Long_Tow_Testing_Summary.pdf

Demonstration Dispersal Barrier & Dispersal Barrier IIA Sparking Potential and Long Tow Testing to Determine Safety Considerations

Prepared By:

U.S. Army Corps of Engineers, Chicago District 111 North Canal Street, Chicago, Illinois 60606

U.S. Army Corps of Engineers, Engineer Research and Development Center Construction Engineering Research Laboratory

P.O. Box 9005, Champaign, Illinois 61826

12 May, 2008

5/12/2008

INTRODUCTION

The US Army Corps of Engineers has maintained a continuous barrier to aquatic nuisance species in the Chicago Sanitary and Ship Canal since the installation of the

Demonstration Electric Dispersal Barrier in 2002. Construction of a permanent barrier was initiated in 2004 and one of the two planned facilities (Barrier IIA) is nearly completed. Design revisions for the second of the two facilities (Barrier IIB) are currently underway with construction planned to begin in the summer of 2008.

Safety considerations regarding the effects of the electrical barriers on vessels in the waterway have been considered in previous reports. In January 2005 testing was conducted with various barge configurations to determine the potential for sparking between vessels due to the operation of the demonstration barrier. As a result of the report on this testing (Reference 1), a

Regulation Navigation Area was established, which requires the use of wire rope to connect barges and prohibits passing and mooring within the barrier area.

Further testing in the spring of 2006 established the electric field strength and sparking potential of Barrier IIA. During this testing, sparking was observed in the fleeting area of

Midwest Generation along the western bank just south of Barrier IIA (Reference 2). As a result of this testing, blasting mats (e.g., large steel meshes) were installed in the waterway in May

2006, and electrically connected to either ground or Barrier IIB electrodes, to provide a low resistance path for the stray electrical current to return to the barrier electrodes.

Subsequent testing in February 2007 was conducted to determine the effect of these mats and the optimal operational configuration for Barrier IIA. No sparking was observed during these tests (Reference 3) and it was determined the best operational configuration included a connection of the mats to the steel electrodes of Barrier IIB already installed in the waterway north of Barrier IIA (Figure 1). The report recommended testing the sparking potential for multiple barge configurations at the Midwestern Generation fleeting area and the effects on multiple barges due to the simultaneous operation of both the demonstration barrier and Barrier

IIA.

The US Army Engineer Research and Development Center, Construction Engineering

Research Laboratory (ERDC-CERL) conducted tests in April 2008, which included:

1) quantifying the voltage potential differences and current flow between barges and evaluating the potential of sparking between barges,

2) quantifying the voltage potential differences between barges in a long tow while passing over the demonstration barrier and Barrier IIA when both barriers are operational.

Technical Objective

The objective of these tests was to evaluate the possibility of sparking during barging operations due to the operation of Fish Barrier IIA both independently and together with the demonstration barrier. In the Fleeting Area Sparking Tests, a tow of two barges in length was bumped into a moored barge at the north end of the Midwest Generation fleeting area. The testing included positioning the moving tow in various locations between the canal walls and connecting the tow boat to the barge tow with wire rope and soft lines.

In the Long Tow Voltage Potential Tests, voltage potentials between barges were measured as a long tow (five barges in length) traversed both the demonstration barrier and Barrier IIA, with both barriers operational. Both tests took place while Barrier IIA operated in the previously defined “I Normal” configuration (Figure 1).

Figure 1. Barrier IIA was operated in “I Normal” mode during testing.

Experimental Approach

Fleeting Area Sparking Tests

Testing at the fleeting area was designed to determine the possibility of sparking between barges if a barge tow is long enough to span both the fleeting area and the Barrier IIA electrodes collides with moored barges in the fleeting area. A tow consisting of two barges was positioned over the electrode arrays of Barrier IIA and bumped into a barge moored in the north end of the fleeting area (Figures 2 and 3).

These tests:

(1) recorded the open circuit voltage potential (shown in Figure 3) between the two bumping barges before and during contact,

(2) recorded the electrical current flowing between two bumping barges before and during contact,

(3) observed whether sparking occurred while the moving barge made and broke contact with the fixed barge.

All of the barges utilized in these test were fully loaded and connected with wire rope. The tow boat was connected to adjacent barges using wire rope in all tests except test runs 6 & 7 where soft lines were used. The initial tests were conducted with Barrier IIA not in operation to establish background conditions. The position of the moving tow within the canal was varied to see if the location between the walls made a difference in the results. During each test run, the barges were bumped together a minimum of three times.

Figure 2. A tow over the Barrier IIA electrodes and bumping a moored barge in the fleeting area.

Tow

Fixed B arge Fixed B arge

M oving Barge

M oving Barge

Figure 3. Electrical measurements between a tow and a moored barge as they bump while the tow is also over the Barrier IIA electrodes.

