Reference_-_Wave_Gene_Beaches_2022_2f_3.pdf

Operation and Maintenance of Ohmsett Contract E17PC00014

Operating Procedures for the Wave Generator and Beach Systems

Prepared for:

Bureau of Safety and Environmental Enforcement (BSEE) Contracting Officer’s Representative (COR)

Frank Jurado BSEE Oil Spill Preparedness Division

45600 Woodland Road Sterling, VA 20166

Email: Frank.Jurado@bsee.gov Ph. 571-279-7896

Prepared by:

Applied Research Associates, Inc.

Operating Contractor

Ohmsett Facility Naval Weapons Station Earle (NWSE)

Waterfront Route 36 P.O. Box 150, Leonardo, NJ 07737

Date: September 30, 2022

Operation and Maintenance of Ohmsett Contract E17PC00014 Operating Procedures for the Wave Generator and Beach Systems i

TABLE OF CONTENTS

1. REQUIREMENT

2. APPROACH

3. OHMSETT CONTROL CONSOLE FOR WAVE GENERATOR AF-11065

4. WAVEMAKER CONSUMABLES

5. CYLINDER MODE

5.1. MAIN MENU

5.2. SERVICE MODE MENU

5.3. HYDRAULIC PUMPS

5.4. INSTRUMENT PANEL

5.5. SINEWAVE MODE MENU

5.5.1. Sinewave Mode Operating Limits for Wavemaker

5.5.2. Sinewave Mode Recipe Menu

5.6. PIERSON MOSKOWITZ SPECTRUM MODE MENU

5.6.1. Pierson Moskowitz Spectrum Mode Operating Limits for Wavemaker

5.7. JONSWAP MODE MENU

5.7.1. JONSWAP Spectrum Mode Operating Limits for Wavemaker

5.8. FM SLIDE MODE MENU

5.8.1. FM Slide Mode Operating Limits for Wavemaker

5.9. ADVANCED SETTINGS

5.10. INPUTS/OUTPUTS

5.11. ALARM

5.12. ALARM HISTORY

5.13. TROUBLESHOOTING, WARNING BANNERS, AND RECOVERY

5.14. EMERGENCY STOP (E-STOP)

6. BEACH SECTION

6.1. BEACH SETTINGS

TABLE OF FIGURES

Figure 1. Side View of Ohmsett Beaches

Operating Procedures for the Wave Generator and Beach Systems

1. REQUIREMENT

Operating procedures manuals detail required routine activities and are to be used as references by the Contractor in operating the systems described. These manuals also guide the routine operations and maintenance of the facility. The Contractor shall update the following manuals as needed when major changes occur.

2. APPROACH

The Ohmsett wave generation and beach system operations manual was submitted by Atlantic Industrial Technologies (AIT) upon completion of the wave generator upgrade in 2009–2010. No significant modifications have been made to the hydraulic drive systems, and the control system was upgraded to new generation of Programable Logic Controller (PLC) and hardware. The obsolete fly-wheel and redundant controls have been removed to streamline the software. A new Human-Machine Interface (HMI) will be installed and tested following the refurbishment.

3. OHMSETT CONTROL CONSOLE FOR WAVE GENERATOR AF-11065

4. WAVEMAKER CONSUMABLES

Hydraulic Oil: Black Bear, 2R10/ISO 46

Bearing Oil: 90 weight gear oil

High Pressure Filter Element: Parker 932678Q, Qty 3

Return Line Filter Element: Parker C933802Q, Qty 2

Pilot Filter Element: 935191

Breather: Parker 934330

Main Motor Fuses: Gould AJT-125 (Class J Time delay, 125 amps)

Pilot Motor Fuses: UL Class CC Time Delay, 25 Amps

Heater Fuses: UL Class CC Time Delay, 10 Amps

Heat Exchanger Motor Fuses: UL Class CC Time Delay, 15 Amps

24 VDC Power Supply Fuses: UL Class CC Time Delay, 15 Amps

5. CYLINDER MODE

5.1. MAIN MENU

Service Display: This display allows operators to move the paddles manually and independently of each other for service and maintenance.

Hydraulic Pumps: Waves cannot be generated without the hydraulic power unit running. This push button brings the operator the Hydraulic Pump Menu.

Instrument Panel: In order to read the many systems parameters that are present in this system, the operator presses this push button for this menu.

Advanced Setting: This menu provides access to settings, I/O status, and other system maintenance functions. The operator presses this push button for this menu.

