This training exercise focuses on the critical emergency shutdown (ESD) systems available on board an LNG carrier. It is designed to help users understand how to correctly configure and test the emergency shutdown systems. The exercise involves several key procedures:

1. ESD System Testing:

• The exercise begins by demonstrating how to test the optical ESD system by configuring the system settings properly.
• The user prepares the system by selecting different switches and opening various valves.
• After setting the configuration, the user is guided to press the ESD button. This action triggers the emergency shutdown, automatically closing the valves and putting the machinery into a trip condition.
• The user is also taught how to correctly reset the ESD system.

2. Overfill Alarm Test:

• The second part of the exercise focuses on testing the overfill alarm.
• The user opens various tank valves, typically used during loading and spray operations.
• By pressing the “TOPS Test” button, the system triggers the closing of the valves, preventing the tank from being filled beyond the prescribed limits, thus ensuring safety.

3. Pneumatic System Configuration:

• The third test involves setting up and configuring the pneumatic system.
• The user learns how the ship’s air is used to trigger the emergency shutdown system, ensuring it functions correctly under various operational conditions.

This exercise not only enhances the user’s understanding of the ESD system’s functionality but also ensures familiarity with the operational procedures needed to maintain safety aboard an LNG carrier.

The purpose of the Emergency Shutdown (ESD) and Tank Protection System (TPS) is for the protection of personnel, equipment and the environment from injury, damage or pollution when at sea or in port.

The ESD system is a requirement of the IMO international code of the construction and equipment of vessels carrying liquefied gases in bulk, IGC Code and the SIGTTO industry guidance for ESD arrangements and a Ship Shore Link (SSL) communication system for liquefied gas carriers.

The SSL is fitted to protect the vessel and the shore terminal in the event of a cryogenic incident or a fire risk on the vessel or at the terminal.

It is vitally important at all stages of the carriage of LNG that the operation can be quickly and safely suspended automatically or manually in the event of an emergency.

Such emergency situations can be listed as:

• LNG leakage on the vessel or shore, or between vessels.
• Cargo tank over-filling during loading or transfer.
• Fire on the vessel or shore, or other vessel.
• Excessive movement of the vessel relative to the shore.
• Low pressure in the vessel’s cargo tanks.

During transfer of LNG, any emergency action taken on board the vessel or ashore can have serious repercussions respectively ashore or on the vessel, therefore, intercommunication between the shore and the vessel is absolutely necessary. This also includes all ship to ship transfer operation, where each vessel is similarly fitted with alarms and trips.

An integrated emergency shutdown circuit, electric ‘Fail-Safe’ type, incorporates alarm contacts together with manually-operated switches and fusible switches in series on the vessel. The actuation of any one of them will de-energise the circuit and initiate the ESD.

The SSL connection is provided on the port and starboard midships for the LNG terminal and is to be connected to the shore before starting cargo operations and remain connected throughout the cargo operation.
During ship to ship transfer, a similar arrangement is made between the vessels.

The SSL connection is either an electrical wired connection, fibre optic or pneumatic hose connection. The electrical signal sends a constant satisfactory signal and is used to transmit ESD data. The pneumatic hose connection is used to confirm a constant pressure, and if this fails, then this initiates the ESD and is initiated from either the vessel or the shore.

In the event of an emergency, such as a fire or a heavy cargo leakage, the officer on watch, or one of the watchkeepers on deck, will immediately initiate an ESD by pressing one of the ESD pushbuttons distributed on deck and raise the alarm in accordance with the vessel’s safety instructions.

The ESD will also be initiated by one of the following:

• Manual activation by personnel using the ESD pushbuttons.
• Fusible links around each tank dome, manifold and cargo machinery room in case of fire with delay of 5 seconds.
• Ship/shore activation of their ESD system (electric, fibre optic or pneumatic) with delay of 2 seconds.
• Vapour main pressure very low 0.3kPa(g) with delay of 5 seconds.
• Cargo tank pressure very low 2kPa(g) with delay of 5 seconds.
• Cargo tank extremely high level 99.4% with delay of 5 seconds.
• Electric power failure with delay of 5 seconds.
• Cargo hydraulic oil pressure low-low 9MPa(g) with delay of 10 seconds.
• Manifold ESD solenoid valve power failure with delay of 5 seconds.
• Master gas valve ESD solenoid valve power failure with delay of 5 seconds.
• Control air pressure low 0.5MPa(g).