Long Tow Voltage Potential Tests

These tests involved a tow of five fully-loaded barges that traversed both the demonstration barrier and Barrier IIA (Figures 4 and 5). This testing was designed to measure the voltage potential between elements within a long tow due to the operation of both barrier systems. This was accomplished by recording five channels of barge open circuit voltage potentials (Figure 5) as the long tow traversed the barrier region. The voltage potential between the components of the long tow (V1 through V5) was measured as shown in Figure 5. The towboat was the reference for each of the barge voltage measurements. The voltage difference between barges was computed by subtracting the barge potential measurements.

All of the barges utilized in these test were fully loaded and connected to each other and the tow boat with wire rope. Four test runs were conducted alternating between upstream and downstream travel. During each test run the entire tow traveled from south of the Romeoville

Road bridge to north of the pipeline arch or vise versa. After the first upstream test run a bow boat was added to the front barge of the tow. The total length of the tow with out the bow boat measured 1,083 feet. With the addition of the bow boat the entire tow measured 1,150 feet in length.

1 2 3 4 5

Figure 4. A long tow consisting of five barges traversing the Regulated Navigation Area.

Figure 5. Five open circuit voltage measurements (V1 through V5) were be simultaneously captured for each of the barges of the long tow.

RESULTS

Fleeting Area Sparking Tests

Table 1 summarizes the testing results for several different barge locations. Table 2 indicates the environmental conditions during the testing. Table 3 indicates the operational conditions during testing. Figures 6 through 36 show the location of the barges during each test run and individual bump, which correspond to the data in Table 1. Each individual test run was conducted to measure either the voltage potential or the electrical current flowing between the moving and stationary barges. The observation of sparking was also noted.

Sparking was not observed during any of the testing runs where wire rope was used to attach the loaded barges to the tow boat. Testing done with alternate barge locations likewise did not produce any sparking. Testing runs using soft lines to connect the tow boat to the adjacent barge did produce sparking (Runs 6 and 7). These results were likely because the tow was no longer a continuous electrical conductor; there was now an electrical break between the towboat and second barge, and this break was located between the two south electrode arrays. When the towboat and adjacent barge were electrically connected, together they spanned both of the south electrode arrays, providing a low resistance and direct path for the current to flow between the two arrays. When the towboat was isolated from the second barge, there was no longer this low resistance electrical path between the arrays, and the electrical current preferred to travel through the tow barges to the fleeting area, providing the extra current needed to initiate sparking.

The current levels during test runs 6 and 7, using the soft lines were the highest levels measured during these tests, though only slightly higher than levels measured during other test runs. Sparking observed during test runs 6 and 7 was not seen in every bump indicating that the measured currents were likely near the sparking threshold. The use of wire rope within the

Regulated Navigation Area will reduce the risk of sparking.

Long Tow Voltage Potential Tests

Figures 37, 38, 39, 40 and 41 present the voltage potential differences between each of the barges during the first of the four test runs. Test results for the other three runs are similar. The peak voltage potential ranges from 3.5 to 5 volts. This is in the same range as the results from the earlier testing conducted over Barrier I and prior to the installation of Barrier IIA (Reference

1) For a tow with two barges in series passing over the demonstration barrier, the maximum voltage potential differences were previously measured as approximately 0.3 volts. For a tow with two barges in parallel passing over the demonstration barrier, the maximum voltage potential differences were previously measured as approximately 2.5 volts. The maximum voltage potential difference between the towboat and barge is within the same order of magnitude as the maximum potential difference within a parallel tow passing over the demonstration barrier alone.

The voltage difference between barge 5 and the towboat is plotted in Figure 41. In this case the peak difference is approximately 9 volts. The peak voltage between towboat and barge is greater than between barges because this is a higher electrical resistance connection. The towboat has rubber bumpers that the barge is pulled up against, so the sole electrical connection is the wire ropes. In addition to the connection by wire ropes, barges have the barge-to-barge electrical connection between them.

The maximum voltage potential differences between barges in a long tow when Barrier

IIA and the demonstration barrier are both operating are only slightly higher than the maximum voltage potential differences between barges in a parallel tow when only the demonstration barrier is operating. Also the maximum voltage potential differences between barges in a long tow when Barrier IIA and the demonstration barrier are both operating are well below the maximum voltage potential differences measured for a tow configured with soft lines passing over the demonstration barrier alone (approximately 250 volts, Reference 1). Therefore, there is minimal additional risk of sparking within a tow configured with wire rope when Barrier IIA and the demonstration barrier are operating simultaneously.