Alarm History: Alarms occasionally occur in a system of this complexity. This menu keeps a chronological tally of all alarms that occur. The operator presses this push button for this menu.

Sinewave Mode: This push button takes you to Sinewave Mode Display.

Pierson Moskowitz Spectrum Mode: This push button takes you to Pierson Moskowitz Spectrum Mode Display.

JONSWAP Spectrum Mode: This push button takes you to JONSWAP Spectrum Mode Display.

FM Slide Mode: This push button takes you to FM Slide Mode Display.

5.2. SERVICE MODE MENU

East Paddle Forward Jog: Pressing “Start” moves paddle forward (North).

East Paddle Backward Jog: Pressing “Start” moves paddle back (South).

West Paddle Forward Jog: Pressing “Start” moves paddle forward (North).

West Paddle Backward Jog: Pressing “Start” moves paddle back (South).

Pumps Status: Displays current hydraulic pumps status.

Hydraulic Pumps Screen: Opens screen to display hydraulic pumps status.

Main Menu: Returns to main menu.

5.3. HYDRAULIC PUMPS

This menu provides control (start and stop) functions for all five hydraulic pumps.

Status: The Status Bar has six different states.

• Ready – The motor is ready to be turned on.

• Inlet Ball Valve – This means that the pump’s Inlet (suction) ball valve is not fully open, and the pump is not permitted to be turned on.

• Running – The motor (and corresponding pump) is currently running.

• Local Control – The H.O.A. (Hand-Off-Auto) switch (which is in the generator room) is not in the

‘Auto’ position. The pump is not under the control of the touch screen operator.

• E-Stop – There is an emergency-stop condition and pumps are not capable of being turned on, either by the operator or locally in the generator room.

• Drive Fault o For Motors 1, 2 and 3 only; there is a condition on the Siemens Reduced Voltage Starter that is causing it to send out a ‘fault’ condition. The unit should be inspected. This may happen after a power outage. To correct this, press the BLUE RESET button in the Motor Control Center (MCC) in the generator room.

• Overload o For Pump Motors 4, 5, and the heat exchanger motor only; this banner indicates an overload condition (i.e., the overload has tripped). The cause for this overload should be investigated further.

Warning Banner: See Section 5.13 Troubleshooting, Warning Banners and Recovery for this information.

Pump Start/Stop: The wave maker needs the minimum of one Main Pump (Pump 1, 2 or 3) and the minimum of one Pilot Pump (Pump 4 or 5) to generate waves.

Pump 1 above is shown Running, note that the START button is grayed out.

Pump 2 above is shown in Drive Fault condition; note that the START and STOP buttons are grayed out and unavailable.

Pump 3 above is shown as Ready; note that the STOP button is grayed out.

Pump 4 above is shown as Ready; note that the STOP button is grayed out.

Pump 5 above is shown Running; note that the START button is grayed out.

Accumulated Hours: The accumulated hours for each of the pumps are displayed here. These readouts can be ‘zeroed’ from the Advanced Setting menu. The operator may choose to zero these settings after servicing the filters or after routine maintenance.

The accumulation will issue a ‘pump maintenance warning’ (and stop accumulating hours) at 500 hours.

At this point the operator should ‘zero’ the ‘maxed out’ timer, so it can resume accumulating hours.

Pressure – Main Pumps: The pressure for each pump (1, 2, and 3) is shown as a number (in PSI). This can be useful in comparing one pump to another. There is no typical reading on these values. The pressure fluctuates with wave maker load.

Pressure – Pilot Pumps: There are two pilot pressure pumps and only one pressure readout. This is because the two pilot pumps are plumbed together creating only one readable pressure. The typical pressure varies from approximately 2 to 150 psi.

Amp Draw: The Amp Draw is an individual readout of amp draw for each motor.

5.4. INSTRUMENT PANEL

Many systems parameters that are present in this system can be read from this menu screen.

Status: The Status Bar (located directly under Pump-Motor 1, 2, 3) has six different states.

• Ready – The motor is ready to be turned on

• Inlet Ball Valve – This means that the pump’s Inlet (suction) Ball Valve is not fully open, and the pump is not allowed to be turned on.

• Running” – The motor (and corresponding pump) is currently running.

• Local Control – The H.O.A. (hand-off-auto) switch (which is in the generator room) is not in the

‘Auto’ position. The pump is not under the control of the operator.

• E-Stop – There is an E-stop condition and pumps are not capable of being turned on, either by the operator, or locally in the generator room.

