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Collision accident & emergency response for liquefied gas carriers

In the event of a collision many of the actions to take will depend upon the seriousness of the damage inflicted to either or both of the vessels involved. For example the collision may only involve a glancing blow where the structural damage is superficial, or it might be more serious and followed by a fire, explosion, serious pollution, stranding or foundering, with the possibility of crew overboard, seriously injured or even killed.



No matter what the eventual outcome of the collision may be, there are several actions that should be initially carried out by ships staff in the event of any collision. These are listed below.


Action to be taken by the bridge team:

  1. Sound the General Alarm and follow this with a public address announcement regarding the situation.


  2. Muster all personnel and check for injured persons or any that are missing. Advise the Bridge of the outcome of the muster.


  3. Contact the Engine room and advise them of the situation and get an initial report of any damage or leaks that are apparent.


  4. Stop engines and engage manual steering (start 2nd steering motor). However, bear in mind the immediate navigation situation. (Other traffic, proximity to shoal patches or other hazards). It may be preferable to maintain minimum steerage way at this stage with hand steering possibly engaged.


  5. Give the instruction to close any ballast hatches etc. that may be open, to maintain the watertight integrity of the vessel.


  6. At night turn on the deck lights; however, again bear in mind the navigation situation.


  7. Utilise VHF Ch16 to advise other ships in the immediate vicinity of the collision using security or Pan Pan. N.U.C. signals may have to be displayed depending on the situation.


  8. Ensure that the GMDSS equipment has vessel current position entered, and then send notification of the collision to the nearest MRCC or coast station. Also contact DPA using initial contact via telephone, if DPA not available then other members of the control group should be contacted. Contact details are available in the S.M.P.E.P. Appendix III.


  9. Contact the other vessel and ascertain if she requires assistance or needs us to standby her and note protest.


  10. Prepare lifeboats for the evacuation of non-essential personnel.


  11. The following information should be recorded a) Mark Engine Room Data logger
    b) Mark Course Recorder
    c) Note Time of Contact
    d) Note Vessels Position
    e) Note Bridge Times
    f) Note Course & Speed at Time of Contact
    g) Note Angle of Contact
    h) Note Times of all Sound Signals Made and Heard
    i) Check if other Vessels require Assistance or require our Vessels to Standby
    j) Obtain particulars of other vessels
    k) Hold other vessels responsible by Letter
    l) Note Protest
    m) Witnesses Names
    n) Notify Anticipated Delay


  12. Endeavour to find out from other vessel the following information and likewise advise the other vessel of our similar details: a) Vessels name b) Port of registry c) Where from d) Where bound e) Owners / Charterers / agents


  13. Establish and enter the following in the Deck Operations Log, if not already noted: a) Exact position of collision b) Exact time of collision c) Course and speed at time of contact d) Angle of contact with other vessel e) Details of any sound signals made or heard prior to the collision f) Transcripts of any communications to or from the other vessel g) Mark the course recorder chart with the time of collision


  14. Issue the other Master with a Letter holding him responsible for the collision.


  15. Make a record of all witnessing vessels / parties.


  16. As soon as practicable after the event all personnel on duty or directly involved in the incident should submit to a drug and alcohol test


  17. Note Protest when vessel arrives at next port of call.


  18. Check that bridge and engine times noted for the time of contact and subsequent movements agree. If they do not, make an entry in the Deck Operations Log and ER Movement Book noting the disparity.


  19. Whilst all the above is being carried out there must, be someone who is keeping an accurate and complete log of all that is occurring. In the absence of a direct order to the contrary, the Third Officer shall compile the log and be responsible for its accuracy. Remember, at an enquiry this log account of the happenings will provide one of the strongest pieces of evidence for or against us. So let’s get it correct. Any mistakes or alterations shall be crossed out using only a single line and initialled by the officer making the change. Erasing or ‘Tippexing’ out entries must not be attempted


  20. When the various information has been received from local control, an updated report including the vessels ‘Voyage Stability Information’ must be sent to the managing office. Note that an updated copy of the vessel stability and stress information, must be made available after every cargo, ballast or bunker operation, and must be updated periodically on extended voyages where there is any significant change in cargo or bunkers.


Action to be taken by deck department:

  1. Other members of the ships complement should be checking and reporting in to the bridge control centre on the following information:


  2. Check all have mustered


  3. If necessary start water pump sprays.


  4. The watertight integrity of the hull. This information may be obtained by visual means and by manually sounding all spaces, tanks and compartments, both on deck and in the engine room.


  5. The integrity of the cargo and its associated systems including hydraulics pipelines and fuel lines.


  6. Check for any signs of leakage of LNG into the interbarrier spaces. (Indications may be given by gas detection alarms or low temperature alarms or high-pressure alarms). Also check and record all levels in tanks.


  7. As appropriate to type of vessel, check for signs of water penetrating the interbarrier and insulation spaces. (Indications may be Interbarrier bilge high level alarms with increased boil off and rising cargo tank pressures).


  8. When the following has been ascertained inform bridge as to the structural condition of vessel.


  9. Ascertain whether there have been any internal oil spills (bunkers and lub-oils.) or any overside pollution. (Should there be any pollution or the likelihood of pollution, vessel is required to notify the facts to the nearest coastal authorities.