Table 1: Fleeting Area Sparking Testing Results

Channel 1 (Voltage) Channel 2 (Current)

Condition

Peak Pulse Value (volts)

Peak Pulse Value right before contact

Peak Pulse Value (amps) Visual

Run 1; Figures 6, 7 & 8

Background / Ambient 3.12 3 Voltage Test

No Sparking

Run 2; Figures 9, 10 & 11

Background / Ambient Current Test 0.3

No Sparking

Run 3; Figures 12, 13 & 14

Barrier Energized / Boat in Center 16 11 to 13 Voltage Test

No Sparking

Run 4; Figures 15 & 16

Barrier Energized / Boat in Center Current Test 1.4

No Sparking

Run 5; Figures 17, 18 & 19

Barrier Energized / Boat on East

Wall 23 14 to 16 Voltage Test No

Sparking

Run 6; Figures 20, 21 & 22

Barrier Energized / Soft Line 21.5 14.5 to 18 Voltage Test

Sparking in 2 of 5 Bumps

Run 7; Figures 23, 24 & 25

Barrier Energized / Soft Line / Boat on West Wall Current Test 1.7

Sparking in 2 of 3 Bumps

Run 8; Figures 26 & 27

Barrier Energized / Boat on West

Wall Current Test 1.1 No

Sparking

Run 9

Barrier Energized / Boat on West

Wall bad data bad data No

Sparking Run 10; Figures

28, 29 & 30 Barrier Energized / Boat in Center 12.8 10 to 11 Voltage Test

No Sparking

Run 11; Figures 31, 32 & 33

Barrier Energized / Boat on West

Wall 12.4 8 to 9.5 Voltage Test No

Sparking

Run 12

Barrier Energized / Boat on West

Wall Current Test 0.98 No

Sparking Run 13; Figures

34, 35 & 36 Barrier Energized / Boat in Center Current Test 1.3

No Sparking

Table 2: Environmental Conditions during Field Testing

Date Time Air

Temperature

(°F)

Relative

Humidity

Precipitation

(in)

Water

Temperature

(°F)

Water

Conductivity

(μS/cm)

4/15/2008 08:30 62 34 0.00 6 1,234

4/15/2008 14:56 69.8 27 0.00 8 736

4/16/2008 10:40 68 34 0.00 8 1,292

Table 3: Barrier IIA Operations during Testing

Date / Time Operating Parameters Observations and Notes

4/15/2008 10:35 – 12:48

S1 & S2 (Pulser 3) 453 V, 1500A S3 & S4 (Pulser 1) 825 V, 2820 A

Fleeting Area Sparking Runs 3, 4, 5, 6 & 7

4/15/2008 15:36 – 16:00

S1 & S2 (Pulser 3) 440 V, 1464A S3 & S4 (Pulser 1) 834 V, 2744 A

Fleeting Area Sparking Runs 8, 9, 10, 11, 12 & 13

4/15/2008 10:35 – 12:35

S1 & S2 (Pulser 3) 425 V, 1050A S3 & S4 (Pulser 1) 828 V, 2676 A

Long Tow Voltage Potential Runs 1, 2, 3, 4 & 5

Time (seconds)

D if fe re n c e V o lt a g e v o lt s

Barge 1 potential minus Barge 2 potential

0 150 300 450 600 750 900 1,050 1,200 -4.5

-3

-1.5

1.5

4.5

Figure 37: Voltage Potential Differences between Barge 1 and Barge 2

D if fe re n c e V o lt a g e v o lt s

Barge 2 potential minus Barge 3 potential

0 150 300 450 600 750 900 1,050 1,200 -4.5

-3

-1.5

1.5

Figure 38: Voltage Potential Differences between Barge 2 and Barge 3

D if fe re n c e V o lt a g e v o lt s

Barge 3 potential minus Barge 4 potential

0 150 300 450 600 750 900 1,050 1,200 -3

-1.5

1.5

Figure 39: Voltage Potential Differences between Barge 3 and Barge 4

D if fe re n c e V o lt a g e v o lt s

Barge 4 potential minus Barge 5 potential

0 150 300 450 600 750 900 1,050 1,200 -6

-4

-2

Figure 10: Voltage Potential Differences between Barge 4 and Barge 5

P o te n ti a l

(v o lt s

Potential of Barge 5 Relative to Towboat

0 150 300 450 600 750 900 1,050 1,200 -9

-6

-3

Figure 41: Voltage Potential Differences between Barge 5 and Tow Boat

REFERENCES

1. Engineering Analysis of the Chicago Sanitary and Ship Canal Electric Fish Barrier: Electrical

Effects on Barges and Tow Vessels, ERDC/CERL, May 2005

2. Dispersal Barrier IIA Electric Field Strength and Sparking Potential Testing, USACE-

Chicago and ERDC/CERL, October 2006

3. Dispersal Barrier IIA Sparking Potential and Electric Field Strength Testing to Determine the

Optimal Operational Configuration, USACE-Chicago and ERDC/CERL, June 2007

ACKNOWLEDGEMENTS

The U.S. Army Corps of Engineers thanks ARTCO for providing barges and towboat operations during the fleeting area sparking tests, Midwest Generation for providing use of their fleeting area during the fleeting area sparking tests, Hanson for providing barges and towboat operations during the long tow voltage potential tests and Illinois Marine Towing for providing bow boat services during the long tow voltage potential tests.