All time delays are adjustable.Emergency Shutdown Activation

The initiation of an ESD will lead to the following:

• Stop the cargo pumps (4 sets).
• Stop the spray pumps (4 sets).
• Stop the fuel gas pumps (2 sets).
• Stop the emergency cargo pump (1 set).
• All ESD manifold valves will close.
• All cargo tank filling valves will close.
• All cargo tank spray valves will close.
• The master fuel gas valves to main engines, generator engines and GCU will close.
• ESD signal to shore (by electric/optical/pneumatic signal).
• The high duty compressors will trip.
• The low duty compressors will trip.
• The LNG and forcing vaporisers will stop.
• Gas combustion unit will trip.

Note: Once an ESD is activated, acknowledge all alarms but do not reset the system until investigations are concluded.

Shore Emergency Shutdown
Whilst there is mainly only one vessel ESD operating in port, for the terminal there is a second level of ESD, a shore ESD. A shore ESD can only be initiated by the terminal, either manually or automatically if the vessel moves outside of the permissible movement envelope for the manifold hard arms.

Therefore, should the moorings become slack to the extent that the vessel moves along the jetty outside of the shore arms limit, a shore ESD may be initiated.

Additionally, if there is a threatened danger, such as a fire at the terminal, that may affect the vessel, or fire on the vessel that may affect the terminal, the shore ESD system could also be initiated by the terminal.

Initiation of the shore ESD system will result in the same shutdown actions as the vessel’s ESD, but will then initiate a dry detachment of the shore arms from the vessel.

The shore hard arms have a Powered Emergency Release Coupling (PERC) as part of their construction. This section of the hard arm is located just above the Quick Release Connection (QRC) to the vessel’s manifold and consists of two ball valves just above the elbow part of the arms.

In the event of a shore ESD being initiated, these two valves will close automatically and then the upper part of the hard arm will detach at the joint which lies between the two ball valves, this leaves the lower part of the shore arm remaining attached to the vessel. The release of the arm may result in a small shower of liquid LNG being released due to the space between the two ball valves.

ESDS and TOPS test familiarization Manual Push Button Test

ESDS and TOPS test familiarization-TOPS Test

ESDS and TOPS test familiarization-Pneumatic ESD

Milestones

• Learning and Training Phase.

1. Set Ship/Shore Link Select Switch to Use.
2. Set Pneumatic Select Switch to Bypass.
3. Set ESD Port Select Switch to Loading.
4. Set ESD Mode Select to Test.
5. Set Optical/Electric Use Lamp to Optical Use in the Ship/Shore Link.
6. Open Port Side ESD Valves for lines L1, L2, V, L3, and L4.
7. Connect manifold arms L1, L2, V, L3, and L4.
8. Press the ESD Manual Push Button and verify the closing of manifold valves.
9. Set ESD Mode Select to Blocking.
10. Reset the ESDS System.
11. Set ESD Mode Select to Test again.
12. Open master and filling valves on liquid lines for all cargo tanks.
13. Open spray nozzles in all cargo tanks.
14. Carry out the Top’s Test for all cargo tanks.
15. Verify the valves’ closing on any of the Cargo System pages.
16. Set ESD Mode Select to Blocking again.
17. Reset the ESDS System.
18. Set ESD Mode Select to Test.
19. Set Pneumatic Select Switch to Normal.
20. Open Pneumatic Manual valves.
21. Set Pneumatic Set Point value.
22. Set Pneumatic Trip Point value.
23. Decrease Pneumatic Set Point Below Trip Point.
24. Set ESD Mode Select To Block.
25. Reset ESDS System.

Alarms & Remarks

Step-by-Step Procedure

1. Configure the ESDS Settings

1. Navigate to the ESDS System Page using the side navigation menu.
2. Perform the following:
   • Set Ship/Shore Link Select Switch to Use by:
     • Clicking the “Use” label, or
     • Dragging the lever to the left.
   • Set Pneumatic Select Switch to Bypass in a similar manner.
   • Set ESD Port Select Switch to Loading.
   • Set ESD Mode Select to Test.
   • Click the Optical Use button to activate the Optical/Electric Use Lamp.