• Drive Fault o For Motors 1, 2 and 3 only; there is a condition on the Siemens Reduced Voltage Starter that is causing it to send out a ‘fault’ condition. The unit should be inspected. This may happen after a power outage. To correct this, press the RESET button in the Motor Control Center (MCC) in the generator room.

• Overload o For Pump Motors 4, 5, and the heat exchanger motor only; there is an overload condition. The overload has tripped. This should be investigated further.

Pressure – Main Pumps: The pressure for each pump (1, 2, and 3) is shown as a number (in PSI) and a bar graph. This can be useful in comparing one pump to another. There is no typical reading on these values.

The pressure fluctuates with Wavemaker load.

Pressure – Pilot Pumps: There are two pilot pressure pumps but only one pressure readout (in PSI). This is because the two pilot pumps are plumbed together creating only on readable pressure. This pressure is also shown as a bar graph. The typical pressure varies from approximately 2 to 150 psi.

Amp Draw: The Amp Draw is an individual readout and bar graph of amp draw for each motor. This can be useful in comparing one motor to another.

Filter Condition Banners: This Banner either reads Filter Clean or Filter Hi DP. The Warning will only flash after the filter condition reads Filter Hi DP AND the temperature of the oil is above 90°F.

Oil Conditions

• Temp F: This is a bar graph and numerical reading of temperature of the hydraulic oil in

Degrees Fahrenheit (°F).

• Hum %: This is a bar graph and numerical reading of the Relative Humidity percentage of the oil.

When it reaches 100%, free water is present in the oil, which is cause for concern.

• Level %: This is a bar graph and numerical reading of the oil level (in the hydraulic reservoir) read in percent. Over 95% full represents overfull, under 73% gives a warning, and under 65% shuts the system down.

• Heaters On/Cooling: This banner only shows Heaters On when the heaters are on (a typical machine idle in the winter condition). The heaters turn ON at 60°F and turn back OFF at 75°F.

This will typically occur when the HPU is not running, and it is wintertime. It shows Cooling when the heat exchanger is running. The Heat Exchanger turns ON at 130°F and turns off at 120°F. When the Heat Exchanger H.O.A switch is in OFF, the banner will read Cooler Off. When the Heat Exchanger H.O.A. switch is forced ON, the banner will read Cooler Forced. When the Temperature is in a safe range, and the unit is running, the banner will read Standby.

• Oil Cold/Oil Temp OK/Oil Hot: This banner shows Oil Cold when the oil is below 51°F. This indicates a problem with the heaters since they should turn ON at 60°F and turn back OFF at 75°F. It shows Oil Temp OK when the temperature is between 51°F and 142°F. When the oil is above 142°F, the Oil Hot banner is present. This indicates a problem with the cooling system and should be investigated.

• Oil Level Hi/Oil Level Ok/Oil Level Low: The Oil Level Hi banner is present when the oil level is over 95%. The Oil Level OK banner is present when the oil level is between 73% and 95%.

• The Oil Level Low banner is present when the oil level is below 73%.

• Oil H2O % Hi/Oil H2O % OK: This banner warns of a “water in oil” condition. The Oil H2O % Hi banner indicated that the Relative humidity of the oil is over 95% (water may present in oil). The Oil H2O % OK banner indicated that the Relative humidity of the oil is below 95% (water is not present in oil).

Motor Inlet Pressure: This is the hydraulic pressure that is present at the inlet to the Hydraulic Motor.

This reading (in PSI) is also shown in bar graph form. This number is directly proportional to the torque that is present at the shaft of the hydraulic motor.

5.5. SINEWAVE MODE MENU

CPM: Input desired Cycles Per Minute for the run. Can be changed at any time during run.

Amplitude: Input desired Amplitude for the run. Input range is -22 to 22 inches. Can be changed at any time during run.

Offset: Input desired offset for the run. Can be changed at any time during run.

Offset number corresponds to deviation from cylinder mid position. Current number becomes zero position for the Sinewave motion. The higher the offset number the smaller the max Sinewave amplitude will be.

Run Duration: Input desired run time in minutes. Works only in “Timed Run” mode.

Elapsed Timer: Displays elapsed run time. Works in all modes.

Start Button: Starts wave making. Disables screen change.

Stop Button: Stops wave making.

Recipe Loaded: Displays current loaded recipe.

Pumps Status: Displays current hydraulic pumps status.

E Stop pressed and wave making disabled.

