $ 1,387 $ 837 $ 959 $ 528 $ 1,107 $ 675
Using HarborSym to Determine Barge Shelf Benefits Deep-draft vessels designated Priority vessels Barges should not cause deep-draft vessels to wait Reaches cannot be two different depths Used combined beam width and combined draft rules Sets the maximum beam/draft of passing vessels, but not the maximum number of vessels
Combined Beam Rule Combined Beam = 0.7 of channel width 530 channel + two 200 barge shelves = 930 Maximum combined beam = 651 Combined beam without barge shelves = 0.62 (329 ) Would allow two crude oil tankers to pass in channel and two 6-barge tows to pass in barge shelves
Combined Draft Rule Combined Draft = 104 Channel depth = 45 Combined draft maximum without barges = 80 (from pilots) Would allow two 40 vessels to pass in channel, and two 12 barges to pass in barge shelves
HarborSym Modeling Constraints Cannot have two depths for the same reach HarborSym rules designed for deep draft traffic With some limited exceptions, cannot make rules apply only to certain types of traffic Hard to ensure 3 deep draft vessels don t pass using the barge shelves Must check output files closely
Barge Shelf NED Benefits Three Scenarios: Without Project Widening (with 45 depth) Widening Plus Barge Shelves (with 45 depth) Barge Shelf NED Benefits = Widening Plus Barge Shelves Widening
HarborSym Output - 2007 Average Vessel Time in System (Hours) Tank Barge 2-barge tow Crude Oil Tanker 100 130 K DWT Bulk Carrier 50 65 K DWT Petrochemical Tanker 45 70 K DWT Without Project Widening Widening + Barge Shelves 8.645 8.475 8.475 18.924 18.906 18.696 49.863 49.863 49.765 16.466 16.455 16.381
Benefits of Barge Shelves Total Costs ($) Without Project Widening Widening + Barge Shelves 2007 39,946,140 39,250,090 39,063,960 2060 72,073,850 70,364,870 70,146,380 Benefits ($) Widening Barge Shelves 2007 696,050 186,130 2060 1,708,980 218,490