2. Connect Manifold Arms

1. Locate the highlighted manifold arms above the liquid manifold on the page.
2. Click on the highlighted arms (L1, L2, V, L3, L4) to initiate the connection process.
3. Ensure all arms are connected. Once done, this milestone is completed.

3. Open Port Side ESD Valves

1. Navigate to the Cargo System Page via the side navigation menu.
2. Open the following valves:
   • CL011
   • CL021
   • CG071
   • CL031
   • CL041
3. Verify that all valves are open to complete this milestone.

4. Press ESD Manual Push Button

1. Navigate to the ESDS System Page via the menu.
2. Locate the ESD Manual Push Button.
   • Open the cover and press the button.
3. Verify manifold valve closure:
   • Confirm that the valves opened in the previous milestone are now closed.

5. Set ESD Mode to Blocking

1. Navigate to the ESDS System Page.
2. Locate the ESD Mode Select lever and set it to Blocking:
   • Either click the “Block” label, or
   • Drag the lever to the Blocking position.

6. Reset the ESDS System

1. While still on the ESDS System Page, locate the Reset Button.
2. Press the Reset Button to reset the system.

7. Reconfigure ESD Mode to Test

Navigate to the ESDS System Page.

Set the ESD Mode Select lever to Test.

8. Open Master and Filling Valves

1. Navigate to the Cargo System Page.
2. Open the following master and filling valves:
   • CL100, CL107, CL200, CL207, CL300, CL307, CL400, CL407 (set all to 100%).

9. Open Spray Nozzles

1. Navigate to the Cargo System Page.
2. Open the following spray nozzles:
   • CS107, CS108, CS207, CS208, CS307, CS308, CS407, CS408.

10. Carry Out the Top’s Test

1. Ensure all liquid line and spray nozzle valves are open.
2. Navigate to the CTS Settings and Configuration Page.
3. Perform the Top’s Test for each tank:
   • Locate the Top’s Test Button for each tank and press it.

11. Verify Valve Closure

1. Navigate to any Cargo System Page.
2. Ensure the following valves are closed:
   • Spray Valves: CS107, CS108, CS207, CS208, CS307, CS308, CS407, CS408.
   • Liquid Line Valves: CL100, CL107, CL200, CL207, CL300, CL307, CL400, CL407.

12. Block And Reset

1. Set ESD Mode Select to Blocking.
2. Reset the ESDS System by pressing the Reset Button.

13. Reconfigure ESD Mode to Test

• Navigate to the ESDS System Page: Open the ESDS system page through the user interface.

• Set the ESD Mode Select lever to Test: Locate the “ESD Mode Select” lever on the ESDS page and set it to the “Test” position. This configures the system for testing mode.

14. Reconfigure Pneumatic Select Switch To Normal

• Navigate to the ESDS System Page: Ensure you’re still on the ESDS system page.

• Set the Pneumatic Select Switch to Normal: Locate the “Pneumatic Select Switch” and set it to “Normal“. This will return the pneumatic system to its normal operating mode.

15. Open Pneumatic Manual Valves

• Open inlet and outlet manual valves: On the ESDS system page, find the manual valves for the pneumatic system and ensure both the inlet and outlet valves are in the “Open” position. This will allow air to flow through the system.

16. Increase Pneumatic Set Point Value

• Click the + Adjustment button under the set point: Locate the pneumatic set point control on the ESDS system page.

• Increase the pressure to 5 bar: Use the + adjustment button to gradually increase the set point value until the pressure reads 5 bar.

17. Increase Pneumatic Trip Point Value

• Click the + Adjustment button under the trip point: Find the pneumatic trip point control and use the + adjustment button to increase the pressure setting.

• Set the pressure to pneumatic set point value: Use the + adjustment button to increase the trip point until the pressure reads 4 bar.

18. Decrease Pneumatic Set Point Value Below Trip Point

• Click the – Adjustment button under the set point: Use the – button to decrease the pneumatic set point value.

• Decrease the pressure below the trip point: Lower the set point until the value is below the current trip point setting (which should be 4 bar based on previous steps).

19. Block And Reset

• Set ESD Mode Select to Blocking: On the ESDS system page, change the “ESD Mode Select” lever to the “Blocking” position. This will block any emergency shutdown actions temporarily.

• Reset the ESDS System: Press the “Reset” button on the system page to reset the ESDS system, returning it to a default or cleared state.