Hydraulic Pumps are off and can be started at any time.

Hydraulic Pumps are on and wave making can be started.

Power failure occurred, wave making is disabled and UPS active

Run Mode: Choose the desired run mode by pressing the button increments through the choices.

Wavemaker will run continuously until stop button is pressed.

Wavemaker will run for preset time.

Wavemaker will follow the selected recipe.

Wavemaker will loop the current recipe indefinitely.

Wavemaker Status: Displays status of the wave maker.

Wavemaker stopped.

Wavemaker running in Timed Mode.

Wavemaker running in Continuous Mode.

Wavemaker running recipe event number.

Open Hydraulic Pumps Screen: Opens screen to display hydraulic pumps status.

Open Recipe Screen: Opens recipe screen.

Main Menu: Returns to main menu. During run, the screen change is disabled, and the button is a Stop button.

5.5.1. Sinewave Mode Operating Limits for Wavemaker

Amplitude CPM Max Offset 3 45 13 4 40 13 5 40 13 6 40 13 7 35 13 8 35 13 9 30 12

10 30 11 11 30 10 12 30 9 13 25 8 14 25 7 15 25 6 16 20 5 17 20 4 18 20 3 19 15 2 20 15 1 21 12 0 22 12 0

5.5.2. Sinewave Mode Recipe Menu

Recipe: This is the list of saved recipes. There can be unlimited number of recipes.

Recipe Name: Recipe nick name that will be displayed in Sinewave Mode run screen.

Create New Recipe: To create a new recipe, click on the button and a window will pop up requesting a name for the new recipe. Click on Edit and enter a new name for the recipe. Then click Enter to save the new name or Esc to discard.

Delete Recipe: To delete a recipe, highlight recipe in the Recipe window and click on the button. Confirm recipe deletion by clicking on Yes when prompted.

Save Recipe: After making changes to the recipe, click on the button to save the changes. If the Save Recipe button is not pressed after making changes to the recipe, the changes are discarded.

Display Recipe: This button displays the current recipe (highlighted in the recipe window) in the event table on the left portion of the screen.

Load Recipe to Run: Loads the current recipe (highlighted in the recipe window) into the PLC for run.

Event: Recipe starts by running the events from 1 to 10. Each event has a Time duration (hours), Cycles Per Minute, Amplitude, and Offset. If the event has no time duration, it is skipped automatically during the recipe run.

5.6. PIERSON MOSKOWITZ SPECTRUM MODE MENU

Depth: Input current depth of the tank.

Wind Speed: Input desired wind speed.

Scale Ratio: Input desired scale ratio.

Run Duration: Input desired run time in minutes. Works only in Timed Run mode.

Elapsed Timer: Displays elapsed run time. Works in all modes.

Start Button: Starts wave making. Disables screen change.

Stop Button: Stops wave making.

Pumps Status: Displays current hydraulic pumps status.

E Stop pressed and wave making disabled.

Hydraulic Pumps are off and can be started at any time.

Hydraulic Pumps are on and wave making can be started

Power failure occurred, wave making is disabled and UPS active

Run Mode: Choose the desired run mode. Pressing the button increments through the choices.

Wave making will run continuously until stop button is pressed.

Wave making will run for preset time.

Wavemaker Status: Displays status of the wave maker.

Wavemaker stopped.

Wavemaker running in Timed Mode.

Wavemaker running in Continuous Mode.

Open Hydraulic Pumps Screen: Opens screen to display hydraulic pumps status.

Main Menu: Returns to main menu. During run, the screen change is disabled, and the button is a Stop button.

5.6.1. Pierson Moskowitz Spectrum Mode Operating Limits for Wavemaker

Wind Speed Min Scale 24–30 12 19–23 10

15–18 8

5.7. JONSWAP MODE MENU

Depth: Input current depth of the tank.

Wind Speed: Input desired wind speed.

Scale Ratio: Input desired scale ratio.

Run Duration: Input desired run time in minutes. Works only in Timed Run mode.

Elapsed Timer: Displays elapsed run time. Works in all modes.

Start Button: Starts wave making. Disables screen change.

Stop Button: Stops wave making.

Pumps Status: Displays current hydraulic pumps status.

E Stop pressed and wave making disabled.

Hydraulic Pumps are off and can be started at any time.

Hydraulic Pumps are on and wave making can be started

Power failure occurred, wave making is disabled and UPS active

Wave making will run continuously until stop button is pressed.

Wave making will run for preset time.