Action to be taken by engine room department

In the machinery spaces a collision if small may not be noticed and the engineers will rely on the bridge to inform them that one has taken place. If however a bump is heard or felt in the machinery space then the bridge is to be informed immediately. The procedures to be followed by the engineers in the event of any collision are as follows.
  1. If a bump was felt or heard in the machinery space notify the bridge immediately.
  2. If the Alarm is sounded report to your respective muster points.
  3. Change the engine room plant over to standby manoeuvring conditions.
  4. Carry out an inspection of the machinery spaces and asses any damage particularly with respect to integrity of the hull, oil tanks, water tanks and dry spaces.
  5. Damage to any machinery or pipe systems should also be looked for.
  6. Sound all tanks and double bottoms and check for losses or ingress of water.
  7. Make relevant notes in the E.R. Log book.


Collision with no apparent rupture of cargo (MEMBRANE)

The ability of the vessel, and in particular, the cargo containment system to survive a collision by absorbing the energy of a colliding vessel is dependent on many factors including the colliding ship’s size, displacement, speed and angle and point of contact. Independent analysis made by various parties and Classification Societies during the design of LNG vessels have estimated that the most critical are the side-on collision (90° approach of colliding vessel) with a bulbous bow design. If a collision is unavoidable and it is possible to reduce the angle of impact from 90° to a more oblique angle, the survivability of the vessel and the cargo containment system will significantly increase.


Following a collision:
  1. If the vessel lists sharply, then it is likely that a ballast tank(s) or other spaces have been breached in the vicinity of the contact and flooding has occurred.


  2. Whether the vessel lists or not, all soundings should be checked immediately and the gas detection system closely monitored.


  3. If the inner hull has been breached, all available means should be employed to keep the secondary insulation space pumped dry of water to prevent degradation of the insulation material.


  4. Regularly monitor the primary insulation space for possible primary membrane leakage. If gas leakage is detected, increase the nitrogen sweep through the primary insulation.


  5. Attempts to right the vessel should only be made after advice from the managing office has been received. In critical circumstances, righting of the vessel may be attempted utilising the information available in the “Damage Stability Booklet” taking care to avoid overstressing of the vessel.


  6. Only essential personnel should be allowed on the deck.


  7. An urgency signal giving relevant details should be made to the local coastal authority and to any vessels in the area. If the survivability of the vessel is in doubt, then a distress signal should be made.


  8. A realistic assessment should be made of the ability of the vessel to remain afloat.


  9. If it is determined that the vessel is unlikely to survive, abandonment should be made in good time.


  10. When it is certain that the vessel is safe and secure, offers of assistance should be made to any other vessel involved in the casualty.


  11. The listing of the vessel may tend to give rise to panic amongst shipboard personnel. To guard against this, it should be explained to all personnel at drills and exercises that LNG vessels have a large reserve buoyancy and that a list resulting from a collision is not necessarily cause for immediate danger.


  12. Officers should be aware of the causes of any list and the implication of a list due to asymmetrical buoyancy or weight and of a loll due to a loss of stability.


  13. Where necessary Ship to Ship transfer of cargo will be arranged by the managing office. In such cases, procedures referenced in the ICS/OCIMF/SIGTTO publication Ship to Ship Transfer Guide (Liquefied Gases) should be followed.


Collision accident and immediate action

1) Raise general alarm

2) Muster the crew to check if anybody is missing or injured

3) Stop cargo operations. Activated ESDS

4) Sound bilges and tanks

5) Advise the terminal

6) Consider - release loading arms (PERC system)

7) Consider - leave terminal

8) Treat injured crew/personnel

9) Check damage to the vessel and evaluate the situation

10) If necessary, start bilge pumps and ballast pumps

11) Keep the ship upright as far as possible in case of flooding of ballast tanks, by ballasting or de-ballasting to other tanks

12) Consider - external assistance. Rescue operations

13) Evaluate possibility to abandon vessel

14) Establish contact with other vessel, and exchange relevant information

15) Offer your assistance if possible to other vessel

16) Collect all facts about the occurrence

17) Consider - send distress signal including vessel position

18) Evaluate risk of pollution

19) Consider - loss of stability. Determine stability and bending moments/shearing force by the loading calculator

20) Supply inert gas to hold spaces for inerting hold spaces if necessary

21) Start water curtain

22) Consider - discharge cargo to sea (Jettisoning nozzle, advisable to run two cargo pumps)

23) Inform CMSI, Owners, Local Authorities, Insurance/ P&I , Classification Society


Collision - Hitting the Quay

1) Stop main engine at once

2) Try to pull the vessel away from quay by tugboats and ship’s main engine

3) Evaluate extent of the damage. Vessel’s damage and damage to quay

4) Consider - use anchors in order to hold position and avoid further damage

5) Watch for pollution by oil, try to minimise/ confine

6) Attend any injured people

7) Consider - leaving port due terminal being temporarily out of service

8) Inform CMSI, Owners, Local Authorities, Agent, Insurance/P&I




Related Information:

  1. Abandonship procedure for liquefied gas carriers


  2. Encountering High Winds and/or Waves - countermeasures


  3. Emergency Procedures for rescue - a guide to salvage operation


  4. Assist Vessel in Distress/Towing of Vessel in Distress




Cargo tank ruptures due to increased pressure - emergency procedure for gas carriers

Loss of power supplies - emergency actions

Risk and hazards of Equipment failure

Loss of Instrumentation during Unloading Operations - Recommended actions by Liquefied Gas carriers

Risk and hazards of Nitrogen Loss

Gas carriers Loss of Instrumentation during Loading Operations

Gas carriers Structural Damage due to Incorrect Loading/Unloading Sequence

Encountering High Winds and/or Waves - countermeasures

Emergency Procedures for rescue - a guide to salvage operation

Assist Vessel in Distress/Towing of Vessel in Distress



External links :

  1. International maritime organization






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