Wavemaker Status: Displays status of the wave maker.

Wavemaker stopped.

Wavemaker running in Timed Mode.

Wavemaker running in Continuous Mode.

Open Hydraulic Pumps Screen: Opens screen to display hydraulic pumps status.

Main Menu: Returns to main menu. During run screen change is disabled and button is a “Stop” Button

5.7.1. JONSWAP Spectrum Mode Operating Limits for Wavemaker

Wind Speed Min Scale 24–30 12

19–23 10 15–18 8

5.8. FM SLIDE MODE MENU

CPM Start: Input desired start Cycles Per Minute for the run.

CPM Stop: Input desired stop Cycles Per Minute for the run.

Amplitude: Input desired Amplitude for the run. Input range is -22 to 20 inches.

Run Duration: Input desired run time in minutes. Works only in Timed Run mode.

Elapsed Timer: Displays elapsed run time. Works in all modes.

Start Button: Starts wave making. Disables screen change.

Stop Button: Stops wave making.

Pumps Status: Displays current hydraulic pumps status.

E Stop pressed and wave making disabled.

Hydraulic Pumps are off and can be started at any time.

Hydraulic Pumps are on and wave making can be started.

Power failure occurred, wave making is disabled and UPS active.

Wave making will run continuously until stop button is pressed.

Wave making will run for preset time.

Wavemaker Status: Displays status of the wave maker.

Wavemaker stopped.

Wavemaker running in Timed Mode.

Wavemaker running in Continuous Mode.

Open Hydraulic Pumps Screen: Opens screen to display hydraulic pumps status.

Main Menu: Returns to main menu. During run, screen change is disabled, and a button is a Stop button,

5.8.1. FM Slide Mode Operating Limits for Wavemaker

Amplitude Max Start CPM Max End CPM 3 40 40 4 40 40 5 40 40 6 40 40 7 30 30 8 30 30 9 30 30

10 30 30 11 30 30 12 30 30 13 20 20 14 20 20 15 20 20 16 20 20 17 20 20 18 20 20 19 12 12 20 12 12 21 12 12 22 12 12

5.9. ADVANCED SETTINGS

Shut Down Touchscreen Application: There are many options on the Allen Bradley Panel View Plus touch screen. Options include brightness, screen saver, and current time and date. To edit these settings, press the Shut Down Touchscreen Application button. After finished, press the Run Application push button to return to the preprogrammed menus.

Inputs/Outputs: This screen exists to assist in debugging inputs and outputs. Press this push button to bring up the Inputs/Outputs screen.

Reset Controller: This push button is used (to reboot) after a power outage to re-initialize the motion controller in this system. This button is only displayed when the pump pressure (on all three main pumps) is below the threshold pressure of 150 psi. This is achieved by stopping all three main pumps.

Zero Pump Timer (1–5): Each pump has an accumulated-hours odometer. Press these pushbuttons to zero the appropriate timers.

Navigation Button: The button (Main Menu) on the far right allows the user to navigate back to the Main Menu.

5.10. INPUTS/OUTPUTS

This screen assists in debugging inputs and outputs. The state of each input and output is shown on this screen. Red is used for outputs and green for inputs.

5.11. ALARM

When an Alarm occurs, this window pops up. The alarm name and description are displayed. To clear the Warning Banner that is displayed, press the Clear Alarm Banner push button. If the alarm has not been rectified, this Alarm screen may reappear.

5.12. ALARM HISTORY

The Alarm History menu shows the history of alarms. The alarms are time- and date-stamped. A means to Acknowledge alarms is available by using the Ack Alarm push buttons; this simply tags the alarm and indicates that a supervisor has acknowledged the alarm. Page Up, Page Down, Home, End, Move Up, and Move Down push buttons are available for navigation.

5.13. TROUBLESHOOTING, WARNING BANNERS, AND RECOVERY

Warning Banner: The Warning Banner will blink WARNING in the following conditions.

• E-Stop o Action: Correct E-stop condition, then resume operation.

• Oil Temperature is above 142°F o Action: Shut down wavemaker ASAP. Investigate whether the heat exchanger fan has been blowing. Check thermometer on reservoir to double check oil temperature.

• Oil Level is below 73% o Action: Fill reservoir with filtered oil to 85% capacity.

• Contactor for Heat Exchanger fan didn’t latch when it was asked to.

o Action: Perhaps the overload has tripped on the heat exchanger motor. The wavemaker hydraulic system will overheat if this is not corrected. Correct this problem before running wavemaker.

• Contactor for Heater 1 didn’t latch when it was asked to.

o Action: Perhaps the overload has tripped on Heater 1. Wavemaker can run at full load in this condition; however, the hydraulic system should be started (to warm the oil) until the oil has reached at least 65°F.

• Contactor for Heater 2 didn’t latch when it was asked to.

o Action: Perhaps the overload has tripped on Heater 2. Wavemaker can run at full load in this condition; however, the hydraulic system should be started (to warm the oil) until the oil has reached at least 65°F.

• Siemens Drive for Motor 1 didn’t reach voltage when asked to.

o Action: The Siemen Drive should be serviced. The wavemaker will have to run using only two main motors until this problem has been corrected.

• Siemens Drive for Motor 2 didn’t reach voltage when asked to.

o Action: The Siemen Drive should be serviced. The wavemaker will have to run using only two main motors until this problem has been corrected.

• Siemens Drive for Motor 3 didn’t reach voltage when asked to.

o Action: The Siemen Drive should be serviced. The wavemaker will have to run using only two main motors until this problem has been corrected.

• Contactor for (Pilot) Pump 4 didn’t latch when it was asked to.

o Action: Perhaps the overload has tripped on Pilot Pump 4. The wavemaker will have to run using only one pilot pump until this problem has been corrected.

• Contactor for (Pilot) Pump 5 didn’t latch when it was asked to.

o Action: Perhaps the overload has tripped on Pilot Pump 5. The wavemaker will have to run using only one pilot pump until this problem has been corrected.

• Pilot Pressure falls below 1,600 psi.

o Action: Try running the other pilot pump. If both pumps are running and this condition still exists, then there is a problem with the relief valve on the pilot circuit, or the Pilot filter is clogged. Correct this problem before running wavemaker.

The Warning Banner will blink in the following conditions.

• Pilot Filter Clogged (only reported after oil reaches 100°F) o Action: replace element.

• High pressure filter for Pump 1 Filter Clogged (only reported after oil reaches 100°F) o Action: replace element.

• High pressure filter for Pump 2 Filter Clogged (only reported after oil reaches 100°F) o Action: replace element.

• High pressure filter for Pump 3 Filter Clogged (only reported after oil reaches 100°F) o Action: replace element.

• Low pressure Return Filter Clogged (only reported after oil reaches 100°F) o Action: replace element.

• Oil Temperature below 60°F o Action: The heater should not allow the oil temp to dip this low. Investigate the heater circuitry and components. Wavemaker can run at full load in this condition; however, the hydraulic system should be started (to warm the oil) until the oil has reached at least 65°F.

• Oil level over 95% o Action: Remove some of the oil in the reservoir. Make sure oil is not cloudy (which indicates a water-in-oil condition). Use the ball valve drain located on the window side of the reservoir.

• Relative humidity of oil over 95% (water may present in oil) o Action: Run an oil vacuum dehydrator on the oil for 48 hours to remove water from the oil.

System Recovery: The following screen walks the user through the process of recovering for a power failure.

Warning Banners: The following screen lists all the RED and YELLOW warnings, and the reasons why they appear.

5.14. EMERGENCY STOP (E-STOP)

There are four (4) E-Stop buttons located:

• Control Tower

• Bridge Control Room

• Two (2) in Generator Room (two red buttons and safety switch on cage door)

The E-stop creates a bang stop to the wave maker. It will close all hydraulic control valves and turn off all pumps. It should only be used in an emergency condition.

6. BEACH SECTION

6.1. BEACH SETTINGS

The Beach System, which consists of six sections, normally operates as a single inclined plane either in the DOWN or UP position. The beach surface consists of horizontally mounted wooden strips that are effective in dampening incoming waves. The selection of beach position depends on the waves to be produced by the Wave Generator. When beaches are employed in the UP position, maximum damping is obtained and is typically used to generate sinusoidal waves. When confused sea (harbor chop) are desired, the beaches are lowered to complete DOWN position, which allows for reflective waves to be generated throughout the test basin.

To raise and lower the weir gate and beaches in front of the gate the operator will activate a push-button on a pedestal located to the right of the weir platform. To raise or lower the other five beaches, the operator will simply push a hand-held pendant, this will energize the winches and rotate the winch drive in the proper direction. At the time of this writing the winches were not on-site but are expected sometime in October of 2022. Once ARA receives them they will be installed.

Figure 1. Side View of Ohmsett Beaches